import copy
from fractions import Fraction
import json
from pathlib import Path
import tempfile
import unittest
from xml.etree import ElementTree

from generator.engraving import Fonts, Style, engrave_tree, layout_score
from generator.engraving.attributes import staff_attributes
from generator.engraving.notation import ScoreIndex
from generator.model import key_from_fifths, parse_pitch_name, rational, validate_document
from generator.practice.generate import generate_practice_scores, key_file_name, practice_document
from generator.score import load_json, write_json
from generator.transposition import TARGET_KEYS, concert_document, shift_key, transpose_document
from tests.test_musicxml import parse, xml_note, xml_score

FONT_ROOT = Path('package/assets/fonts/petaluma')

def key_change(old, new, local=False, attributes=''):
  initial = f'<key><fifths>{old}</fifths></key>' + attributes
  change = f'<attributes><key><cancel>{old}</cancel><fifths>{new}</fifths></key></attributes>'
  if local:
    return parse(xml_score(xml_note(duration=2, kind='half') + change + xml_note(duration=2, kind='half'), initial))
  root = ElementTree.fromstring(xml_score(xml_note(), initial))
  root.find('part').append(ElementTree.fromstring('<measure number="2">' + change + xml_note() + '</measure>'))
  return parse(ElementTree.tostring(root, encoding='unicode'))

class KeyCancellationTests(unittest.TestCase):
  @classmethod
  def setUpClass(cls):
    cls.fonts = Fonts(FONT_ROOT)
  def test_sharp_flat_and_cross_sign_changes_keep_their_placement(self):
    cases = [(1, 0, 'A', 3, 2, -54), (-2, -1, 'Ab', -4, -3, -36),
      (-1, -2, 'G', 1, 0, -48), (1, 2, 'F', -1, 0, -24)]
    for old, new, target, expected_old, expected_new, natural_y in cases:
      for local in (False, True):
        with self.subTest(old=old, new=new, target=target, local=local):
          source = key_change(old, new, local)
          before = copy.deepcopy(source)
          result = transpose_document(source, target)
          validate_document(result)
          measures = result['staves'][0]['measures']
          self.assertEqual(measures[0]['key'], key_from_fifths(expected_old))
          change = measures[0]['attributes'][0] if local else measures[1]
          self.assertEqual(change['key'], key_from_fifths(expected_new) | {'cancel': expected_old})
          self.assertEqual(len(measures), 1 if local else 2)
          if local:
            self.assertEqual(len(measures[0]['attributes']), 1)
            self.assertEqual(change['onset'], rational(2))
          else:
            self.assertTrue(all(not m['attributes'] for m in measures))
            self.assertEqual(change['number'], '2')
          time = Fraction(2 if local else 4)
          index = ScoreIndex(result)
          glyphs = staff_attributes(index, index.state(time), time, self.fonts, 12, 'change', ('key',))
          naturals = [p for p in glyphs if p.value == 'accidentalNatural']
          self.assertEqual(len(naturals), 1)
          self.assertEqual(naturals[0].points[0][1], natural_y)
          self.assertEqual([p.value for p in glyphs[1:]], ['accidentalSharp' if expected_new > 0 else 'accidentalFlat'] * abs(expected_new))
          layout = layout_score(result, Style(), self.fonts)
          reference = 'measure-1:attributes:0' if local else 'measure-2:initial'
          drawn = [p for page in layout.pages for p in page.primitives if p.role == 'accidental' and p.sources == (reference,)]
          self.assertEqual([p.value for p in drawn], [p.value for p in glyphs])
          self.assertEqual([p.points[0][1] - drawn[0].points[0][1] for p in drawn], [p.points[0][1] - glyphs[0].points[0][1] for p in glyphs])
          self.assertEqual(source, before)
  def test_metadata_and_initial_signature_transpose_cancellation(self):
    source = parse(xml_score(xml_note(), '<key><cancel>1</cancel><fifths>0</fifths></key>'))
    result = transpose_document(source, 'D', octave_shift=1)
    expected = key_from_fifths(2) | {'cancel': 3}
    self.assertEqual(result['metadata']['key'], expected)
    self.assertEqual(result['staves'][0]['measures'][0]['key'], expected)
  def test_zero_and_modal_cancellations_reference_the_old_signature(self):
    for mode in ('major', 'minor', 'dorian', 'none'):
      with self.subTest(mode=mode):
        key = key_from_fifths(-1, mode) | {'cancel': 0}
        result = shift_key(key, 1, 2)
        self.assertEqual(result['cancel'], 2)
        self.assertEqual(result['mode'], mode)
        self.assertEqual(result['alterations'], key_from_fifths(1)['alterations'])
  def test_unchanged_accidentals_do_not_receive_naturals(self):
    for old, new, target in [(1, 0, 'F'), (-1, 0, 'G'), (1, 1, 'A')]:
      with self.subTest(old=old, new=new, target=target):
        result = transpose_document(key_change(old, new), target)
        index = ScoreIndex(result)
        glyphs = staff_attributes(index, index.state(Fraction(4)), Fraction(4), self.fonts, 12, 'change', ('key',))
        self.assertNotIn('accidentalNatural', [p.value for p in glyphs])
  def test_unrepresentable_cancellation_fails_without_mutating_source(self):
    for fifths, steps, semitones in [(14, 1, 2), (-14, -1, -2), (0, 0, Fraction(1, 2))]:
      key = key_from_fifths(0) | {'cancel': fifths}
      before = copy.deepcopy(key)
      with self.subTest(fifths=fifths, semitones=semitones), self.assertRaisesRegex(ValueError, 'key cancellation.*represented'):
        shift_key(key, steps, semitones)
      self.assertEqual(key, before)
    for local in (False, True):
      source = key_change(0, 0, local)
      measures = source['staves'][0]['measures']
      change = measures[0]['attributes'][0] if local else measures[1]
      change['key']['cancel'] = 14
      before = copy.deepcopy(source)
      with self.subTest(local=local), self.assertRaisesRegex(ValueError, 'key cancellation.*represented'):
        transpose_document(source, 'D')
      self.assertEqual(source, before)
  def test_concert_transposition_uses_the_same_interval_for_cancellation(self):
    attributes = '<transpose><diatonic>1</diatonic><chromatic>2</chromatic></transpose>'
    for local in (False, True):
      with self.subTest(local=local):
        source = key_change(1, 0, local, attributes)
        result = concert_document(source)
        self.assertEqual(result, concert_document(result))
        measures = result['staves'][0]['measures']
        change = measures[0]['attributes'][0] if local else measures[1]
        self.assertEqual(change['key'], key_from_fifths(2) | {'cancel': 3})

