// for optional dependency
/++
	Module for interacting with the user's terminal, including color output, cursor manipulation, and full-featured real-time mouse and keyboard input. Also includes high-level convenience methods, like [Terminal.getline], which gives the user a line editor with history, completion, etc. See the [#examples].


	The main interface for this module is the Terminal struct, which
	encapsulates the output functions and line-buffered input of the terminal, and
	RealTimeConsoleInput, which gives real time input.
	
	Creating an instance of these structs will perform console initialization. When the struct
	goes out of scope, any changes in console settings will be automatically reverted.

	Note: on Posix, it traps SIGINT and translates it into an input event. You should
	keep your event loop moving and keep an eye open for this to exit cleanly; simply break
	your event loop upon receiving a UserInterruptionEvent. (Without
	the signal handler, ctrl+c can leave your terminal in a bizarre state.)

	As a user, if you have to forcibly kill your program and the event doesn't work, there's still ctrl+\

	On Mac Terminal btw, a lot of hacks are needed and mouse support doesn't work. Most functions basically
	work now though.

	Future_Roadmap:
	$(LIST
		* The CharacterEvent and NonCharacterKeyEvent types will be removed. Instead, use KeyboardEvent
		  on new programs.

		* The ScrollbackBuffer will be expanded to be easier to use to partition your screen. It might even
		  handle input events of some sort. Its API may change.

		* getline I want to be really easy to use both for code and end users. It will need multi-line support
		  eventually.

		* I might add an expandable event loop and base level widget classes. This may be Linux-specific in places and may overlap with similar functionality in simpledisplay.d. If I can pull it off without a third module, I want them to be compatible with each other too so the two modules can be combined easily. (Currently, they are both compatible with my eventloop.d and can be easily combined through it, but that is a third module.)

		* More advanced terminal features as functions, where available, like cursor changing and full-color functions.

		* More documentation.
	)

	WHAT I WON'T DO:
	$(LIST
		* support everything under the sun. If it isn't default-installed on an OS I or significant number of other people
		  might actually use, and isn't written by me, I don't really care about it. This means the only supported terminals are:
		  $(LIST

		  * xterm (and decently xterm compatible emulators like Konsole)
		  * Windows console
		  * rxvt (to a lesser extent)
		  * Linux console
		  * My terminal emulator family of applications https://github.com/adamdruppe/terminal-emulator
		  )

		  Anything else is cool if it does work, but I don't want to go out of my way for it.

		* Use other libraries, unless strictly optional. terminal.d is a stand-alone module by default and
		  always will be.

		* Do a full TUI widget set. I might do some basics and lay a little groundwork, but a full TUI
		  is outside the scope of this module (unless I can do it really small.)
	)
+/
module arsd.terminal;

// FIXME: needs to support VT output on Windows too in certain situations
// FIXME: paste on Windows and alt+NNNN codes in getline function

/++
	$(H3 Get Line)

	This example will demonstrate the high-level getline interface.

	The user will be able to type a line and navigate around it with cursor keys and even the mouse on some systems, as well as perform editing as they expect (e.g. the backspace and delete keys work normally) until they press enter.  Then, the final line will be returned to your program, which the example will simply print back to the user.
+/
version(demos) unittest {
	import arsd.terminal;

	void main() {
		auto terminal = Terminal(ConsoleOutputType.linear);
		string line = terminal.getline();
		terminal.writeln("You wrote: ", line);
	}

	main; // exclude from docs
}

/++
	$(H3 Color)

	This example demonstrates color output, using [Terminal.color]
	and the output functions like [Terminal.writeln].
+/
version(demos) unittest {
	import arsd.terminal;

	void main() {
		auto terminal = Terminal(ConsoleOutputType.linear);
		terminal.color(Color.green, Color.black);
		terminal.writeln("Hello world, in green on black!");
		terminal.color(Color.DEFAULT, Color.DEFAULT);
		terminal.writeln("And back to normal.");
	}

	main; // exclude from docs
}

/++
	$(H3 Single Key)

	This shows how to get one single character press using
	the [RealTimeConsoleInput] structure.
+/
version(demos) unittest {
	import arsd.terminal;

	void main() {
		auto terminal = Terminal(ConsoleOutputType.linear);
		auto input = RealTimeConsoleInput(&terminal, ConsoleInputFlags.raw);

		terminal.writeln("Press any key to continue...");
		auto ch = input.getch();
		terminal.writeln("You pressed ", ch);
	}

	main; // exclude from docs
}

/*
	Widgets:
		tab widget
		scrollback buffer
		partitioned canvas
*/

// FIXME: ctrl+d eof on stdin

// FIXME: http://msdn.microsoft.com/en-us/library/windows/desktop/ms686016%28v=vs.85%29.aspx

version(Posix) {
	enum SIGWINCH = 28;
	__gshared bool windowSizeChanged = false;
	__gshared bool interrupted = false; /// you might periodically check this in a long operation and abort if it is set. Remember it is volatile. It is also sent through the input event loop via RealTimeConsoleInput
	__gshared bool hangedUp = false; /// similar to interrupted.

	version(with_eventloop)
		struct SignalFired {}

	extern(C)
	void sizeSignalHandler(int sigNumber) nothrow {
		windowSizeChanged = true;
		version(with_eventloop) {
			import arsd.eventloop;
			try
				send(SignalFired());
			catch(Exception) {}
		}
	}
	extern(C)
	void interruptSignalHandler(int sigNumber) nothrow {
		interrupted = true;
		version(with_eventloop) {
			import arsd.eventloop;
			try
				send(SignalFired());
			catch(Exception) {}
		}
	}
	extern(C)
	void hangupSignalHandler(int sigNumber) nothrow {
		hangedUp = true;
		version(with_eventloop) {
			import arsd.eventloop;
			try
				send(SignalFired());
			catch(Exception) {}
		}
	}

}

// parts of this were taken from Robik's ConsoleD
// https://github.com/robik/ConsoleD/blob/master/consoled.d

// Uncomment this line to get a main() to demonstrate this module's
// capabilities.
//version = Demo

version(Windows) {
	import core.sys.windows.windows;
	import std.string : toStringz;
	private {
		enum RED_BIT = 4;
		enum GREEN_BIT = 2;
		enum BLUE_BIT = 1;
	}
}

version(Posix) {
	import core.sys.posix.termios;
	import core.sys.posix.unistd;
	import unix = core.sys.posix.unistd;
	import core.sys.posix.sys.types;
	import core.sys.posix.sys.time;
	import core.stdc.stdio;
	private {
		enum RED_BIT = 1;
		enum GREEN_BIT = 2;
		enum BLUE_BIT = 4;
	}

	version(linux) {
		extern(C) int ioctl(int, int, ...);
		enum int TIOCGWINSZ = 0x5413;
	} else version(OSX) {
		import core.stdc.config;
		extern(C) int ioctl(int, c_ulong, ...);
		enum TIOCGWINSZ = 1074295912;
	} else static assert(0, "confirm the value of tiocgwinsz");

	struct winsize {
		ushort ws_row;
		ushort ws_col;
		ushort ws_xpixel;
		ushort ws_ypixel;
	}

	// I'm taking this from the minimal termcap from my Slackware box (which I use as my /etc/termcap) and just taking the most commonly used ones (for me anyway).

	// this way we'll have some definitions for 99% of typical PC cases even without any help from the local operating system

	enum string builtinTermcap = `
# Generic VT entry.
vg|vt-generic|Generic VT entries:\
	:bs:mi:ms:pt:xn:xo:it#8:\
	:RA=\E[?7l:SA=\E?7h:\
	:bl=^G:cr=^M:ta=^I:\
	:cm=\E[%i%d;%dH:\
	:le=^H:up=\E[A:do=\E[B:nd=\E[C:\
	:LE=\E[%dD:RI=\E[%dC:UP=\E[%dA:DO=\E[%dB:\
	:ho=\E[H:cl=\E[H\E[2J:ce=\E[K:cb=\E[1K:cd=\E[J:sf=\ED:sr=\EM:\
	:ct=\E[3g:st=\EH:\
	:cs=\E[%i%d;%dr:sc=\E7:rc=\E8:\
	:ei=\E[4l:ic=\E[@:IC=\E[%d@:al=\E[L:AL=\E[%dL:\
	:dc=\E[P:DC=\E[%dP:dl=\E[M:DL=\E[%dM:\
	:so=\E[7m:se=\E[m:us=\E[4m:ue=\E[m:\
	:mb=\E[5m:mh=\E[2m:md=\E[1m:mr=\E[7m:me=\E[m:\
	:sc=\E7:rc=\E8:kb=\177:\
	:ku=\E[A:kd=\E[B:kr=\E[C:kl=\E[D:


# Slackware 3.1 linux termcap entry (Sat Apr 27 23:03:58 CDT 1996):
lx|linux|console|con80x25|LINUX System Console:\
        :do=^J:co#80:li#25:cl=\E[H\E[J:sf=\ED:sb=\EM:\
        :le=^H:bs:am:cm=\E[%i%d;%dH:nd=\E[C:up=\E[A:\
        :ce=\E[K:cd=\E[J:so=\E[7m:se=\E[27m:us=\E[36m:ue=\E[m:\
        :md=\E[1m:mr=\E[7m:mb=\E[5m:me=\E[m:is=\E[1;25r\E[25;1H:\
        :ll=\E[1;25r\E[25;1H:al=\E[L:dc=\E[P:dl=\E[M:\
        :it#8:ku=\E[A:kd=\E[B:kr=\E[C:kl=\E[D:kb=^H:ti=\E[r\E[H:\
        :ho=\E[H:kP=\E[5~:kN=\E[6~:kH=\E[4~:kh=\E[1~:kD=\E[3~:kI=\E[2~:\
        :k1=\E[[A:k2=\E[[B:k3=\E[[C:k4=\E[[D:k5=\E[[E:k6=\E[17~:\
	:F1=\E[23~:F2=\E[24~:\
        :k7=\E[18~:k8=\E[19~:k9=\E[20~:k0=\E[21~:K1=\E[1~:K2=\E[5~:\
        :K4=\E[4~:K5=\E[6~:\
        :pt:sr=\EM:vt#3:xn:km:bl=^G:vi=\E[?25l:ve=\E[?25h:vs=\E[?25h:\
        :sc=\E7:rc=\E8:cs=\E[%i%d;%dr:\
        :r1=\Ec:r2=\Ec:r3=\Ec:

# Some other, commonly used linux console entries.
lx|con80x28:co#80:li#28:tc=linux:
lx|con80x43:co#80:li#43:tc=linux:
lx|con80x50:co#80:li#50:tc=linux:
lx|con100x37:co#100:li#37:tc=linux:
lx|con100x40:co#100:li#40:tc=linux:
lx|con132x43:co#132:li#43:tc=linux:

# vt102 - vt100 + insert line etc. VT102 does not have insert character.
v2|vt102|DEC vt102 compatible:\
	:co#80:li#24:\
	:ic@:IC@:\
	:is=\E[m\E[?1l\E>:\
	:rs=\E[m\E[?1l\E>:\
	:eA=\E)0:as=^N:ae=^O:ac=aaffggjjkkllmmnnooqqssttuuvvwwxx:\
	:ks=:ke=:\
	:k1=\EOP:k2=\EOQ:k3=\EOR:k4=\EOS:\
	:tc=vt-generic:

# vt100 - really vt102 without insert line, insert char etc.
vt|vt100|DEC vt100 compatible:\
	:im@:mi@:al@:dl@:ic@:dc@:AL@:DL@:IC@:DC@:\
	:tc=vt102:


# Entry for an xterm. Insert mode has been disabled.
vs|xterm|screen|screen.xterm|screen.xterm-256color|xterm-color|xterm-256color|vs100|xterm terminal emulator (X Window System):\
	:am:bs:mi@:km:co#80:li#55:\
	:im@:ei@:\
	:cl=\E[H\E[J:\
	:ct=\E[3k:ue=\E[m:\
	:is=\E[m\E[?1l\E>:\
	:rs=\E[m\E[?1l\E>:\
	:vi=\E[?25l:ve=\E[?25h:\
	:eA=\E)0:as=^N:ae=^O:ac=aaffggjjkkllmmnnooqqssttuuvvwwxx:\
	:kI=\E[2~:kD=\E[3~:kP=\E[5~:kN=\E[6~:\
	:k1=\EOP:k2=\EOQ:k3=\EOR:k4=\EOS:k5=\E[15~:\
	:k6=\E[17~:k7=\E[18~:k8=\E[19~:k9=\E[20~:k0=\E[21~:\
	:F1=\E[23~:F2=\E[24~:\
	:kh=\E[H:kH=\E[F:\
	:ks=:ke=:\
	:te=\E[2J\E[?47l\E8:ti=\E7\E[?47h:\
	:tc=vt-generic:


#rxvt, added by me
rxvt|rxvt-unicode|rxvt-unicode-256color:\
	:am:bs:mi@:km:co#80:li#55:\
	:im@:ei@:\
	:ct=\E[3k:ue=\E[m:\
	:is=\E[m\E[?1l\E>:\
	:rs=\E[m\E[?1l\E>:\
	:vi=\E[?25l:\
	:ve=\E[?25h:\
	:eA=\E)0:as=^N:ae=^O:ac=aaffggjjkkllmmnnooqqssttuuvvwwxx:\
	:kI=\E[2~:kD=\E[3~:kP=\E[5~:kN=\E[6~:\
	:k1=\E[11~:k2=\E[12~:k3=\E[13~:k4=\E[14~:k5=\E[15~:\
	:k6=\E[17~:k7=\E[18~:k8=\E[19~:k9=\E[20~:k0=\E[21~:\
	:F1=\E[23~:F2=\E[24~:\
	:kh=\E[7~:kH=\E[8~:\
	:ks=:ke=:\
	:te=\E[2J\E[?47l\E8:ti=\E7\E[?47h:\
	:tc=vt-generic:


# Some other entries for the same xterm.
v2|xterms|vs100s|xterm small window:\
	:co#80:li#24:tc=xterm:
vb|xterm-bold|xterm with bold instead of underline:\
	:us=\E[1m:tc=xterm:
vi|xterm-ins|xterm with insert mode:\
	:mi:im=\E[4h:ei=\E[4l:tc=xterm:

Eterm|Eterm Terminal Emulator (X11 Window System):\
        :am:bw:eo:km:mi:ms:xn:xo:\
        :co#80:it#8:li#24:lm#0:pa#64:Co#8:AF=\E[3%dm:AB=\E[4%dm:op=\E[39m\E[49m:\
        :AL=\E[%dL:DC=\E[%dP:DL=\E[%dM:DO=\E[%dB:IC=\E[%d@:\
        :K1=\E[7~:K2=\EOu:K3=\E[5~:K4=\E[8~:K5=\E[6~:LE=\E[%dD:\
        :RI=\E[%dC:UP=\E[%dA:ae=^O:al=\E[L:as=^N:bl=^G:cd=\E[J:\
        :ce=\E[K:cl=\E[H\E[2J:cm=\E[%i%d;%dH:cr=^M:\
        :cs=\E[%i%d;%dr:ct=\E[3g:dc=\E[P:dl=\E[M:do=\E[B:\
        :ec=\E[%dX:ei=\E[4l:ho=\E[H:i1=\E[?47l\E>\E[?1l:ic=\E[@:\
        :im=\E[4h:is=\E[r\E[m\E[2J\E[H\E[?7h\E[?1;3;4;6l\E[4l:\
        :k1=\E[11~:k2=\E[12~:k3=\E[13~:k4=\E[14~:k5=\E[15~:\
        :k6=\E[17~:k7=\E[18~:k8=\E[19~:k9=\E[20~:kD=\E[3~:\
        :kI=\E[2~:kN=\E[6~:kP=\E[5~:kb=^H:kd=\E[B:ke=:kh=\E[7~:\
        :kl=\E[D:kr=\E[C:ks=:ku=\E[A:le=^H:mb=\E[5m:md=\E[1m:\
        :me=\E[m\017:mr=\E[7m:nd=\E[C:rc=\E8:\
        :sc=\E7:se=\E[27m:sf=^J:so=\E[7m:sr=\EM:st=\EH:ta=^I:\
        :te=\E[2J\E[?47l\E8:ti=\E7\E[?47h:ue=\E[24m:up=\E[A:\
        :us=\E[4m:vb=\E[?5h\E[?5l:ve=\E[?25h:vi=\E[?25l:\
        :ac=aaffggiijjkkllmmnnooppqqrrssttuuvvwwxxyyzz{{||}}~~:

# DOS terminal emulator such as Telix or TeleMate.
# This probably also works for the SCO console, though it's incomplete.
an|ansi|ansi-bbs|ANSI terminals (emulators):\
	:co#80:li#24:am:\
	:is=:rs=\Ec:kb=^H:\
	:as=\E[m:ae=:eA=:\
	:ac=0\333+\257,\256.\031-\030a\261f\370g\361j\331k\277l\332m\300n\305q\304t\264u\303v\301w\302x\263~\025:\
	:kD=\177:kH=\E[Y:kN=\E[U:kP=\E[V:kh=\E[H:\
	:k1=\EOP:k2=\EOQ:k3=\EOR:k4=\EOS:k5=\EOT:\
	:k6=\EOU:k7=\EOV:k8=\EOW:k9=\EOX:k0=\EOY:\
	:tc=vt-generic:

	`;
}

/// A modifier for [Color]
enum Bright = 0x08;

/// Defines the list of standard colors understood by Terminal.
/// See also: [Bright]
enum Color : ushort {
	black = 0, /// .
	red = RED_BIT, /// .
	green = GREEN_BIT, /// .
	yellow = red | green, /// .
	blue = BLUE_BIT, /// .
	magenta = red | blue, /// .
	cyan = blue | green, /// .
	white = red | green | blue, /// .
	DEFAULT = 256,
}

