var fs = require('fs')
var path = require('path')
var pull = require('pull-stream')
var File = require('pull-file')
var Split = require('pull-split')
var PNG = require('pngjs').PNG
var common = require('./common')

var start = common.startTime
var startDay = Math.floor(start / 86400000)
var startWeek = Math.floor(start / 86400000 / 7)
var startMonth = Math.floor(start / 86400000 / 30.43666666666666666666)
var startT

var now = Date.now()
var nowDay = Math.floor(now / 86400000)
var nowWeek = Math.floor(now / 86400000 / 7)
var nowMonth = Math.floor(now / 86400000 / 30.43666666666666666666)

var series = process.argv[2]
if (!series) throw new TypeError('Missing series argument')

if (series === 'day') {
  width = nowDay - startDay
  startT = startDay
} else if (series === 'week') {
  width = nowWeek - startWeek
  startT = startWeek
} else if (series === 'month') {
  width = nowMonth - startMonth
  startT = startMonth
} else {
  throw new TypeError('Invalid series')
}

var info = JSON.parse(fs.readFileSync(path.join(__dirname, series + '.json')))
var ids = JSON.parse(fs.readFileSync(path.join(__dirname, 'ids.json')))

var width
var height = info.max

var png = new PNG({
  width: width,
  height: height,
  colorType: 6
})

var userColors = common.computeIdColors(ids)
var userNumbers = {}
for (var i = 0; i < ids.length; i++) {
  var id = ids[i]
  userNumbers[id] = i
}

function setPixel(data, x, y, color) {
  var i = (y * width + x) << 2
  data[i] = color[0]
  data[i+1] = color[1]
  data[i+2] = color[2]
  data[i+3] = color[3]
}

function compareIds(a, b) {
  return userNumbers[a] - userNumbers[b]
}

pull(
  File(path.join(__dirname, series + '.jsonp')),
  Split(),
  pull.filter(Boolean),
  pull.map(JSON.parse),
  pull.drain(function (interval) {
    var x = interval.time - startT
    var ids = interval.ids.sort(compareIds)
    for (var i = 0; i < ids.length; i++) {
      var id = ids[i]
      var y = height - i
      var color = userColors[id] || [0, 0, 0, 255]
      setPixel(png.data, x, y, color)
    }
  }, function (err) {
    if (err) throw err
    png.pack().pipe(fs.createWriteStream(series + '.png'))
  })
)