import 'models.dart';
import 'writing_feedback.dart';

class AssessmentTask {
  const AssessmentTask({
    required this.id,
    required this.skill,
    required this.prompt,
    this.audio,
    this.choices = const [],
    this.answerIndex,
    this.requiredWords = const [],
    required this.abilityId,
  });
  final String id;
  final AssessmentSkill skill;
  final String prompt;
  final String? audio;
  final List<String> choices;
  final int? answerIndex;
  final List<String> requiredWords;
  final String abilityId;
}

class AssessmentPack {
  const AssessmentPack({required this.id, required this.tasks});
  final String id;
  final List<AssessmentTask> tasks;
  List<AssessmentTask> forSkill(AssessmentSkill skill) =>
      tasks.where((task) => task.skill == skill).toList();
}

final a0AssessmentPacks = [
  AssessmentPack(
    id: 'A0-E1',
    tasks: _tasks(
      'A',
      const [
        'Hello. I’m Mia.|自我介绍|买东西|问时间|0',
        'How do you spell your name?|问姓名拼写|问地点|问时间|0',
        'I’m tired today.|很好|累|来自哪里|1',
        'seven|6|7|8|1',
        'one-three-eight|138|183|318|0',
        'It’s a key.|书|钥匙|包|1',
        'I’m from Hong Kong.|香港|伦敦|北京|0',
        'This is my mother.|妈妈|姐姐|朋友|0',
        'It is Monday.|星期一|星期二|星期三|0',
        'I like tea.|茶|咖啡|电影|0',
      ],
      const [
        'Mia: I’m from Hong Kong.\nShen: I’m good.\nMia: My number is one-three-eight.|Mia 来自哪里？|Hong Kong|London|0',
        'Mia: It is Monday.\nShen: It is three o’clock.|几点？|three|one|0',
        'Mia: This is my brother.\nShen: Nice to meet you.|谁是家人？|brother|mother|0',
        'Mia: I like music.\nShen: I like tea.|Shen 喜欢什么？|tea|music|0',
        'Mia: What’s this?\nShen: It’s a pen.|这是什么？|pen|bag|0',
      ],
      const [
        '用英语介绍自己。|i,m',
        '用英语说明你来自哪里。|i,m,from',
        '用英语说一个喜好。|i,like',
        '用英语说“这是一支笔”。|it,s,pen',
        '用英语说明星期或整点。|it,s',
      ],
      const [
        '介绍姓名、地点、状态/喜好并反问。|hello,i,m,from',
        '完整拼读一个四字母姓名。|a,l,e,x',
        '说一个三位虚拟号码。|one,three,eight',
        '介绍一位家人。|this,my',
        '说明星期。|it,s,monday',
        '说明整点。|it,s,o,clock',
        '请求对方重复或放慢。|please',
        '说出一个物品。|it,s',
      ],
    ),
  ),
  AssessmentPack(
    id: 'A0-E2',
    tasks: _tasks(
      'B',
      const [
        'Hi. My name is Leo.|自我介绍|买东西|问号码|0',
        'How do you spell that?|问姓名拼写|问喜好|问家人|0',
        'I’m okay.|很好|还可以|累|1',
        'four|3|4|5|1',
        'two-nine-six|296|269|926|0',
        'It’s a bag.|笔|包|水|1',
        'I’m from London.|伦敦|香港|北京|0',
        'This is my sister.|姐姐|妈妈|朋友|0',
        'It is Friday.|星期五|星期一|星期日|0',
        'I like coffee.|茶|咖啡|音乐|1',
      ],
      const [
        'Mia: I’m from London.\nLeo: I’m okay.\nMia: My number is two-nine-six.|号码是多少？|296|269|0',
        'Mia: It is Friday.\nLeo: It is six o’clock.|几点？|six|three|0',
        'Mia: This is my father.\nLeo: Hi!|谁是家人？|father|brother|0',
        'Mia: I like movies.\nLeo: I like coffee.|Leo 喜欢什么？|coffee|movies|0',
        'Mia: What’s this?\nLeo: It’s water.|这是什么？|water|book|0',
      ],
      const [
        '用英语介绍自己。|my,name,is',
        '用英语说明你来自哪里。|i,m,from',
        '用英语说一个喜好。|i,like',
        '用英语说“这是一个包”。|it,s,bag',
        '用英语说明星期或整点。|it,s',
      ],
      const [
        '介绍姓名、地点、状态/喜好并反问。|hi,i,m,from',
        '完整拼读一个四字母姓名。|l,e,o,n',
        '说一个三位虚拟号码。|two,nine,six',
        '介绍一位家人。|this,my',
        '说明星期。|it,s,friday',
        '说明整点。|it,s,o,clock',
        '请求对方重复或放慢。|please',
        '说出一个物品。|it,s',
      ],
    ),
  ),
];

/// Replacement packs use different people, places, numbers, days and likes.
/// They keep the same assessed ability but are not immediate replays.
final a0ReplacementPacks = [
  _replacementPack(a0AssessmentPacks[0], 'A0-E1R', const {
    'Mia': 'Nora',
    'Shen': 'Kai',
    'Hong Kong': 'London',
    'Monday': 'Friday',
    'one-three-eight': 'two-four-seven',
    '138': '247',
    'three o’clock': 'six o’clock',
    'tea': 'coffee',
    'key': 'bag',
    'mother': 'father',
  }),
  _replacementPack(a0AssessmentPacks[1], 'A0-E2R', const {
    'Mia': 'Ava',
    'Leo': 'Bo',
    'London': 'Hong Kong',
    'Friday': 'Tuesday',
    'two-nine-six': 'five-one-four',
    '296': '514',
    'six o’clock': 'two o’clock',
    'coffee': 'music',
    'bag': 'book',
    'sister': 'brother',
  }),
];

