"""Score document validation, above pure musical values and instrument rules."""
from __future__ import annotations
import fractions

import generator.fretboard
import generator.model
import generator.pitch

def validate_document(document: dict) -> None:
  if not isinstance(document, dict) or not isinstance(document.get('metadata'), dict):
    raise ValueError('score requires a metadata object')
  if any(not isinstance(document['metadata'].get(name), str) for name in ('title', 'composer', 'key_signature', 'time_signature')):
    raise ValueError('score metadata requires title, composer, key_signature and time_signature strings')
  staves = document.get('staves', [])
  if not isinstance(staves, list) or len(staves) != 1 or not isinstance(staves[0], dict):
    raise ValueError('exactly one staff is currently supported')
  if not isinstance(staves[0].get('measures'), list) or not staves[0]['measures']:
    raise ValueError('score requires measures')
  instruments = staves[0].get('instruments', [])
  instrument_ids = {i['id'] for i in instruments}
  if len(instruments) != len(instrument_ids) or any(not isinstance(i, str) or not i for i in instrument_ids):
    raise ValueError('score instruments require unique nonempty IDs')
  ids: set[str] = set()
  events: dict[str, dict] = {}
  tones: dict[str, tuple[dict, fractions.Fraction, fractions.Fraction, str]] = {}
  ownership: dict[str, str] = {}
  absolute = fractions.Fraction()
  for measure in staves[0]['measures']:
    if {'repeats', 'endings', 'initial_attributes'} & measure.keys():
      raise ValueError('repeat notation is unsupported; regenerate scores from music written out in reading order')
    length = generator.model.fraction(measure['duration'])
    if length <= 0:
      raise ValueError('measure duration must be positive')
    voices = measure.get('voices', [])
    if not voices or len({v['id'] for v in voices}) != len(voices) or any(not v['id'] for v in voices):
      raise ValueError('measure requires uniquely identified voice lanes')
    previous_ends = {v['id']: fractions.Fraction() for v in voices}
    for voice, note in ((v, n) for v in voices for n in v['notes']):
      if any({'sound_ties', 'printed_ties'} & pitch.keys() for pitch in note['pitches']):
        raise ValueError('pass-specific tie metadata is unsupported; regenerate scores')
      if not note['id'] or note['id'] in ids:
        raise ValueError(f'duplicate event ID: {note["id"]}')
      ids.add(note['id'])
      events[note['id']] = note
      ownership[note['id']] = voice['id']
      if note.get('voice', voice['id']) != voice['id']:
        raise ValueError('event voice ownership disagrees with its lane')
      onset, duration = generator.model.fraction(note['onset']), generator.model.fraction(note['duration'])
      if onset < 0 or duration < 0 or onset + duration > length:
        raise ValueError(f'event outside measure: {note["id"]}')
      if note['kind'] not in ('note', 'rest', 'spacer'):
        raise ValueError('invalid event kind')
      if not note.get('grace'):
        if duration == 0 or onset < previous_ends[voice['id']]:
          raise ValueError('overlapping events in one rhythmic voice')
        previous_ends[voice['id']] = onset + duration
      elif duration != 0:
        raise ValueError('grace notes must not advance metric time')
      expected = generator.model.metric_length(note['written'])
      if not note.get('grace') and not note.get('measure_rest') and duration != expected:
        raise ValueError('metric and written event durations disagree')
      if note['kind'] != 'note' and note.get('pitches'):
        raise ValueError('rests and spacers cannot contain pitches')
      if note['kind'] == 'note' and not note.get('pitches') and note.get('notehead') != 'slash':
        raise ValueError('pitched event requires at least one pitch')
      for p in note.get('pitches', []):
        if p.get('instrument') and p['instrument'] not in instrument_ids:
          raise ValueError('note refers to an unknown score instrument')
        if 'unpitched' in p:
          position = p['unpitched']
          if position['letter'] not in generator.model.LETTERS or type(position['octave']) is not int:
            raise ValueError('invalid unpitched display position')
        else:
          generator.model.pitch_number(p)
        if staves[0].get('tablature'):
          tab = p.get('tablature', {})
          string, fret = tab.get('string'), tab.get('fret')
          if type(string) is not int or type(fret) is not int or string not in dict(generator.fretboard.STANDARD_TUNING) or not generator.fretboard.MIN_FRET <= fret <= generator.fretboard.MAX_FRET:
            raise ValueError(f'{p["id"]}: invalid generated tablature position')
          state = dict(measure)
          for change in measure.get('attributes', []):
            if generator.model.fraction(change['onset']) <= onset:
              state.update(change)
          if dict(generator.fretboard.STANDARD_TUNING)[string] + fret != generator.pitch.sounding_pitch(p, state):
            raise ValueError(f'{p["id"]}: tablature disagrees with sounding pitch')
        pd = generator.model.fraction(p['duration'])
        if pd < 0 or (pd == 0 and not note.get('grace')) or pd > duration or not p['id'] or p['id'] in tones:
