const io = require('socket.io-client');
const EventEmitter = require('events');

class GatewayConnection extends EventEmitter {
    constructor(url) {
        super();
        this.isConnected = false;
        this.socket = null;
        this.url = url;
    }
}

GatewayConnection.prototype.disconnect = function() {
    if (this.socket) this.socket.disconnect();
    this.socket = null;
    this.isConnected = false;
};

GatewayConnection.prototype.connect = function(token) {
    console.log('[*] [gateway] [handshake] Trying to connect to gateway');
    this.socket = io(`${this.url}/gateway`, {
        query: {
            token
        },
        transports: ['websocket']
    });

    this.socket.on('connect', () => {
        this.socket.once('hello', (debugInfo) => {
            console.log('[*] [gateway] [handshake] Got hello from server, sending yoo...', debugInfo);
            this.socket.emit('yoo');
            this.isConnected = true;
            this.debugInfo = debugInfo;
            this.emit('connect', { message: 'CONNECT_RECEIVED_HELLO' });
            console.log('[*] [gateway] [handshake] Assuming that server received yoo and that connection is completed.');
        });
    })

    this.socket.on('error', (e) => {
        console.log('[E] [gateway] Gateway error', e);
        this.isConnected = false;
        this.socket = null;
        this.emit('disconnect', { message: 'DISCONNECT_ERR' });
    });
    this.socket.on('disconnectNotification', (e) => {
        console.log('[E] [gateway] Received disconnect notfication', e);
        this.isConnected = false;
        this.socket = null;
        this.emit('disconnect', { message: 'DISCONNECT_NOTIF', reason: e });
    });
    this.socket.on('disconnect', (e) => {
        console.log('[E] [gateway] Disconnected from gateway: ', e);
        this.isConnected = false;
        this.emit('disconnect', { message: 'DISCONNECT', reason: e });
    });

    this.socket.on('message', (e) => this.emit('message', e));
    this.socket.on('refreshClient', (e) => this.emit('refreshClient', e));
    this.socket.on('clientListUpdate', (e) => this.emit('clientListUpdate', e));
};

GatewayConnection.prototype.sendMessage = function(categoryId, content, { nickAuthor, destUser }) {
    if (!this.isConnected) return 1;
    if (content.length >= 2000) return 1;

    this.socket.emit('message', {
        category: {
            _id: categoryId
        },
        nickAuthor,
        destUser,
        content
    });
};

GatewayConnection.prototype.subscribeToCategoryChat = function(categoryId) {
    if (!this.isConnected) return;

    const request = [categoryId];

    console.log('[*] [gateway] Subscribing to channel(s)', request);

    this.socket.emit('subscribe', request);

    return categoryId;
};

module.exports = GatewayConnection;