/// When capturing input, what events are you interested in?
///
/// Note: these flags can be OR'd together to select more than one option at a time.
///
/// Ctrl+C and other keyboard input is always captured, though it may be line buffered if you don't use raw.
/// The rationale for that is to ensure the Terminal destructor has a chance to run, since the terminal is a shared resource and should be put back before the program terminates.
enum ConsoleInputFlags {
	raw = 0, /// raw input returns keystrokes immediately, without line buffering
	echo = 1, /// do you want to automatically echo input back to the user?
	mouse = 2, /// capture mouse events
	paste = 4, /// capture paste events (note: without this, paste can come through as keystrokes)
	size = 8, /// window resize events

	releasedKeys = 64, /// key release events. Not reliable on Posix.

	allInputEvents = 8|4|2, /// subscribe to all input events. Note: in previous versions, this also returned release events. It no longer does, use allInputEventsWithRelease if you want them.
	allInputEventsWithRelease = allInputEvents|releasedKeys, /// subscribe to all input events, including (unreliable on Posix) key release events.
}

/// Defines how terminal output should be handled.
enum ConsoleOutputType {
	linear = 0, /// do you want output to work one line at a time?
	cellular = 1, /// or do you want access to the terminal screen as a grid of characters?
	//truncatedCellular = 3, /// cellular, but instead of wrapping output to the next line automatically, it will truncate at the edges

	minimalProcessing = 255, /// do the least possible work, skips most construction and desturction tasks. Only use if you know what you're doing here
}

/// Some methods will try not to send unnecessary commands to the screen. You can override their judgement using a ForceOption parameter, if present
enum ForceOption {
	automatic = 0, /// automatically decide what to do (best, unless you know for sure it isn't right)
	neverSend = -1, /// never send the data. This will only update Terminal's internal state. Use with caution.
	alwaysSend = 1, /// always send the data, even if it doesn't seem necessary
}

// we could do it with termcap too, getenv("TERMCAP") then split on : and replace \E with \033 and get the pieces

/// Encapsulates the I/O capabilities of a terminal.
///
/// Warning: do not write out escape sequences to the terminal. This won't work
/// on Windows and will confuse Terminal's internal state on Posix.
struct Terminal {
	///
	@disable this();
	@disable this(this);
	private ConsoleOutputType type;

	/++
		Terminal is only valid to use on an actual console device or terminal
		handle. You should not attempt to construct a Terminal instance if this
		returns false;
	+/
	static bool stdoutIsTerminal() {
		version(Posix) {
			import core.sys.posix.unistd;
			return cast(bool) isatty(1);
		} else version(Windows) {
			auto hConsole = GetStdHandle(STD_OUTPUT_HANDLE);
			CONSOLE_SCREEN_BUFFER_INFO originalSbi;
			if(GetConsoleScreenBufferInfo(hConsole, &originalSbi) == 0)
				return false;
			else
				return true;
		} else static assert(0);
	}

	version(Posix) {
		private int fdOut;
		private int fdIn;
		private int[] delegate() getSizeOverride;
		void delegate(in void[]) _writeDelegate; // used to override the unix write() system call, set it magically
	}

	version(Posix) {
		bool terminalInFamily(string[] terms...) {
			import std.process;
			import std.string;
			auto term = environment.get("TERM");
			foreach(t; terms)
				if(indexOf(term, t) != -1)
					return true;

			return false;
		}

		// This is a filthy hack because Terminal.app and OS X are garbage who don't
		// work the way they're advertised. I just have to best-guess hack and hope it
		// doesn't break anything else. (If you know a better way, let me know!)
		bool isMacTerminal() {
			import std.process;
			import std.string;
			auto term = environment.get("TERM");
			return term == "xterm-256color";
		}

		static string[string] termcapDatabase;
		static void readTermcapFile(bool useBuiltinTermcap = false) {
			import std.file;
			import std.stdio;
			import std.string;

			//if(!exists("/etc/termcap"))
				useBuiltinTermcap = true;

			string current;

			void commitCurrentEntry() {
				if(current is null)
					return;

				string names = current;
				auto idx = indexOf(names, ":");
				if(idx != -1)
					names = names[0 .. idx];

				foreach(name; split(names, "|"))
					termcapDatabase[name] = current;

				current = null;
			}

			void handleTermcapLine(in char[] line) {
				if(line.length == 0) { // blank
					commitCurrentEntry();
					return; // continue
				}
				if(line[0] == '#') // comment
					return; // continue
				size_t termination = line.length;
				if(line[$-1] == '\\')
					termination--; // cut off the \\
				current ~= strip(line[0 .. termination]);
				// termcap entries must be on one logical line, so if it isn't continued, we know we're done
				if(line[$-1] != '\\')
					commitCurrentEntry();
			}

			if(useBuiltinTermcap) {
				foreach(line; splitLines(builtinTermcap)) {
					handleTermcapLine(line);
				}
			} else {
				foreach(line; File("/etc/termcap").byLine()) {
					handleTermcapLine(line);
				}
			}
		}

		static string getTermcapDatabase(string terminal) {
			import std.string;

			if(termcapDatabase is null)
				readTermcapFile();

			auto data = terminal in termcapDatabase;
			if(data is null)
				return null;

			auto tc = *data;
			auto more = indexOf(tc, ":tc=");
			if(more != -1) {
				auto tcKey = tc[more + ":tc=".length .. $];
				auto end = indexOf(tcKey, ":");
				if(end != -1)
					tcKey = tcKey[0 .. end];
				tc = getTermcapDatabase(tcKey) ~ tc;
			}

			return tc;
		}

		string[string] termcap;
		void readTermcap() {
			import std.process;
			import std.string;
			import std.array;

			string termcapData = environment.get("TERMCAP");
			if(termcapData.length == 0) {
				termcapData = getTermcapDatabase(environment.get("TERM"));
			}

			auto e = replace(termcapData, "\\\n", "\n");
			termcap = null;

			foreach(part; split(e, ":")) {
				// FIXME: handle numeric things too

				auto things = split(part, "=");
				if(things.length)
					termcap[things[0]] =
						things.length > 1 ? things[1] : null;
			}
		}

		string findSequenceInTermcap(in char[] sequenceIn) {
			char[10] sequenceBuffer;
			char[] sequence;
			if(sequenceIn.length > 0 && sequenceIn[0] == '\033') {
				if(!(sequenceIn.length < sequenceBuffer.length - 1))
					return null;
				sequenceBuffer[1 .. sequenceIn.length + 1] = sequenceIn[];
				sequenceBuffer[0] = '\\';
				sequenceBuffer[1] = 'E';
				sequence = sequenceBuffer[0 .. sequenceIn.length + 1];
			} else {
				sequence = sequenceBuffer[1 .. sequenceIn.length + 1];
			}

			import std.array;
			foreach(k, v; termcap)
				if(v == sequence)
					return k;
			return null;
		}

		string getTermcap(string key) {
			auto k = key in termcap;
			if(k !is null) return *k;
			return null;
		}

		// Looks up a termcap item and tries to execute it. Returns false on failure
		bool doTermcap(T...)(string key, T t) {
			import std.conv;
			auto fs = getTermcap(key);
			if(fs is null)
				return false;

			int swapNextTwo = 0;

			R getArg(R)(int idx) {
				if(swapNextTwo == 2) {
					idx ++;
					swapNextTwo--;
				} else if(swapNextTwo == 1) {
					idx --;
					swapNextTwo--;
				}

				foreach(i, arg; t) {
					if(i == idx)
						return to!R(arg);
				}
				assert(0, to!string(idx) ~ " is out of bounds working " ~ fs);
			}

			char[256] buffer;
			int bufferPos = 0;

			void addChar(char c) {
				import std.exception;
				enforce(bufferPos < buffer.length);
				buffer[bufferPos++] = c;
			}

			void addString(in char[] c) {
				import std.exception;
				enforce(bufferPos + c.length < buffer.length);
				buffer[bufferPos .. bufferPos + c.length] = c[];
				bufferPos += c.length;
			}

			void addInt(int c, int minSize) {
				import std.string;
				auto str = format("%0"~(minSize ? to!string(minSize) : "")~"d", c);
				addString(str);
			}

			bool inPercent;
			int argPosition = 0;
			int incrementParams = 0;
			bool skipNext;
			bool nextIsChar;
			bool inBackslash;

			foreach(char c; fs) {
				if(inBackslash) {
					if(c == 'E')
						addChar('\033');
					else
						addChar(c);
					inBackslash = false;
				} else if(nextIsChar) {
					if(skipNext)
						skipNext = false;
					else
						addChar(cast(char) (c + getArg!int(argPosition) + (incrementParams ? 1 : 0)));
					if(incrementParams) incrementParams--;
					argPosition++;
					inPercent = false;
				} else if(inPercent) {
					switch(c) {
						case '%':
							addChar('%');
							inPercent = false;
						break;
						case '2':
						case '3':
						case 'd':
							if(skipNext)
								skipNext = false;
							else
								addInt(getArg!int(argPosition) + (incrementParams ? 1 : 0),
									c == 'd' ? 0 : (c - '0')
								);
							if(incrementParams) incrementParams--;
							argPosition++;
							inPercent = false;
						break;
						case '.':
							if(skipNext)
								skipNext = false;
							else
								addChar(cast(char) (getArg!int(argPosition) + (incrementParams ? 1 : 0)));
							if(incrementParams) incrementParams--;
							argPosition++;
						break;
						case '+':
							nextIsChar = true;
							inPercent = false;
						break;
						case 'i':
							incrementParams = 2;
							inPercent = false;
						break;
						case 's':
							skipNext = true;
							inPercent = false;
						break;
						case 'b':
							argPosition--;
							inPercent = false;
						break;
						case 'r':
							swapNextTwo = 2;
							inPercent = false;
						break;
						// FIXME: there's more
						// http://www.gnu.org/software/termutils/manual/termcap-1.3/html_mono/termcap.html

						default:
							assert(0, "not supported " ~ c);
					}
				} else {
					if(c == '%')
						inPercent = true;
					else if(c == '\\')
						inBackslash = true;
					else
						addChar(c);
				}
			}

			writeStringRaw(buffer[0 .. bufferPos]);
			return true;
		}
	}

	version(Posix)
	/**
	 * Constructs an instance of Terminal representing the capabilities of
	 * the current terminal.
	 *
	 * While it is possible to override the stdin+stdout file descriptors, remember
	 * that is not portable across platforms and be sure you know what you're doing.
	 *
	 * ditto on getSizeOverride. That's there so you can do something instead of ioctl.
	 */
	this(ConsoleOutputType type, int fdIn = 0, int fdOut = 1, int[] delegate() getSizeOverride = null) {
		this.fdIn = fdIn;
		this.fdOut = fdOut;
		this.getSizeOverride = getSizeOverride;
		this.type = type;

		readTermcap();

		if(type == ConsoleOutputType.minimalProcessing) {
			_suppressDestruction = true;
			return;
		}

		if(type == ConsoleOutputType.cellular) {
			doTermcap("ti");
			clear();
			moveTo(0, 0, ForceOption.alwaysSend); // we need to know where the cursor is for some features to work, and moving it is easier than querying it
		}

		if(terminalInFamily("xterm", "rxvt", "screen")) {
			writeStringRaw("\033[22;0t"); // save window title on a stack (support seems spotty, but it doesn't hurt to have it)
		}
	}

	version(Windows) {
		HANDLE hConsole;
		CONSOLE_SCREEN_BUFFER_INFO originalSbi;
	}

	version(Windows)
	/// ditto
	this(ConsoleOutputType type) {
		if(type == ConsoleOutputType.cellular) {
			hConsole = CreateConsoleScreenBuffer(GENERIC_READ | GENERIC_WRITE, 0, null, CONSOLE_TEXTMODE_BUFFER, null);
			if(hConsole == INVALID_HANDLE_VALUE) {
				import std.conv;
				throw new Exception(to!string(GetLastError()));
			}

			SetConsoleActiveScreenBuffer(hConsole);
			/*
http://msdn.microsoft.com/en-us/library/windows/desktop/ms686125%28v=vs.85%29.aspx
http://msdn.microsoft.com/en-us/library/windows/desktop/ms683193%28v=vs.85%29.aspx
			*/
			COORD size;
			/*
			CONSOLE_SCREEN_BUFFER_INFO sbi;
			GetConsoleScreenBufferInfo(hConsole, &sbi);
			size.X = cast(short) GetSystemMetrics(SM_CXMIN);
			size.Y = cast(short) GetSystemMetrics(SM_CYMIN);
			*/

			// FIXME: this sucks, maybe i should just revert it. but there shouldn't be scrollbars in cellular mode
			//size.X = 80;
			//size.Y = 24;
			//SetConsoleScreenBufferSize(hConsole, size);

			clear();
		} else {
			hConsole = GetStdHandle(STD_OUTPUT_HANDLE);
		}

		if(GetConsoleScreenBufferInfo(hConsole, &originalSbi) == 0)
			throw new Exception("not a user-interactive terminal");

		defaultForegroundColor = cast(Color) (originalSbi.wAttributes & 0x0f);
		defaultBackgroundColor = cast(Color) ((originalSbi.wAttributes >> 4) & 0x0f);

		// this is unnecessary since I use the W versions of other functions
		// and can cause weird font bugs, so I'm commenting unless some other
		// need comes up.
		/*
		oldCp = GetConsoleOutputCP();
		SetConsoleOutputCP(65001); // UTF-8

		oldCpIn = GetConsoleCP();
		SetConsoleCP(65001); // UTF-8
		*/
	}

	version(Windows) {
		private Color defaultBackgroundColor = Color.black;
		private Color defaultForegroundColor = Color.white;
		UINT oldCp;
		UINT oldCpIn;
	}

	// only use this if you are sure you know what you want, since the terminal is a shared resource you generally really want to reset it to normal when you leave...
	bool _suppressDestruction;

	version(Posix)
	~this() {
		if(_suppressDestruction) {
			flush();
			return;
		}
		if(type == ConsoleOutputType.cellular) {
			doTermcap("te");
		}
		if(terminalInFamily("xterm", "rxvt", "screen")) {
			writeStringRaw("\033[23;0t"); // restore window title from the stack
		}
		showCursor();
		reset();
		flush();

		if(lineGetter !is null)
			lineGetter.dispose();
	}

	version(Windows)
	~this() {
		flush(); // make sure user data is all flushed before resetting
		reset();
		showCursor();

		if(lineGetter !is null)
			lineGetter.dispose();


		SetConsoleOutputCP(oldCp);
		SetConsoleCP(oldCpIn);

		auto stdo = GetStdHandle(STD_OUTPUT_HANDLE);
		SetConsoleActiveScreenBuffer(stdo);
		if(hConsole !is stdo)
			CloseHandle(hConsole);
	}

	// lazily initialized and preserved between calls to getline for a bit of efficiency (only a bit)
	// and some history storage.
	LineGetter lineGetter;

	int _currentForeground = Color.DEFAULT;
	int _currentBackground = Color.DEFAULT;
	RGB _currentForegroundRGB;
	RGB _currentBackgroundRGB;
	bool reverseVideo = false;

	/++
		Attempts to set color according to a 24 bit value (r, g, b, each >= 0 and < 256).


		This is not supported on all terminals. It will attempt to fall back to a 256-color
		or 8-color palette in those cases automatically.

		Returns: true if it believes it was successful (note that it cannot be completely sure),
		false if it had to use a fallback.
	+/
	bool setTrueColor(RGB foreground, RGB background, ForceOption force = ForceOption.automatic) {
		if(force == ForceOption.neverSend) {
			_currentForeground = -1;
			_currentBackground = -1;
			_currentForegroundRGB = foreground;
			_currentBackgroundRGB = background;
			return true;
		}

		if(force == ForceOption.automatic && _currentForeground == -1 && _currentBackground == -1 && (_currentForegroundRGB == foreground && _currentBackgroundRGB == background))
			return true;

		_currentForeground = -1;
		_currentBackground = -1;
		_currentForegroundRGB = foreground;
		_currentBackgroundRGB = background;

		version(Windows) {
			flush();
			ushort setTob = cast(ushort) approximate16Color(background);
			ushort setTof = cast(ushort) approximate16Color(foreground);
			SetConsoleTextAttribute(
				hConsole,
				cast(ushort)((setTob << 4) | setTof));
			return false;
		} else {
			// FIXME: if the terminal reliably does support 24 bit color, use it
			// instead of the round off. But idk how to detect that yet...

