'use strict'

// `node diffMultiBenchOutput.js beforeBench.txt afterBench.txt`

var fs = require('fs')
var file1 = process.argv[2]
var file2 = process.argv[3]

if (!file1 || !file2) {
  console.log('Please supply two file arguments:')
  var n = __filename
  n = n.substring(n.lastIndexOf('/', n.length))
  console.log('    node .' + n + ' benchBefore.txt benchAfter.txt\n')
  console.log('To generate the benchmark files, run')
  console.log('    npm run benchmark > benchBefore.txt\n')
  console.log('Thank you for benchmarking responsibly.')
  process.exit(1)
}

var beforeLines = fs.readFileSync(file1, 'utf8').split('\n')
var afterLines = fs.readFileSync(file2, 'utf8').split('\n')

console.log('Comparing before,', file1, '(', beforeLines.length, 'lines)', 'to after,', file2, '(', afterLines.length, 'lines)')

function isWhitespace (s) {
  return !!s.trim()
}

function pad (input, len, chr, right) {
  var str = input.toString()
  chr = chr || ' '

  if (right) {
    while (str.length < len) {
      str += chr
    }
  } else {
    while (str.length < len) {
      str = chr + str
    }
  }
  return str
}

// green if greater than 0, red otherwise
function humanizeDiff (num, unit, toFixed) {
  unit = unit || ''
  if (num > 0) {
    return ' +' + pad(num.toFixed(toFixed || 0) + unit, 7)
  }
  return ' -' + pad(Math.abs(num).toFixed(toFixed || 0) + unit, 7)
}

function commandName (words) {
  var line = words.join(' ')
  return line.substr(0, line.indexOf(','))
}

beforeLines.forEach(function (b, i) {
  var a = afterLines[i]
  if (!a || !b || !b.trim() || !a.trim()) {
    // console.log('#ignored#', '>'+a+'<', '>'+b+'<');
    return
  }
  var bWords = b.split(' ').filter(isWhitespace)
  var aWords = a.split(' ').filter(isWhitespace)

  var ops = [bWords, aWords].map(function (words) {
    // console.log(words);
    return words.slice(-2, -1) | 0
  }).filter(function (num) {
    var isNaN = !num && num !== 0
    return !isNaN
  })
  if (ops.length !== 2) {
    return
  }
  var delta = ops[1] - ops[0]
  var pct = +((delta / ops[0]) * 100)
  ops[0] = pad(ops[0], 6)
  ops[1] = pad(ops[1], 6)
  delta = humanizeDiff(delta)
  var smallDelta = pct < 3 && pct > -3
  // Let's mark differences above 20% bold
  var bigDelta = pct > 20 || pct < -20 ? ';1' : ''
  pct = humanizeDiff(pct, '', 2) + '%'
  var str = pad((commandName(aWords) === commandName(bWords) ? commandName(aWords) + ':' : '404:'), 14, false, true) +
        (pad(ops.join(' -> '), 15) + ' ops/sec (∆' + delta + pct + ')')
  str = (smallDelta ? '' : (/-[^>]/.test(str) ? '\x1b[31' : '\x1b[32') + bigDelta + 'm') + str + '\x1b[0m'
  console.log(str)
})