messenger.js/client.js

const channelSocket = new WebSocket("ws://localhost:9091/connect");
const __messengerjs__ = {
	"sessionID": null, 
	"imTheChannelOwner": false, 
	"myNickname": "", 
	"onloadfunction": null, 
	"onloadargs": null, 
	"fade": null
}
__messengerjs__.fade = document.createElement("div");
__messengerjs__.fade.style.cssText = "position: absolute;top:0;left:0;width:100%;height:100%;background:rgba(0,0,0,0.75);color:white;text-align:center;font-family:sans-serif;";
__messengerjs__.fade.textContent = "connecting to WebSocket server...";

const beforeUnloadHandler = function(ev, reason) {
	Channel_OnAppClose();
	channelSocket.send(new TextEncoder("utf8").encode(EncodeCommandString(["disconnect"])));
	channelSocket.close(1000, ((typeof (reason)) === "string") ? reason : "unloading");
};
/** @section guacamole **/
const ParseCommandString = function(instruction) {
	if(typeof instruction !== "string") {
		return;
	}
	let position = -1;
	let sections = new Array();

	for(;;) {
		let length = instruction.indexOf('.', position + 1);

		if(length === -1) {
			break;
		}

		position = (parseInt(instruction.slice(position + 1, length)) + length) + 1; // todo: not overflow
		sections.push(instruction.slice(length + 1, position)
			.replace(/'/g,	"'")
			.replace(/"/g,	'"')
			.replace(///g,	'/')
			.replace(/&lt;/g,	'<')
			.replace(/&gt;/g,	'>')
			.replace(/&amp;/g,	'&')
		);

		if(instruction.slice(position, position + 1) === ';') {
			break;
		}
	}
	return sections;
}
const EncodeCommandString = function(sections) {
	if(Array.isArray(sections) === false) {
		return;
	}
	let instruction = new String();
	const argv = sections;
	for (let argc = 0; argc < sections.length ; argc++) {
		if(typeof sections[argc] !== "string") {
			argv[argc] = sections[argc].toString();
		}
		argv[argc] = argv[argc]
			.replace(/'/g,	"&#x27;")
			.replace(/"/g,	'&quot;')
			.replace(/\//g,	'&#x2F'	)
			.replace(/</g,	'&lt;'	)
			.replace(/>/g,	'&gt;'	)
			.replace(/&/g,	'&amp;'	)
		;
		instruction = instruction.concat(argv[argc].length.toString(), ".", argv[argc])
		instruction += (argc === sections.length - 1) ? ';' : ',';
	}
	return instruction;
}

/** window.external **/
window.external.CloseApp = function() {
	beforeUnloadHandler(null, "called CloseApp");
}
// this is important because things expect it
/** window.external.Channel **/
window.external.Channel = {"Data": "", "SendData": null, "Initialize": null, "Error": {"Data": ""}}; // "Type" is a defined property
window.external.Channel.SendData = function(d) {channelSocket.send(d)}; // this is dumb but trying to redirect this gives you TypeError's
window.external.Channel.Initialize = function() {
	// no idea
};
Object.defineProperty(window.external.Channel, "Type", {
	get: function Type() {
		if(channelSocket.readyState === 1) {
			return 1; // Indirect;
		} else {
			return 2; // Disconnected;
		}
	}
});
/** window.external.Users **/
// This sadly needs to be already configured before an activity tries using it...
// We can't just block execution until we've got the session...
window.external.yellows111_Users = [
	{"Name": "Initiator", "Email": "initiator@messenger.js", "GlobalIP": "0.0.0.0", "LocalIP": "0.0.0.0", "PUID": "0"},
	{"Name": "Target", "Email": "target@messenger.js", "GlobalIP": "0.0.0.0", "LocalIP": "0.0.0.1", "PUID": "1"}
];

window.external.Users = {"Me": null, "Inviter": null, "Item": null}; // "Count" is a defined property
/** window.external.Users._NewEnum **/
window.external.Users[Symbol.iterator] = function*() {
	yield window.external.yellows111_Users[0];
	yield window.external.yellows111_Users[1];
};
window.external.Users.Item = function(which){
	return window.external.yellows111_Users[which];
}
Object.defineProperty(window.external.Users, "Count", {
	get: function Count() {
		return window.external.yellows111_Users.length; // 2
	}
});
/** Some early activities use a lower case "Me", support that like this... **/
Object.defineProperty(window.external.Users, "me", {
	get: function me() {
		return window.external.Users.Me;
	}
});

