"use strict";

var auth = require("auth");
var app = require("app");

var gProcessIndex = 0;
var gProcesses = {};
var gSessionIndex = 0;
var gStatsTimer = false;

var gGlobalSettings = {
	index: "/~core/index",
};

var kGlobalSettingsFile = "data/global/settings.json";

var kPingInterval = 60 * 1000;

function getCookies(headers) {
	var cookies = {};

	if (headers.cookie) {
		var parts = headers.cookie.split(/,|;/);
		for (var i in parts) {
			var equals = parts[i].indexOf("=");
			var name = parts[i].substring(0, equals).trim();
			var value = parts[i].substring(equals + 1).trim();
			cookies[name] = value;
		}
	}

	return cookies;
}

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

function printError(out, error) {
	if (error.stackTrace) {
		out.print(error.fileName + ":" + error.lineNumber + ": " + error.message);
		out.print(error.stackTrace);
	} else {
		for (var i in error) {
			out.print(i);
		}
		out.print(error.toString());
	}
}

function invoke(handlers, argv) {
	var promises = [];
	if (handlers) {
		for (var i = 0; i < handlers.length; ++i) {
			try {
				promises.push(handlers[i](...argv));
			} catch (error) {
				handlers.splice(i, 1);
				i--;
				promises.push(new Promise(function(resolve, reject) { reject(error); }));
			}
		}
	}
	return Promise.all(promises);
}

function broadcastEvent(eventName, argv) {
	var promises = [];
	for (var i in gProcesses) {
		var process = gProcesses[i];
		if (process.eventHandlers[eventName]) {
			promises.push(invoke(process.eventHandlers[eventName], argv));
		}
	}
	return Promise.all(promises);
}

function broadcast(message) {
	var sender = this;
	var promises = [];
	for (var i in gProcesses) {
		var process = gProcesses[i];
		if (process != sender
			&& process.packageOwner == sender.packageOwner
			&& process.packageName == sender.packageName) {
			var from = getUser(process, sender);
			promises.push(postMessageInternal(from, process, message));
		}
	}
	return Promise.all(promises);
}

function getUser(caller, process) {
	return {
		name: process.userName,
		key: process.key,
		index: process.index,
		packageOwner: process.packageOwner,
		packageName: process.packageName,
		credentials: process.credentials,
		postMessage: postMessageInternal.bind(caller, caller, process),
	};
}

function getApps(user, process) {
	if (process.credentials &&
		process.credentials.session &&
		process.credentials.session.name) {
		if (user && user !== process.credentials.session.name && user !== 'core') {
			return {};
		} else if (!user) {
			user = process.credentials.session.name;
		}
	}
	if (user) {
		var db = new Database(user);
		try {
			var names = JSON.parse(db.get('apps'));
			return Object.fromEntries(names.map(name => [name, db.get('path:' + name)]));
		} catch {
		}
	}
	return {};
}

function postMessageInternal(from, to, message) {
	if (to.eventHandlers['message']) {
		return invoke(to.eventHandlers['message'], [getUser(from, from), message]);
	}
}

async function getSessionProcessBlob(blobId, session, options) {
	var actualOptions = {timeout: kPingInterval};
	if (options) {
		for (var i in options) {
			actualOptions[i] = options[i];
		}
	}
	return getProcessBlob(blobId, 'session_' + session, actualOptions);
}

let gManifestCache = {};