			// fallback to 16 color for term that i know don't take it well
			import std.process;
			import std.string;
			if(environment.get("TERM") == "rxvt" || environment.get("TERM") == "linux") {
				// not likely supported, use 16 color fallback
				auto setTof = approximate16Color(foreground);
				auto setTob = approximate16Color(background);

				writeStringRaw(format("\033[%dm\033[3%dm\033[4%dm",
					(setTof & Bright) ? 1 : 0,
					cast(int) (setTof & ~Bright),
					cast(int) (setTob & ~Bright)
				));

				return false;
			}

			// otherwise, assume it is probably supported and give it a try
			writeStringRaw(format("\033[38;5;%dm\033[48;5;%dm",
				colorToXTermPaletteIndex(foreground),
				colorToXTermPaletteIndex(background)
			));

			/+ // this is the full 24 bit color sequence
			writeStringRaw(format("\033[38;2;%d;%d;%dm", foreground.r, foreground.g, foreground.b));
			writeStringRaw(format("\033[48;2;%d;%d;%dm", background.r, background.g, background.b));
			+/

			return true;
		}
	}

	/// Changes the current color. See enum Color for the values.
	void color(int foreground, int background, ForceOption force = ForceOption.automatic, bool reverseVideo = false) {
		if(force != ForceOption.neverSend) {
			version(Windows) {
				// assuming a dark background on windows, so LowContrast == dark which means the bit is NOT set on hardware
				/*
				foreground ^= LowContrast;
				background ^= LowContrast;
				*/

				ushort setTof = cast(ushort) foreground;
				ushort setTob = cast(ushort) background;

				// this isn't necessarily right but meh
				if(background == Color.DEFAULT)
					setTob = defaultBackgroundColor;
				if(foreground == Color.DEFAULT)
					setTof = defaultForegroundColor;

				if(force == ForceOption.alwaysSend || reverseVideo != this.reverseVideo || foreground != _currentForeground || background != _currentBackground) {
					flush(); // if we don't do this now, the buffering can screw up the colors...
					if(reverseVideo) {
						if(background == Color.DEFAULT)
							setTof = defaultBackgroundColor;
						else
							setTof = cast(ushort) background | (foreground & Bright);

						if(background == Color.DEFAULT)
							setTob = defaultForegroundColor;
						else
							setTob = cast(ushort) (foreground & ~Bright);
					}
					SetConsoleTextAttribute(
						hConsole,
						cast(ushort)((setTob << 4) | setTof));
				}
			} else {
				import std.process;
				// I started using this envvar for my text editor, but now use it elsewhere too
				// if we aren't set to dark, assume light
				/*
				if(getenv("ELVISBG") == "dark") {
					// LowContrast on dark bg menas
				} else {
					foreground ^= LowContrast;
					background ^= LowContrast;
				}
				*/

				ushort setTof = cast(ushort) foreground & ~Bright;
				ushort setTob = cast(ushort) background & ~Bright;

				if(foreground & Color.DEFAULT)
					setTof = 9; // ansi sequence for reset
				if(background == Color.DEFAULT)
					setTob = 9;

				import std.string;

				if(force == ForceOption.alwaysSend || reverseVideo != this.reverseVideo || foreground != _currentForeground || background != _currentBackground) {
					writeStringRaw(format("\033[%dm\033[3%dm\033[4%dm\033[%dm",
						(foreground != Color.DEFAULT && (foreground & Bright)) ? 1 : 0,
						cast(int) setTof,
						cast(int) setTob,
						reverseVideo ? 7 : 27
					));
				}
			}
		}

		_currentForeground = foreground;
		_currentBackground = background;
		this.reverseVideo = reverseVideo;
	}

	private bool _underlined = false;

	/// Note: the Windows console does not support underlining
	void underline(bool set, ForceOption force = ForceOption.automatic) {
		if(set == _underlined && force != ForceOption.alwaysSend)
			return;
		version(Posix) {
			if(set)
				writeStringRaw("\033[4m");
			else
				writeStringRaw("\033[24m");
		}
		_underlined = set;
	}
	// FIXME: do I want to do bold and italic?

	/// Returns the terminal to normal output colors
	void reset() {
		version(Windows)
			SetConsoleTextAttribute(
				hConsole,
				originalSbi.wAttributes);
		else
			writeStringRaw("\033[0m");

		_underlined = false;
		_currentForeground = Color.DEFAULT;
		_currentBackground = Color.DEFAULT;
		reverseVideo = false;
	}

	// FIXME: add moveRelative

	/// The current x position of the output cursor. 0 == leftmost column
	@property int cursorX() {
		return _cursorX;
	}

	/// The current y position of the output cursor. 0 == topmost row
	@property int cursorY() {
		return _cursorY;
	}

	private int _cursorX;
	private int _cursorY;

	/// Moves the output cursor to the given position. (0, 0) is the upper left corner of the screen. The force parameter can be used to force an update, even if Terminal doesn't think it is necessary
	void moveTo(int x, int y, ForceOption force = ForceOption.automatic) {
		if(force != ForceOption.neverSend && (force == ForceOption.alwaysSend || x != _cursorX || y != _cursorY)) {
			executeAutoHideCursor();
			version(Posix) {
				doTermcap("cm", y, x);
			} else version(Windows) {

				flush(); // if we don't do this now, the buffering can screw up the position
				COORD coord = {cast(short) x, cast(short) y};
				SetConsoleCursorPosition(hConsole, coord);
			} else static assert(0);
		}

		_cursorX = x;
		_cursorY = y;
	}

	/// shows the cursor
	void showCursor() {
		version(Posix)
			doTermcap("ve");
		else {
			CONSOLE_CURSOR_INFO info;
			GetConsoleCursorInfo(hConsole, &info);
			info.bVisible = true;
			SetConsoleCursorInfo(hConsole, &info);
		}
	}

	/// hides the cursor
	void hideCursor() {
		version(Posix) {
			doTermcap("vi");
		} else {
			CONSOLE_CURSOR_INFO info;
			GetConsoleCursorInfo(hConsole, &info);
			info.bVisible = false;
			SetConsoleCursorInfo(hConsole, &info);
		}

	}

	private bool autoHidingCursor;
	private bool autoHiddenCursor;
	// explicitly not publicly documented
	// Sets the cursor to automatically insert a hide command at the front of the output buffer iff it is moved.
	// Call autoShowCursor when you are done with the batch update.
	void autoHideCursor() {
		autoHidingCursor = true;
	}

	private void executeAutoHideCursor() {
		if(autoHidingCursor) {
			version(Windows)
				hideCursor();
			else version(Posix) {
				// prepend the hide cursor command so it is the first thing flushed
				writeBuffer = "\033[?25l" ~ writeBuffer;
			}

			autoHiddenCursor = true;
			autoHidingCursor = false; // already been done, don't insert the command again
		}
	}

	// explicitly not publicly documented
	// Shows the cursor if it was automatically hidden by autoHideCursor and resets the internal auto hide state.
	void autoShowCursor() {
		if(autoHiddenCursor)
			showCursor();

		autoHidingCursor = false;
		autoHiddenCursor = false;
	}

	/*
	// alas this doesn't work due to a bunch of delegate context pointer and postblit problems
	// instead of using: auto input = terminal.captureInput(flags)
	// use: auto input = RealTimeConsoleInput(&terminal, flags);
	/// Gets real time input, disabling line buffering
	RealTimeConsoleInput captureInput(ConsoleInputFlags flags) {
		return RealTimeConsoleInput(&this, flags);
	}
	*/

	/// Changes the terminal's title
	void setTitle(string t) {
		version(Windows) {
			SetConsoleTitleA(toStringz(t));
		} else {
			import std.string;
			if(terminalInFamily("xterm", "rxvt", "screen"))
				writeStringRaw(format("\033]0;%s\007", t));
		}
	}

	/// Flushes your updates to the terminal.
	/// It is important to call this when you are finished writing for now if you are using the version=with_eventloop
	void flush() {
		if(writeBuffer.length == 0)
			return;

		version(Posix) {
			if(_writeDelegate !is null) {
				_writeDelegate(writeBuffer);
			} else {
				ssize_t written;

				while(writeBuffer.length) {
					written = unix.write(this.fdOut, writeBuffer.ptr, writeBuffer.length);
					if(written < 0)
						throw new Exception("write failed for some reason");
					writeBuffer = writeBuffer[written .. $];
				}
			}
		} else version(Windows) {
			import std.conv;
			// FIXME: I'm not sure I'm actually happy with this allocation but
			// it probably isn't a big deal. At least it has unicode support now.
			wstring writeBufferw = to!wstring(writeBuffer);
			while(writeBufferw.length) {
				DWORD written;
				WriteConsoleW(hConsole, writeBufferw.ptr, cast(DWORD)writeBufferw.length, &written, null);
				writeBufferw = writeBufferw[written .. $];
			}

			writeBuffer = null;
		}
	}

	int[] getSize() {
		version(Windows) {
			CONSOLE_SCREEN_BUFFER_INFO info;
			GetConsoleScreenBufferInfo( hConsole, &info );
        
			int cols, rows;
        
			cols = (info.srWindow.Right - info.srWindow.Left + 1);
			rows = (info.srWindow.Bottom - info.srWindow.Top + 1);

			return [cols, rows];
		} else {
			if(getSizeOverride is null) {
				winsize w;
				ioctl(0, TIOCGWINSZ, &w);
				return [w.ws_col, w.ws_row];
			} else return getSizeOverride();
		}
	}

	void updateSize() {
		auto size = getSize();
		_width = size[0];
		_height = size[1];
	}

	private int _width;
	private int _height;

	/// The current width of the terminal (the number of columns)
	@property int width() {
		if(_width == 0 || _height == 0)
			updateSize();
		return _width;
	}

	/// The current height of the terminal (the number of rows)
	@property int height() {
		if(_width == 0 || _height == 0)
			updateSize();
		return _height;
	}

	/*
	void write(T...)(T t) {
		foreach(arg; t) {
			writeStringRaw(to!string(arg));
		}
	}
	*/

	/// Writes to the terminal at the current cursor position.
	void writef(T...)(string f, T t) {
		import std.string;
		writePrintableString(format(f, t));
	}

	/// ditto
	void writefln(T...)(string f, T t) {
		writef(f ~ "\n", t);
	}

	/// ditto
	void write(T...)(T t) {
		import std.conv;
		string data;
		foreach(arg; t) {
			data ~= to!string(arg);
		}

		writePrintableString(data);
	}

	/// ditto
	void writeln(T...)(T t) {
		write(t, "\n");
	}

	/+
	/// A combined moveTo and writef that puts the cursor back where it was before when it finishes the write.
	/// Only works in cellular mode. 
	/// Might give better performance than moveTo/writef because if the data to write matches the internal buffer, it skips sending anything (to override the buffer check, you can use moveTo and writePrintableString with ForceOption.alwaysSend)
	void writefAt(T...)(int x, int y, string f, T t) {
		import std.string;
		auto toWrite = format(f, t);

		auto oldX = _cursorX;
		auto oldY = _cursorY;

		writeAtWithoutReturn(x, y, toWrite);

		moveTo(oldX, oldY);
	}

	void writeAtWithoutReturn(int x, int y, in char[] data) {
		moveTo(x, y);
		writeStringRaw(toWrite, ForceOption.alwaysSend);
	}
	+/

	void writePrintableString(in char[] s, ForceOption force = ForceOption.automatic) {
		// an escape character is going to mess things up. Actually any non-printable character could, but meh
		// assert(s.indexOf("\033") == -1);

		// tracking cursor position
		foreach(ch; s) {
			switch(ch) {
				case '\n':
					_cursorX = 0;
					_cursorY++;
				break;
				case '\r':
					_cursorX = 0;
				break;
				case '\t':
					_cursorX ++;
					_cursorX += _cursorX % 8; // FIXME: get the actual tabstop, if possible
				break;
				default:
					if(ch <= 127) // way of only advancing once per dchar instead of per code unit
						_cursorX++;
			}

			if(_wrapAround && _cursorX > width) {
				_cursorX = 0;
				_cursorY++;
			}

			if(_cursorY == height)
				_cursorY--;

			/+
			auto index = getIndex(_cursorX, _cursorY);
			if(data[index] != ch) {
				data[index] = ch;
			}
			+/
		}

		writeStringRaw(s);
	}

	/* private */ bool _wrapAround = true;

	deprecated alias writePrintableString writeString; /// use write() or writePrintableString instead

	private string writeBuffer;

	// you really, really shouldn't use this unless you know what you are doing
	/*private*/ void writeStringRaw(in char[] s) {
		// FIXME: make sure all the data is sent, check for errors
		version(Posix) {
			writeBuffer ~= s; // buffer it to do everything at once in flush() calls
		} else version(Windows) {
			writeBuffer ~= s;
		} else static assert(0);
	}

	/// Clears the screen.
	void clear() {
		version(Posix) {
			doTermcap("cl");
		} else version(Windows) {
			// http://support.microsoft.com/kb/99261
			flush();

			DWORD c;
			CONSOLE_SCREEN_BUFFER_INFO csbi;
			DWORD conSize;
			GetConsoleScreenBufferInfo(hConsole, &csbi);
			conSize = csbi.dwSize.X * csbi.dwSize.Y;
			COORD coordScreen;
			FillConsoleOutputCharacterA(hConsole, ' ', conSize, coordScreen, &c);
			FillConsoleOutputAttribute(hConsole, csbi.wAttributes, conSize, coordScreen, &c);
			moveTo(0, 0, ForceOption.alwaysSend);
		}

		_cursorX = 0;
		_cursorY = 0;
	}

	/// gets a line, including user editing. Convenience method around the LineGetter class and RealTimeConsoleInput facilities - use them if you need more control.
	/// You really shouldn't call this if stdin isn't actually a user-interactive terminal! So if you expect people to pipe data to your app, check for that or use something else.
	// FIXME: add a method to make it easy to check if stdin is actually a tty and use other methods there.
	string getline(string prompt = null) {
		if(lineGetter is null)
			lineGetter = new LineGetter(&this);
		// since the struct might move (it shouldn't, this should be unmovable!) but since
		// it technically might, I'm updating the pointer before using it just in case.
		lineGetter.terminal = &this;

		if(prompt !is null)
			lineGetter.prompt = prompt;

		auto input = RealTimeConsoleInput(&this, ConsoleInputFlags.raw);
		auto line = lineGetter.getline(&input);

		// lineGetter leaves us exactly where it was when the user hit enter, giving best
		// flexibility to real-time input and cellular programs. The convenience function,
		// however, wants to do what is right in most the simple cases, which is to actually
		// print the line (echo would be enabled without RealTimeConsoleInput anyway and they
		// did hit enter), so we'll do that here too.
		writePrintableString("\n");

		return line;
	}

}

/+
struct ConsoleBuffer {
	int cursorX;
	int cursorY;
	int width;
	int height;
	dchar[] data;

	void actualize(Terminal* t) {
		auto writer = t.getBufferedWriter();

		this.copyTo(&(t.onScreen));
	}

	void copyTo(ConsoleBuffer* buffer) {
		buffer.cursorX = this.cursorX;
		buffer.cursorY = this.cursorY;
		buffer.width = this.width;
		buffer.height = this.height;
		buffer.data[] = this.data[];
	}
}
+/

/**
 * Encapsulates the stream of input events received from the terminal input.
 */
struct RealTimeConsoleInput {
	@disable this();
	@disable this(this);

	version(Posix) {
		private int fdOut;
		private int fdIn;
		private sigaction_t oldSigWinch;
		private sigaction_t oldSigIntr;
		private sigaction_t oldHupIntr;
		private termios old;
		ubyte[128] hack;
		// apparently termios isn't the size druntime thinks it is (at least on 32 bit, sometimes)....
		// tcgetattr smashed other variables in here too that could create random problems
		// so this hack is just to give some room for that to happen without destroying the rest of the world
	}

	version(Windows) {
		private DWORD oldInput;
		private DWORD oldOutput;
		HANDLE inputHandle;
	}

	private ConsoleInputFlags flags;
	private Terminal* terminal;
	private void delegate()[] destructor;

	/// To capture input, you need to provide a terminal and some flags.
	public this(Terminal* terminal, ConsoleInputFlags flags) {
		this.flags = flags;
		this.terminal = terminal;

		version(Windows) {
			inputHandle = GetStdHandle(STD_INPUT_HANDLE);

			GetConsoleMode(inputHandle, &oldInput);

			DWORD mode = 0;
			mode |= ENABLE_PROCESSED_INPUT /* 0x01 */; // this gives Ctrl+C which we probably want to be similar to linux
			//if(flags & ConsoleInputFlags.size)
			mode |= ENABLE_WINDOW_INPUT /* 0208 */; // gives size etc
			if(flags & ConsoleInputFlags.echo)
				mode |= ENABLE_ECHO_INPUT; // 0x4
			if(flags & ConsoleInputFlags.mouse)
				mode |= ENABLE_MOUSE_INPUT; // 0x10
			// if(flags & ConsoleInputFlags.raw) // FIXME: maybe that should be a separate flag for ENABLE_LINE_INPUT

			SetConsoleMode(inputHandle, mode);
			destructor ~= { SetConsoleMode(inputHandle, oldInput); };


			GetConsoleMode(terminal.hConsole, &oldOutput);
			mode = 0;
			// we want this to match linux too
			mode |= ENABLE_PROCESSED_OUTPUT; /* 0x01 */
			mode |= ENABLE_WRAP_AT_EOL_OUTPUT; /* 0x02 */
			SetConsoleMode(terminal.hConsole, mode);
			destructor ~= { SetConsoleMode(terminal.hConsole, oldOutput); };

			// FIXME: change to UTF8 as well
		}

		version(Posix) {
			this.fdIn = terminal.fdIn;
			this.fdOut = terminal.fdOut;

			if(fdIn != -1) {
				tcgetattr(fdIn, &old);
				auto n = old;

				auto f = ICANON;
				if(!(flags & ConsoleInputFlags.echo))
					f |= ECHO;

				n.c_lflag &= ~f;
				tcsetattr(fdIn, TCSANOW, &n);
			}

			// some weird bug breaks this, https://github.com/robik/ConsoleD/issues/3
			//destructor ~= { tcsetattr(fdIn, TCSANOW, &old); };

			if(flags & ConsoleInputFlags.size) {
				import core.sys.posix.signal;
				sigaction_t n;
				n.sa_handler = &sizeSignalHandler;
				n.sa_mask = cast(sigset_t) 0;
				n.sa_flags = 0;
				sigaction(SIGWINCH, &n, &oldSigWinch);
			}

			{
				import core.sys.posix.signal;
				sigaction_t n;
				n.sa_handler = &interruptSignalHandler;
				n.sa_mask = cast(sigset_t) 0;
				n.sa_flags = 0;
				sigaction(SIGINT, &n, &oldSigIntr);
			}

			{
				import core.sys.posix.signal;
				sigaction_t n;
				n.sa_handler = &hangupSignalHandler;
				n.sa_mask = cast(sigset_t) 0;
				n.sa_flags = 0;
				sigaction(SIGHUP, &n, &oldHupIntr);
			}



			if(flags & ConsoleInputFlags.mouse) {
				// basic button press+release notification

				// FIXME: try to get maximum capabilities from all terminals
				// right now this works well on xterm but rxvt isn't sending movements...

				terminal.writeStringRaw("\033[?1000h");
				destructor ~= { terminal.writeStringRaw("\033[?1000l"); };
				// the MOUSE_HACK env var is for the case where I run screen
				// but set TERM=xterm (which I do from putty). The 1003 mouse mode
				// doesn't work there, breaking mouse support entirely. So by setting
				// MOUSE_HACK=1002 it tells us to use the other mode for a fallback.
				import std.process : environment;
				if(terminal.terminalInFamily("xterm") && environment.get("MOUSE_HACK") != "1002") {
					// this is vt200 mouse with full motion tracking, supported by xterm
					terminal.writeStringRaw("\033[?1003h");
					destructor ~= { terminal.writeStringRaw("\033[?1003l"); };
				} else if(terminal.terminalInFamily("rxvt", "screen") || environment.get("MOUSE_HACK") == "1002") {
					terminal.writeStringRaw("\033[?1002h"); // this is vt200 mouse with press/release and motion notification iff buttons are pressed
					destructor ~= { terminal.writeStringRaw("\033[?1002l"); };
				}
			}
			if(flags & ConsoleInputFlags.paste) {
				if(terminal.terminalInFamily("xterm", "rxvt", "screen")) {
					terminal.writeStringRaw("\033[?2004h"); // bracketed paste mode
					destructor ~= { terminal.writeStringRaw("\033[?2004l"); };
				}
			}

			// try to ensure the terminal is in UTF-8 mode
			if(terminal.terminalInFamily("xterm", "screen", "linux") && !terminal.isMacTerminal()) {
				terminal.writeStringRaw("\033%G");
			}

			terminal.flush();
		}


		version(with_eventloop) {
			import arsd.eventloop;
			version(Windows)
				auto listenTo = inputHandle;
			else version(Posix)
				auto listenTo = this.fdIn;
			else static assert(0, "idk about this OS");

			version(Posix)
			addListener(&signalFired);

			if(listenTo != -1) {
				addFileEventListeners(listenTo, &eventListener, null, null);
				destructor ~= { removeFileEventListeners(listenTo); };
			}
			addOnIdle(&terminal.flush);
			destructor ~= { removeOnIdle(&terminal.flush); };
		}
	}

	void fdReadyReader() {
		auto queue = readNextEvents();
		foreach(event; queue)
			userEventHandler(event);
	}

	void delegate(InputEvent) userEventHandler;

	/++
		If you are using [arsd.simpledisplay] and want terminal interop too, you can call
		this function to add it to the sdpy event loop and get the callback called on new
		input.

