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';
import 'package:practice_engine/logic/attempt_service.dart';
import 'package:practice_engine/logic/deck_service.dart';

void main() {
  group('Attempt Flow', () {
    late Deck deck;
    late AttemptService attemptService;

    setUp(() {
      final config = const DeckConfig(
        defaultAttemptSize: 5,
        requiredConsecutiveCorrect: 3,
      );

      final questions = List.generate(10, (i) {
        return Question(
          id: 'q$i',
          prompt: 'Question $i',
          answers: ['A', 'B', 'C'],
          correctAnswerIndices: [0],
          priorityPoints: i,
        );
      });

      deck = Deck(
        id: 'deck1',
        title: 'Test Deck',
        description: 'Test',
        questions: questions,
        config: config,
      );

      attemptService = AttemptService(seed: 42);
    });

    test('createAttempt selects correct number of questions', () {
      final attempt = attemptService.createAttempt(deck: deck);

      expect(attempt.questions.length, equals(deck.config.defaultAttemptSize));
    });

    test('createAttempt uses custom attempt size', () {
      final attempt = attemptService.createAttempt(
        deck: deck,
        attemptSize: 3,
      );

      expect(attempt.questions.length, equals(3));
    });

    test('createAttempt has no duplicate questions', () {
      final attempt = attemptService.createAttempt(deck: deck);

      final ids = attempt.questions.map((q) => q.id).toList();
      final uniqueIds = ids.toSet();

      expect(uniqueIds.length, equals(ids.length));
    });

    test('processAttempt updates deck with results', () {
      final attempt = attemptService.createAttempt(deck: deck);
      final answers = <String, int>{};

      // Answer all questions correctly
      for (final question in attempt.questions) {
        answers[question.id] = question.correctIndices.first;
      }

      final result = attemptService.processAttempt(
        deck: deck,
        attempt: attempt,
        answers: answers,
      );

      expect(result.updatedDeck.currentAttemptIndex,
          equals(deck.currentAttemptIndex + 1));
    });

    test('processAttempt calculates correct percentage', () {
      final attempt = attemptService.createAttempt(
        deck: deck,
        attemptSize: 3,
      );
      final answers = <String, int>{};

      // Answer 2 out of 3 correctly
      answers[attempt.questions[0].id] =
          attempt.questions[0].correctIndices.first;
      answers[attempt.questions[1].id] =
          attempt.questions[1].correctIndices.first;
      answers[attempt.questions[2].id] = 999; // Wrong answer

      final result = attemptService.processAttempt(
        deck: deck,
        attempt: attempt,
        answers: answers,
      );

      expect(result.result.percentageCorrect, closeTo(66.67, 0.01));
      expect(result.result.correctCount, equals(2));
    });

    test('processAttempt tracks incorrect questions', () {
      final attempt = attemptService.createAttempt(
        deck: deck,
        attemptSize: 3,
      );
      final answers = <String, int>{};

      // Answer first correctly, rest incorrectly
      answers[attempt.questions[0].id] =
          attempt.questions[0].correctIndices.first;
      answers[attempt.questions[1].id] = 999;
      answers[attempt.questions[2].id] = 999;

      final result = attemptService.processAttempt(
        deck: deck,
        attempt: attempt,
        answers: answers,
      );

      expect(result.result.incorrectQuestions.length, equals(2));
    });

    test('processAttempt updates question streaks correctly', () {
      final question = Question(
        id: 'q1',
        prompt: 'Test',
        answers: ['A', 'B'],
        correctAnswerIndices: [0],
        consecutiveCorrect: 2,
      );

      final testDeck = deck.copyWith(questions: [question]);
      final attempt = attemptService.createAttempt(
        deck: testDeck,
        attemptSize: 1,
      );

      final answers = {question.id: question.correctIndices.first};

      final result = attemptService.processAttempt(
        deck: testDeck,
        attempt: attempt,
        answers: answers,
      );

      final updated = result.updatedDeck.questions.first;
      expect(updated.consecutiveCorrect, equals(3));
      expect(updated.isKnown, equals(true));
    });

    test('processAttempt preserves manual mark as known when using current deck state', () {
      // One question, not known, no streak
      final question = Question(
        id: 'q1',
        prompt: 'Test',
        answers: ['A', 'B'],
        correctAnswerIndices: [0],
        consecutiveCorrect: 0,
        isKnown: false,
      );

      final testDeck = Deck(
        id: 'deck1',
        title: 'Test',
        description: 'Test',
        questions: [question],
        config: const DeckConfig(requiredConsecutiveCorrect: 3),
      );

      final attempt = attemptService.createAttempt(
        deck: testDeck,
        attemptSize: 1,
      );
      expect(attempt.questions.single.isKnown, isFalse);

      // User marks as known during the attempt (as in the app)
      final deckWithManualKnown = DeckService.markQuestionAsKnown(
        deck: testDeck,
        questionId: question.id,
      );
      expect(deckWithManualKnown.questions.single.isKnown, isTrue);

      // Complete attempt with correct answer, passing deck that has manual known
      final answers = {question.id: question.correctIndices.first};
      final result = attemptService.processAttempt(
        deck: deckWithManualKnown,
        attempt: attempt,
        answers: answers,
      );

      // Manual "known" must be preserved in the result
      final updated = result.updatedDeck.questions.first;
      expect(updated.isKnown, isTrue, reason: 'Manual mark as known must count towards known after attempt');
    });
  });
}