from fractions import Fraction
from pathlib import Path
import tempfile
import unittest

from generator.musicxml import MusicXMLError, load_musicxml
from generator.model import NOTE_TYPES, TYPE_LENGTHS, fraction, pitch_number

def xml_score(content, attributes='', *, divisions=1, implicit=False):
  return ('<?xml version="1.0"?>'
    '<score-partwise version="4.0"><work><work-title>Fixture</work-title></work>'
    '<part-list><score-part id="P1"><part-name>Lead</part-name></score-part></part-list>'
    f'<part id="P1"><measure number="1" implicit="{"yes" if implicit else "no"}">'
    f'<attributes><divisions>{divisions}</divisions><key><fifths>0</fifths></key>'
    '<time><beats>4</beats><beat-type>4</beat-type></time>'
    f'<clef><sign>G</sign><line>2</line></clef>{attributes}</attributes>'
    f'{content}</measure></part></score-partwise>')

def xml_note(step='C', duration=4, kind='whole', extra='', prefix='', alter=0, octave=4):
  return (f'<note>{prefix}<pitch><step>{step}</step><alter>{alter}</alter><octave>{octave}</octave></pitch>'
    f'<duration>{duration}</duration><type>{kind}</type>{extra}</note>')

def parse(text):
  with tempfile.TemporaryDirectory() as directory:
    path = Path(directory) / 'fixture.xml'
    path.write_text(text, encoding='utf-8')
    return load_musicxml(path)

def notes(document, measure=0):
  return document['staves'][0]['measures'][measure]['voices'][0]['notes']