          raise ValueError('invalid chord-tone duration or duplicate ID')
        if not note.get('grace') and pd != generator.model.metric_length(p['written']):
          raise ValueError('metric and written chord-tone durations disagree')
        tones[p['id']] = (p, absolute + onset, pd, voice['id'])
    for harmony in measure.get('harmonies', []):
      if not 0 <= generator.model.fraction(harmony['onset']) < length:
        raise ValueError('harmony outside measure')
    for change in measure.get('attributes', []):
      if not 0 <= generator.model.fraction(change['onset']) < length:
        raise ValueError('attribute change outside measure')
    for state in [measure, *measure.get('attributes', [])]:
      if 'meter' in state:
        generator.model.validate_meter(state['meter'])
      if 'key' in state:
        if len(state['key']['alterations']) != 7:
          raise ValueError('key alterations must contain seven exact alterations')
        for value in state['key']['alterations']:
          generator.model.alteration(value)
      if 'clef' in state and (state['clef']['sign'] not in ('G', 'F', 'C', 'percussion', 'none') or not 1 <= state['clef']['line'] <= 6 or not -3 <= state['clef']['octave_change'] <= 3):
        raise ValueError('invalid clef')
    absolute += length
  for identifier, (p, start, duration, voice) in tones.items():
    if target := p.get('tie_to'):
      if target not in tones:
        raise ValueError(f'dangling tie: {identifier} -> {target}')
      other, next_start, _, next_voice = tones[target]
      same_pitch = all(p.get(k) == other.get(k) for k in ('unpitched', 'instrument')) if 'unpitched' in p else all(p.get(k) == other.get(k) for k in ('letter', 'alter', 'octave'))
      if other.get('tie_from') != identifier or not same_pitch or next_voice != voice or next_start != start + duration:
        raise ValueError(f'invalid tie: {identifier} -> {target}')
      if staves[0].get('tablature') and p['tablature'] != other['tablature']:
        raise ValueError(f'{identifier}: tied guitar tones must retain their string and fret')
    if source := p.get('tie_from'):
      if source not in tones or tones[source][0].get('tie_to') != identifier:
        raise ValueError(f'dangling incoming tie: {identifier}')
  span_ids = set()
  event_order = {identifier: index for index, identifier in enumerate(events)}
  for span in staves[0].get('tuplets', []):
    if not span['id'] or span['id'] in span_ids or span['start'] not in ids or span['end'] not in ids or not 0 < span['note_count'] <= 1000000 or not 0 < span['space_count'] <= 1000000 or not 0 <= span['depth'] <= 16:
      raise ValueError('invalid tuplet span')
    members = [n['id'] for n in events.values() if span['id'] in n.get('tuplet_ids', [])]
    if not members or members[0] != span['start'] or members[-1] != span['end'] or event_order[span['start']] > event_order[span['end']]:
      raise ValueError('tuplet endpoints disagree with member events')
    if len({ownership[n] for n in members}) != 1 or span.get('voice', ownership[members[0]]) != ownership[members[0]]:
      raise ValueError('tuplet crosses independent voice lanes')
    if span.get('bracket', 'auto') not in ('yes', 'no', 'auto') or span.get('show_number', 'actual') not in ('none', 'actual', 'both'):
      raise ValueError('invalid tuplet appearance')
    span_ids.add(span['id'])
  for note in events.values():
    for verse in note.get('lyrics', []):
      start = tones[note['pitches'][0]['id']][1] if note['pitches'] else fractions.Fraction()
      if 'extend_to' in verse and not start < generator.model.fraction(verse['extend_to']) <= absolute:
        raise ValueError('lyric extension endpoint is outside the score')
    if any(t not in span_ids for t in note.get('tuplet_ids', [])):
      raise ValueError('event refers to an unknown tuplet')
    if tremolo := note.get('tremolo'):
      if tremolo['type'] not in ('single', 'start', 'stop') or type(tremolo['marks']) is not int or not 0 <= tremolo['marks'] <= 8:
        raise ValueError('invalid measured tremolo')
      if tremolo['type'] in ('start', 'stop'):
        other = events.get(tremolo.get('partner'))
        expected_type = 'stop' if tremolo['type'] == 'start' else 'start'
        if not other or other.get('tremolo', {}).get('partner') != note['id'] or other['tremolo']['type'] != expected_type or other['tremolo']['marks'] != tremolo['marks']:
          raise ValueError('invalid paired tremolo')
  for span in staves[0].get('octave_shifts', []):
    if not 0 <= generator.model.fraction(span['start']) < generator.model.fraction(span['end']) <= absolute or not -3 <= span['octaves'] <= 3:
      raise ValueError('invalid octave-shift span')
  previous_end = fractions.Fraction()
  for span in staves[0].get('scale_spans', []):
    start, end = generator.model.fraction(span['start']), generator.model.fraction(span['end'])
    if not previous_end <= start < end <= absolute or not isinstance(span.get('label'), str) or not span['label'].strip() or type(span.get('matched')) is not bool:
      raise ValueError('invalid solo scale span')
    if not isinstance(span.get('id'), str) or not span['id'] or span['id'] in ids:
      raise ValueError('solo scale spans require unique IDs')
    ids.add(span['id'])
    previous_end = end