from __future__ import annotations

from pathlib import Path

from generator.guitar import place_guitar
from generator.musicxml import load_musicxml
from generator.parts import PART_TYPES, build_measure, propagated_chords, validate_source
from generator.pitch import concert_document
from generator.scat import add_scat
from generator.score import make_arranged_document, reidentify, source_staff, write_json

def practice_document(document: dict, part_type: str) -> dict:
  if part_type not in PART_TYPES:
    raise ValueError(f'unknown practice part: {part_type}')
  validate_source(document, practice=True)
  document = concert_document(document, octave_transposing=True)
  staff = source_staff(document)
  previous = propagated_chords(staff['measures'])
  role = {'acoustic': 'accompaniment', 'electric': 'melody', 'vocal': 'vocal'}[part_type]
  measures = [build_measure(m, f'measure-{i + 1}', role, part_type, previous[i], m.get('section_label', '')) for i, m in enumerate(staff['measures'])]
  for measure in measures:
    for chord in measure['harmonies']:
      chord.pop('chord_optional', None)
  tuplets = reidentify(measures, staff.get('tuplets', []))
  result = make_arranged_document(document, staff, staff_id='staff-practice-' + part_type, staff_name=part_type.capitalize(), role='vocal' if part_type == 'vocal' else 'guitar', arrangement_part_type=part_type, measures=measures, tuplets=tuplets, octave_shifts=staff.get('octave_shifts', []) if role in ('melody', 'vocal') else [])
  if part_type == 'vocal':
    add_scat(result)
  else:
    place_guitar(result)
  return result

def generate_practice_scores(source_dir: Path, output_dir: Path) -> int:
  if not source_dir.is_dir():
    raise ValueError(f'practice source directory not found: {source_dir}')
  sources = sorted(source_dir.rglob('*.xml'))
  for path in sources:
    if path.parent != source_dir or len(path.stem) != 3 or not path.stem.isascii() or not path.stem.isdecimal():
      raise ValueError(f'{path}: practice sources require a three-digit filename directly under data/practice')
  for path in sources:
    document = load_musicxml(path)
    for part in PART_TYPES:
      try:
        write_json(output_dir / path.stem / (part + '.json'), practice_document(document, part))
      except ValueError as error:
        raise ValueError(f'{path}, part {part}: {error}') from error
  return len(sources) * len(PART_TYPES)