class MusicXMLTests(unittest.TestCase):
  def test_measure_sound_tempo_matches_direction_sound(self):
    sound = '<sound tempo="120"/>'
    direct = parse(xml_score(sound + xml_note()))
    direction = parse(xml_score('<direction>' + sound + '</direction>' + xml_note()))
    self.assertEqual(direct, direction)
    with self.assertRaises(MusicXMLError):
      parse(xml_score('<sound tempo="0"/>' + xml_note()))
    with self.assertRaises(MusicXMLError):
      parse(xml_score('<sound dacapo="yes"/>' + xml_note()))
  def test_regression_fixture(self):
    score = load_musicxml(Path('tests/fixtures/notation.xml'))
    self.assertEqual(len(score['staves'][0]['measures']), 4)
    self.assertEqual(len(score['staves'][0]['octave_shifts']), 1)
  def test_catalogue_imports(self):
    sources = sorted(Path('data').rglob('*.xml'))
    self.assertTrue(sources)
    for path in sources:
      with self.subTest(path=path):
        self.assertEqual(load_musicxml(path)['schema_version'], 3)
  def test_all_written_values_and_dots(self):
    for kind in NOTE_TYPES:
      for dots in (0, 1, 2, 3):
        value = TYPE_LENGTHS[kind] * (2 - Fraction(1, 2**dots))
        score = parse(xml_score(xml_note(duration=value.numerator, kind=kind, extra='<dot/>' * dots), divisions=value.denominator, implicit=True))
        self.assertEqual(fraction(notes(score)[0]['duration']), value)
        self.assertEqual(notes(score)[0]['written'], {'type': kind, 'dots': dots})
  def test_divisions_do_not_change_music(self):
    a = parse(xml_score(xml_note(duration=4)))
    b = parse(xml_score(xml_note(duration=1920), divisions=480))
    self.assertEqual(a, b)
  def test_doctype_allowed_but_entities_rejected(self):
    source = xml_score(xml_note())
    source = source.replace('<score-partwise', '<!DOCTYPE score-partwise SYSTEM "https://invalid.test/partwise.dtd"><score-partwise', 1)
    self.assertEqual(parse(source)['schema_version'], 3)
    malicious = xml_score(xml_note()).replace('<score-partwise', '<!DOCTYPE score-partwise [<!ENTITY secret SYSTEM "file:///etc/passwd">]><score-partwise', 1)
    with self.assertRaises(MusicXMLError):
      parse(malicious)
    with self.assertRaises(MusicXMLError):
      parse('<score-partwise')
  def test_harmony_inside_sustained_note_remains_independent(self):
    h = '<harmony><root><root-step>F</root-step></root><kind>major</kind><offset>-2</offset></harmony>'
    score = parse(xml_score(xml_note() + h))
    self.assertEqual(len(notes(score)), 1)
    self.assertEqual(fraction(score['staves'][0]['measures'][0]['harmonies'][0]['onset']), 2)
  def test_partial_chord_ties_and_unequal_tones(self):
    source = xml_note(duration=2, kind='half', extra='<tie type="start"/>')
    source += xml_note('E', 1, 'quarter', prefix='<chord/>')
    source += xml_note(duration=2, kind='half', extra='<tie type="stop"/>')
    source += xml_note('G', 2, 'half', prefix='<chord/>')
    result = notes(parse(xml_score(source)))
    self.assertEqual(fraction(result[0]['pitches'][1]['duration']), 1)
    self.assertEqual(result[0]['pitches'][0]['tie_to'], result[1]['pitches'][0]['id'])
    self.assertNotIn('tie_to', result[0]['pitches'][1])
  def test_grace_cue_and_measured_tremolo(self):
    grace = '<note><grace slash="yes"/><pitch><step>D</step><octave>4</octave></pitch><type>16th</type></note>'
    regular = xml_note(extra='<notations><ornaments><tremolo type="single">3</tremolo></ornaments></notations>', prefix='<cue/>')
    result = notes(parse(xml_score(grace + regular)))
    self.assertEqual(fraction(result[0]['duration']), 0)
    self.assertTrue(result[0]['grace']['slash'])
    self.assertTrue(result[1]['cue'])
    self.assertEqual(result[1]['tremolo']['marks'], 3)
  def test_exact_quintuplets(self):
    content = ''
    for i in range(5):
      tuplet = '<tuplet type="start"/>' if i == 0 else '<tuplet type="stop"/>' if i == 4 else ''
      extra = '<time-modification><actual-notes>5</actual-notes><normal-notes>4</normal-notes></time-modification>'
      extra += '<notations>' + tuplet + '</notations>'
      content += xml_note(duration=4, kind='quarter', extra=extra)
    result = parse(xml_score(content, divisions=5))
    self.assertEqual(sum(fraction(n['duration']) for n in notes(result)), 4)
    self.assertTrue(all(fraction(n['duration']) == Fraction(4, 5) for n in notes(result)))
    self.assertEqual(result['staves'][0]['tuplets'][0]['note_count'], 5)
  def test_inconsistent_written_timing_is_rejected(self):
    modulation = '<time-modification><actual-notes>3</actual-notes><normal-notes>2</normal-notes></time-modification>'
    with self.assertRaisesRegex(MusicXMLError, 'disagrees with written duration'):
      parse(xml_score(xml_note(extra=modulation)))
    with self.assertRaisesRegex(MusicXMLError, 'disagrees with written duration'):
      parse(xml_score(xml_note(kind='half')))