		Note that you will probably need to call `terminal.flush()` when you are doing doing
		output, as the sdpy event loop doesn't know to do that (yet). I will probably change
		that in a future version, but it doesn't hurt to call it twice anyway, so I recommend
		calling flush yourself in any code you write using this.
	+/
	void integrateWithSimpleDisplayEventLoop()(void delegate(InputEvent) userEventHandler) {
		this.userEventHandler = userEventHandler;
		import arsd.simpledisplay;
		version(Windows)
			auto listener = new WindowsHandleReader(&fdReadyReader, terminal.hConsole);
		else version(linux)
			auto listener = new PosixFdReader(&fdReadyReader, fdIn);
		else static assert(0, "sdpy event loop integration not implemented on this platform");
	}

	version(with_eventloop) {
		version(Posix)
		void signalFired(SignalFired) {
			if(interrupted) {
				interrupted = false;
				send(InputEvent(UserInterruptionEvent(), terminal));
			}
			if(windowSizeChanged)
				send(checkWindowSizeChanged());
			if(hangedUp) {
				hangedUp = false;
				send(InputEvent(HangupEvent(), terminal));
			}
		}

		import arsd.eventloop;
		void eventListener(OsFileHandle fd) {
			auto queue = readNextEvents();
			foreach(event; queue)
				send(event);
		}
	}

	~this() {
		// the delegate thing doesn't actually work for this... for some reason
		version(Posix)
			if(fdIn != -1)
				tcsetattr(fdIn, TCSANOW, &old);

		version(Posix) {
			if(flags & ConsoleInputFlags.size) {
				// restoration
				sigaction(SIGWINCH, &oldSigWinch, null);
			}
			sigaction(SIGINT, &oldSigIntr, null);
			sigaction(SIGHUP, &oldHupIntr, null);
		}

		// we're just undoing everything the constructor did, in reverse order, same criteria
		foreach_reverse(d; destructor)
			d();
	}

	/**
		Returns true if there iff getch() would not block.

		WARNING: kbhit might consume input that would be ignored by getch. This
		function is really only meant to be used in conjunction with getch. Typically,
		you should use a full-fledged event loop if you want all kinds of input. kbhit+getch
		are just for simple keyboard driven applications.
	*/
	bool kbhit() {
		auto got = getch(true);

		if(got == dchar.init)
			return false;

		getchBuffer = got;
		return true;
	}

	/// Check for input, waiting no longer than the number of milliseconds
	bool timedCheckForInput(int milliseconds) {
		if(inputQueue.length || timedCheckForInput_bypassingBuffer(milliseconds))
			return true;
		version(Posix)
			if(interrupted || windowSizeChanged || hangedUp)
				return true;
		return false;
	}

	/* private */ bool anyInput_internal(int timeout = 0) {
		return timedCheckForInput(timeout);
	}

	bool timedCheckForInput_bypassingBuffer(int milliseconds) {
		version(Windows) {
			auto response = WaitForSingleObject(terminal.hConsole, milliseconds);
			if(response  == 0)
				return true; // the object is ready
			return false;
		} else version(Posix) {
			if(fdIn == -1)
				return false;

			timeval tv;
			tv.tv_sec = 0;
			tv.tv_usec = milliseconds * 1000;

			fd_set fs;
			FD_ZERO(&fs);

			FD_SET(fdIn, &fs);
			if(select(fdIn + 1, &fs, null, null, &tv) == -1) {
				return false;
			}

			return FD_ISSET(fdIn, &fs);
		}
	}

	private dchar getchBuffer;

	/// Get one key press from the terminal, discarding other
	/// events in the process. Returns dchar.init upon receiving end-of-file.
	///
	/// Be aware that this may return non-character key events, like F1, F2, arrow keys, etc., as private use Unicode characters. Check them against KeyboardEvent.Key if you like.
	dchar getch(bool nonblocking = false) {
		if(getchBuffer != dchar.init) {
			auto a = getchBuffer;
			getchBuffer = dchar.init;
			return a;
		}

		if(nonblocking && !anyInput_internal())
			return dchar.init;

		auto event = nextEvent();
		while(event.type != InputEvent.Type.KeyboardEvent || event.keyboardEvent.pressed == false) {
			if(event.type == InputEvent.Type.UserInterruptionEvent)
				throw new UserInterruptionException();
			if(event.type == InputEvent.Type.HangupEvent)
				throw new HangupException();
			if(event.type == InputEvent.Type.EndOfFileEvent)
				return dchar.init;

			if(nonblocking && !anyInput_internal())
				return dchar.init;

			event = nextEvent();
		}
		return event.keyboardEvent.which;
	}

	//char[128] inputBuffer;
	//int inputBufferPosition;
	version(Posix)
	int nextRaw(bool interruptable = false) {
		if(fdIn == -1)
			return 0;

		char[1] buf;
		try_again:
		auto ret = read(fdIn, buf.ptr, buf.length);
		if(ret == 0)
			return 0; // input closed
		if(ret == -1) {
			import core.stdc.errno;
			if(errno == EINTR)
				// interrupted by signal call, quite possibly resize or ctrl+c which we want to check for in the event loop
				if(interruptable)
					return -1;
				else
					goto try_again;
			else
				throw new Exception("read failed");
		}

		//terminal.writef("RAW READ: %d\n", buf[0]);

		if(ret == 1)
			return inputPrefilter ? inputPrefilter(buf[0]) : buf[0];
		else
			assert(0); // read too much, should be impossible
	}

	version(Posix)
		int delegate(char) inputPrefilter;

	version(Posix)
	dchar nextChar(int starting) {
		if(starting <= 127)
			return cast(dchar) starting;
		char[6] buffer;
		int pos = 0;
		buffer[pos++] = cast(char) starting;

		// see the utf-8 encoding for details
		int remaining = 0;
		ubyte magic = starting & 0xff;
		while(magic & 0b1000_000) {
			remaining++;
			magic <<= 1;
		}

		while(remaining && pos < buffer.length) {
			buffer[pos++] = cast(char) nextRaw();
			remaining--;
		}

		import std.utf;
		size_t throwAway; // it insists on the index but we don't care
		return decode(buffer[], throwAway);
	}

	InputEvent checkWindowSizeChanged() {
		auto oldWidth = terminal.width;
		auto oldHeight = terminal.height;
		terminal.updateSize();
		version(Posix)
		windowSizeChanged = false;
		return InputEvent(SizeChangedEvent(oldWidth, oldHeight, terminal.width, terminal.height), terminal);
	}


	// character event
	// non-character key event
	// paste event
	// mouse event
	// size event maybe, and if appropriate focus events

	/// Returns the next event.
	///
	/// Experimental: It is also possible to integrate this into
	/// a generic event loop, currently under -version=with_eventloop and it will
	/// require the module arsd.eventloop (Linux only at this point)
	InputEvent nextEvent() {
		terminal.flush();
		if(inputQueue.length) {
			auto e = inputQueue[0];
			inputQueue = inputQueue[1 .. $];
			return e;
		}

		wait_for_more:
		version(Posix)
		if(interrupted) {
			interrupted = false;
			return InputEvent(UserInterruptionEvent(), terminal);
		}

		version(Posix)
		if(hangedUp) {
			hangedUp = false;
			return InputEvent(HangupEvent(), terminal);
		}

		version(Posix)
		if(windowSizeChanged) {
			return checkWindowSizeChanged();
		}

		auto more = readNextEvents();
		if(!more.length)
			goto wait_for_more; // i used to do a loop (readNextEvents can read something, but it might be discarded by the input filter) but now it goto's above because readNextEvents might be interrupted by a SIGWINCH aka size event so we want to check that at least

		assert(more.length);

		auto e = more[0];
		inputQueue = more[1 .. $];
		return e;
	}

	InputEvent* peekNextEvent() {
		if(inputQueue.length)
			return &(inputQueue[0]);
		return null;
	}

	enum InjectionPosition { head, tail }
	void injectEvent(InputEvent ev, InjectionPosition where) {
		final switch(where) {
			case InjectionPosition.head:
				inputQueue = ev ~ inputQueue;
			break;
			case InjectionPosition.tail:
				inputQueue ~= ev;
			break;
		}
	}

	InputEvent[] inputQueue;

	version(Windows)
	InputEvent[] readNextEvents() {
		terminal.flush(); // make sure all output is sent out before waiting for anything

		INPUT_RECORD[32] buffer;
		DWORD actuallyRead;
			// FIXME: ReadConsoleInputW
		auto success = ReadConsoleInputW(inputHandle, buffer.ptr, buffer.length, &actuallyRead);
		if(success == 0)
			throw new Exception("ReadConsoleInput");

		InputEvent[] newEvents;
		input_loop: foreach(record; buffer[0 .. actuallyRead]) {
			switch(record.EventType) {
				case KEY_EVENT:
					auto ev = record.KeyEvent;
					KeyboardEvent ke;
					CharacterEvent e;
					NonCharacterKeyEvent ne;

					e.eventType = ev.bKeyDown ? CharacterEvent.Type.Pressed : CharacterEvent.Type.Released;
					ne.eventType = ev.bKeyDown ? NonCharacterKeyEvent.Type.Pressed : NonCharacterKeyEvent.Type.Released;

					ke.pressed = ev.bKeyDown ? true : false;

					// only send released events when specifically requested
					if(!(flags & ConsoleInputFlags.releasedKeys) && !ev.bKeyDown)
						break;

					e.modifierState = ev.dwControlKeyState;
					ne.modifierState = ev.dwControlKeyState;
					ke.modifierState = ev.dwControlKeyState;

					if(ev.UnicodeChar) {
						// new style event goes first
						ke.which = cast(dchar) cast(wchar) ev.UnicodeChar;
						newEvents ~= InputEvent(ke, terminal);

						// old style event then follows as the fallback
						e.character = cast(dchar) cast(wchar) ev.UnicodeChar;
						newEvents ~= InputEvent(e, terminal);
					} else {
						// old style event
						ne.key = cast(NonCharacterKeyEvent.Key) ev.wVirtualKeyCode;

						// new style event. See comment on KeyboardEvent.Key
						ke.which = cast(KeyboardEvent.Key) (ev.wVirtualKeyCode + 0xF0000);

						// FIXME: make this better. the goal is to make sure the key code is a valid enum member
						// Windows sends more keys than Unix and we're doing lowest common denominator here
						foreach(member; __traits(allMembers, NonCharacterKeyEvent.Key))
							if(__traits(getMember, NonCharacterKeyEvent.Key, member) == ne.key) {
								newEvents ~= InputEvent(ke, terminal);
								newEvents ~= InputEvent(ne, terminal);
								break;
							}
					}
				break;
				case MOUSE_EVENT:
					auto ev = record.MouseEvent;
					MouseEvent e;

					e.modifierState = ev.dwControlKeyState;
					e.x = ev.dwMousePosition.X;
					e.y = ev.dwMousePosition.Y;

					switch(ev.dwEventFlags) {
						case 0:
							//press or release
							e.eventType = MouseEvent.Type.Pressed;
							static DWORD lastButtonState;
							auto lastButtonState2 = lastButtonState;
							e.buttons = ev.dwButtonState;
							lastButtonState = e.buttons;

							// this is sent on state change. if fewer buttons are pressed, it must mean released
							if(cast(DWORD) e.buttons < lastButtonState2) {
								e.eventType = MouseEvent.Type.Released;
								// if last was 101 and now it is 100, then button far right was released
								// so we flip the bits, ~100 == 011, then and them: 101 & 011 == 001, the
								// button that was released
								e.buttons = lastButtonState2 & ~e.buttons;
							}
						break;
						case MOUSE_MOVED:
							e.eventType = MouseEvent.Type.Moved;
							e.buttons = ev.dwButtonState;
						break;
						case 0x0004/*MOUSE_WHEELED*/:
							e.eventType = MouseEvent.Type.Pressed;
							if(ev.dwButtonState > 0)
								e.buttons = MouseEvent.Button.ScrollDown;
							else
								e.buttons = MouseEvent.Button.ScrollUp;
						break;
						default:
							continue input_loop;
					}

					newEvents ~= InputEvent(e, terminal);
				break;
				case WINDOW_BUFFER_SIZE_EVENT:
					auto ev = record.WindowBufferSizeEvent;
					auto oldWidth = terminal.width;
					auto oldHeight = terminal.height;
					terminal._width = ev.dwSize.X;
					terminal._height = ev.dwSize.Y;
					newEvents ~= InputEvent(SizeChangedEvent(oldWidth, oldHeight, terminal.width, terminal.height), terminal);
				break;
				// FIXME: can we catch ctrl+c here too?
				default:
					// ignore
			}
		}

		return newEvents;
	}

	version(Posix)
	InputEvent[] readNextEvents() {
		terminal.flush(); // make sure all output is sent out before we try to get input

		// we want to starve the read, especially if we're called from an edge-triggered
		// epoll (which might happen in version=with_eventloop.. impl detail there subject
		// to change).
		auto initial = readNextEventsHelper();

		// lol this calls select() inside a function prolly called from epoll but meh,
		// it is the simplest thing that can possibly work. The alternative would be
		// doing non-blocking reads and buffering in the nextRaw function (not a bad idea
		// btw, just a bit more of a hassle).
		while(timedCheckForInput_bypassingBuffer(0)) {
			auto ne = readNextEventsHelper();
			initial ~= ne;
			foreach(n; ne)
				if(n.type == InputEvent.Type.EndOfFileEvent)
					return initial; // hit end of file, get out of here lest we infinite loop
					// (select still returns info available even after we read end of file)
		}
		return initial;
	}

	// The helper reads just one actual event from the pipe...
	version(Posix)
	InputEvent[] readNextEventsHelper() {
		InputEvent[] charPressAndRelease(dchar character) {
			if((flags & ConsoleInputFlags.releasedKeys))
				return [
					// new style event
					InputEvent(KeyboardEvent(true, character, 0), terminal),
					InputEvent(KeyboardEvent(false, character, 0), terminal),
					// old style event
					InputEvent(CharacterEvent(CharacterEvent.Type.Pressed, character, 0), terminal),
					InputEvent(CharacterEvent(CharacterEvent.Type.Released, character, 0), terminal),
				];
			else return [
				// new style event
				InputEvent(KeyboardEvent(true, character, 0), terminal),
				// old style event
				InputEvent(CharacterEvent(CharacterEvent.Type.Pressed, character, 0), terminal)
			];
		}
		InputEvent[] keyPressAndRelease(NonCharacterKeyEvent.Key key, uint modifiers = 0) {
			if((flags & ConsoleInputFlags.releasedKeys))
				return [
					// new style event FIXME: when the old events are removed, kill the +0xF0000 from here!
					InputEvent(KeyboardEvent(true, cast(dchar)(key) + 0xF0000, modifiers), terminal),
					InputEvent(KeyboardEvent(false, cast(dchar)(key) + 0xF0000, modifiers), terminal),
					// old style event
					InputEvent(NonCharacterKeyEvent(NonCharacterKeyEvent.Type.Pressed, key, modifiers), terminal),
					InputEvent(NonCharacterKeyEvent(NonCharacterKeyEvent.Type.Released, key, modifiers), terminal),
				];
			else return [
				// new style event FIXME: when the old events are removed, kill the +0xF0000 from here!
				InputEvent(KeyboardEvent(true, cast(dchar)(key) + 0xF0000, modifiers), terminal),
				// old style event
				InputEvent(NonCharacterKeyEvent(NonCharacterKeyEvent.Type.Pressed, key, modifiers), terminal)
			];
		}

		char[30] sequenceBuffer;