AssessmentPack? replacementFor(String packId) => switch (packId) {
  'A0-E1' => a0ReplacementPacks[0],
  'A0-E2' => a0ReplacementPacks[1],
  _ => null,
};

/// Local checks for the frozen A0 exit tasks. They accept variable names and
/// places, but require the communicative information named by each task.
bool checkOpenAssessmentAnswer(AssessmentTask task, String input) {
  final text = input
      .toLowerCase()
      .replaceAll('’', "'")
      .replaceAll('‘', "'")
      .replaceAll(RegExp(r"\s+"), " ")
      .trim();
  final words = RegExp(
    r"[a-z]+(?:'[a-z]+)?",
  ).allMatches(text).map((match) => match.group(0)!).toSet();
  bool has(String word) => words.contains(
    word
        .toLowerCase()
        .replaceAll('’', "'")
        .replaceAll('‘', "'")
        .trim(),
  );
  bool phrase(String value) {
    final normVal = value
        .toLowerCase()
        .replaceAll('’', "'")
        .replaceAll('‘', "'")
        .replaceAll(RegExp(r"\s+"), " ")
        .trim();
    return text.contains(normVal);
  }
  bool hasAny(Iterable<String> values) => values.any(has);
  final introduction = phrase("i'm") || phrase('i am') || phrase('my name is');
  final itIs = phrase("it's") || phrase('it is');
  final numberWords = RegExp(
    r'\b(zero|one|two|three|four|five|six|seven|eight|nine|ten)\b',
  ).allMatches(text).length;
  final position = int.tryParse(
    RegExp(r'(\d+)$').firstMatch(task.id)?.group(1) ?? '',
  );
  if (position == null) return false;

  if (task.skill == AssessmentSkill.writing) {
    const lessonIds = ['a0-01', 'a0-06', 'a0-09', 'a0-05', 'a0-08'];
    return position >= 1 &&
        position <= lessonIds.length &&
        WritingFeedback.check(lessonIds[position - 1], input).complete;
  }
  if (task.skill != AssessmentSkill.speaking) return false;
  return switch (position) {
    1 =>
      hasAny(['hello', 'hi']) &&
          introduction &&
          has('from') &&
          (has('like') || hasAny(['good', 'okay', 'tired'])) &&
          hasAny(['what', 'where', 'how', 'do']),
    2 => RegExp(r'[a-z](?:[ -]?[a-z]){3,}').hasMatch(text),
    3 => numberWords >= 3,
    4 =>
      phrase('this is my') && hasAny(['mother', 'father', 'sister', 'brother']),
    5 =>
      itIs &&
          hasAny([
            'monday',
            'tuesday',
            'wednesday',
            'thursday',
            'friday',
            'saturday',
            'sunday',
          ]),
    6 =>
      itIs &&
          (has('clock') ||
              has("o'clock") ||
              has('oclock') ||
              phrase("o'clock")),
    7 => has('please') && hasAny(['say', 'speak', 'repeat', 'slow', 'slowly']),
    8 => itIs && hasAny(['book', 'pen', 'bag', 'key', 'water']),
    _ => false,
  };
}

AssessmentPack _replacementPack(
  AssessmentPack source,
  String id,
  Map<String, String> values,
) {
  String replace(String value) {
    var result = value;
    for (final entry in values.entries) {
      result = result.replaceAll(entry.key, entry.value);
    }
    return result;
  }

  return AssessmentPack(
    id: id,
    tasks: source.tasks
        .map(
          (task) => AssessmentTask(
            id: task.id.replaceFirst(
              source.id.split('-').last,
              id.split('-').last,
            ),
            skill: task.skill,
            prompt: replace(task.prompt),
            audio: task.audio == null ? null : replace(task.audio!),
            choices: task.choices.map(replace).toList(),
            answerIndex: task.answerIndex,
            requiredWords: task.requiredWords.map(replace).toList(),
            abilityId: task.abilityId,
          ),
        )
        .toList(),
  );
}

List<AssessmentTask> _tasks(
  String version,
  List<String> listening,
  List<String> reading,
  List<String> writing,
  List<String> speaking,
) {
  AssessmentTask choice(String raw, AssessmentSkill skill, int index) {
    final fields = raw.split('|');
    return AssessmentTask(
      id: 'A0-$version-${skill.name[0].toUpperCase()}${index + 1}',
      skill: skill,
      audio: skill == AssessmentSkill.listening ? fields[0] : null,
      prompt: skill == AssessmentSkill.listening ? '选择正确答案' : fields[0],
      choices: skill == AssessmentSkill.listening
          ? fields.sublist(1, 4)
          : fields.sublist(1, 3),
      answerIndex: int.parse(fields.last),
      abilityId: 'A0-C${(index % 10 + 1).toString().padLeft(2, '0')}',
    );
  }

  AssessmentTask open(String raw, AssessmentSkill skill, int index) {
    final fields = raw.split('|');
    return AssessmentTask(
      id: 'A0-$version-${skill.name[0].toUpperCase()}${index + 1}',
      skill: skill,
      prompt: fields[0],
      requiredWords: fields[1].split(','),
      abilityId: 'A0-C${(index % 10 + 1).toString().padLeft(2, '0')}',
    );
  }

  return [
    ...List.generate(
      listening.length,
      (i) => choice(listening[i], AssessmentSkill.listening, i),
    ),
    ...List.generate(
      reading.length,
      (i) => choice(reading[i], AssessmentSkill.reading, i),
    ),
    ...List.generate(
      writing.length,
      (i) => open(writing[i], AssessmentSkill.writing, i),
    ),
    ...List.generate(
      speaking.length,
      (i) => open(speaking[i], AssessmentSkill.speaking, i),
    ),
  ];
}