class AuthoredKeyMetadataTests(unittest.TestCase):
  def test_eb_authored_key_survives_every_generated_practice_variant(self):
    with tempfile.TemporaryDirectory() as temp:
      source, output = Path(temp) / 'source', Path(temp) / 'output'
      text = xml_score(xml_note('E', alter=-1), '<key><fifths>-3</fifths></key>')
      source.mkdir()
      path = source / '001.xml'
      path.write_text(text, encoding='utf-8')
      self.assertEqual(generate_practice_scores(source, output), 12)
      for key in TARGET_KEYS:
        with self.subTest(key=key):
          result = load_json(output / '001' / key_file_name(key))
          self.assertEqual(result['schema_version'], 3)
          self.assertEqual(result['metadata']['authored_key_signature'], 'Eb')
          self.assertEqual(result['metadata']['key_signature'], key)
          self.assertEqual(result['metadata']['variant_tonic'], key)
      self.assertEqual(path.read_text(encoding='utf-8'), text)
  def test_modes_and_keyless_authored_labels_survive_variants(self):
    for mode, fifths, label in [('minor', -3, 'C minor'), ('dorian', -2, 'C dorian'), ('mixolydian', -1, 'C mixolydian'), ('none', 0, 'No key')]:
      source = parse(xml_score(xml_note(), f'<key><fifths>{fifths}</fifths><mode>{mode}</mode></key>'))
      if mode == 'none':
        source['metadata']['transpose_origin'] = parse_pitch_name('C')
      before = copy.deepcopy(source)
      base = practice_document(source)
      self.assertEqual(base['metadata']['authored_key_signature'], label)
      for key in TARGET_KEYS:
        with self.subTest(mode=mode, key=key):
          result = transpose_document(base, key)
          validate_document(result)
          self.assertEqual(result['metadata']['authored_key_signature'], label)
          self.assertEqual(result['metadata']['key_signature'], 'No key' if mode == 'none' else f'{key} {mode}')
          self.assertEqual(result['metadata']['variant_tonic'], key)
      self.assertEqual(source, before)
  def test_existing_authored_key_is_retained_when_practice_is_rebuilt(self):
    source = parse(xml_score(xml_note('E', alter=-1), '<key><fifths>-3</fifths></key>'))
    before = copy.deepcopy(source)
    variant = transpose_document(practice_document(source), 'D')
    result = transpose_document(practice_document(variant), 'F')
    self.assertEqual(result['metadata']['authored_key_signature'], 'Eb')
    self.assertEqual(result['metadata']['key_signature'], 'F')
    self.assertEqual(source, before)
  def test_schema3_bundles_accept_optional_authored_key(self):
    source = parse(xml_score(xml_note('E', alter=-1), '<key><fifths>-3</fifths></key>'))
    self.assertNotIn('authored_key_signature', source['metadata'])
    for authored in (False, True):
      with self.subTest(authored=authored), tempfile.TemporaryDirectory() as temp:
        result = transpose_document(practice_document(source) if authored else source, 'D')
        root = Path(temp)
        path = root / 'variant.json'
        write_json(path, result)
        engrave_tree(root, FONT_ROOT)
        bundle = json.loads(path.read_text(encoding='utf-8'))
        self.assertEqual(bundle['schema_version'], 3)
        self.assertEqual(bundle['music']['metadata']['key_signature'], 'D')
        self.assertEqual(bundle['music']['metadata'].get('authored_key_signature'), 'Eb' if authored else None)
        self.assertEqual(load_json(path), result)