		// this assumes you just read "\033["
		char[] readEscapeSequence(char[] sequence) {
			int sequenceLength = 2;
			sequence[0] = '\033';
			sequence[1] = '[';

			while(sequenceLength < sequence.length) {
				auto n = nextRaw();
				sequence[sequenceLength++] = cast(char) n;
				// I think a [ is supposed to termiate a CSI sequence
				// but the Linux console sends CSI[A for F1, so I'm
				// hacking it to accept that too
				if(n >= 0x40 && !(sequenceLength == 3 && n == '['))
					break;
			}

			return sequence[0 .. sequenceLength];
		}

		InputEvent[] translateTermcapName(string cap) {
			switch(cap) {
				//case "k0":
					//return keyPressAndRelease(NonCharacterKeyEvent.Key.F1);
				case "k1":
					return keyPressAndRelease(NonCharacterKeyEvent.Key.F1);
				case "k2":
					return keyPressAndRelease(NonCharacterKeyEvent.Key.F2);
				case "k3":
					return keyPressAndRelease(NonCharacterKeyEvent.Key.F3);
				case "k4":
					return keyPressAndRelease(NonCharacterKeyEvent.Key.F4);
				case "k5":
					return keyPressAndRelease(NonCharacterKeyEvent.Key.F5);
				case "k6":
					return keyPressAndRelease(NonCharacterKeyEvent.Key.F6);
				case "k7":
					return keyPressAndRelease(NonCharacterKeyEvent.Key.F7);
				case "k8":
					return keyPressAndRelease(NonCharacterKeyEvent.Key.F8);
				case "k9":
					return keyPressAndRelease(NonCharacterKeyEvent.Key.F9);
				case "k;":
				case "k0":
					return keyPressAndRelease(NonCharacterKeyEvent.Key.F10);
				case "F1":
					return keyPressAndRelease(NonCharacterKeyEvent.Key.F11);
				case "F2":
					return keyPressAndRelease(NonCharacterKeyEvent.Key.F12);


				case "kb":
					return charPressAndRelease('\b');
				case "kD":
					return keyPressAndRelease(NonCharacterKeyEvent.Key.Delete);

				case "kd":
				case "do":
					return keyPressAndRelease(NonCharacterKeyEvent.Key.DownArrow);
				case "ku":
				case "up":
					return keyPressAndRelease(NonCharacterKeyEvent.Key.UpArrow);
				case "kl":
					return keyPressAndRelease(NonCharacterKeyEvent.Key.LeftArrow);
				case "kr":
				case "nd":
					return keyPressAndRelease(NonCharacterKeyEvent.Key.RightArrow);

				case "kN":
				case "K5":
					return keyPressAndRelease(NonCharacterKeyEvent.Key.PageDown);
				case "kP":
				case "K2":
					return keyPressAndRelease(NonCharacterKeyEvent.Key.PageUp);

				case "ho": // this might not be a key but my thing sometimes returns it... weird...
				case "kh":
				case "K1":
					return keyPressAndRelease(NonCharacterKeyEvent.Key.Home);
				case "kH":
					return keyPressAndRelease(NonCharacterKeyEvent.Key.End);
				case "kI":
					return keyPressAndRelease(NonCharacterKeyEvent.Key.Insert);
				default:
					// don't know it, just ignore
					//import std.stdio;
					//writeln(cap);
			}

			return null;
		}


		InputEvent[] doEscapeSequence(in char[] sequence) {
			switch(sequence) {
				case "\033[200~":
					// bracketed paste begin
					// we want to keep reading until
					// "\033[201~":
					// and build a paste event out of it


					string data;
					for(;;) {
						auto n = nextRaw();
						if(n == '\033') {
							n = nextRaw();
							if(n == '[') {
								auto esc = readEscapeSequence(sequenceBuffer);
								if(esc == "\033[201~") {
									// complete!
									break;
								} else {
									// was something else apparently, but it is pasted, so keep it
									data ~= esc;
								}
							} else {
								data ~= '\033';
								data ~= cast(char) n;
							}
						} else {
							data ~= cast(char) n;
						}
					}
					return [InputEvent(PasteEvent(data), terminal)];
				case "\033[M":
					// mouse event
					auto buttonCode = nextRaw() - 32;
						// nextChar is commented because i'm not using UTF-8 mouse mode
						// cuz i don't think it is as widely supported
					auto x = cast(int) (/*nextChar*/(nextRaw())) - 33; /* they encode value + 32, but make upper left 1,1. I want it to be 0,0 */
					auto y = cast(int) (/*nextChar*/(nextRaw())) - 33; /* ditto */


					bool isRelease = (buttonCode & 0b11) == 3;
					int buttonNumber;
					if(!isRelease) {
						buttonNumber = (buttonCode & 0b11);
						if(buttonCode & 64)
							buttonNumber += 3; // button 4 and 5 are sent as like button 1 and 2, but code | 64
							// so button 1 == button 4 here

						// note: buttonNumber == 0 means button 1 at this point
						buttonNumber++; // hence this


						// apparently this considers middle to be button 2. but i want middle to be button 3.
						if(buttonNumber == 2)
							buttonNumber = 3;
						else if(buttonNumber == 3)
							buttonNumber = 2;
					}

					auto modifiers = buttonCode & (0b0001_1100);
						// 4 == shift
						// 8 == meta
						// 16 == control

					MouseEvent m;

					if(buttonCode & 32)
						m.eventType = MouseEvent.Type.Moved;
					else
						m.eventType = isRelease ? MouseEvent.Type.Released : MouseEvent.Type.Pressed;

					// ugh, if no buttons are pressed, released and moved are indistinguishable...
					// so we'll count the buttons down, and if we get a release
					static int buttonsDown = 0;
					if(!isRelease && buttonNumber <= 3) // exclude wheel "presses"...
						buttonsDown++;

					if(isRelease && m.eventType != MouseEvent.Type.Moved) {
						if(buttonsDown)
							buttonsDown--;
						else // no buttons down, so this should be a motion instead..
							m.eventType = MouseEvent.Type.Moved;
					}


					if(buttonNumber == 0)
						m.buttons = 0; // we don't actually know :(
					else
						m.buttons = 1 << (buttonNumber - 1); // I prefer flags so that's how we do it
					m.x = x;
					m.y = y;
					m.modifierState = modifiers;

					return [InputEvent(m, terminal)];
				default:
					// look it up in the termcap key database
					auto cap = terminal.findSequenceInTermcap(sequence);
					if(cap !is null) {
						return translateTermcapName(cap);
					} else {
						if(terminal.terminalInFamily("xterm")) {
							import std.conv, std.string;
							auto terminator = sequence[$ - 1];
							auto parts = sequence[2 .. $ - 1].split(";");
							// parts[0] and terminator tells us the key
							// parts[1] tells us the modifierState

							uint modifierState;

							int modGot;
							if(parts.length > 1)
								modGot = to!int(parts[1]);
							mod_switch: switch(modGot) {
								case 2: modifierState |= ModifierState.shift; break;
								case 3: modifierState |= ModifierState.alt; break;
								case 4: modifierState |= ModifierState.shift | ModifierState.alt; break;
								case 5: modifierState |= ModifierState.control; break;
								case 6: modifierState |= ModifierState.shift | ModifierState.control; break;
								case 7: modifierState |= ModifierState.alt | ModifierState.control; break;
								case 8: modifierState |= ModifierState.shift | ModifierState.alt | ModifierState.control; break;
								case 9:
								..
								case 16:
									modifierState |= ModifierState.meta;
									if(modGot != 9) {
										modGot -= 8;
										goto mod_switch;
									}
								break;

								// this is an extension in my own terminal emulator
								case 20:
								..
								case 36:
									modifierState |= ModifierState.windows;
									modGot -= 20;
									goto mod_switch;
								default:
							}

							switch(terminator) {
								case 'A': return keyPressAndRelease(NonCharacterKeyEvent.Key.UpArrow, modifierState);
								case 'B': return keyPressAndRelease(NonCharacterKeyEvent.Key.DownArrow, modifierState);
								case 'C': return keyPressAndRelease(NonCharacterKeyEvent.Key.RightArrow, modifierState);
								case 'D': return keyPressAndRelease(NonCharacterKeyEvent.Key.LeftArrow, modifierState);

								case 'H': return keyPressAndRelease(NonCharacterKeyEvent.Key.Home, modifierState);
								case 'F': return keyPressAndRelease(NonCharacterKeyEvent.Key.End, modifierState);

								case 'P': return keyPressAndRelease(NonCharacterKeyEvent.Key.F1, modifierState);
								case 'Q': return keyPressAndRelease(NonCharacterKeyEvent.Key.F2, modifierState);
								case 'R': return keyPressAndRelease(NonCharacterKeyEvent.Key.F3, modifierState);
								case 'S': return keyPressAndRelease(NonCharacterKeyEvent.Key.F4, modifierState);

								case '~': // others
									switch(parts[0]) {
										case "5": return keyPressAndRelease(NonCharacterKeyEvent.Key.PageUp, modifierState);
										case "6": return keyPressAndRelease(NonCharacterKeyEvent.Key.PageDown, modifierState);
										case "2": return keyPressAndRelease(NonCharacterKeyEvent.Key.Insert, modifierState);
										case "3": return keyPressAndRelease(NonCharacterKeyEvent.Key.Delete, modifierState);

										case "15": return keyPressAndRelease(NonCharacterKeyEvent.Key.F5, modifierState);
										case "17": return keyPressAndRelease(NonCharacterKeyEvent.Key.F6, modifierState);
										case "18": return keyPressAndRelease(NonCharacterKeyEvent.Key.F7, modifierState);
										case "19": return keyPressAndRelease(NonCharacterKeyEvent.Key.F8, modifierState);
										case "20": return keyPressAndRelease(NonCharacterKeyEvent.Key.F9, modifierState);
										case "21": return keyPressAndRelease(NonCharacterKeyEvent.Key.F10, modifierState);
										case "23": return keyPressAndRelease(NonCharacterKeyEvent.Key.F11, modifierState);
										case "24": return keyPressAndRelease(NonCharacterKeyEvent.Key.F12, modifierState);
										default:
									}
								break;

								default:
							}
						} else if(terminal.terminalInFamily("rxvt")) {
							// FIXME: figure these out. rxvt seems to just change the terminator while keeping the rest the same
							// though it isn't consistent. ugh.
						} else {
							// maybe we could do more terminals, but linux doesn't even send it and screen just seems to pass through, so i don't think so; xterm prolly covers most them anyway
							// so this space is semi-intentionally left blank
						}
					}
			}

			return null;
		}

		auto c = nextRaw(true);
		if(c == -1)
			return null; // interrupted; give back nothing so the other level can recheck signal flags
		if(c == 0)
			return [InputEvent(EndOfFileEvent(), terminal)];
		if(c == '\033') {
			if(timedCheckForInput(50)) {
				// escape sequence
				c = nextRaw();
				if(c == '[') { // CSI, ends on anything >= 'A'
					return doEscapeSequence(readEscapeSequence(sequenceBuffer));
				} else if(c == 'O') {
					// could be xterm function key
					auto n = nextRaw();

					char[3] thing;
					thing[0] = '\033';
					thing[1] = 'O';
					thing[2] = cast(char) n;

					auto cap = terminal.findSequenceInTermcap(thing);
					if(cap is null) {
						return keyPressAndRelease(NonCharacterKeyEvent.Key.escape) ~
							charPressAndRelease('O') ~
							charPressAndRelease(thing[2]);
					} else {
						return translateTermcapName(cap);
					}
				} else {
					// I don't know, probably unsupported terminal or just quick user input or something
					return keyPressAndRelease(NonCharacterKeyEvent.Key.escape) ~ charPressAndRelease(nextChar(c));
				}
			} else {
				// user hit escape (or super slow escape sequence, but meh)
				return keyPressAndRelease(NonCharacterKeyEvent.Key.escape);
			}
		} else {
			// FIXME: what if it is neither? we should check the termcap
			auto next = nextChar(c);
			if(next == 127) // some terminals send 127 on the backspace. Let's normalize that.
				next = '\b';
			return charPressAndRelease(next);
		}
	}
}

/// The new style of keyboard event
struct KeyboardEvent {
	bool pressed; ///
	dchar which; ///
	uint modifierState; ///

	///
	bool isCharacter() {
		return !(which >= Key.min && which <= Key.max);
	}

	// these match Windows virtual key codes numerically for simplicity of translation there
	// but are plus a unicode private use area offset so i can cram them in the dchar
	// http://msdn.microsoft.com/en-us/library/windows/desktop/dd375731%28v=vs.85%29.aspx
	/// .
	enum Key : dchar {
		escape = 0x1b + 0xF0000, /// .
		F1 = 0x70 + 0xF0000, /// .
		F2 = 0x71 + 0xF0000, /// .
		F3 = 0x72 + 0xF0000, /// .
		F4 = 0x73 + 0xF0000, /// .
		F5 = 0x74 + 0xF0000, /// .
		F6 = 0x75 + 0xF0000, /// .
		F7 = 0x76 + 0xF0000, /// .
		F8 = 0x77 + 0xF0000, /// .
		F9 = 0x78 + 0xF0000, /// .
		F10 = 0x79 + 0xF0000, /// .
		F11 = 0x7A + 0xF0000, /// .
		F12 = 0x7B + 0xF0000, /// .
		LeftArrow = 0x25 + 0xF0000, /// .
		RightArrow = 0x27 + 0xF0000, /// .
		UpArrow = 0x26 + 0xF0000, /// .
		DownArrow = 0x28 + 0xF0000, /// .
		Insert = 0x2d + 0xF0000, /// .
		Delete = 0x2e + 0xF0000, /// .
		Home = 0x24 + 0xF0000, /// .
		End = 0x23 + 0xF0000, /// .
		PageUp = 0x21 + 0xF0000, /// .
		PageDown = 0x22 + 0xF0000, /// .
	}


}

/// Deprecated: use KeyboardEvent instead in new programs
/// Input event for characters
struct CharacterEvent {
	/// .
	enum Type {
		Released, /// .
		Pressed /// .
	}

	Type eventType; /// .
	dchar character; /// .
	uint modifierState; /// Don't depend on this to be available for character events
}

/// Deprecated: use KeyboardEvent instead in new programs
struct NonCharacterKeyEvent {
	/// .
	enum Type {
		Released, /// .
		Pressed /// .
	}
	Type eventType; /// .

	// these match Windows virtual key codes numerically for simplicity of translation there
	//http://msdn.microsoft.com/en-us/library/windows/desktop/dd375731%28v=vs.85%29.aspx
	/// .
	enum Key : int {
		escape = 0x1b, /// .
		F1 = 0x70, /// .
		F2 = 0x71, /// .
		F3 = 0x72, /// .
		F4 = 0x73, /// .
		F5 = 0x74, /// .
		F6 = 0x75, /// .
		F7 = 0x76, /// .
		F8 = 0x77, /// .
		F9 = 0x78, /// .
		F10 = 0x79, /// .
		F11 = 0x7A, /// .
		F12 = 0x7B, /// .
		LeftArrow = 0x25, /// .
		RightArrow = 0x27, /// .
		UpArrow = 0x26, /// .
		DownArrow = 0x28, /// .
		Insert = 0x2d, /// .
		Delete = 0x2e, /// .
		Home = 0x24, /// .
		End = 0x23, /// .
		PageUp = 0x21, /// .
		PageDown = 0x22, /// .
		}
	Key key; /// .

	uint modifierState; /// A mask of ModifierState. Always use by checking modifierState & ModifierState.something, the actual value differs across platforms

}

/// .
struct PasteEvent {
	string pastedText; /// .
}

/// .
struct MouseEvent {
	// these match simpledisplay.d numerically as well
	/// .
	enum Type {
		Moved = 0, /// .
		Pressed = 1, /// .
		Released = 2, /// .
		Clicked, /// .
	}

	Type eventType; /// .

	// note: these should numerically match simpledisplay.d for maximum beauty in my other code
	/// .
	enum Button : uint {
		None = 0, /// .
		Left = 1, /// .
		Middle = 4, /// .
		Right = 2, /// .
		ScrollUp = 8, /// .
		ScrollDown = 16 /// .
	}
	uint buttons; /// A mask of Button
	int x; /// 0 == left side
	int y; /// 0 == top
	uint modifierState; /// shift, ctrl, alt, meta, altgr. Not always available. Always check by using modifierState & ModifierState.something
}

/// When you get this, check terminal.width and terminal.height to see the new size and react accordingly.
struct SizeChangedEvent {
	int oldWidth;
	int oldHeight;
	int newWidth;
	int newHeight;
}

/// the user hitting ctrl+c will send this
/// You should drop what you're doing and perhaps exit when this happens.
struct UserInterruptionEvent {}

/// If the user hangs up (for example, closes the terminal emulator without exiting the app), this is sent.
/// If you receive it, you should generally cleanly exit.
struct HangupEvent {}

/// Sent upon receiving end-of-file from stdin.
struct EndOfFileEvent {}

interface CustomEvent {}

version(Windows)
enum ModifierState : uint {
	shift = 0x10,
	control = 0x8 | 0x4, // 8 == left ctrl, 4 == right ctrl

	// i'm not sure if the next two are available
	alt = 2 | 1, //2 ==left alt, 1 == right alt

	// FIXME: I don't think these are actually available
	windows = 512,
	meta = 4096, // FIXME sanity

	// I don't think this is available on Linux....
	scrollLock = 0x40,
}
else
enum ModifierState : uint {
	shift = 4,
	alt = 2,
	control = 16,
	meta = 8,

	windows = 512 // only available if you are using my terminal emulator; it isn't actually offered on standard linux ones
}

version(DDoc)
///
enum ModifierState : uint {
	///
	shift = 4,
	///
	alt = 2,
	///
	control = 16,

}

/++
	[RealTimeConsoleInput.nextEvent] returns one of these. Check the type, then use the [InputEvent.get|get] method to get the more detailed information about the event.
++/
struct InputEvent {
	/// .
	enum Type {
		KeyboardEvent, /// Keyboard key pressed (or released, where supported)
		CharacterEvent, /// Do not use this in new programs, use KeyboardEvent instead
		NonCharacterKeyEvent, /// Do not use this in new programs, use KeyboardEvent instead
		PasteEvent, /// The user pasted some text. Not always available, the pasted text might come as a series of character events instead.
		MouseEvent, /// only sent if you subscribed to mouse events
		SizeChangedEvent, /// only sent if you subscribed to size events
		UserInterruptionEvent, /// the user hit ctrl+c
		EndOfFileEvent, /// stdin has received an end of file
		HangupEvent, /// the terminal hanged up - for example, if the user closed a terminal emulator
		CustomEvent /// .
	}

	/// .
	@property Type type() { return t; }

	/// Returns a pointer to the terminal associated with this event.
	/// (You can usually just ignore this as there's only one terminal typically.)
	///
	/// It may be null in the case of program-generated events;
	@property Terminal* terminal() { return term; }

	/++
		Gets the specific event instance. First, check the type (such as in a `switch` statement), then extract the correct one from here. Note that the template argument is a $(B value type of the enum above), not a type argument. So to use it, do $(D event.get!(InputEvent.Type.KeyboardEvent)), for example.