async function getProcessBlob(blobId, key, options) {
	var process = gProcesses[key];
	if (!process
		&& !(options && "create" in options && !options.create)) {
		try {
			print("Creating task for " + blobId + " " + key);
			process = {};
			process.key = key;
			process.index = gProcessIndex++;
			process.userName = 'user' + process.index;
			process.credentials = options.credentials || {};
			process.task = new Task();
			process.eventHandlers = {};
			process.app = new App();
			process.lastActive = Date.now();
			process.lastPing = null;
			process.timeout = options.timeout;
			process.stats = false;
			var resolveReady;
			var rejectReady;
			process.ready = new Promise(function(resolve, reject) {
				resolveReady = resolve;
				rejectReady = reject;
			});
			gProcesses[key] = process;
			process.task.onExit = function(exitCode, terminationSignal) {
				broadcastEvent('onSessionEnd', [getUser(process, process)]);
				process.task = null;
				delete gProcesses[key];
			};
			var imports = {
				'core': {
					'broadcast': broadcast.bind(process),
					'register': function(eventName, handler) {
						if (!process.eventHandlers[eventName]) {
							process.eventHandlers[eventName] = [];
						}
						process.eventHandlers[eventName].push(handler);
					},
					'unregister': function(eventHandle, handler) {
						if (process.eventHandlers[eventName]) {
							let index = process.eventHandlers[eventName].indexOf(handler);
							if (index != -1) {
								process.eventHandlers[eventName].splice(index, 1);
							}
							if (process.eventHandlers[eventName].length == 0) {
								delete process.eventHandlers[eventName];
							}
						}
					},
					'user': getUser(process, process),
					'apps': user => getApps(user, process),
				}
			};
			if (options.api) {
				imports.app = {};
				for (let i in options.api) {
					let api = options.api[i];
					imports.app[api[0]] = process.app.makeFunction(api);
				}
			}
			process.task.onPrint = function(args) {
				process.app.send({action: 'print', args: args});
			};
			process.task.onError = function(error) {
				try {
					process.app.send({action: 'error', error: error});
				} catch(e) {
					print(e);
				}
			};
			imports.ssb = Object.fromEntries(Object.keys(ssb).map(key => [key, ssb[key].bind(ssb)]));
			if (process.credentials &&
				process.credentials.session &&
				process.credentials.session.name) {
				imports.database = function(key) {
					var db = new Database(process.credentials.session.name + ':' + key);
					return Object.fromEntries(Object.keys(db).map(x => [x, db[x].bind(db)]));
				};
			}
			process.task.setImports(imports);
			process.task.activate();
			let source = await getBlobOrContent(blobId);
			var appSourceName = blobId;
			var appSource = utf8Decode(source);
			try {
				var app = JSON.parse(appSource);
				if (app.type == "tildefriends-app") {
					appSourceName = 'app.js';
					var id = app.files[appSourceName];
					var blob = await getBlobOrContent(id);
					appSource = utf8Decode(blob);
					await Promise.all(Object.keys(app.files).map(async function(f) {
						await process.task.loadFile([f, await getBlobOrContent(app.files[f])]);
					}));
				}
			} catch (e) {
				printError({print: print}, e);
			}
			broadcastEvent('onSessionBegin', [getUser(process, process)]);
			resolveReady(process);
			if (process.app) {
				process.app.send({action: "ready"});
			}
			await process.task.execute({name: appSourceName, source: appSource});
		} catch (error) {
			if (process.app) {
				process.app.send({action: 'error', error: error});
			} else {
				printError({print: print}, error);
			}
			rejectReady();
		}
	}
	return process;
}

function setGlobalSettings(settings) {
	gGlobalSettings = settings;
	try {
		return new Database('core').set('settings', JSON.stringify(settings));
	} catch (error) {
		print('Error storing settings:', error);
	}
}

var kStaticFiles = [
	{uri: '/', path: 'index.html', type: 'text/html; charset=UTF-8'},
	{uri: '/style.css', type: 'text/css; charset=UTF-8'},
	{uri: '/favicon.png', type: 'image/png'},
	{uri: '/client.js', type: 'text/javascript; charset=UTF-8'},
	{uri: '/robots.txt', type: 'text/plain; charset=UTF-8'},

