function mk(e) {return document.createElement(e)}
function q1(s) {return document.querySelector(s)}
function qa(s) {return document.querySelectorAll(s)}

//
// Terminal class
//
(function () {
	var W, H;
	var cursor = {a: false, x: 0, y: 0, suppress: false, hidden: false};
	var screen = [];

	/** Colors table */
	var CLR = [// dark gray #2E3436
		// 0 black, 1 red, 2 green, 3 yellow
		// 4 blue, 5 mag, 6 cyan, 7 white
		'#111213','#CC0000','#4E9A06','#C4A000',
		'#3465A4','#75507B','#06989A','#D3D7CF',
		// BRIGHT
		// 8 black, 9 red, 10 green, 11 yellow
		// 12 blue, 13 mag, 14 cyan, 15 white
		'#555753','#EF2929','#8AE234','#FCE94F',
		'#729FCF','#AD7FA8','#34E2E2','#EEEEEC'
	];

	/** Clear screen */
	function cls() {
		screen.forEach(function(cell, i) {
			cell.t = ' ';
			cell.fg = 7;
			cell.bg = 0;
			blit(cell);
		});
	}

	/** Set text and color at XY */
	function cellAt(y, x) {
		return screen[y*W+x];
	}

	/** Get cell under cursor */
	function cursorCell() {
		return cellAt(cursor.y, cursor.x);
	}

	/** Enable or disable cursor visibility */
	function cursorEnable(enable) {
		cursor.hidden = !enable;
		cursor.a &= enable;
		blit(cursorCell(), cursor.a);
	}

	/** Safely move cursor */
	function cursorSet(y, x) {
		// Hide and prevent from showing up during the move
		cursor.suppress = true;
		blit(cursorCell(), false);

		cursor.x = x;
		cursor.y = y;

		// Show again
		cursor.suppress = false;
		blit(cursorCell(), cursor.a);
	}

	/** Update cell on display. inv = invert (for cursor) */
	function blit(cell, inv) {
		var e = cell.e, fg, bg;
		// Colors
		fg = inv ? cell.bg : cell.fg;
		bg = inv ? cell.fg : cell.bg;
		// Update
		e.innerText = (cell.t+' ')[0];
		e.style.color = colorHex(fg);
		e.style.backgroundColor = colorHex(bg);
		e.style.fontWeight = fg > 7 ? 'bold' : 'normal';
	}

	/** Show entire screen */
	function blitAll() {
		screen.forEach(function(cell, i) {
			/* Invert if under cursor & cursor active */
			var inv = cursor.a && (i == cursor.y*W+cursor.x);
			blit(cell, inv);
		});
	}

	/** Load screen content from a 'binary' sequence */
	function load(obj) {
		cursor.x = obj.x;
        cursor.y = obj.y;

        // full re-init if size changed
        if (obj.w != W || obj.h != H) {
        	Term.init(obj);
        	return;
		}

        // Simple compression - hexFG hexBG 'ASCII' (r/s/t/u NUM{1,2,3,4})?
		// comma instead of both colors = same as before

		var i = 0, ci = 0, str = obj.screen;
		var fg = 7, bg = 0;
		while(i < str.length && ci<W*H) {
			var cell = screen[ci++];

			var j = str[i];
			if (j != ',') { // comma = repeat last colors
                fg = cell.fg = parseInt(str[i++], 16);
                bg = cell.bg = parseInt(str[i++], 16);
            } else {
				i++;
                cell.fg = fg;
                cell.bg = bg;
			}

            var t = cell.t = str[i++];

			var repchars = 0;
            switch(str[i]) {
				case 'r': repchars = 1; break;
                case 's': repchars = 2; break;
                case 't': repchars = 3; break;
                case 'u': repchars = 4; break;
				default: repchars = 0;
			}

            if (repchars > 0) {
				var rep = parseInt(str.substr(i+1,repchars));
				i = i + repchars + 1;
				for (; rep>0 && ci<W*H; rep--) {
                    cell = screen[ci++];
                    cell.fg = fg;
                    cell.bg = bg;
                    cell.t = t;
				}
			}
        }

		blitAll();
	}

	/** Parse color */
	function colorHex(c) {
		c = parseInt(c);
		if (c < 0 || c > 15) c = 0;
		return CLR[c];
	}