		See_Also:

		The event types:
			[KeyboardEvent], [MouseEvent], [SizeChangedEvent],
			[PasteEvent], [UserInterruptionEvent], 
			[EndOfFileEvent], [HangupEvent], [CustomEvent]

		And associated functions:
			[RealTimeConsoleInput], [ConsoleInputFlags]
	++/
	@property auto get(Type T)() {
		if(type != T)
			throw new Exception("Wrong event type");
		static if(T == Type.CharacterEvent)
			return characterEvent;
		else static if(T == Type.KeyboardEvent)
			return keyboardEvent;
		else static if(T == Type.NonCharacterKeyEvent)
			return nonCharacterKeyEvent;
		else static if(T == Type.PasteEvent)
			return pasteEvent;
		else static if(T == Type.MouseEvent)
			return mouseEvent;
		else static if(T == Type.SizeChangedEvent)
			return sizeChangedEvent;
		else static if(T == Type.UserInterruptionEvent)
			return userInterruptionEvent;
		else static if(T == Type.EndOfFileEvent)
			return endOfFileEvent;
		else static if(T == Type.HangupEvent)
			return hangupEvent;
		else static if(T == Type.CustomEvent)
			return customEvent;
		else static assert(0, "Type " ~ T.stringof ~ " not added to the get function");
	}

	/// custom event is public because otherwise there's no point at all
	this(CustomEvent c, Terminal* p = null) {
		t = Type.CustomEvent;
		customEvent = c;
	}

	private {
		this(CharacterEvent c, Terminal* p) {
			t = Type.CharacterEvent;
			characterEvent = c;
		}
		this(KeyboardEvent c, Terminal* p) {
			t = Type.KeyboardEvent;
			keyboardEvent = c;
		}
		this(NonCharacterKeyEvent c, Terminal* p) {
			t = Type.NonCharacterKeyEvent;
			nonCharacterKeyEvent = c;
		}
		this(PasteEvent c, Terminal* p) {
			t = Type.PasteEvent;
			pasteEvent = c;
		}
		this(MouseEvent c, Terminal* p) {
			t = Type.MouseEvent;
			mouseEvent = c;
		}
		this(SizeChangedEvent c, Terminal* p) {
			t = Type.SizeChangedEvent;
			sizeChangedEvent = c;
		}
		this(UserInterruptionEvent c, Terminal* p) {
			t = Type.UserInterruptionEvent;
			userInterruptionEvent = c;
		}
		this(HangupEvent c, Terminal* p) {
			t = Type.HangupEvent;
			hangupEvent = c;
		}
		this(EndOfFileEvent c, Terminal* p) {
			t = Type.EndOfFileEvent;
			endOfFileEvent = c;
		}

		Type t;
		Terminal* term;

		union {
			KeyboardEvent keyboardEvent;
			CharacterEvent characterEvent;
			NonCharacterKeyEvent nonCharacterKeyEvent;
			PasteEvent pasteEvent;
			MouseEvent mouseEvent;
			SizeChangedEvent sizeChangedEvent;
			UserInterruptionEvent userInterruptionEvent;
			HangupEvent hangupEvent;
			EndOfFileEvent endOfFileEvent;
			CustomEvent customEvent;
		}
	}
}

version(Demo)
/// View the source of this!
void main() {
	auto terminal = Terminal(ConsoleOutputType.cellular);

	//terminal.color(Color.DEFAULT, Color.DEFAULT);

	//
	///*
	auto getter = new FileLineGetter(&terminal, "test");
	getter.prompt = "> ";
	getter.history = ["abcdefghijklmnopqrstuvwzyz1234567890ABCDEFGHIJKLMNOPQRSTUVWXYZ"];
	terminal.writeln("\n" ~ getter.getline());
	terminal.writeln("\n" ~ getter.getline());
	terminal.writeln("\n" ~ getter.getline());
	getter.dispose();
	//*/

	terminal.writeln(terminal.getline());
	terminal.writeln(terminal.getline());
	terminal.writeln(terminal.getline());

	//input.getch();

	// return;
	//

	terminal.setTitle("Basic I/O");
	auto input = RealTimeConsoleInput(&terminal, ConsoleInputFlags.raw | ConsoleInputFlags.allInputEvents);
	terminal.color(Color.green | Bright, Color.black);

	terminal.write("test some long string to see if it wraps or what because i dont really know what it is going to do so i just want to test i think it will wrap but gotta be sure lolololololololol");
	terminal.writefln("%d %d", terminal.cursorX, terminal.cursorY);

	terminal.color(Color.DEFAULT, Color.DEFAULT);

	int centerX = terminal.width / 2;
	int centerY = terminal.height / 2;

	bool timeToBreak = false;

	void handleEvent(InputEvent event) {
		terminal.writef("%s\n", event.type);
		final switch(event.type) {
			case InputEvent.Type.UserInterruptionEvent:
			case InputEvent.Type.HangupEvent:
			case InputEvent.Type.EndOfFileEvent:
				timeToBreak = true;
				version(with_eventloop) {
					import arsd.eventloop;
					exit();
				}
			break;
			case InputEvent.Type.SizeChangedEvent:
				auto ev = event.get!(InputEvent.Type.SizeChangedEvent);
				terminal.writeln(ev);
			break;
			case InputEvent.Type.KeyboardEvent:
				auto ev = event.get!(InputEvent.Type.KeyboardEvent);
					terminal.writef("\t%s", ev);
				terminal.writef(" (%s)", cast(KeyboardEvent.Key) ev.which);
				terminal.writeln();
				if(ev.which == 'Q') {
					timeToBreak = true;
					version(with_eventloop) {
						import arsd.eventloop;
						exit();
					}
				}

				if(ev.which == 'C')
					terminal.clear();
			break;
			case InputEvent.Type.CharacterEvent: // obsolete
				auto ev = event.get!(InputEvent.Type.CharacterEvent);
				terminal.writef("\t%s\n", ev);
			break;
			case InputEvent.Type.NonCharacterKeyEvent: // obsolete
				terminal.writef("\t%s\n", event.get!(InputEvent.Type.NonCharacterKeyEvent));
			break;
			case InputEvent.Type.PasteEvent:
				terminal.writef("\t%s\n", event.get!(InputEvent.Type.PasteEvent));
			break;
			case InputEvent.Type.MouseEvent:
				terminal.writef("\t%s\n", event.get!(InputEvent.Type.MouseEvent));
			break;
			case InputEvent.Type.CustomEvent:
			break;
		}

		terminal.writefln("%d %d", terminal.cursorX, terminal.cursorY);

		/*
		if(input.kbhit()) {
			auto c = input.getch();
			if(c == 'q' || c == 'Q')
				break;
			terminal.moveTo(centerX, centerY);
			terminal.writef("%c", c);
			terminal.flush();
		}
		usleep(10000);
		*/
	}

	version(with_eventloop) {
		import arsd.eventloop;
		addListener(&handleEvent);
		loop();
	} else {
		loop: while(true) {
			auto event = input.nextEvent();
			handleEvent(event);
			if(timeToBreak)
				break loop;
		}
	}
}

/**
	FIXME: support lines that wrap
	FIXME: better controls maybe

	FIXME: support multi-line "lines" and some form of line continuation, both
	       from the user (if permitted) and from the application, so like the user
	       hits "class foo { \n" and the app says "that line needs continuation" automatically.

	FIXME: fix lengths on prompt and suggestion

	A note on history:

	To save history, you must call LineGetter.dispose() when you're done with it.
	History will not be automatically saved without that call!

	The history saving and loading as a trivially encountered race condition: if you
	open two programs that use the same one at the same time, the one that closes second
	will overwrite any history changes the first closer saved.

	GNU Getline does this too... and it actually kinda drives me nuts. But I don't know
	what a good fix is except for doing a transactional commit straight to the file every
	time and that seems like hitting the disk way too often.

	We could also do like a history server like a database daemon that keeps the order
	correct but I don't actually like that either because I kinda like different bashes
	to have different history, I just don't like it all to get lost.

	Regardless though, this isn't even used in bash anyway, so I don't think I care enough
	to put that much effort into it. Just using separate files for separate tasks is good
	enough I think.
*/
class LineGetter {
	/* A note on the assumeSafeAppends in here: since these buffers are private, we can be
	   pretty sure that stomping isn't an issue, so I'm using this liberally to keep the
	   append/realloc code simple and hopefully reasonably fast. */

	// saved to file
	string[] history;

	// not saved
	Terminal* terminal;
	string historyFilename;

	/// Make sure that the parent terminal struct remains in scope for the duration
	/// of LineGetter's lifetime, as it does hold on to and use the passed pointer
	/// throughout.
	///
	/// historyFilename will load and save an input history log to a particular folder.
	/// Leaving it null will mean no file will be used and history will not be saved across sessions.
	this(Terminal* tty, string historyFilename = null) {
		this.terminal = tty;
		this.historyFilename = historyFilename;

		line.reserve(128);

		if(historyFilename.length)
			loadSettingsAndHistoryFromFile();

		regularForeground = cast(Color) terminal._currentForeground;
		background = cast(Color) terminal._currentBackground;
		suggestionForeground = Color.blue;
	}

	/// Call this before letting LineGetter die so it can do any necessary
	/// cleanup and save the updated history to a file.
	void dispose() {
		if(historyFilename.length)
			saveSettingsAndHistoryToFile();
	}

	/// Override this to change the directory where history files are stored
	///
	/// Default is $HOME/.arsd-getline on linux and %APPDATA%/arsd-getline/ on Windows.
	/* virtual */ string historyFileDirectory() {
		version(Windows) {
			char[1024] path;
			// FIXME: this doesn't link because the crappy dmd lib doesn't have it
			if(0) { // SHGetFolderPathA(null, CSIDL_APPDATA, null, 0, path.ptr) >= 0) {
				import core.stdc.string;
				return cast(string) path[0 .. strlen(path.ptr)] ~ "\\arsd-getline";
			} else {
				import std.process;
				return environment["APPDATA"] ~ "\\arsd-getline";
			}
		} else version(Posix) {
			import std.process;
			return environment["HOME"] ~ "/.arsd-getline";
		}
	}

	/// You can customize the colors here. You should set these after construction, but before
	/// calling startGettingLine or getline.
	Color suggestionForeground;
	Color regularForeground; /// .
	Color background; /// .
	//bool reverseVideo;

	/// Set this if you want a prompt to be drawn with the line. It does NOT support color in string.
	string prompt;

	/// Turn on auto suggest if you want a greyed thing of what tab
	/// would be able to fill in as you type.
	///
	/// You might want to turn it off if generating a completion list is slow.
	bool autoSuggest = true;


	/// Override this if you don't want all lines added to the history.
	/// You can return null to not add it at all, or you can transform it.
	/* virtual */ string historyFilter(string candidate) {
		return candidate;
	}

	/// You may override this to do nothing
	/* virtual */ void saveSettingsAndHistoryToFile() {
		import std.file;
		if(!exists(historyFileDirectory))
			mkdir(historyFileDirectory);
		auto fn = historyPath();
		import std.stdio;
		auto file = File(fn, "wt");
		foreach(item; history)
			file.writeln(item);
	}

	private string historyPath() {
		import std.path;
		auto filename = historyFileDirectory() ~ dirSeparator ~ historyFilename ~ ".history";
		return filename;
	}

	/// You may override this to do nothing
	/* virtual */ void loadSettingsAndHistoryFromFile() {
		import std.file;
		history = null;
		auto fn = historyPath();
		if(exists(fn)) {
			import std.stdio;
			foreach(line; File(fn, "rt").byLine)
				history ~= line.idup;

		}
	}

	/**
		Override this to provide tab completion. You may use the candidate
		argument to filter the list, but you don't have to (LineGetter will
		do it for you on the values you return).

		Ideally, you wouldn't return more than about ten items since the list
		gets difficult to use if it is too long.

		Default is to provide recent command history as autocomplete.
	*/
	/* virtual */ protected string[] tabComplete(in dchar[] candidate) {
		return history.length > 20 ? history[0 .. 20] : history;
	}

	private string[] filterTabCompleteList(string[] list) {
		if(list.length == 0)
			return list;

		string[] f;
		f.reserve(list.length);

		foreach(item; list) {
			import std.algorithm;
			if(startsWith(item, line[0 .. cursorPosition]))
				f ~= item;
		}

		return f;
	}

	/// Override this to provide a custom display of the tab completion list
	protected void showTabCompleteList(string[] list) {
		if(list.length) {
			// FIXME: allow mouse clicking of an item, that would be cool

			// FIXME: scroll
			//if(terminal.type == ConsoleOutputType.linear) {
				terminal.writeln();
				foreach(item; list) {
					terminal.color(suggestionForeground, background);
					import std.utf;
					auto idx = codeLength!char(line[0 .. cursorPosition]);
					terminal.write("  ", item[0 .. idx]);
					terminal.color(regularForeground, background);
					terminal.writeln(item[idx .. $]);
				}
				updateCursorPosition();
				redraw();
			//}
		}
	}

	/// One-call shop for the main workhorse
	/// If you already have a RealTimeConsoleInput ready to go, you
	/// should pass a pointer to yours here. Otherwise, LineGetter will
	/// make its own.
	public string getline(RealTimeConsoleInput* input = null) {
		startGettingLine();
		if(input is null) {
			auto i = RealTimeConsoleInput(terminal, ConsoleInputFlags.raw | ConsoleInputFlags.allInputEvents);
			while(workOnLine(i.nextEvent())) {}
		} else
			while(workOnLine(input.nextEvent())) {}
		return finishGettingLine();
	}

	private int currentHistoryViewPosition = 0;
	private dchar[] uncommittedHistoryCandidate;
	void loadFromHistory(int howFarBack) {
		if(howFarBack < 0)
			howFarBack = 0;
		if(howFarBack > history.length) // lol signed/unsigned comparison here means if i did this first, before howFarBack < 0, it would totally cycle around.
			howFarBack = cast(int) history.length;
		if(howFarBack == currentHistoryViewPosition)
			return;
		if(currentHistoryViewPosition == 0) {
			// save the current line so we can down arrow back to it later
			if(uncommittedHistoryCandidate.length < line.length) {
				uncommittedHistoryCandidate.length = line.length;
			}

			uncommittedHistoryCandidate[0 .. line.length] = line[];
			uncommittedHistoryCandidate = uncommittedHistoryCandidate[0 .. line.length];
			uncommittedHistoryCandidate.assumeSafeAppend();
		}

		currentHistoryViewPosition = howFarBack;

		if(howFarBack == 0) {
			line.length = uncommittedHistoryCandidate.length;
			line.assumeSafeAppend();
			line[] = uncommittedHistoryCandidate[];
		} else {
			line = line[0 .. 0];
			line.assumeSafeAppend();
			foreach(dchar ch; history[$ - howFarBack])
				line ~= ch;
		}

		cursorPosition = cast(int) line.length;
		scrollToEnd();
	}

	bool insertMode = true;
	bool multiLineMode = false;

	private dchar[] line;
	private int cursorPosition = 0;
	private int horizontalScrollPosition = 0;

	private void scrollToEnd() {
		horizontalScrollPosition = (cast(int) line.length);
		horizontalScrollPosition -= availableLineLength();
		if(horizontalScrollPosition < 0)
			horizontalScrollPosition = 0;
	}

	// used for redrawing the line in the right place
	// and detecting mouse events on our line.
	private int startOfLineX;
	private int startOfLineY;

	// private string[] cachedCompletionList;

	// FIXME
	// /// Note that this assumes the tab complete list won't change between actual
	// /// presses of tab by the user. If you pass it a list, it will use it, but
	// /// otherwise it will keep track of the last one to avoid calls to tabComplete.
	private string suggestion(string[] list = null) {
		import std.algorithm, std.utf;
		auto relevantLineSection = line[0 .. cursorPosition];
		// FIXME: see about caching the list if we easily can
		if(list is null)
			list = filterTabCompleteList(tabComplete(relevantLineSection));

		if(list.length) {
			string commonality = list[0];
			foreach(item; list[1 .. $]) {
				commonality = commonPrefix(commonality, item);
			}

			if(commonality.length) {
				return commonality[codeLength!char(relevantLineSection) .. $];
			}
		}

		return null;
	}

	/// Adds a character at the current position in the line. You can call this too if you hook events for hotkeys or something.
	/// You'll probably want to call redraw() after adding chars.
	void addChar(dchar ch) {
		assert(cursorPosition >= 0 && cursorPosition <= line.length);
		if(cursorPosition == line.length)
			line ~= ch;
		else {
			assert(line.length);
			if(insertMode) {
				line ~= ' ';
				for(int i = cast(int) line.length - 2; i >= cursorPosition; i --)
					line[i + 1] = line[i];
			}
			line[cursorPosition] = ch;
		}
		cursorPosition++;

		if(cursorPosition >= horizontalScrollPosition + availableLineLength())
			horizontalScrollPosition++;
	}