	{uri: '/split.min.js'},
	{uri: '/split.min.js.map'},
	{uri: '/smoothie.js'},
	{uri: '/codemirror/codemirror.min.js'},
	{uri: '/codemirror/base16-dark.min.css'},
	{uri: '/codemirror/matchesonscrollbar.min.css'},
	{uri: '/codemirror/dialog.min.css'},
	{uri: '/codemirror/codemirror.min.css'},
	{uri: '/codemirror/trailingspace.min.js'},
	{uri: '/codemirror/dialog.min.js'},
	{uri: '/codemirror/search.min.js'},
	{uri: '/codemirror/searchcursor.min.js'},
	{uri: '/codemirror/jump-to-line.min.js'},
	{uri: '/codemirror/matchesonscrollbar.min.js'},
	{uri: '/codemirror/annotatescrollbar.min.js'},
	{uri: '/codemirror/javascript.min.js'},
	{uri: '/codemirror/css.min.js'},
	{uri: '/codemirror/xml.min.js'},
	{uri: '/codemirror/htmlmixed.min.js'},
];

function startsWithBytes(data, bytes) {
	if (data.byteLength >= bytes.length) {
		var dataBytes = new Uint8Array(data.slice(0, bytes.length));
		for (var i = 0; i < bytes.length; i++) {
			if (dataBytes[i] != bytes[i] && bytes[i] !== null) {
				return;
			}
		}
		return true;
	}
}

async function staticFileHandler(request, response, blobId, uri) {
	for (var i in kStaticFiles) {
		if (uri === kStaticFiles[i].uri) {
			var path = kStaticFiles[i].path || uri.substring(1);
			var type = kStaticFiles[i].type || guessType(path);
			var data = await File.readFile("core/" + path);
			response.writeHead(200, {"Content-Type": type, "Content-Length": data.byteLength});
			response.end(data);
			return;
		}
	}

	response.writeHead(404, {"Content-Type": "text/plain; charset=utf-8", "Content-Length": "File not found".length});
	response.end("File not found");
}

const k_mime_types = {
	'json': 'text/json',
	'js': 'text/javascript',
	'html': 'text/html',
	'css': 'text/css',
	'map': 'application/json',
};

async function perfettoHandler(request, response, uri) {
	var filename = uri || 'index.html';
	if (filename.indexOf('..') != -1) {
		response.writeHead(404, {"Content-Type": "text/plain; charset=utf-8", "Content-Length": "File not found".length});
		response.end("File not found");
		return;
	}

	try {
		var data = await File.readFile("deps/perfetto/" + filename);
		response.writeHead(200, {"Content-Type": k_mime_types[filename.split('.').pop()] || 'text/plain', "Content-Length": data.byteLength});
		response.end(data);
	} catch {
		response.writeHead(404, {"Content-Type": "text/plain; charset=utf-8", "Content-Length": "File not found".length});
		response.end("File not found");
	}
}

async function wellKnownHandler(request, response, path) {
	var data = await File.readFile("data/global/.well-known/" + path);
	if (data) {
		response.writeHead(200, {"Content-Type": "text/plain", "Content-Length": data.length});
		response.end(data);
	} else {
		response.writeHead(404, {"Content-Type": "text/plain", "Content-Length": "File not found".length});
		response.end("File not found");
	}
}

function sendData(response, data, type, headers) {
	if (data) {
		if (startsWithBytes(data, [0xff, 0xd8, 0xff, 0xdb]) ||
			startsWithBytes(data, [0xff, 0xd8, 0xff, 0xe0, 0x00, 0x10, 0x4a, 0x46, 0x49, 0x46, 0x00, 0x01]) ||
			startsWithBytes(data, [0xff, 0xd8, 0xff, 0xee]) ||
			startsWithBytes(data, [0xff, 0xd8, 0xff, 0xe1, null, null, 0x45, 0x78, 0x69, 0x66, 0x00, 0x00])) {
			response.writeHead(200, Object.assign({"Content-Type": "image/jpeg", "Content-Length": data.byteLength}, headers || {}));
			response.end(data);
		} else if (startsWithBytes(data, [0x89, 0x50, 0x4e, 0x47, 0x0d, 0x0a, 0x1a, 0x0a])) {
			response.writeHead(200, Object.assign({"Content-Type": "image/png", "Content-Length": data.byteLength}, headers || {}));
			response.end(data);
		} else if (startsWithBytes(data, [0x47, 0x49, 0x46, 0x38, 0x37, 0x61]) ||
			startsWithBytes(data, [0x47, 0x49, 0x46, 0x38, 0x39, 0x61])) {
			response.writeHead(200, Object.assign({"Content-Type": "image/gif", "Content-Length": data.byteLength}, headers || {}));
			response.end(data);
		} else {
			response.writeHead(200, Object.assign({"Content-Type": type || "text/javascript; charset=utf-8", "Content-Length": data.byteLength}, headers || {}));
			response.end(data);
		}
	} else {
		response.writeHead(404, Object.assign({"Content-Type": "text/plain; charset=utf-8", "Content-Length": "File not found".length}, headers || {}));
		response.end("File not found");
	}
}

