/*
 * MIDI Dump - Parse and print MIDI file contents
 *
 * Usage: cell run examples/dump.ce <midi_file>
 */

var io = use('cellfs')
var midi = use('midi')

if (length(args) < 1) {
  log.console("Usage: cell run examples/dump.ce <midi_file>")
  log.console("Example: cell run examples/dump.ce examples/invent8.mid")
  $stop()
}

var midi_file = args[0]

log.console("Loading MIDI: " + midi_file)
var midi_blob = io.slurp(midi_file)
if (!midi_blob) {
  log.console("Error: Could not load MIDI file: " + midi_file)
  $stop()
}

var song = midi.parse(midi_blob)

log.console("Duration: " + text((song.duration_ms / 1000)) + "s")
log.console("Notes: " + text(song.note_count))
log.console("Events: " + text(length(song.events)))
log.console("")

var NOTE_NAMES = ['C', 'C#', 'D', 'D#', 'E', 'F', 'F#', 'G', 'G#', 'A', 'A#', 'B']

function note_name(key) {
  var octave = floor(key / 12) - 1
  var name = NOTE_NAMES[key % 12]
  return name + text(octave)
}

function pad(s, n) {
  var _s = text(s)
  while (length(_s) < n) {
    _s = _s + ' '
  }
  return _s
}

var events = song.events
var i = 0
var evt = null
var line = ''

for (i = 0; i < length(events); i++) {
  evt = events[i]
  line = pad(text(evt.time / 1000) + 's', 10)
  line = line + 'ch=' + pad(evt.channel, 4)

  if (evt.type == 'note_on') {
    line = line + pad('note_on', 12) + note_name(evt.key) + ' vel=' + text(evt.velocity)
  } else if (evt.type == 'note_off') {
    line = line + pad('note_off', 12) + note_name(evt.key)
  } else if (evt.type == 'control') {
    line = line + pad('control', 12) + 'cc=' + text(evt.control) + ' val=' + text(evt.value)
  } else if (evt.type == 'program') {
    line = line + pad('program', 12) + 'preset=' + text(evt.program)
  } else if (evt.type == 'pitch_bend') {
    line = line + pad('pitch_bend', 12) + 'val=' + text(evt.pitch_bend)
  } else if (evt.type == 'tempo') {
    line = line + pad('tempo', 12) + 'bpm=' + text(evt.tempo)
  }

  log.console(line)
}