/**
 * User input
 *
 * --- Rx messages: ---
 * S - screen content (binary encoding of the entire screen with simple compression)
 * T - text labels - Title and buttons, \0x01-separated
 * B - beep
 * . - heartbeat
 *
 * --- Tx messages ---
 * s - string
 * b - action button
 * p - mb press
 * r - mb release
 * m - mouse move
 */
var Input = (function() {
	var opts = {
		np_alt: false,
		cu_alt: false,
		fn_alt: false,
		mt_click: false,
		mt_move: false,
		no_keys: false,
	};

	/** Send a literal message */
	function sendStrMsg(str) {
		return Conn.send("s"+str);
	}

	/** Send a button event */
	function sendBtnMsg(n) {
		Conn.send("b"+Chr(n));
	}

	/** Fn alt choice for key message */
	function fa(alt, normal) {
		return opts.fn_alt ? alt : normal;
	}

	/** Cursor alt choice for key message */
	function ca(alt, normal) {
		return opts.cu_alt ? alt : normal;
	}

	/** Numpad alt choice for key message */
	function na(alt, normal) {
		return opts.np_alt ? alt : normal;
	}

	function _bindFnKeys() {
		var keymap = {
			'tab': '\x09',
			'backspace': '\x08',
			'enter': '\x0d',
			'ctrl+enter': '\x0a',
			'esc': '\x1b',
			'up': ca('\x1bOA', '\x1b[A'),
			'down': ca('\x1bOB', '\x1b[B'),
			'right': ca('\x1bOC', '\x1b[C'),
			'left': ca('\x1bOD', '\x1b[D'),
			'home': ca('\x1bOH', fa('\x1b[H', '\x1b[1~')),
			'insert': '\x1b[2~',
			'delete': '\x1b[3~',
			'end': ca('\x1bOF', fa('\x1b[F', '\x1b[4~')),
			'pageup': '\x1b[5~',
			'pagedown': '\x1b[6~',
			'f1': fa('\x1bOP', '\x1b[11~'),
			'f2': fa('\x1bOQ', '\x1b[12~'),
			'f3': fa('\x1bOR', '\x1b[13~'),
			'f4': fa('\x1bOS', '\x1b[14~'),
			'f5': '\x1b[15~', // note the disconnect
			'f6': '\x1b[17~',
			'f7': '\x1b[18~',
			'f8': '\x1b[19~',
			'f9': '\x1b[20~',
			'f10': '\x1b[21~', // note the disconnect
			'f11': '\x1b[23~',
			'f12': '\x1b[24~',
			'shift+f1': fa('\x1bO1;2P', '\x1b[25~'),
			'shift+f2': fa('\x1bO1;2Q', '\x1b[26~'), // note the disconnect
			'shift+f3': fa('\x1bO1;2R', '\x1b[28~'),
			'shift+f4': fa('\x1bO1;2S', '\x1b[29~'), // note the disconnect
			'shift+f5': fa('\x1b[15;2~', '\x1b[31~'),
			'shift+f6': fa('\x1b[17;2~', '\x1b[32~'),
			'shift+f7': fa('\x1b[18;2~', '\x1b[33~'),
			'shift+f8': fa('\x1b[19;2~', '\x1b[34~'),
			'shift+f9': fa('\x1b[20;2~', '\x1b[35~'), // 35-38 are not standard - but what is?
			'shift+f10': fa('\x1b[21;2~', '\x1b[36~'),
			'shift+f11': fa('\x1b[22;2~', '\x1b[37~'),
			'shift+f12': fa('\x1b[23;2~', '\x1b[38~'),
			'np_0': na('\x1bOp', '0'),
			'np_1': na('\x1bOq', '1'),
			'np_2': na('\x1bOr', '2'),
			'np_3': na('\x1bOs', '3'),
			'np_4': na('\x1bOt', '4'),
			'np_5': na('\x1bOu', '5'),
			'np_6': na('\x1bOv', '6'),
			'np_7': na('\x1bOw', '7'),
			'np_8': na('\x1bOx', '8'),
			'np_9': na('\x1bOy', '9'),
			'np_mul': na('\x1bOR', '*'),
			'np_add': na('\x1bOl', '+'),
			'np_sub': na('\x1bOS', '-'),
			'np_point': na('\x1bOn', '.'),
			'np_div': na('\x1bOQ', '/'),
			// we don't implement numlock key (should change in numpad_alt mode, but it's even more useless than the rest)
		};

		for (var k in keymap) {
			if (keymap.hasOwnProperty(k)) {
				bind(k, keymap[k]);
			}
		}
	}

