api.js

const fetch = require('node-fetch');
const ccxt = require('ccxt');
const {getOrderBookType} = require('./utils');
const HttpsProxyAgent = require('https-proxy-agent');
// const _ = require('lodash');
const Bottleneck = require('bottleneck');

const bittrex = new ccxt.bittrex();
const binance = new ccxt.binance();
const poloniex = new ccxt.poloniex();

const cache = require('memory-cache');

let proxies = [
    '',
    'http://MyWk3P:TB4SmC@185.232.169.111:9110',
    'http://6WwC7T:jsw6hZ@185.232.168.169:9741',
    'http://P3Mo9t:kgJ9d1@185.232.171.98:9363',
    'http://WWJvXz:9jqYoH@185.233.203.31:9703',
    'http://WWJvXz:9jqYoH@185.233.201.138:9398',
    'http://WWJvXz:9jqYoH@185.233.200.10:9357'
];

const bittrexLimiter = new Bottleneck({
    minTime: 200,
    // maxConcurrent: 1
});
const binanceLimiter = new Bottleneck({
    minTime: 300,
    // maxConcurrent: 3
});

const poloniexLimiter = new Bottleneck({
    minTime: 300,
    // maxConcurrent: 3
});

const bittrexProxyIterator = ProxyIterator(proxies);
const binanceProxyIterator = ProxyIterator(proxies);
const poloniexProxyIterator = ProxyIterator(proxies);


//bittrex 500, один стакан
//binance 1000, оба стакана, передавать глубину вторым аргументом
//kucoin limit не больше 100
//bitfinex null, {limit_bids: 10000, limit_asks: 10000
//poloniex 10000

let counter = 0;
let cacheCounter = 0;

async function getOrderBook(task) {
    const {exchange, currency, bookType} = task;

    let data;

    let proxy;

    const hash = `${exchange}-${currency}-${bookType}`;

    let cachedData = cache.get(hash);

    if (cachedData) {
        // console.log(hash, 'from cache');
        cacheCounter++;
        return cachedData
    }

    // console.log(hash);

    try {

        if (exchange === 'bittrex') {
            proxy = bittrexProxyIterator.next();
            if (proxy) exchange.agent = new HttpsProxyAgent(proxy);

            data = await bittrexLimiter.schedule(() => bittrex.fetchOrderBook(`${currency}/BTC`, null, {type: getOrderBookType(bookType)}));
        }
        if (exchange === 'binance') {
            proxy = binanceProxyIterator.next();
            if (proxy) exchange.agent = new HttpsProxyAgent(proxy);

            data = await binanceLimiter.schedule(() => binance.fetchOrderBook(`${currency}/BTC`, 1000))
        }
        if (exchange === 'poloniex') {
            proxy = poloniexProxyIterator.next();
            if (proxy) exchange.agent = new HttpsProxyAgent(proxy);

            data = await poloniexLimiter.schedule(() => poloniex.fetchOrderBook(`${currency}/BTC`, 1000))
        }
        counter++;

    } catch (e) {
        // console.log(e.message, 'creating recursive request');

        if (e instanceof ccxt.RequestTimeout) {
            console.log(task.exchange, task.currency, 'request timeout');
            return getOrderBook(task);
        } else {
            return console.log(e.message)
        }

    }
    // console.log(hash, proxy);

    let result;

    if (bookType === 1) result = data.bids.length && data.bids;
    if (bookType === 2) result = data.asks.length && data.asks;

    cache.put(hash, result, 50000);

    // console.log(result.length, new Date());
    return result
}


// const exchange = new ccxt.bitfinex();
// const proxyIterator = ProxyIterator(proxies);
// let testCounter = 0;

// setInterval(async () => {
//     const proxy = proxyIterator.next();
//     if (proxy) exchange.agent = new HttpsProxyAgent(proxy);
//
//     try {
//         let data = await exchange.fetchOrderBook('LTC/BTC', null,
//             {limit_asks: 1000, limit_bids: 1000}
//             );
//         let sum = 0;
//         data.bids.forEach(item => {
//             sum += item[0] * item[1]
//         });
//         // console.log((await exchange.fetchOrderBook('LTC/BTC', 1000)).bids.length, proxy) // polo
//         console.log(data.bids.length, sum, proxy); // bittrex
//
//
//         testCounter++;
//     } catch (e) {
//         console.log(e.message, proxy)
//
//     }
// }, 1000);
//
// setInterval(() => {
//     console.log('REQUESTS PER MIN', counter, cacheCounter);
//     counter = 0;
//     cacheCounter = 0;
// }, 60000);


function ProxyIterator(array) {
    let nextIndex = 0;
    let copy = array.slice();

    return {
        next: () => {
            if (nextIndex >= copy.length) nextIndex = 0;
            return copy[nextIndex++]
        }
    }
}


module.exports = {
    getOrderBook
};