'use strict'
const EventEmitter = require('events').EventEmitter;
const util = require('./util');
const initSocket = require('./init_socket');
const connectSocket = require('./connect_socket');

class Client {
    constructor(port, host, protocol = 'tcp', options = void 0) {
        this.id = 0;
        this.port = port;
        this.host = host;
        this.callback_message_queue = {};
        this.subscribe = new EventEmitter();
        this.conn = initSocket(this, protocol, options);
        this.mp = new util.MessageParser((body, n) => {
            this.onMessage(body, n);
        });
        this.status = 0
    }

    async connect() {
	    if(this.status) {
		    return Promise.resolve({ error: false, data: "" });
	    }
	    const connectionResponse = await connectSocket(this.conn, this.port, this.host);
	    this.status = connectionResponse.error === true ? 0 : 1;
	    return Promise.resolve(connectionResponse);
    }

    close(){
        if (!this.status) {
            return;
        }
        this.conn.end();
        this.conn.destroy();
        this.status = 0;
    }

    request(method, params) {
        if (!this.status) {
            return Promise.reject(new Error('ESOCKET'));
        }
        return new Promise((resolve, reject) => {
            const id = ++this.id;
            const content = util.makeRequest(method, params, id);
            this.callback_message_queue[id] = util.createPromiseResult(resolve, reject);
            this.conn.write(content + '\n');
        });
    }
    
    requestBatch(method, params, secondParam) {
        if (!this.status) {
            return Promise.reject(new Error('ESOCKET'));
        }
        return new Promise((resolve, reject) => {
            let arguments_far_calls = {};
            let contents = [];
            for (let param of params) {
                const id = ++this.id;
                if (secondParam !== undefined) {
                    contents.push(util.makeRequest(method, [param, secondParam], id));
                } else {
                    contents.push(util.makeRequest(method, [param], id));
                }
                arguments_far_calls[id] = param;
            }
            const content = '[' + contents.join(',') + ']';
            this.callback_message_queue[this.id] = util.createPromiseResultBatch(resolve, reject, arguments_far_calls);
            // callback will exist only for max id
            this.conn.write(content + '\n');
        });
    }
    
    response(msg) {
        let callback;
        if (!msg.id && msg[0] && msg[0].id) {
            // this is a response from batch request
            for (let m of msg) {
                if (m.id && this.callback_message_queue[m.id]) {
                    callback = this.callback_message_queue[m.id];
                    delete this.callback_message_queue[m.id];
                }
            }
        } else {
            callback = this.callback_message_queue[msg.id];
        }
        
        if (callback) {
            delete this.callback_message_queue[msg.id];
            if (msg.error) {
                callback(msg.error);
            } else {
                callback(null, msg.result || msg);
            }
        } else {
            console.log("Can't get callback"); // can't get callback
        }
    }

    onMessage(body, n){
        const msg = JSON.parse(body);
        if (msg instanceof Array) {
            this.response(msg);
        } else {
            if (msg.id !== void 0) {
                this.response(msg)
            } else {
                this.subscribe.emit(msg.method, msg.params);
            }
        }
    }

    onConnect(){
    }

    onClose(){
        Object.keys(this.callback_message_queue).forEach((key) => {
            this.callback_message_queue[key](new Error('close connect'))
            delete this.callback_message_queue[key]
        })
    }

    onRecv(chunk){
        this.mp.run(chunk)
    }

    onEnd(){
    }

    onError(e){
    }

}

module.exports = Client;