bashcoin.js

#!/usr/bin/env node

/*
 * bashcoin
 * Bitcoin market stats from the command line
 * usage: $ bashcoin [stat]
 * uses Mt.Gox API
 * Dan Motzenbecker
 * MIT License
 */

process.title  = 'bashcoin';
var https      = require('https'),
    bashcoin   = require('commander'),
    req        = false,
    ticker     = null,
    history    = null,
    strikeouts = 0;

bashcoin
  .version('0.1.2')
  .option('-c, --cont', 'run continuously, query every 30 seconds')
  .option('-b, --buy', 'output buy')
  .option('-s, --sell', 'output sell')
  .option('-S, --spread', 'output spread (rounded)')
  .option('-H, --high', 'output high')
  .option('-L, --low', 'output low')
  .option('-a, --avg', 'output average')
  .option('-v, --vol', 'output volume')
  .option('-p, --vwap', 'output volume-weighted average price')
  .option('-l, --last', 'output last')
  .option('-A, --all', 'output all available stats')
  .option('-i, --interval [seconds]', 'custom interval for continuous output')
  .parse(process.argv);

var reqOptions = {
  host:    'data.mtgox.com',
  path:    '/api/2/BTCUSD/money/ticker',
  port:    443,
  headers: {'User-Agent': 'bashcoin'}
}

var terms = ['buy', 'sell', 'high', 'low', 'avg', 'vol', 'vwap', 'last'];

var query = function(){
  req && req.abort();
  req = https.get(reqOptions, function(res) {
    var data = '';
    res.on('data', function(chunk) {
      data += chunk;
    }).on('end', function() {
      try {
        handleStats(JSON.parse(data));
      } catch(e) {
        return outputError(e);
      }
    });
    }
  ).on('error', function(e) {
    outputError(e);
  }).end();
}


var getDelta = function(term) {
  if (bashcoin.cont && history !== null) {
    var delta = 100 - (history[term].value / ticker[term].value * 100);

    if (delta === 0 || isNaN(delta) || !isFinite(delta)) {
      return '';
    }

    delta = delta.toFixed(2);
    if (delta === '0.00') {
      return '';
    }

    if (parseFloat(delta, 10) > 0) {
      return ' \x1b[32m+' + delta + '%\x1b[0m';
    } else {
      return ' \x1b[31m' + delta + '%\x1b[0m';
    }

  } else {
    return '';
  }
}


var handleStats = function(obj) {
  ticker = obj.data;
  console.log('');
  if (!bashcoin.all &&
    (
      (!bashcoin.cont && process.argv.length < 3) ||
      ( bashcoin.cont && process.argv.length < 4)
    )
  ) {
      bashcoin.buy = bashcoin.sell = bashcoin.high = bashcoin.low = true;
  }

  for (var i = 0, len = terms.length; i < len; i++) {
    var term = terms[i];
    if (bashcoin[term] || bashcoin.all) {
      console.log(' ' + term + '\t' + ticker[term].display + getDelta(term));
    }
  }

  if (bashcoin.spread || bashcoin.all) {
    ticker.spread = '$' + (ticker.sell.value - ticker.buy.value).toFixed(2);
    console.log(' spread' + '\t' + ticker.spread + getDelta('spread'));
  }

  history = ticker;
  console.log('');
}


var outputError = function(e) {
  strikeouts++;
  console.error(' \x1b[31msomething went wrong accessing the stats.\x1b[0m\n');
  (!bashcoin.cont || (bashcoin.cont && strikeouts > 4)) && process.exit(1);
}



query();
bashcoin.cont && setInterval(query, bashcoin.interval * 1000 || 30000);