const { Client } = require('discord.js');
const escapeRegex = require('escape-string-regexp');

const options = require('../../options.json');

const Registry = require('./Registry.js');
const EventHooker = require('./EventHooker.js');
const Dispatcher = require('./Dispatcher.js');
const Resolver = require('./Resolver.js');
const Logger = require('./Logger.js');
const LocaleLoader = require('../language/LocaleLoader.js');
const RateLimiter = require('./RateLimiter.js');

const StorageManager = require('../storage/StorageManager.js');
const ModerationManager = require('../moderation/ModerationManager.js');

const { Guild, GuildMember, User, Message, TextChannel, Role } = require('../../structure/extensions/'); //eslint-disable-line no-unused-vars
const { Command, Observer, Inhibitor, Setting } = require('../../structure/interfaces/');
const { DefaultGuild, DefaultUser } = require('../../util/defaults/');
const { Emojis } = require('../../util/');

class DiscordClient extends Client {

    constructor(options) {

        super(options.bot.clientOptions);
    
        this.registry = new Registry(this);
        this.eventHooker = new EventHooker(this);
        this.dispatcher = new Dispatcher(this);
        this.resolver = new Resolver(this);
        this.logger = new Logger(this);
        this.localeLoader = new LocaleLoader(this);
        this.rateLimiter = new RateLimiter(this);

        this.storageManager = new StorageManager(this, options.storage);
        this.moderationManager = new ModerationManager(this);

        this._options = options;
        this._built = false;
        this._devOnly = options.devOnly;

        //TODO: Default config for users and guilds.
        this._defaultConfig = {};
        this._permissionCheck = null;

        this._evals = new Map();

        process.on('message', this._handleMessage.bind(this));
        if (this._options.libDebug) this.on('debug', this.logger.debug.bind(this.logger));
        this.on('ready', () => {
            this.user.setActivity(`over ${this.guilds.cache.size} servers.`, { type: 'WATCHING' });
        });

    }

    async build() {

        if(this._built) return undefined;

        const beforeTime = Date.now();
        await super.login(this._options.bot.token);

        this.localeLoader.loadLanguages();

        await this.storageManager.initialize();

        await this.registry.loadComponents('components/inhibitors/', Inhibitor);
        await this.registry.loadComponents('components/commands/', Command);
        await this.registry.loadComponents('components/observers/', Observer);
        await this.registry.loadComponents('components/settings/', Setting);

        await this.moderationManager.initialize();
        await this.dispatcher.dispatch();

        this.logger.info(`Took ${Date.now()-beforeTime}ms to build the client.`);

        this._built = true;
        return this._built;

    }

    format(language, index, parameters = { }, code = false) {

        let template = this.localeLoader.template(language, index); //.languages[language][index];

        for(const emoji of Object.keys(Emojis)) {
            parameters[`emoji_${emoji}`] = Emojis[emoji];
        }

        if(!template) {
            return `**Missing language index \`${language} [${index}]\` in languages. Contact a bot developer about this.**`;
        }

        for (const [param, val] of Object.entries(parameters)) {
            // eslint-disable-next-line require-unicode-regexp
            template = template.replace(new RegExp(`{${escapeRegex(param.toLowerCase())}}`, 'gi'), val);
        }

        if(code) {
            try {
                // eslint-disable-next-line no-eval
                template = eval(template);
            } catch(error) {
                this.client.logger.error(`Error in locale ${language}:${index} while executing code.\n${error.stack || error}`);
            }
        }

        return template;

    }

    async resolveUsers() {

        // eslint-disable-next-line prefer-rest-params
        return this.resolver.resolveUsers(...arguments);

    }

    async resolveUser() {

        // eslint-disable-next-line prefer-rest-params
        return this.resolver.resolveUser(...arguments);

    }

    async _handleMessage(message) {
        //Handle misc. messages.
        if (message._evalResult) this.evalResult(message);
    }

    async managerEval(script) {

        return new Promise((resolve, reject) => {

            this._evals.set(script, { resolve, reject });
            process.send({ _mEval: true, script });

        });

    }

    evalResult({ script, result, error }) {

        const promise = this._evals.get(script);
        if (result) promise.resolve(result);
        else promise.reject(error);
        this._evals.delete(script);

    }

    defaultConfig(type) {
        if(this._defaultConfig[type]) return this._defaultConfig[type];
        const settings = this.registry.components.filter((c) => c.type === 'setting' && c.resolve === type);
        let def = type === 'GUILD' ? DefaultGuild : DefaultUser;
        for(const setting of settings.values()) {
            if(setting.default !== null) {
                def = {
                    ...def,
                    ...setting.default
                };
            }
        }
        this._defaultConfig[type] = def;
        return def;
    
    }

    get permissions() {
        if(this._permissionCheck) return this._permissionCheck;
        return this._permissionCheck = this.registry.components.get('inhibitor:permissions'); //eslint-disable-line no-return-assign
    }

    get prefix() {
        return this._options.prefix;
    }

    get storage() {
        return this.storageManager;
    }

    async aggregateStatistics() {

    }

}

module.exports = DiscordClient;

const client = new DiscordClient(options);
client.build();

process.on("unhandledRejection", (error) => {
    console.error("Unhandled promise rejection:", error); //eslint-disable-line no-console
});