tildefriends/core/app.js

import * as auth from './auth.js';
import * as core from './core.js';

let g_next_id = 1;
let g_calls = {};

let gSessionIndex = 0;

function makeSessionId() {
	return (gSessionIndex++).toString();
}

function App() {
	this._on_output = null;
	this._send_queue = [];
	return this;
}

App.prototype.readOutput = function(callback) {
	this._on_output = callback;
}

App.prototype.makeFunction = function(api) {
	let self = this;
	let id = g_next_id++;
	while (!id || g_calls[id]) {
		id = g_next_id++;
	}
	let promise = new Promise(function(resolve, reject) {
		g_calls[id] = {resolve: resolve, reject: reject};
	});
	let result = function() {
		let message = {
			message: 'tfrpc',
			method: api[0],
			params: [...arguments],
			id: id,
		};
		self.send(message);
		return promise;
	};
	Object.defineProperty(result, 'name', {value: api[0], writable: false});
	return result;
}

App.prototype.send = function(message) {
	if (this._send_queue) {
		if (this._on_output) {
			this._send_queue.forEach(x => this._on_output(x));
			this._send_queue = null;
		} else if (message) {
			this._send_queue.push(message);
		}
	}
	if (message && this._on_output) {
		this._on_output(message);
	}
}

function socket(request, response, client) {
	let process;
	let options = {};
	let credentials = auth.query(request.headers);

	response.onClose = async function() {
		if (process && process.task) {
			process.task.kill();
		}
	}

	response.onError = async function(error) {
		if (process && process.task) {
			process.task.kill();
		}
	}

	response.onMessage = async function(event) {
		if (event.opCode == 0x1 || event.opCode == 0x2) {
			let message;
			try {
				message = JSON.parse(event.data);
			} catch (error) {
				print("ERROR", error, event.data, event.data.length, event.opCode);
				return;
			}
			if (message.action == "hello") {
				let packageOwner;
				let packageName;
				let blobId;
				let match;
				let parentApp;
				if (match = /^\/([&%][^\.]{44}(?:\.\w+)?)(\/?.*)/.exec(message.path)) {
					blobId = match[1];
				} else if (match = /^\/\~([^\/]+)\/([^\/]+)\/$/.exec(message.path)) {
					packageOwner = match[1];
					packageName = match[2];
					blobId = await new Database(packageOwner).get('path:' + packageName);
					if (!blobId) {
						response.send(JSON.stringify({action: "error", error: message.path + ' not found'}), 0x1);
						return;
					}
					if (packageOwner != 'core') {
						let coreId = await new Database('core').get('path:' + packageName);
						parentApp = {
							path: '/~core/' + packageName + '/',
							id: coreId,
						};
					}
				}
				response.send(JSON.stringify({
					action: "session",
					credentials: credentials,
					parentApp: parentApp,
					id: blobId,
				}), 0x1);

				options.api = message.api || [];
				options.credentials = credentials;
				options.packageOwner = packageOwner;
				options.packageName = packageName;
				let sessionId = makeSessionId();
				if (blobId) {
					process = await core.getSessionProcessBlob(blobId, sessionId, options);
				}
				if (process) {
					process.app.readOutput(function(message) {
						response.send(JSON.stringify(message), 0x1);
					});
					process.app.send();
				}

				let ping = function() {
					let now = Date.now();
					let again = true;
					if (now - process.lastActive < process.timeout) {
						// Active.
					} else if (process.lastPing > process.lastActive) {
						// We lost them.
						if (process.task) {
							process.task.kill();
						}
						again = false;
					} else {
						// Idle.  Ping them.
						response.send("", 0x9);
						process.lastPing = now;
					}

					if (again) {
						setTimeout(ping, process.timeout);
					}
				}

				if (process && process.timeout > 0) {
					setTimeout(ping, process.timeout);
				}
			} else if (message.action == 'enableStats') {
				if (process) {
					core.enableStats(process, message.enabled);
				}
			} else if (message.action == 'permission') {
				core.setPermission(process, message.id, message.granted);
			} else if (message.message == 'tfrpc') {
				if (message.id && g_calls[message.id]) {
					if (message.error !== undefined) {
						g_calls[message.id].reject(message.error);
					} else {
						g_calls[message.id].resolve(message.result);
					}
					delete g_calls[message.id];
				}
			} else {
				if (process && process.eventHandlers['message']) {
					await core.invoke(process.eventHandlers['message'], [message]);
				}
			}
		} else if (event.opCode == 0x8) {
			// Close.
			if (process && process.task) {
				process.task.kill();
			}
			response.send(event.data, 0x8);
		} else if (event.opCode == 0xa) {
			// PONG
		}

		if (process) {
			process.lastActive = Date.now();
		}
	}
}

export { socket, App };