"""Exact notated attacks used to compare arrangements; no audio rendering."""
import fractions
import generator.model
import generator.pitch

def timeline(document):
  events, linked = [], {}
  absolute = fractions.Fraction()
  for measure in document['staves'][0]['measures']:
    for voice in measure['voices']:
      state = {key: measure[key] for key in ('transpose', 'clef', 'staff_details')}
      changes = iter(sorted(measure.get('attributes', []), key=lambda a: generator.model.fraction(a['onset'])))
      change = next(changes, None)
      for note in voice['notes']:
        onset = generator.model.fraction(note['onset'])
        while change is not None and generator.model.fraction(change['onset']) <= onset:
          state.update({key: change[key] for key in state if key in change})
          change = next(changes, None)
        if note.get('cue') or note.get('grace'):
          continue
        for pitch in note['pitches']:
          if pitch.get('cue'):
            continue
          length = generator.model.fraction(pitch['duration'])
          value = generator.pitch.sounding_pitch(pitch, state)
          if pitch.get('tie_from'):
            previous = linked[pitch['tie_from']]
            assert generator.model.fraction(previous['onset']) + generator.model.fraction(previous['duration']) == absolute + onset
            assert generator.model.fraction(previous['pitch']) == value
            previous['duration'] = generator.model.rational(generator.model.fraction(previous['duration']) + length)
            linked[pitch['id']] = previous
          else:
            event = dict(id=pitch['id'], pitch=generator.model.rational(value), onset=generator.model.rational(absolute + onset), duration=generator.model.rational(length))
            events.append(event)
            linked[pitch['id']] = event
    absolute += generator.model.fraction(measure['duration'])
  events.sort(key=lambda e: (generator.model.fraction(e['onset']), e['id']))
  return dict(duration=generator.model.rational(absolute), events=events)