"""Pure score navigation, cloning and identity operations."""
from __future__ import annotations
import copy
import re

def slugify(value: str) -> str:
  return re.sub(r'[^a-z0-9]+', '_', value.strip().lower()).strip('_') or 'score'

def source_staff(document: dict) -> dict:
  if len(document.get('staves', [])) != 1:
    raise ValueError('exactly one source staff is required')
  return document['staves'][0]

def measure_notes(measure: dict) -> list[dict]:
  return [note for voice in measure['voices'] for note in voice['notes']]

def leading_pickup_measure_index(measures: list[dict]) -> int | None:
  return 0 if len(measures) > 1 and measures[0].get('implicit') else None

def body_start_measure_index(measures: list[dict]) -> int:
  return 1 if leading_pickup_measure_index(measures) is not None else 0

def copy_source_voices(measure: dict, *, strip_lyrics: bool) -> list[dict]:
  voices = copy.deepcopy(measure['voices'])
  if strip_lyrics:
    for note in (n for v in voices for n in v['notes']):
      note.pop('lyric', None)
      note.pop('lyric_notation', None)
      note.pop('lyrics', None)
  return voices

def make_measure(measure_id: str, source: dict, notes: list[dict], *, section_label: str = '') -> dict:
  result = copy.deepcopy(source)
  result.update({'id': measure_id, 'section_label': section_label, 'voices': [{'id': 'voice_arranged', 'notes': notes}]})
  for note in notes:
    note['voice'] = 'voice_arranged'
  return result

def reidentify(measures: list[dict], source_tuplets: list[dict]) -> list[dict]:
  """Clone-local links survive; links cut by an arrangement boundary become attacks."""
  tone_map, event_map = {}, {}
  tuplets = []
  for measure in measures:
    for hi, harmony in enumerate(measure.get('harmonies', [])):
      harmony['id'] = f'{measure["id"]}_h{hi + 1}'
    for ni, note in enumerate(measure_notes(measure)):
      old = note['id']
      note['id'] = f'{measure["id"]}_n{ni + 1}'
      event_map[old] = note['id']
      for pi, pitch in enumerate(note['pitches']):
        old_pitch = pitch['id']
        pitch['id'] = f'{note["id"]}_p{pi + 1}'
        tone_map[old_pitch] = pitch['id']
  for measure in measures:
    for note in measure_notes(measure):
      for p in note['pitches']:
        for field in ('tie_from', 'tie_to'):
          if p.get(field) in tone_map:
            p[field] = tone_map[p[field]]
          else:
            p.pop(field, None)
      if note.get('tremolo', {}).get('partner'):
        partner = note['tremolo']['partner']
        if partner in event_map:
          note['tremolo']['partner'] = event_map[partner]
        else:
          note['tremolo'] = {**note['tremolo'], 'type': 'single'}
          note['tremolo'].pop('partner', None)
  for source in source_tuplets:
    members = [n for m in measures for n in measure_notes(m) if source['id'] in n.get('tuplet_ids', [])]
    if not members:
      continue
    t = copy.deepcopy(source)
    t.update({'id': f'{measures[0]["id"]}_{source["id"]}', 'start': members[0]['id'], 'end': members[-1]['id'], 'continued_start': source['start'] not in event_map, 'continued_end': source['end'] not in event_map})
    for n in members:
      n['tuplet_ids'] = [t['id'] if v == source['id'] else v for v in n['tuplet_ids']]
    tuplets.append(t)
  return tuplets

def make_arranged_document(source_document: dict, staff: dict, *, staff_id: str, staff_name: str, role: str, arrangement_part_type: str, measures: list[dict], tuplets=None, octave_shifts=None) -> dict:
  return {'metadata': copy.deepcopy(source_document['metadata']), 'staves': [{'id': staff_id, 'name': staff_name, 'clef': copy.deepcopy(staff['clef']), 'role': role, 'arranged': True, 'arrangement_part_type': arrangement_part_type, 'measures': measures, 'tuplets': tuplets or [], 'octave_shifts': copy.deepcopy(octave_shifts or []), 'instruments': copy.deepcopy(staff.get('instruments', []))}]}