	/** Init the terminal */
	function init(obj) {
		W = obj.w;
		H = obj.h;

		/* Build screen & show */
		var e, cell, scr = q1('#screen');

		// Empty the screen node
		while (scr.firstChild) scr.removeChild(scr.firstChild);

		screen = [];

		for(var i = 0; i < W*H; i++) {
			e = mk('span');

			(function() {
				var x = i % W;
				var y = Math.floor(i / W);
				e.addEventListener('click', function () {
					Kinp.onTap(y, x);
				});
			})();

			/* End of line */
			if ((i > 0) && (i % W == 0)) {
				scr.appendChild(mk('br'));
			}
			/* The cell */
			scr.appendChild(e);

			cell = {t: ' ', fg: 7, bg: 0, e: e};
			screen.push(cell);
			blit(cell);
		}

		/* Cursor blinking */
		setInterval(function() {
			cursor.a = !cursor.a;
			if (cursor.hidden) {
				cursor.a = false;
			}

			if (!cursor.suppress) {
				blit(cursorCell(), cursor.a);
			}
		}, 500);

		load(obj);
	}

	// publish
	window.Term = {
		init: init,
		load: load,
		setCursor: cursorSet,
		enableCursor: cursorEnable,
		clear: cls
	};
})();

//
// Connection class
//
(function() {
	var wsUri = "ws://"+window.location.host+"/ws/update.cgi";
	var ws;

	function onOpen(evt) {
		console.log("CONNECTED");
	}

	function onClose(evt) {
		console.error("SOCKET CLOSED");
	}

	function onMessage(evt) {
		try {
            console.log("RX: ", evt.data);
			// Assume all our messages are screen updates
            Term.load(JSON.parse(evt.data));
        } catch(e) {
			console.error(e);
		}
	}

	function onError(evt) {
		console.error(evt.data);
	}

	function doSend(message) {
		console.log("TX: ", message);
		if (ws.readyState != 1) {
			console.error("Socket not ready");
			return;
		}
		if (typeof message != "string") {
			message = JSON.stringify(message);
        }
		ws.send(message);
	}
		
	function init() {
		ws = new WebSocket(wsUri);
		ws.onopen = onOpen;
		ws.onclose = onClose;
		ws.onmessage = onMessage;
		ws.onerror = onError;
		
		console.log("Opening socket.");
	}
	
	window.Conn = {
		ws: null,
		init: init,
		send: doSend
	};
})();

//
// Keyboard (& mouse) input
//
(function() {
	function sendStrMsg(str) {
		Conn.send("STR:"+str);
	}

	function sendPosMsg(y, x) {
		Conn.send("TAP:"+y+','+x);
	}

	function sendBtnMsg(n) {
		Conn.send("BTN:"+n);
	}

	function init() {
		window.addEventListener('keypress', function(e) {
			var code = +e.which;
			if (code >= 32 && code < 127) {
				var ch = String.fromCharCode(code);
				//console.log("Typed ", ch, "code", code, e);
				sendStrMsg(ch);
			}
		});

		window.addEventListener('keydown', function(e) {
			var code = e.keyCode;
			//console.log("Down ", code, e);
			switch(code) {
				case 8: sendStrMsg('\x08'); break;
				case 13: sendStrMsg('\x0d\x0a'); break;
				case 27: sendStrMsg('\x1b'); break; // this allows to directly enter control sequences
				case 37: sendStrMsg('\x1b[D'); break;
				case 38: sendStrMsg('\x1b[A'); break;
				case 39: sendStrMsg('\x1b[C'); break;
				case 40: sendStrMsg('\x1b[B'); break;
			}
		});

		qa('#buttons button').forEach(function(s) {
			s.addEventListener('click', function() {
				sendBtnMsg(+this.dataset['n']);
			});
		});
	}

	window.Kinp = {
		init: init,
		onTap: sendPosMsg
	};
})();


function init(obj) {
	Term.init(obj);
	Conn.init();
	Kinp.init();
}