	/// .
	void addString(string s) {
		// FIXME: this could be more efficient
		// but does it matter? these lines aren't super long anyway. But then again a paste could be excessively long (prolly accidental, but still)
		foreach(dchar ch; s)
			addChar(ch);
	}

	/// Deletes the character at the current position in the line.
	/// You'll probably want to call redraw() after deleting chars.
	void deleteChar() {
		if(cursorPosition == line.length)
			return;
		for(int i = cursorPosition; i < line.length - 1; i++)
			line[i] = line[i + 1];
		line = line[0 .. $-1];
		line.assumeSafeAppend();
	}

	///
	void deleteToEndOfLine() {
		while(cursorPosition < line.length)
			deleteChar();
	}

	int availableLineLength() {
		return terminal.width - startOfLineX - cast(int) prompt.length - 1;
	}

	private int lastDrawLength = 0;
	void redraw() {
		terminal.hideCursor();
		scope(exit) {
			terminal.flush();
			terminal.showCursor();
		}
		terminal.moveTo(startOfLineX, startOfLineY);

		auto lineLength = availableLineLength();
		if(lineLength < 0)
			throw new Exception("too narrow terminal to draw");

		terminal.write(prompt);

		auto towrite = line[horizontalScrollPosition .. $];
		auto cursorPositionToDrawX = cursorPosition - horizontalScrollPosition;
		auto cursorPositionToDrawY = 0;

		if(towrite.length > lineLength) {
			towrite = towrite[0 .. lineLength];
		}

		terminal.write(towrite);

		lineLength -= towrite.length;

		string suggestion;

		if(lineLength >= 0) {
			suggestion = ((cursorPosition == towrite.length) && autoSuggest) ? this.suggestion() : null;
			if(suggestion.length) {
				terminal.color(suggestionForeground, background);
				terminal.write(suggestion);
				terminal.color(regularForeground, background);
			}
		}

		// FIXME: graphemes and utf-8 on suggestion/prompt
		auto written = cast(int) (towrite.length + suggestion.length + prompt.length);

		if(written < lastDrawLength)
		foreach(i; written .. lastDrawLength)
			terminal.write(" ");
		lastDrawLength = written;

		terminal.moveTo(startOfLineX + cursorPositionToDrawX + cast(int) prompt.length, startOfLineY + cursorPositionToDrawY);
	}

	/// Starts getting a new line. Call workOnLine and finishGettingLine afterward.
	///
	/// Make sure that you've flushed your input and output before calling this
	/// function or else you might lose events or get exceptions from this.
	void startGettingLine() {
		// reset from any previous call first
		cursorPosition = 0;
		horizontalScrollPosition = 0;
		justHitTab = false;
		currentHistoryViewPosition = 0;
		if(line.length) {
			line = line[0 .. 0];
			line.assumeSafeAppend();
		}

		updateCursorPosition();
		terminal.showCursor();

		lastDrawLength = availableLineLength();
		redraw();
	}

	private void updateCursorPosition() {
		terminal.flush();

		// then get the current cursor position to start fresh
		version(Windows) {
			CONSOLE_SCREEN_BUFFER_INFO info;
			GetConsoleScreenBufferInfo(terminal.hConsole, &info);
			startOfLineX = info.dwCursorPosition.X;
			startOfLineY = info.dwCursorPosition.Y;
		} else {
			// request current cursor position

			// we have to turn off cooked mode to get this answer, otherwise it will all
			// be messed up. (I hate unix terminals, the Windows way is so much easer.)

			// We also can't use RealTimeConsoleInput here because it also does event loop stuff
			// which would be broken by the child destructor :( (maybe that should be a FIXME)

			ubyte[128] hack2;
			termios old;
			ubyte[128] hack;
			tcgetattr(terminal.fdIn, &old);
			auto n = old;
			n.c_lflag &= ~(ICANON | ECHO);
			tcsetattr(terminal.fdIn, TCSANOW, &n);
			scope(exit)
				tcsetattr(terminal.fdIn, TCSANOW, &old);


			terminal.writeStringRaw("\033[6n");
			terminal.flush();

			import core.sys.posix.unistd;
			// reading directly to bypass any buffering
			ubyte[16] buffer;
			auto len = read(terminal.fdIn, buffer.ptr, buffer.length);
			if(len <= 0)
				throw new Exception("Couldn't get cursor position to initialize get line");
			auto got = buffer[0 .. len];
			if(got.length < 6)
				throw new Exception("not enough cursor reply answer");
			if(got[0] != '\033' || got[1] != '[' || got[$-1] != 'R')
				throw new Exception("wrong answer for cursor position");
			auto gots = cast(char[]) got[2 .. $-1];

			import std.conv;
			import std.string;

			auto pieces = split(gots, ";");
			if(pieces.length != 2) throw new Exception("wtf wrong answer on cursor position");

			startOfLineX = to!int(pieces[1]) - 1;
			startOfLineY = to!int(pieces[0]) - 1;
		}

		// updating these too because I can with the more accurate info from above
		terminal._cursorX = startOfLineX;
		terminal._cursorY = startOfLineY;
	}

	private bool justHitTab;

	/// for integrating into another event loop
	/// you can pass individual events to this and
	/// the line getter will work on it
	///
	/// returns false when there's nothing more to do
	bool workOnLine(InputEvent e) {
		switch(e.type) {
			case InputEvent.Type.EndOfFileEvent:
				justHitTab = false;
				// FIXME: this should be distinct from an empty line when hit at the beginning
				return false;
			//break;
			case InputEvent.Type.KeyboardEvent:
				auto ev = e.keyboardEvent;
				if(ev.pressed == false)
					return true;
				/* Insert the character (unless it is backspace, tab, or some other control char) */
				auto ch = ev.which;
				switch(ch) {
					case 4: // ctrl+d will also send a newline-equivalent 
					case '\r':
					case '\n':
						justHitTab = false;
						return false;
					case '\t':
						auto relevantLineSection = line[0 .. cursorPosition];
						auto possibilities = filterTabCompleteList(tabComplete(relevantLineSection));
						import std.utf;

						if(possibilities.length == 1) {
							auto toFill = possibilities[0][codeLength!char(relevantLineSection) .. $];
							if(toFill.length) {
								addString(toFill);
								redraw();
							}
							justHitTab = false;
						} else {
							if(justHitTab) {
								justHitTab = false;
								showTabCompleteList(possibilities);
							} else {
								justHitTab = true;
								/* fill it in with as much commonality as there is amongst all the suggestions */
								auto suggestion = this.suggestion(possibilities);
								if(suggestion.length) {
									addString(suggestion);
									redraw();
								}
							}
						}
					break;
					case '\b':
						justHitTab = false;
						if(cursorPosition) {
							cursorPosition--;
							for(int i = cursorPosition; i < line.length - 1; i++)
								line[i] = line[i + 1];
							line = line[0 .. $ - 1];
							line.assumeSafeAppend();

							if(!multiLineMode) {
								if(horizontalScrollPosition > cursorPosition - 1)
									horizontalScrollPosition = cursorPosition - 1 - availableLineLength();
								if(horizontalScrollPosition < 0)
									horizontalScrollPosition = 0;
							}

							redraw();
						}
					break;
					case KeyboardEvent.Key.LeftArrow:
						justHitTab = false;
						if(cursorPosition)
							cursorPosition--;
						if(!multiLineMode) {
							if(cursorPosition < horizontalScrollPosition)
								horizontalScrollPosition--;
						}

						redraw();
					break;
					case KeyboardEvent.Key.RightArrow:
						justHitTab = false;
						if(cursorPosition < line.length)
							cursorPosition++;
						if(!multiLineMode) {
							if(cursorPosition >= horizontalScrollPosition + availableLineLength())
								horizontalScrollPosition++;
						}

						redraw();
					break;
					case KeyboardEvent.Key.UpArrow:
						justHitTab = false;
						loadFromHistory(currentHistoryViewPosition + 1);
						redraw();
					break;
					case KeyboardEvent.Key.DownArrow:
						justHitTab = false;
						loadFromHistory(currentHistoryViewPosition - 1);
						redraw();
					break;
					case KeyboardEvent.Key.PageUp:
						justHitTab = false;
						loadFromHistory(cast(int) history.length);
						redraw();
					break;
					case KeyboardEvent.Key.PageDown:
						justHitTab = false;
						loadFromHistory(0);
						redraw();
					break;
					case 1: // ctrl+a does home too in the emacs keybindings
					case KeyboardEvent.Key.Home:
						justHitTab = false;
						cursorPosition = 0;
						horizontalScrollPosition = 0;
						redraw();
					break;
					case 5: // ctrl+e from emacs
					case KeyboardEvent.Key.End:
						justHitTab = false;
						cursorPosition = cast(int) line.length;
						scrollToEnd();
						redraw();
					break;
					case KeyboardEvent.Key.Insert:
						justHitTab = false;
						insertMode = !insertMode;
						// FIXME: indicate this on the UI somehow
						// like change the cursor or something
					break;
					case KeyboardEvent.Key.Delete:
						justHitTab = false;
						if(ev.modifierState & ModifierState.control)
							deleteToEndOfLine();
						else
							deleteChar();
						redraw();
					break;
					case 11: // ctrl+k is delete to end of line from emacs
						justHitTab = false;
						deleteToEndOfLine();
						redraw();
					break;
					default:
						justHitTab = false;
						if(e.keyboardEvent.isCharacter)
							addChar(ch);
						redraw();
				}
			break;
			case InputEvent.Type.PasteEvent:
				justHitTab = false;
				addString(e.pasteEvent.pastedText);
				redraw();
			break;
			case InputEvent.Type.MouseEvent:
				/* Clicking with the mouse to move the cursor is so much easier than arrowing
				   or even emacs/vi style movements much of the time, so I'ma support it. */

				auto me = e.mouseEvent;
				if(me.eventType == MouseEvent.Type.Pressed) {
					if(me.buttons & MouseEvent.Button.Left) {
						if(me.y == startOfLineY) {
							// FIXME: prompt.length should be graphemes or at least code poitns
							int p = me.x - startOfLineX - cast(int) prompt.length + horizontalScrollPosition;
							if(p >= 0 && p < line.length) {
								justHitTab = false;
								cursorPosition = p;
								redraw();
							}
						}
					}
				}
			break;
			case InputEvent.Type.SizeChangedEvent:
				/* We'll adjust the bounding box. If you don't like this, handle SizeChangedEvent
				   yourself and then don't pass it to this function. */
				// FIXME
			break;
			case InputEvent.Type.UserInterruptionEvent:
				/* I'll take this as canceling the line. */
				throw new UserInterruptionException();
			//break;
			case InputEvent.Type.HangupEvent:
				/* I'll take this as canceling the line. */
				throw new HangupException();
			//break;
			default:
				/* ignore. ideally it wouldn't be passed to us anyway! */
		}

		return true;
	}

	string finishGettingLine() {
		import std.conv;
		auto f = to!string(line);
		auto history = historyFilter(f);
		if(history !is null)
			this.history ~= history;

		// FIXME: we should hide the cursor if it was hidden in the call to startGettingLine
		return f;
	}
}

/// Adds default constructors that just forward to the superclass
mixin template LineGetterConstructors() {
	this(Terminal* tty, string historyFilename = null) {
		super(tty, historyFilename);
	}
}

/// This is a line getter that customizes the tab completion to
/// fill in file names separated by spaces, like a command line thing.
class FileLineGetter : LineGetter {
	mixin LineGetterConstructors;

	/// You can set this property to tell it where to search for the files
	/// to complete.
	string searchDirectory = ".";

	override protected string[] tabComplete(in dchar[] candidate) {
		import std.file, std.conv, std.algorithm, std.string;
		const(dchar)[] soFar = candidate;
		auto idx = candidate.lastIndexOf(" ");
		if(idx != -1)
			soFar = candidate[idx + 1 .. $];

		string[] list;
		foreach(string name; dirEntries(searchDirectory, SpanMode.breadth)) {
			// try without the ./
			if(startsWith(name[2..$], soFar))
				list ~= text(candidate, name[searchDirectory.length + 1 + soFar.length .. $]);
			else // and with
			if(startsWith(name, soFar))
				list ~= text(candidate, name[soFar.length .. $]);
		}

		return list;
	}
}

version(Windows) {
	// to get the directory for saving history in the line things
	enum CSIDL_APPDATA = 26;
	extern(Windows) HRESULT SHGetFolderPathA(HWND, int, HANDLE, DWORD, LPSTR);
}





/* Like getting a line, printing a lot of lines is kinda important too, so I'm including
   that widget here too. */


struct ScrollbackBuffer {

	bool demandsAttention;

	this(string name) {
		this.name = name;
	}

	void write(T...)(T t) {
		import std.conv : text;
		addComponent(text(t), foreground_, background_, null);
	}

	void writeln(T...)(T t) {
		write(t, "\n");
	}

	void writef(T...)(string fmt, T t) {
		import std.format: format;
		write(format(fmt, t));
	}

	void writefln(T...)(string fmt, T t) {
		writef(fmt, t, "\n");
	}

	void clear() {
		lines.clear();
		clickRegions = null;
		scrollbackPosition = 0;
	}

	int foreground_ = Color.DEFAULT, background_ = Color.DEFAULT;
	void color(int foreground, int background) {
		this.foreground_ = foreground;
		this.background_ = background;
	}

	void addComponent(string text, int foreground, int background, bool delegate() onclick) {
		if(lines.length == 0) {
			addLine();
		}
		bool first = true;
		import std.algorithm;
		foreach(t; splitter(text, "\n")) {
			if(!first) addLine();
			first = false;
			lines[$-1].components ~= LineComponent(t, foreground, background, onclick);
		}
	}

	void addLine() {
		lines ~= Line();
		if(scrollbackPosition) // if the user is scrolling back, we want to keep them basically centered where they are
			scrollbackPosition++;
	}

	void addLine(string line) {
		lines ~= Line([LineComponent(line)]);
		if(scrollbackPosition) // if the user is scrolling back, we want to keep them basically centered where they are
			scrollbackPosition++;
	}

	void scrollUp(int lines = 1) {
		scrollbackPosition += lines;
		//if(scrollbackPosition >= this.lines.length)
		//	scrollbackPosition = cast(int) this.lines.length - 1;
	}

	void scrollDown(int lines = 1) {
		scrollbackPosition -= lines;
		if(scrollbackPosition < 0)
			scrollbackPosition = 0;
	}

	void scrollToBottom() {
		scrollbackPosition = 0;
	}

	// this needs width and height to know how to word wrap it
	void scrollToTop(int width, int height) {
		scrollbackPosition = scrollTopPosition(width, height);
	}




	struct LineComponent {
		string text;
		bool isRgb;
		union {
			int color;
			RGB colorRgb;
		}
		union {
			int background;
			RGB backgroundRgb;
		}
		bool delegate() onclick; // return true if you need to redraw

		// 16 color ctor
		this(string text, int color = Color.DEFAULT, int background = Color.DEFAULT, bool delegate() onclick = null) {
			this.text = text;
			this.color = color;
			this.background = background;
			this.onclick = onclick;
			this.isRgb = false;
		}

		// true color ctor
		this(string text, RGB colorRgb, RGB backgroundRgb = RGB(0, 0, 0), bool delegate() onclick = null) {
			this.text = text;
			this.colorRgb = colorRgb;
			this.backgroundRgb = backgroundRgb;
			this.onclick = onclick;
			this.isRgb = true;
		}
	}

	struct Line {
		LineComponent[] components;
		int length() {
			int l = 0;
			foreach(c; components)
				l += c.text.length;
			return l;
		}
	}

	static struct CircularBuffer(T) {
		T[] backing;

		enum maxScrollback = 8192; // as a power of 2, i hope the compiler optimizes the % below to a simple bit mask...

		int start;
		int length_;

		void clear() {
			backing = null;
			start = 0;
			length_ = 0;
		}

		size_t length() {
			return length_;
		}

		void opOpAssign(string op : "~")(T line) {
			if(length_ < maxScrollback) {
				backing.assumeSafeAppend();
				backing ~= line;
				length_++;
			} else {
				backing[start] = line;
				start++;
				if(start == maxScrollback)
					start = 0;
			}
		}

		T opIndex(int idx) {
			return backing[(start + idx) % maxScrollback];
		}
		T opIndex(Dollar idx) {
			return backing[(start + (length + idx.offsetFromEnd)) % maxScrollback];
		}

		CircularBufferRange opSlice(int startOfIteration, Dollar end) {
			return CircularBufferRange(&this, startOfIteration, cast(int) length - startOfIteration + end.offsetFromEnd);
		}
		CircularBufferRange opSlice(int startOfIteration, int end) {
			return CircularBufferRange(&this, startOfIteration, end - startOfIteration);
		}
		CircularBufferRange opSlice() {
			return CircularBufferRange(&this, 0, cast(int) length);
		}

		static struct CircularBufferRange {
			CircularBuffer* item;
			int position;
			int remaining;
			this(CircularBuffer* item, int startOfIteration, int count) {
				this.item = item;
				position = startOfIteration;
				remaining = count;
			}

			T front() { return (*item)[position]; }
			bool empty() { return remaining <= 0; }
			void popFront() {
				position++;
				remaining--;
			}

			T back() { return (*item)[remaining - 1 - position]; }
			void popBack() {
				remaining--;
			}
		}

		static struct Dollar {
			int offsetFromEnd;
			Dollar opBinary(string op : "-")(int rhs) {
				return Dollar(offsetFromEnd - rhs);
			}
		}
		Dollar opDollar() { return Dollar(0); }
	}

	CircularBuffer!Line lines;
	string name;

	int x, y, width, height;

	int scrollbackPosition;


	int scrollTopPosition(int width, int height) {
		int lineCount;

		foreach_reverse(line; lines) {
			int written = 0;
			comp_loop: foreach(cidx, component; line.components) {
				auto towrite = component.text;
				foreach(idx, dchar ch; towrite) {
					if(written >= width) {
						lineCount++;
						written = 0;
					}

					if(ch == '\t')
						written += 8; // FIXME
					else
						written++;
				}
			}
			lineCount++;
		}

		//if(lineCount > height)
			return lineCount - height;
		//return 0;
	}

	void drawInto(Terminal* terminal, in int x = 0, in int y = 0, int width = 0, int height = 0) {
		if(lines.length == 0)
			return;

		if(width == 0)
			width = terminal.width;
		if(height == 0)
			height = terminal.height;

		this.x = x;
		this.y = y;
		this.width = width;
		this.height = height;

		/* We need to figure out how much is going to fit
		   in a first pass, so we can figure out where to
		   start drawing */

		int remaining = height + scrollbackPosition;
		int start = cast(int) lines.length;
		int howMany = 0;

		bool firstPartial = false;

		static struct Idx {
			size_t cidx;
			size_t idx;
		}

		Idx firstPartialStartIndex;

		// this is private so I know we can safe append
		clickRegions.length = 0;
		clickRegions.assumeSafeAppend();

		// FIXME: should prolly handle \n and \r in here too.

