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.musicxml'
        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_regression_fixture(self):
        score = load_musicxml(Path('tests/fixtures/notation.musicxml'))
        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('*.musicxml'))
        self.assertEqual(len(sources), 6)
        for path in sources:
            with self.subTest(path=path):
                self.assertEqual(load_musicxml(path)['schema_version'], 2)

    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'], 2)
        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><repeat direction="backward"/></barline>', '<backup><duration>4</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))
        with self.assertRaises(MusicXMLError):
            parse(xml_score(xml_note(alter='0.5')))
        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))