"use strict";

const _ = require("lodash");
const log = require("./log");
const colors = require("chalk");
const fs = require("fs");
const path = require("path");
const Client = require("./client");
const Helper = require("./helper");
const WebPush = require("./plugins/webpush");

module.exports = ClientManager;

function ClientManager() {
	this.clients = [];
}

ClientManager.prototype.init = function(identHandler, sockets) {
	this.sockets = sockets;
	this.identHandler = identHandler;
	this.webPush = new WebPush();

	if (!Helper.config.public && !Helper.config.ldap.enable) {
		this.autoloadUsers();
	}
};

ClientManager.prototype.findClient = function(name) {
	return this.clients.find((u) => u.name === name);
};

ClientManager.prototype.autoloadUsers = function() {
	const users = this.getUsers();
	const noUsersWarning = `There are currently no users. Create one with ${colors.bold("thelounge add <name>")}.`;

	if (users.length === 0) {
		log.info(noUsersWarning);
	}

	users.forEach((name) => this.loadUser(name));

	fs.watch(Helper.getUsersPath(), _.debounce(() => {
		const loaded = this.clients.map((c) => c.name);
		const updatedUsers = this.getUsers();

		if (updatedUsers.length === 0) {
			log.info(noUsersWarning);
		}

		// Reload all users. Existing users will only have their passwords reloaded.
		updatedUsers.forEach((name) => this.loadUser(name));

		// Existing users removed since last time users were loaded
		_.difference(loaded, updatedUsers).forEach((name) => {
			const client = _.find(this.clients, {name});

			if (client) {
				client.quit(true);
				this.clients = _.without(this.clients, client);
				log.info(`User ${colors.bold(name)} disconnected and removed.`);
			}
		});
	}, 1000, {maxWait: 10000}));
};

ClientManager.prototype.loadUser = function(name) {
	const userConfig = readUserConfig(name);

	if (!userConfig) {
		return;
	}

	let client = this.findClient(name);

	if (client) {
		if (userConfig.password !== client.config.password) {
			/**
			 * If we happen to reload an existing client, make super duper sure we
			 * have their latest password. We're not replacing the entire config
			 * object, because that could have undesired consequences.
			 *
			 * @see https://github.com/thelounge/thelounge/issues/598
			 */
			client.config.password = userConfig.password;
			log.info(`Password for user ${colors.bold(name)} was reset.`);
		}
	} else {
		client = new Client(this, name, userConfig);
		this.clients.push(client);
	}

	return client;
};

ClientManager.prototype.getUsers = function() {
	return fs
		.readdirSync(Helper.getUsersPath())
		.filter((file) => file.endsWith(".json"))
		.map((file) => file.slice(0, -5));
};

ClientManager.prototype.addUser = function(name, password, enableLog) {
	if (path.basename(name) !== name) {
		throw new Error(`${name} is an invalid username.`);
	}

	const userPath = Helper.getUserConfigPath(name);

	if (fs.existsSync(userPath)) {
		log.error(`User ${colors.green(name)} already exists.`);
		return false;
	}

	const user = {
		password: password || "",
		log: enableLog,
		awayMessage: "",
		networks: [],
		sessions: {},
		clientSettings: {},
		browser: {},
	};

	try {
		fs.writeFileSync(userPath, JSON.stringify(user, null, "\t"));
	} catch (e) {
		log.error(`Failed to create user ${colors.green(name)} (${e})`);
		throw e;
	}

	return true;
};

ClientManager.prototype.updateUser = function(name, opts, callback) {
	const user = readUserConfig(name);

	if (!user) {
		return callback ? callback(true) : false;
	}

	const currentUser = JSON.stringify(user, null, "\t");
	_.assign(user, opts);
	const newUser = JSON.stringify(user, null, "\t");

	// Do not touch the disk if object has not changed
	if (currentUser === newUser) {
		return callback ? callback() : true;
	}

	try {
		fs.writeFileSync(Helper.getUserConfigPath(name), newUser);
		return callback ? callback() : true;
	} catch (e) {
		log.error(`Failed to update user ${colors.green(name)} (${e})`);

		if (callback) {
			callback(e);
		}
	}
};

ClientManager.prototype.removeUser = function(name) {
	const userPath = Helper.getUserConfigPath(name);

	if (!fs.existsSync(userPath)) {
		log.error(`Tried to remove non-existing user ${colors.green(name)}.`);
		return false;
	}

	fs.unlinkSync(userPath);

	return true;
};

function readUserConfig(name) {
	const userPath = Helper.getUserConfigPath(name);

	if (!fs.existsSync(userPath)) {
		log.error(`Tried to read non-existing user ${colors.green(name)}`);
		return false;
	}

	try {
		const data = fs.readFileSync(userPath, "utf-8");
		return JSON.parse(data);
	} catch (e) {
		log.error(`Failed to read user ${colors.bold(name)}: ${e}`);
	}

	return false;
}