		// we'll work backwards to figure out how much will fit...
		// this will give accurate per-line things even with changing width and wrapping
		// while being generally efficient - we usually want to show the end of the list
		// anyway; actually using the scrollback is a bit of an exceptional case.

		// It could probably do this instead of on each redraw, on each resize or insertion.
		// or at least cache between redraws until one of those invalidates it.
		foreach_reverse(line; lines) {
			int written = 0;
			int brokenLineCount;
			Idx[16] lineBreaksBuffer;
			Idx[] lineBreaks = lineBreaksBuffer[];
			comp_loop: foreach(cidx, component; line.components) {
				auto towrite = component.text;
				foreach(idx, dchar ch; towrite) {
					if(written >= width) {
						if(brokenLineCount == lineBreaks.length)
							lineBreaks ~= Idx(cidx, idx);
						else
							lineBreaks[brokenLineCount] = Idx(cidx, idx);

						brokenLineCount++;

						written = 0;
					}

					if(ch == '\t')
						written += 8; // FIXME
					else
						written++;
				}
			}

			lineBreaks = lineBreaks[0 .. brokenLineCount];

			foreach_reverse(lineBreak; lineBreaks) {
				if(remaining == 1) {
					firstPartial = true;
					firstPartialStartIndex = lineBreak;
					break;
				} else {
					remaining--;
				}
				if(remaining <= 0)
					break;
			}

			remaining--;

			start--;
			howMany++;
			if(remaining <= 0)
				break;
		}

		// second pass: actually draw it
		int linePos = remaining;

		foreach(line; lines[start .. start + howMany]) {
			int written = 0;

			if(linePos < 0) {
				linePos++;
				continue;
			}
		
			terminal.moveTo(x, y + ((linePos >= 0) ? linePos : 0));

			auto todo = line.components;

			if(firstPartial) {
				todo = todo[firstPartialStartIndex.cidx .. $];
			}

			foreach(ref component; todo) {
				if(component.isRgb)
					terminal.setTrueColor(component.colorRgb, component.backgroundRgb);
				else
					terminal.color(component.color, component.background);
				auto towrite = component.text;

				again:

				if(linePos >= height)
					break;

				if(firstPartial) {
					towrite = towrite[firstPartialStartIndex.idx .. $];
					firstPartial = false;
				}

				foreach(idx, dchar ch; towrite) {
					if(written >= width) {
						clickRegions ~= ClickRegion(&component, terminal.cursorX, terminal.cursorY, written);
						terminal.write(towrite[0 .. idx]);
						towrite = towrite[idx .. $];
						linePos++;
						written = 0;
						terminal.moveTo(x, y + linePos);
						goto again;
					}

					if(ch == '\t')
						written += 8; // FIXME
					else
						written++;
				}

				if(towrite.length) {
					clickRegions ~= ClickRegion(&component, terminal.cursorX, terminal.cursorY, written);
					terminal.write(towrite);
				}
			}

			if(written < width) {
				terminal.color(Color.DEFAULT, Color.DEFAULT);
				foreach(i; written .. width)
					terminal.write(" ");
			}

			linePos++;

			if(linePos >= height)
				break;
		}

		if(linePos < height) {
			terminal.color(Color.DEFAULT, Color.DEFAULT);
			foreach(i; linePos .. height) {
				if(i >= 0 && i < height) {
					terminal.moveTo(x, y + i);
					foreach(w; 0 .. width)
						terminal.write(" ");
				}
			}
		}
	}

	private struct ClickRegion {
		LineComponent* component;
		int xStart;
		int yStart;
		int length;
	}
	private ClickRegion[] clickRegions;

	/// Default event handling for this widget. Call this only after drawing it into a rectangle
	/// and only if the event ought to be dispatched to it (which you determine however you want;
	/// you could dispatch all events to it, or perhaps filter some out too)
	///
	/// Returns true if it should be redrawn
	bool handleEvent(InputEvent e) {
		final switch(e.type) {
			case InputEvent.Type.KeyboardEvent:
				auto ev = e.keyboardEvent;

				demandsAttention = false;

				switch(ev.which) {
					case KeyboardEvent.Key.UpArrow:
						scrollUp();
						return true;
					case KeyboardEvent.Key.DownArrow:
						scrollDown();
						return true;
					case KeyboardEvent.Key.PageUp:
						scrollUp(height);
						return true;
					case KeyboardEvent.Key.PageDown:
						scrollDown(height);
						return true;
					default:
						// ignore
				}
			break;
			case InputEvent.Type.MouseEvent:
				auto ev = e.mouseEvent;
				if(ev.x >= x && ev.x < x + width && ev.y >= y && ev.y < y + height) {
					demandsAttention = false;
					// it is inside our box, so do something with it
					auto mx = ev.x - x;
					auto my = ev.y - y;

					if(ev.eventType == MouseEvent.Type.Pressed) {
						if(ev.buttons & MouseEvent.Button.Left) {
							foreach(region; clickRegions)
								if(ev.x >= region.xStart && ev.x < region.xStart + region.length && ev.y == region.yStart)
									if(region.component.onclick !is null)
										return region.component.onclick();
						}
						if(ev.buttons & MouseEvent.Button.ScrollUp) {
							scrollUp();
							return true;
						}
						if(ev.buttons & MouseEvent.Button.ScrollDown) {
							scrollDown();
							return true;
						}
					}
				} else {
					// outside our area, free to ignore
				}
			break;
			case InputEvent.Type.SizeChangedEvent:
				// (size changed might be but it needs to be handled at a higher level really anyway)
				// though it will return true because it probably needs redrawing anyway.
				return true;
			case InputEvent.Type.UserInterruptionEvent:
				throw new UserInterruptionException();
			case InputEvent.Type.HangupEvent:
				throw new HangupException();
			case InputEvent.Type.EndOfFileEvent:
				// ignore, not relevant to this
			break;
			case InputEvent.Type.CharacterEvent:
			case InputEvent.Type.NonCharacterKeyEvent:
				// obsolete, ignore them until they are removed
			break;
			case InputEvent.Type.CustomEvent:
			case InputEvent.Type.PasteEvent:
				// ignored, not relevant to us
			break;
		}

		return false;
	}
}


class UserInterruptionException : Exception {
	this() { super("Ctrl+C"); }
}
class HangupException : Exception {
	this() { super("Hup"); }
}



/*

	// more efficient scrolling
	http://msdn.microsoft.com/en-us/library/windows/desktop/ms685113%28v=vs.85%29.aspx
	// and the unix sequences


	rxvt documentation:
	use this to finish the input magic for that


       For the keypad, use Shift to temporarily override Application-Keypad
       setting use Num_Lock to toggle Application-Keypad setting if Num_Lock
       is off, toggle Application-Keypad setting. Also note that values of
       Home, End, Delete may have been compiled differently on your system.

                         Normal       Shift         Control      Ctrl+Shift
       Tab               ^I           ESC [ Z       ^I           ESC [ Z
       BackSpace         ^H           ^?            ^?           ^?
       Find              ESC [ 1 ~    ESC [ 1 $     ESC [ 1 ^    ESC [ 1 @
       Insert            ESC [ 2 ~    paste         ESC [ 2 ^    ESC [ 2 @
       Execute           ESC [ 3 ~    ESC [ 3 $     ESC [ 3 ^    ESC [ 3 @
       Select            ESC [ 4 ~    ESC [ 4 $     ESC [ 4 ^    ESC [ 4 @
       Prior             ESC [ 5 ~    scroll-up     ESC [ 5 ^    ESC [ 5 @
       Next              ESC [ 6 ~    scroll-down   ESC [ 6 ^    ESC [ 6 @
       Home              ESC [ 7 ~    ESC [ 7 $     ESC [ 7 ^    ESC [ 7 @
       End               ESC [ 8 ~    ESC [ 8 $     ESC [ 8 ^    ESC [ 8 @
       Delete            ESC [ 3 ~    ESC [ 3 $     ESC [ 3 ^    ESC [ 3 @
       F1                ESC [ 11 ~   ESC [ 23 ~    ESC [ 11 ^   ESC [ 23 ^
       F2                ESC [ 12 ~   ESC [ 24 ~    ESC [ 12 ^   ESC [ 24 ^
       F3                ESC [ 13 ~   ESC [ 25 ~    ESC [ 13 ^   ESC [ 25 ^
       F4                ESC [ 14 ~   ESC [ 26 ~    ESC [ 14 ^   ESC [ 26 ^
       F5                ESC [ 15 ~   ESC [ 28 ~    ESC [ 15 ^   ESC [ 28 ^
       F6                ESC [ 17 ~   ESC [ 29 ~    ESC [ 17 ^   ESC [ 29 ^
       F7                ESC [ 18 ~   ESC [ 31 ~    ESC [ 18 ^   ESC [ 31 ^
       F8                ESC [ 19 ~   ESC [ 32 ~    ESC [ 19 ^   ESC [ 32 ^
       F9                ESC [ 20 ~   ESC [ 33 ~    ESC [ 20 ^   ESC [ 33 ^
       F10               ESC [ 21 ~   ESC [ 34 ~    ESC [ 21 ^   ESC [ 34 ^
       F11               ESC [ 23 ~   ESC [ 23 $    ESC [ 23 ^   ESC [ 23 @
       F12               ESC [ 24 ~   ESC [ 24 $    ESC [ 24 ^   ESC [ 24 @
       F13               ESC [ 25 ~   ESC [ 25 $    ESC [ 25 ^   ESC [ 25 @
       F14               ESC [ 26 ~   ESC [ 26 $    ESC [ 26 ^   ESC [ 26 @
       F15 (Help)        ESC [ 28 ~   ESC [ 28 $    ESC [ 28 ^   ESC [ 28 @
       F16 (Menu)        ESC [ 29 ~   ESC [ 29 $    ESC [ 29 ^   ESC [ 29 @

       F17               ESC [ 31 ~   ESC [ 31 $    ESC [ 31 ^   ESC [ 31 @
       F18               ESC [ 32 ~   ESC [ 32 $    ESC [ 32 ^   ESC [ 32 @
       F19               ESC [ 33 ~   ESC [ 33 $    ESC [ 33 ^   ESC [ 33 @
       F20               ESC [ 34 ~   ESC [ 34 $    ESC [ 34 ^   ESC [ 34 @
                                                                 Application
       Up                ESC [ A      ESC [ a       ESC O a      ESC O A
       Down              ESC [ B      ESC [ b       ESC O b      ESC O B
       Right             ESC [ C      ESC [ c       ESC O c      ESC O C
       Left              ESC [ D      ESC [ d       ESC O d      ESC O D
       KP_Enter          ^M                                      ESC O M
       KP_F1             ESC O P                                 ESC O P
       KP_F2             ESC O Q                                 ESC O Q
       KP_F3             ESC O R                                 ESC O R
       KP_F4             ESC O S                                 ESC O S
       XK_KP_Multiply    *                                       ESC O j
       XK_KP_Add         +                                       ESC O k
       XK_KP_Separator   ,                                       ESC O l
       XK_KP_Subtract    -                                       ESC O m
       XK_KP_Decimal     .                                       ESC O n
       XK_KP_Divide      /                                       ESC O o
       XK_KP_0           0                                       ESC O p
       XK_KP_1           1                                       ESC O q
       XK_KP_2           2                                       ESC O r
       XK_KP_3           3                                       ESC O s
       XK_KP_4           4                                       ESC O t
       XK_KP_5           5                                       ESC O u
       XK_KP_6           6                                       ESC O v
       XK_KP_7           7                                       ESC O w
       XK_KP_8           8                                       ESC O x
       XK_KP_9           9                                       ESC O y
*/

version(Demo_kbhit)
void main() {
	auto terminal = Terminal(ConsoleOutputType.linear);
	auto input = RealTimeConsoleInput(&terminal, ConsoleInputFlags.raw);

	int a;
	char ch = '.';
	while(a < 1000) {
		a++;
		if(a % terminal.width == 0) {
			terminal.write("\r");
			if(ch == '.')
				ch = ' ';
			else
				ch = '.';
		}

		if(input.kbhit())
			terminal.write(input.getch());
		else
			terminal.write(ch);

		terminal.flush();

		import core.thread;
		Thread.sleep(50.msecs);
	}
}

/*
	The Xterm palette progression is:
	[0, 95, 135, 175, 215, 255]

	So if I take the color and subtract 55, then div 40, I get
	it into one of these areas. If I add 20, I get a reasonable
	rounding.
*/

ubyte colorToXTermPaletteIndex(RGB color) {
	/*
		Here, I will round off to the color ramp or the
		greyscale. I will NOT use the bottom 16 colors because
		there's duplicates (or very close enough) to them in here
	*/

	if(color.r == color.g && color.g == color.b) {
		// grey - find one of them:
		if(color.r == 0) return 0;
		// meh don't need those two, let's simplify branche
		//if(color.r == 0xc0) return 7;
		//if(color.r == 0x80) return 8;
		// it isn't == 255 because it wants to catch anything
		// that would wrap the simple algorithm below back to 0.
		if(color.r >= 248) return 15;

		// there's greys in the color ramp too, but these
		// are all close enough as-is, no need to complicate
		// algorithm for approximation anyway

		return cast(ubyte) (232 + ((color.r - 8) / 10));
	}

	// if it isn't grey, it is color

	// the ramp goes blue, green, red, with 6 of each,
	// so just multiplying will give something good enough

	// will give something between 0 and 5, with some rounding
	auto r = (cast(int) color.r - 35) / 40;
	auto g = (cast(int) color.g - 35) / 40;
	auto b = (cast(int) color.b - 35) / 40;

	return cast(ubyte) (16 + b + g*6 + r*36);
}

/++
	Represents a 24-bit color.


	$(TIP You can convert these to and from [arsd.color.Color] using
	      `.tupleof`:

		---
	      	RGB rgb;
		Color c = Color(rgb.tupleof);
		---
	)
+/
struct RGB {
	ubyte r; ///
	ubyte g; ///
	ubyte b; ///
	// terminal can't actually use this but I want the value
	// there for assignment to an arsd.color.Color
	private ubyte a = 255;
}

// This is an approximation too for a few entries, but a very close one.
RGB xtermPaletteIndexToColor(int paletteIdx) {
	RGB color;

	if(paletteIdx < 16) {
		if(paletteIdx == 7)
			return RGB(0xc0, 0xc0, 0xc0);
		else if(paletteIdx == 8)
			return RGB(0x80, 0x80, 0x80);

		color.r = (paletteIdx & 0b001) ? ((paletteIdx & 0b1000) ? 0xff : 0x80) : 0x00;
		color.g = (paletteIdx & 0b010) ? ((paletteIdx & 0b1000) ? 0xff : 0x80) : 0x00;
		color.b = (paletteIdx & 0b100) ? ((paletteIdx & 0b1000) ? 0xff : 0x80) : 0x00;

	} else if(paletteIdx < 232) {
		// color ramp, 6x6x6 cube
		color.r = cast(ubyte) ((paletteIdx - 16) / 36 * 40 + 55);
		color.g = cast(ubyte) (((paletteIdx - 16) % 36) / 6 * 40 + 55);
		color.b = cast(ubyte) ((paletteIdx - 16) % 6 * 40 + 55);

		if(color.r == 55) color.r = 0;
		if(color.g == 55) color.g = 0;
		if(color.b == 55) color.b = 0;
	} else {
		// greyscale ramp, from 0x8 to 0xee
		color.r = cast(ubyte) (8 + (paletteIdx - 232) * 10);
		color.g = color.r;
		color.b = color.g;
	}

	return color;
}

int approximate16Color(RGB color) {
	int c;
	c |= color.r > 64 ? RED_BIT : 0;
	c |= color.g > 64 ? GREEN_BIT : 0;
	c |= color.b > 64 ? BLUE_BIT : 0;

	c |= (((color.r + color.g + color.b) / 3) > 80) ? Bright : 0;

	return c;
}

/*
void main() {
	auto terminal = Terminal(ConsoleOutputType.linear);
	terminal.setTrueColor(RGB(255, 0, 255), RGB(255, 255, 255));
	terminal.writeln("Hello, world!");
}
*/