	/** Bind a keystroke to message */
	function bind(combo, str) {
		// mac fix - allow also cmd
		if (combo.indexOf('ctrl+') !== -1) {
			combo += ',' + combo.replace('ctrl', 'command');
		}

		// unbind possible old binding
		key.unbind(combo);

		key(combo, function (e) {
			if (opts.no_keys) return;
			e.preventDefault();
			sendStrMsg(str)
		});
	}

	/** Bind/rebind key messages */
	function _initKeys() {
		// This takes care of text characters typed
		window.addEventListener('keypress', function(evt) {
			if (opts.no_keys) return;
			var str = '';
			if (evt.key) str = evt.key;
			else if (evt.which) str = String.fromCodePoint(evt.which);
			if (str.length>0 && str.charCodeAt(0) >= 32) {
//				console.log("Typed ", str);
				// prevent space from scrolling
				if (evt.which === 32) evt.preventDefault();
				sendStrMsg(str);
			}
		});

		// ctrl-letter codes are sent as simple low ASCII codes
		for (var i = 1; i<=26;i++) {
			bind('ctrl+' + String.fromCharCode(96+i), String.fromCharCode(i));
		}
		bind('ctrl+]', '\x1b'); // alternate way to enter ESC
		bind('ctrl+\\', '\x1c');
		bind('ctrl+[', '\x1d');
		bind('ctrl+^', '\x1e');
		bind('ctrl+_', '\x1f');

		_bindFnKeys();
	}

	// mouse button states
	var mb1 = 0;
	var mb2 = 0;
	var mb3 = 0;

	/** Init the Input module */
	function init() {
		_initKeys();

		// Button presses
		$('#action-buttons button').forEach(function(s) {
			s.addEventListener('click', function() {
				sendBtnMsg(+this.dataset['n']);
			});
		});

		// global mouse state tracking - for motion reporting
		window.addEventListener('mousedown', function(evt) {
			if (evt.button == 0) mb1 = 1;
			if (evt.button == 1) mb2 = 1;
			if (evt.button == 2) mb3 = 1;
		});

		window.addEventListener('mouseup', function(evt) {
			if (evt.button == 0) mb1 = 0;
			if (evt.button == 1) mb2 = 0;
			if (evt.button == 2) mb3 = 0;
		});
	}

	/** Prepare modifiers byte for mouse message */
	function packModifiersForMouse() {
		return (key.isModifier('ctrl')?1:0) |
			(key.isModifier('shift')?2:0) |
			(key.isModifier('alt')?4:0) |
			(key.isModifier('meta')?8:0);
	}

	return {
		/** Init the Input module */
		init: init,

		/** Send a literal string message */
		sendString: sendStrMsg,

		/** Enable alternate key modes (cursors, numpad, fn) */
		setAlts: function(cu, np, fn) {
			if (opts.cu_alt != cu || opts.np_alt != np || opts.fn_alt != fn) {
				opts.cu_alt = cu;
				opts.np_alt = np;
				opts.fn_alt = fn;

				// rebind keys - codes have changed
				_bindFnKeys();
			}
		},

		setMouseMode: function(click, move) {
			opts.mt_click = click;
			opts.mt_move = move;
		},

		// Mouse events
		onMouseMove: function (x, y) {
			if (!opts.mt_move) return;
			var b = mb1 ? 1 : mb2 ? 2 : mb3 ? 3 : 0;
			var m = packModifiersForMouse();
			Conn.send("m" + encode2B(y) + encode2B(x) + encode2B(b) + encode2B(m));
		},
		onMouseDown: function (x, y, b) {
			if (!opts.mt_click) return;
			if (b > 3 || b < 1) return;
			var m = packModifiersForMouse();
			Conn.send("p" + encode2B(y) + encode2B(x) + encode2B(b) + encode2B(m));
			// console.log("B ",b," M ",m);
		},
		onMouseUp: function (x, y, b) {
			if (!opts.mt_click) return;
			if (b > 3 || b < 1) return;
			var m = packModifiersForMouse();
			Conn.send("r" + encode2B(y) + encode2B(x) + encode2B(b) + encode2B(m));
			// console.log("B ",b," M ",m);
		},
		onMouseWheel: function (x, y, dir) {
			if (!opts.mt_click) return;
			// -1 ... btn 4 (away from user)
			// +1 ... btn 5 (towards user)
			var m = packModifiersForMouse();
			var b = (dir < 0 ? 4 : 5);
			Conn.send("p" + encode2B(y) + encode2B(x) + encode2B(b) + encode2B(m));
			// console.log("B ",b," M ",m);
		},
		mouseTracksClicks: function() {
			return opts.mt_click;
		},
		blockKeys: function(yes) {
			opts.no_keys = yes;
		}
	};
})();