  def test_paired_tremolo_timing(self):
    modulation = '<time-modification><actual-notes>2</actual-notes><normal-notes>1</normal-notes></time-modification>'
    content = ''.join(xml_note(step, 2, 'whole', extra=modulation + f'<notations><ornaments><tremolo type="{action}">3</tremolo></ornaments></notations>')
      for step, action in [('C', 'start'), ('G', 'stop')])
    result = notes(parse(xml_score(content)))
    self.assertEqual(result[0]['tremolo']['partner'], result[1]['id'])
    self.assertEqual(fraction(result[0]['duration']), 2)
  def test_mid_measure_clef_and_key_changes(self):
    change = '<attributes><key><fifths>-3</fifths><mode>minor</mode></key><clef><sign>C</sign><line>3</line></clef></attributes>'
    result = parse(xml_score(xml_note(duration=2, kind='half') + change + xml_note(duration=2, kind='half')))
    attr = result['staves'][0]['measures'][0]['attributes'][0]
    self.assertEqual(fraction(attr['onset']), 2)
    self.assertEqual(attr['key']['mode'], 'minor')
    self.assertEqual(attr['clef']['sign'], 'C')
  def test_optional_marker_contract(self):
    marker = '<direction><direction-type><words>vamp:optional-chord</words></direction-type></direction>'
    h = '<harmony><root><root-step>C</root-step></root><kind>major</kind></harmony>'
    score = parse(xml_score(marker + h + xml_note()))
    self.assertTrue(score['staves'][0]['measures'][0]['harmonies'][0]['chord_optional'])
    for content in (marker + xml_note(), marker + marker + h + xml_note(), marker.replace('optional-chord', 'unknown') + xml_note()):
      with self.assertRaisesRegex(MusicXMLError, 'measure 1'):
        parse(xml_score(content))
  def test_rejects_musical_content_outside_contract(self):
    extras = ['<notations><slur type="start"/></notations>', '<notations><articulations><accent/></articulations></notations>',
      '<voice>2</voice><staff>2</staff>', '<pitch><unpitched/></pitch>',
      '<notations><ornaments><trill-mark/></ornaments></notations>']
    for extra in extras:
      with self.subTest(extra=extra), self.assertRaises(MusicXMLError):
        parse(xml_score(xml_note(extra=extra)))
    for extra in ('<barline location="middle"><repeat direction="backward"/></barline>', '<backup><duration>5</duration></backup>', '<direction><direction-type><dynamics><ff/></dynamics></direction-type></direction>'):
      with self.subTest(extra=extra), self.assertRaises(MusicXMLError):
        parse(xml_score(xml_note() + extra))
    self.assertEqual(fraction(notes(parse(xml_score(xml_note(alter='0.5'))))[0]['pitches'][0]['alter']), Fraction(1, 2))
    with self.assertRaises(MusicXMLError):
      parse(xml_score(xml_note(extra='<tie type="stop"/>')))
    with self.assertRaises(MusicXMLError):
      parse(xml_score(xml_note(duration=5)))
  def test_b_sharp_c_flat_preserve_octave(self):
    b = notes(parse(xml_score(xml_note('B', alter=1))))[0]['pitches'][0]
    c = notes(parse(xml_score(xml_note('C', alter=-1))))[0]['pitches'][0]
    self.assertEqual(pitch_number(b), 72)
    self.assertEqual(pitch_number(c), 59)
  def test_musicxml_degree_alterations_are_relative(self):
    h = '<harmony><root><root-step>C</root-step></root><kind>minor</kind><degree><degree-value>3</degree-value><degree-alter>1</degree-alter><degree-type>alter</degree-type></degree></harmony>'
    from generator.harmony import degrees
    score = parse(xml_score(h + xml_note()))
    self.assertEqual(degrees(score['staves'][0]['measures'][0]['harmonies'][0])[3], 0)
    h = h.replace('<kind>minor</kind>', '<kind text="maj7">minor</kind>')
    with self.assertRaisesRegex(MusicXMLError, 'contradictory'):
      parse(xml_score(h + xml_note()))
  def test_nested_and_cross_bar_tuplets(self):
    modulation = '<time-modification><actual-notes>9</actual-notes><normal-notes>4</normal-notes></time-modification>'
    def tuplet(number, action):
      details = '<tuplet-actual><tuplet-number>3</tuplet-number></tuplet-actual><tuplet-normal><tuplet-number>2</tuplet-number></tuplet-normal>' if action == 'start' else ''
      return f'<tuplet number="{number}" type="{action}">{details}</tuplet>'
    first = xml_note(duration=4, kind='quarter', extra=modulation + '<notations>' + tuplet(1, 'start') + tuplet(2, 'start') + '</notations>')
    last = xml_note(duration=4, kind='quarter', extra=modulation + '<notations>' + tuplet(2, 'stop') + tuplet(1, 'stop') + '</notations>')
    text = xml_score(first, divisions=9, implicit=True)
    text = text.replace('</measure></part>', '</measure><measure number="2" implicit="yes">' + last + '</measure></part>')
    result = parse(text)
    spans = result['staves'][0]['tuplets']
    self.assertEqual([t['depth'] for t in spans], [0, 1])
    self.assertEqual(fraction(notes(result, 1)[0]['duration']), Fraction(4, 9))
    self.assertTrue(all(t['end'] == notes(result, 1)[0]['id'] for t in spans))