async function getBlobOrContent(id) {
	if (!id) {
		return;
	} else if (id.startsWith('&')) {
		return ssb.blobGet(id);
	} else if (id.startsWith('%')) {
		return ssb.messageContentGet(id);
	}
}

function guessType(path) {
	const k_extension_to_type = {
		'css': 'text/css',
		'html': 'text/html',
		'js': 'text/javascript',
	};
	var extension = path.split('.').pop();
	return k_extension_to_type[extension];
}

async function blobHandler(request, response, blobId, uri) {
	var found = false;
	if (!found) {
		for (var i in kStaticFiles) {
			if (uri === kStaticFiles[i].uri) {
				found = true;
				var data = await File.readFile("core/" + kStaticFiles[i].path);
				response.writeHead(200, {"Content-Type": kStaticFiles[i].type, "Content-Length": data.byteLength});
				response.end(data);
				break;
			}
		}
	}

	if (!uri) {
		response.writeHead(303, {"Location": (request.client.tls ? 'https://' : 'http://') + request.headers.host + blobId + '/', "Content-Length": "0"});
		response.end(data);
		return;
	}

	if (!found) {
		var process;
		if (uri == "/view") {
			var data;
			if (match = /^\/\~(\w+)\/(\w+)$/.exec(blobId)) {
				var id = await new Database(match[1]).get('path:' + match[2]);
				if (id) {
					if (request.headers['if-none-match'] && request.headers['if-none-match'] == '"' + id + '"') {
						response.writeHead(304, {});
						response.end();
					} else {
						data = await getBlobOrContent(id);
						if (match[3]) {
							var app = JSON.parse(data);
							data = app.files[match[3]];
						}
						sendData(response, data, undefined, {etag: '"' + id + '"'});
					}
				} else {
					sendData(response, data);
				}
			} else {
				data = await getBlobOrContent(blobId);
				sendData(response, data);
			}
		} else if (uri == "/save") {
			let newBlobId = await ssb.blobStore(request.body);

			var match;
			if (match = /^\/\~(\w+)\/(\w+)$/.exec(blobId)) {
				var user = match[1];
				var app = match[2];
				var credentials = auth.query(request.headers);
				if (credentials && credentials.session &&
					(credentials.session.name == user ||
					(credentials.permissions.administration && user == 'core'))) {
					var database = new Database(user);
					var apps = new Set();
					try {
						apps = new Set(JSON.parse(database.get('apps')));
					} catch {
					}
					if (!apps.has(app)) {
						apps.add(app);
						database.set('apps', JSON.stringify([...apps]));
					}
					database.set('path:' + app, newBlobId);
				} else {
					response.writeHead(401, {"Content-Type": "text/plain; charset=utf-8"});
					response.end("401 Unauthorized");
					return;
				}
			}

