import 'package:test/test.dart';
import 'package:practice_engine/models/deck.dart';
import 'package:practice_engine/models/deck_config.dart';
import 'package:practice_engine/models/question.dart';

void main() {
  group('Deck', () {
    late DeckConfig defaultConfig;
    late List<Question> sampleQuestions;

    setUp(() {
      defaultConfig = const DeckConfig();
      sampleQuestions = [
        Question(
          id: 'q1',
          prompt: 'What is 2+2?',
          answers: ['3', '4', '5'],
          correctAnswerIndices: [1],
          isKnown: true,
        ),
        Question(
          id: 'q2',
          prompt: 'What is 3+3?',
          answers: ['5', '6', '7'],
          correctAnswerIndices: [1],
          isKnown: false,
        ),
        Question(
          id: 'q3',
          prompt: 'What is 4+4?',
          answers: ['7', '8', '9'],
          correctAnswerIndices: [1],
          isKnown: true,
        ),
      ];
    });

    test('calculates numberOfQuestions correctly', () {
      final deck = Deck(
        id: 'deck1',
        title: 'Math Deck',
        description: 'Basic math',
        questions: sampleQuestions,
        config: defaultConfig,
      );

      expect(deck.numberOfQuestions, equals(3));
    });

    test('calculates knownCount correctly', () {
      final deck = Deck(
        id: 'deck1',
        title: 'Math Deck',
        description: 'Basic math',
        questions: sampleQuestions,
        config: defaultConfig,
      );

      expect(deck.knownCount, equals(2));
    });

    test('calculates practicePercentage correctly', () {
      final deck = Deck(
        id: 'deck1',
        title: 'Math Deck',
        description: 'Basic math',
        questions: sampleQuestions,
        config: defaultConfig,
      );

      expect(deck.practicePercentage, closeTo(66.67, 0.01));
    });

    test('practicePercentage is 0 for empty deck', () {
      final deck = Deck(
        id: 'deck1',
        title: 'Empty Deck',
        description: 'No questions',
        questions: [],
        config: defaultConfig,
      );

      expect(deck.practicePercentage, equals(0.0));
    });

    test('practicePercentage is 100 when all questions are known', () {
      final allKnown = sampleQuestions.map((q) => q.copyWith(isKnown: true)).toList();
      final deck = Deck(
        id: 'deck1',
        title: 'All Known',
        description: 'All known',
        questions: allKnown,
        config: defaultConfig,
      );

      expect(deck.practicePercentage, equals(100.0));
    });

    test('progressPercentage is 0 for empty deck', () {
      final deck = Deck(
        id: 'deck1',
        title: 'Empty Deck',
        description: 'No questions',
        questions: [],
        config: defaultConfig,
      );

      expect(deck.progressPercentage, equals(0.0));
    });

    test('progressPercentage equals practicePercentage when no partial streak', () {
      final deck = Deck(
        id: 'deck1',
        title: 'Math Deck',
        description: 'Basic math',
        questions: sampleQuestions,
        config: defaultConfig,
      );

      expect(deck.progressPercentage, closeTo(deck.practicePercentage, 0.01));
    });

    test('progressPercentage is 100 when all questions are known', () {
      final allKnown = sampleQuestions.map((q) => q.copyWith(isKnown: true)).toList();
      final deck = Deck(
        id: 'deck1',
        title: 'All Known',
        description: 'All known',
        questions: allKnown,
        config: defaultConfig,
      );

      expect(deck.progressPercentage, equals(100.0));
    });

    test('progressPercentage includes partial credit from consecutiveCorrect', () {
      // requiredConsecutiveCorrect is 3 (default). 3 questions: none known, each at 2/3
      final withPartial = [
        Question(id: 'q1', prompt: 'A', answers: ['x'], correctAnswerIndices: [0], consecutiveCorrect: 2, isKnown: false),
        Question(id: 'q2', prompt: 'B', answers: ['x'], correctAnswerIndices: [0], consecutiveCorrect: 2, isKnown: false),
        Question(id: 'q3', prompt: 'C', answers: ['x'], correctAnswerIndices: [0], consecutiveCorrect: 2, isKnown: false),
      ];
      final deck = Deck(
        id: 'deck1',
        title: 'Partial',
        description: 'Partial progress',
        questions: withPartial,
        config: defaultConfig,
      );

      expect(deck.practicePercentage, equals(0.0));
      expect(deck.progressPercentage, closeTo(66.67, 0.01)); // 3 * (2/3) / 3 * 100
    });

    test('progressPercentage mixes known and partial correctly', () {
      final config = DeckConfig(requiredConsecutiveCorrect: 3);
      final questions = [
        Question(id: 'q1', prompt: 'A', answers: ['x'], correctAnswerIndices: [0], isKnown: true),
        Question(id: 'q2', prompt: 'B', answers: ['x'], correctAnswerIndices: [0], consecutiveCorrect: 2, isKnown: false),
        Question(id: 'q3', prompt: 'C', answers: ['x'], correctAnswerIndices: [0], consecutiveCorrect: 0, isKnown: false),
      ];
      final deck = Deck(
        id: 'deck1',
        title: 'Mixed',
        description: 'Mixed',
        questions: questions,
        config: config,
      );

      // 1.0 + 2/3 + 0 = 1.667; 1.667/3*100 ≈ 55.56
      expect(deck.progressPercentage, closeTo(55.56, 0.01));
    });

    test('copyWith creates new deck with updated fields', () {
      final deck = Deck(
        id: 'deck1',
        title: 'Math Deck',
        description: 'Basic math',
        questions: sampleQuestions,
        config: defaultConfig,
      );

      final updated = deck.copyWith(title: 'Updated Title');
      expect(updated.title, equals('Updated Title'));
      expect(updated.id, equals(deck.id));
      expect(updated.questions, equals(deck.questions));
    });
  });
}