/** websocket stuff **/
channelSocket.binaryType = "arraybuffer"; // the alternative is blob.arrayBuffer(); IT'S A PROMISE CALL AND PROMISES SUXX
channelSocket.onmessage = function(event) {
	switch(event.data.constructor.name) {
		case "String": {
			// is a Activity message
			window.external.Channel.Data = event.data;
			Channel_OnDataReceived();
			break;
		}
		case "ArrayBuffer": {
			// is a Command message
			let args = ParseCommandString(new TextDecoder("utf8").decode(event.data));
			switch(args[0]) {
				case "rename": {
					__messengerjs__.myNickname = args[3];
					break;
				}
				case "connect": {
					switch(args[1]) {
						case "0": {
								console.error("channel is full or not avaliable");
								// regenerate channel ID if we get 0'd
								__messengerjs__.sessionID = Math.random().toString(36).split('.')[1].substring(0,8);
								history.pushState(null, "", `#channel=${__messengerjs__.sessionID}`);
								channelSocket.send(new TextEncoder("utf8").encode(EncodeCommandString(["connect", __messengerjs__.sessionID])));
							break;
						}
						case "1": {
							console.log("joined channel successfully.");
							__messengerjs__.fade.textContent = "waiting for opponent to join this channel...";
							window.addEventListener("beforeunload", beforeUnloadHandler);
							if(args[2] === "1") {
								__messengerjs__.imTheChannelOwner = false;
							} else {
								__messengerjs__.imTheChannelOwner = true;
								if(window.external.Users.Inviter !== window.external.Users.Me) {
									// This channel has already been closed. Create a new one.
									beforeUnloadHandler(null, "channel was empty when expecting host");
									history.replaceState(null, "", window.location.href.split("?")[0]);
									window.location.reload(); // it's still jank and probably should just be handled elsewhere
								}
							}
							break;
						}
						case "2": {
							console.log("disconnected gracefully.");
							break;
						}
					}
					break;
				}
				case "disconnect": {
					// code will never reach here normally (should announce from server on ^C, though)
					channelSocket.close(1000, "goodbye");
					Channel_OnTypeChanged();
				}
				case "adduser": {
					__messengerjs__.fade.style.display = "none";
					if(__messengerjs__.imTheChannelOwner === false) {
						window.external.yellows111_Users[1].Name = __messengerjs__.myNickname;
						window.external.yellows111_Users[0].Name = args[2];
					} else {
						window.external.yellows111_Users[1].Name = args[2];
						window.external.yellows111_Users[0].Name = __messengerjs__.myNickname;
					}
					if(__messengerjs__.imTheChannelOwner === true) {
						window.external.Users.Me = window.external.yellows111_Users[0];
						window.external.Users.Inviter = window.external.yellows111_Users[0];
					} else {
						window.external.Users.Me = window.external.yellows111_Users[1];
						window.external.Users.Inviter = window.external.yellows111_Users[0];
					}
					document.title = __messengerjs__.myNickname + ": " + document.title;
					/** beyond even hack territory **/
					if(typeof __messengerjs__.onloadfunction === "function") {
						__messengerjs__.onloadfunction(__messengerjs__.onloadargs);
					}
					Channel_OnRemoteAppLoaded();
					Channel_OnTypeChanged();
					break;
				}
				case "remuser": {
					__messengerjs__.fade.textContent = "opponent (" + args[1] + ") disconnected. refresh to get a new session!";
					__messengerjs__.fade.style.display = "block";
					window.removeEventListener("beforeunload", beforeUnloadHandler);
					Channel_OnRemoteAppClosed();
					beforeUnloadHandler(null, "other user disconnected"); // disconnect ourselves
					break;
				}
				case "sync": {
					channelSocket.send(new TextEncoder("utf8").encode(EncodeCommandString(["sync", (new Date).getTime()])));
					break;
				}
				default: {
					console.warn("unknown instruction sequence:", args);
				}
			}
			break;
		}
	}
}
channelSocket.onerror = function(ev) {
	window.external.Channel.Error.Data = "WebSocket generic error";
	__messengerjs__.fade.textContent = "encountered a WebSocket error"
	__messengerjs__.fade.style.display = "block";
	Channel_OnDataError();
}
channelSocket.onclose = function() {
	Channel_OnTypeChanged();
}

function createWSEventsNowThatImReady() {
	if(channelSocket.readyState === 1) {
		// if we're already there
		channelSocket.send(new TextEncoder("utf8").encode(EncodeCommandString(["rename"])));
		channelSocket.send(new TextEncoder("utf8").encode(EncodeCommandString(["connect", __messengerjs__.sessionID])));
	}
	channelSocket.onopen = function() {
		channelSocket.send(new TextEncoder("utf8").encode(EncodeCommandString(["rename"])));
		channelSocket.send(new TextEncoder("utf8").encode(EncodeCommandString(["connect", __messengerjs__.sessionID])));
	}
}
/** pure evil **/
__messengerjs__.OnLoadInterrupt = function(ev) {
	document.body.appendChild(__messengerjs__.fade);
	if(new URL(location.href).hash.substring(1).split("=")[0] === "channel") {
		__messengerjs__.sessionID = new URL(location.href).hash.substring(1).split("=")[1];
	} else {
		__messengerjs__.sessionID = Math.random().toString(36).split('.')[1].substring(0,8);
		history.pushState(null, "", `#channel=${__messengerjs__.sessionID}`);
	}
	createWSEventsNowThatImReady();
	__messengerjs__.onloadargs = ev;
}
document.addEventListener("DOMContentLoaded", (event) => {
	// do document.body.onload too since some things suck
	if(typeof document.body.onload === "function") {
		__messengerjs__.onloadfunction = document.body.onload;
	}
	window.onload = __messengerjs__.OnLoadInterrupt;
	Object.defineProperty(window, "onload", {
		set: function onload(fn) {
			__messengerjs__.onloadfunction = fn;
		}
	});
});