if (! window.$D) {
	window.$D = function (id) {
		return document.getElementById(id);
	};
}

function Telnet(target, connect_callback, disconnect_callback, initscr) {
	var that = {},  // Public API interface
		vd, ws, sQ = [];

	termType = "Viewdata";

	Array.prototype.pushStr = function (str) {
		var n = str.length;

		for (var i=0; i<n; i++) {
			this.push(str.charCodeAt(i));
		}
	}

	function do_send() {
		Log.Debug('>> do_send');

		if (sQ.length > 0) {
			ws.send(sQ);
			sQ = [];
		}
	}

	function do_recv() {
		Log.Debug('>> do_recv');

		vd.write(ws.rQshiftStr(ws.rQlen()));
	}

	that.addEvent = function(obj, evType, fn) {
		if (obj.attachEvent) {
			var r = obj.attachEvent("on"+evType, fn);
			return r;

		} else if (obj.addEventListener){
			obj.addEventListener(evType, fn, false);
			return true;

		} else {
			throw("Handler could not be attached");
		}
	};

	that.removeEvent = function(obj, evType, fn){
		if (obj.detachEvent) {
			var r = obj.detachEvent("on"+evType, fn);
			return r;

		} else if (obj.removeEventListener) {
			obj.removeEventListener(evType, fn, false);
			return true;

		} else {
			throw("Handler could not be removed");
		}
	};

	that.stopEvent = function(e) {
		if (e.stopPropagation) {
			e.stopPropagation();

		} else {
			e.cancelBubble = true;
		}

		if (e.preventDefault) {
			e.preventDefault();
		} else {
			e.returnValue = false;
		}
	};

	that.connect = function(host, port, encrypt, url) {
		Log.Debug('>> connect');

		var host = host,
			port = port,
			scheme = "ws://", uri;

		if ((!host) || (!port)) {
			console.log("must set host and port");
			return;
		}

		if (ws) {
			ws.close();
		}

		if (encrypt) {
			scheme = "wss://";
		}

		uri = scheme + host + ":" + port + url;

		ws.open(uri);

		//vd.write("\x1e\x11Connecting, hang tight...");
		vd.write("\x0c"+vd.txthash('#0:QIECBAgQIECBAgQIECBAgQIECBAgQIECBAgQIECBAgQIECA0XboW7V61ete7Fuh1oWr1q3QoECBAgQIECBAgQIECBAgQIDRfqw6tWrVq16sOrDUgatWvVqwYMGCBAgQIECBAgQIECBAg')+' '.repeat(40));
	}

	that.disconnect = function() {
		if (ws) {
			ws.close();
		}

		disconnect_callback();
	}

	function constructor() {
		/* Initialize Websock object */
		ws = new Websock();

		ws.on('message', do_recv);
		ws.on('open', function(e) {
			vd.curs_set(true, true);
			connect_callback();
		});
		ws.on('close', function(e) {
			that.disconnect();
		});
		ws.on('error', function(e) {
			that.disconnect();
		});

		/* Initialize the terminal emulator/renderer */
		vd = new VD(40,24,target,initscr);

		// Override VD I/O routines
		// Set handler for sending characters
		vd.getch(
			function send_chr(chr, vt) {
				var i;
				for (i = 0; i < chr.length; i++) {
					sQ.push(chr.charCodeAt(i));
				}
				do_send();
				vd.getch(send_chr);
			}
		);

		vd.curs_set = function(vis, grab, eventist) {
			if (vis !== undefined)
				this.cursor_vis_ = (vis > 0);

			if (eventist === undefined)
				eventist = window;

			if (grab === true || grab === false) {
				if (grab === this.grab_events_)
					return;

				if (grab) {
					this.grab_events_ = true;
					VD.the_vt_ = this;
					that.addEvent(eventist, 'keydown', vd.key_down);
					that.addEvent(eventist, 'keyup', vd.key_up);
				} else {
					that.removeEvent(eventist, 'keydown', vd.key_down);
					that.removeEvent(eventist, 'keyup', vd.key_up);
					this.grab_events_ = false;
					VD.the_vt_ = undefined;
				}
			}
		}

		vd.key_down = function(e) {
			var vt = VD.the_vt_, keysym, ch, str = '';

			if (vt === undefined)
				return true;

			keysym = getKeysym(e);

			if (keysym < 128) {
				if (e.ctrlKey) {
					if (keysym == 64) {
						// control 0
						ch = 0;

					} else if ((keysym >= 97) && (keysym <= 122)) {
						// control codes 1-26
						ch = keysym - 96;

					} else if ((keysym >= 91) && (keysym <= 95)) {
						// control codes 27-31
						ch = keysym - 64;
					}

				} else {
					ch = keysym;

					switch (ch) {
						case 34:
							ch = 126; break;
						case 126:
							ch = 0x40; break;
						case 64:
							ch = 0x22; break;
						case 39:
							ch = 0x5f; break;
						case 95:
							ch = 0x23; break;
						case 96:
							ch = 0x27; break;
					}
				}

				str = String.fromCharCode(ch);

			} else {
				switch (keysym) {
					case 65505: // Shift, do not send directly
						break;
					case 65507: // Ctrl, do not send directly
						break;
					case 65293: // Carriage return, line feed
						str = '_'; break;
					case 65288: // Backspace
						str = '\b'; break;
					case 65307: // Escape
						str = '\x1b'; break;
					case 65361: // Left arrow
						str = '\x08'; break;
					case 65362: // Up arrow
						str = '\x0b'; break;
					case 65363: // Right arrow
						str = '\x09'; break;
					case 65364: // Down arrow
						str = '\x0a'; break;

					case 0xffc0: // f3
						vd.reveal_ ^= 1;
						vd.refresh();
						break;

					case 0xffc4: // f7
						str = '\x1b'; break
				}
			}

			if (str) {
				vt.key_buf_.push(str);
				setTimeout(VD.go_getch_,0);
			}

			that.stopEvent(e);
			return false;
		}

		vd.key_up = function(e) {
			var vt = VD.the_vt_;

			if (vt === undefined)
				return true;

			that.stopEvent(e);
			return false;
		}

		return that;
	}

	return constructor(); // Return the public API interface
}