			response.writeHead(200, {"Content-Type": "text/plain; charset=utf-8"});
			response.end("/" + newBlobId);
		} else {
			var data;
			var type;
			var headers;
			if (match = /^\/\~(\w+)\/(\w+)$/.exec(blobId)) {
				var db = new Database(match[1]);
				var id = await db.get('path:' + match[2]);
				if (id) {
					if (request.headers['if-none-match'] && request.headers['if-none-match'] == '"' + id + '"') {
						response.writeHead(304, {});
						response.end();
					} else {
						data = utf8Decode(await getBlobOrContent(id));
						var app = JSON.parse(data);
						data = app.files[uri.substring(1)];
						data = await getBlobOrContent(data);
						type = guessType(uri);
						headers = {'ETag': '"' + id + '"'};
						sendData(response, data, type, headers);
					}
				} else {
					sendData(response, data, type, headers);
				}
			} else {
				data = utf8Decode(await getBlobOrContent(blobId));
				var app = JSON.parse(data);
				data = app.files[uri.substring(1)];
				data = await getBlobOrContent(data);
				sendData(response, data, type, headers);
			}
		}
	}
}

ssb.addEventListener('broadcasts', function() {
	broadcastEvent('onBroadcastsChanged', []);
});

ssb.addEventListener('connections', function() {
	broadcastEvent('onConnectionsChanged', []);
});

async function loadSettings() {
	var data;

	try {
		var settings = new Database('core').get('settings');
		if (settings) {
			data = JSON.parse(settings);
		}
	} catch (error) {
		print("Settings not found in database:", error);
	}

	if (!data) {
		try {
			data = JSON.parse(utf8Decode(await File.readFile(kGlobalSettingsFile)));
			new Database('core').set('settings', JSON.stringify(data));
		} catch (error) {
			print("Unable to load settings from " + kGlobalSettingsFile + ":", error);
		}
	}

	if (data) {
		gGlobalSettings = data;
	}
}

function sendStats() {
	var any = false;
	for (var process of Object.values(gProcesses)) {
		if (process.app && process.stats) {
			process.app.send({action: 'stats', stats: getStats()});
			any = true;
		}
	}

	if (any) {
		setTimeout(sendStats, 1000);
	} else {
		gStatsTimer = false;
	}
}

loadSettings().then(function() {
	var auth = require("auth");
	var httpd = require("httpd");
	httpd.all("/login", auth.handler);
	httpd.all("", function(request, response) {
		var match;
		if (request.uri === "/" || request.uri === "") {
			response.writeHead(303, {"Location": (request.client.tls ? 'https://' : 'http://') + request.headers.host + gGlobalSettings.index, "Content-Length": "0"});
			return response.end();
		} else if (match = /^(\/~[^\/]+\/[^\/]+)(\/?.*)$/.exec(request.uri)) {
			return blobHandler(request, response, match[1], match[2]);
		} else if (match = /^\/([&\%][^\.]{44}(?:\.\w+)?)(\/?.*)/.exec(request.uri)) {
			return blobHandler(request, response, match[1], match[2]);
		} else if (match = /^\/static(\/.*)/.exec(request.uri)) {
			return staticFileHandler(request, response, null, match[1]);
		} else if (match = /^\/perfetto\/([\.\w-/]*)$/.exec(request.uri)) {
			return perfettoHandler(request, response, match[1]);
		} else if (match = /^(.*)(\/save?)$/.exec(request.uri)) {
			return blobHandler(request, response, match[1], match[2]);
		} else if (match = /^\/trace$/.exec(request.uri)) {
			var data = trace();
			response.writeHead(200, {"Content-Type": "application/json; charset=utf-8", "Content-Length": data.length.toString()});
			return response.end(data);
		} else if (request.uri == "/robots.txt") {
			return blobHandler(request, response, null, request.uri);
		} else if ((match = /^\/.well-known\/(.*)/.exec(request.uri)) && request.uri.indexOf("..") == -1) {
			return wellKnownHandler(request, response, match[1]);
		} else {
			var data = "File not found.";
			response.writeHead(404, {"Content-Type": "text/plain; charset=utf-8", "Content-Length": data.length.toString()});
			return response.end(data);
		}
	});
	httpd.registerSocketHandler("/app/socket", app.socket);
}).catch(function(error) {
	print('Failed to load settings.');
});