bitflyer.js

const app = require('express')();
const server = require('http').Server(app);
const request = require('request');
const io = require('socket.io-client');



server.listen(3005);

app.get('/', function (req, res, err) {
  res.sendfile('/index.html');

  if (err) {
    console.log(err)
  }
});


function getPairs(){
  return new Promise((resolve, reject)=>{
      request('https://api.bitflyer.jp/v1/markets', function(error, res, body){
        if (res.statusCode == 200 && !error){
        var result = JSON.parse(body)
        var pairs = [];
        var i;

        for(i=0; i<result.length; i++){
          if (Object.keys(result[i]).length ==1 && !Object.values(result[i])[0].startsWith('FX')){
              pairs.push("lightning_ticker_"+Object.values(result[i])[0])
          }
        }
      }
        resolve(pairs)
    });
  });
}


async function queryMaker(){
  var pairs = await getPairs()
  const socket = io("https://io.lightstream.bitflyer.com", { transports: ["websocket"] });
  var i;

  socket.on("connect", () => {
     for(i=0; i<pairs.length; i++){
       console.log(pairs[i]);
       socket.emit("subscribe", pairs[i]);
    }
  });

  for(i=0; i<pairs.length; i++){
    socket.on(pairs[i], message => {
      var result = JSON.parse(JSON.stringify(message));
      var pair = result.product_code.replace("_","");
      var price =  result.ltp;
      console.log( { pair, price });
      socket.emit('price_data', { pair, price});
    });
  }
}




queryMaker()