'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', net, tls) {
        this.net = net;
        this.tls = tls;
        this.id = 0;
        this.port = port;
        this.host = host;
        this.callback_message_queue = {};
        this.subscribe = new EventEmitter();
        this.conn = initSocket(this, protocol);
        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('Connection to server lost, please retry'));
        }
        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');
        });
    }

    requestObjectBatch(method, params, secondParam) {
        return new Promise((resolve, reject) => {
            let arguments_far_calls = {};
            let contents = [];
            const { key, data } = params;
            if (Array.isArray(data)) {
                for (let item of data) {
                    const id = ++this.id;
                    let param = "";
                    if (key in item) param = item[key];
                    if (secondParam !== undefined) {
                        contents.push(util.makeRequest(method, [param, secondParam], id));
                    } else {
                        contents.push(util.makeRequest(method, [param], id));
                    }
                    arguments_far_calls[id] = { param, data: item };
                }
            } else {
                for (let item of Object.keys(data)) {
                    const id = ++this.id;
                    let param = "";
                    if (key in data[item]) param = data[item][key];
                    if (secondParam !== undefined) {
                        contents.push(util.makeRequest(method, [param, secondParam], id));
                    } else {
                        contents.push(util.makeRequest(method, [param], id));
                    }
                    arguments_far_calls[id] = { param, data: data[item] };
                }
            }
            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');
        });
    }

    requestBatch(method, params, secondParam) {
        if (!this.status) {
            return Promise.reject(new Error('Connection to server lost, please retry'));
        }
        if (typeof params === "object" && "key" in params && "data" in params) {
            return this.requestObjectBatch(method, params, secondParam)
        }
        return new Promise((resolve, reject) => {
            let arguments_far_calls = {};
            let contents = [];
            for (let param of params) {
                const id = ++this.id;
                let data = {};
                if (secondParam !== undefined) {
                    contents.push(util.makeRequest(method, [param, secondParam], id));
                } else {
                    contents.push(util.makeRequest(method, [param], id));
                }
                arguments_far_calls[id] = { param, data };
            }
            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) {
        try {
            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);
                }
            }
        } catch (error) {
            this.conn.end();
            this.conn.destroy();
            this.onClose(error);
        }
    }

    onConnect(){
    }

    onClose(){
        this.status = 0;
        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)
    }

    onError(e){
        console.log('OnError:' + e);
    }
}

module.exports = Client;