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

void main() {
  group('PriorityManager', () {
    late DeckConfig config;

    setUp(() {
      config = const DeckConfig(
        priorityIncreaseOnIncorrect: 5,
        priorityDecreaseOnCorrect: 2,
      );
    });

    test('increases priority on incorrect answer', () {
      final question = Question(
        id: 'q1',
        prompt: 'Test',
        answers: ['A', 'B'],
        correctAnswerIndices: [0],
        priorityPoints: 10,
      );

      final updated = PriorityManager.applyAnswerResult(
        question: question,
        isCorrect: false,
        config: config,
      );

      expect(updated.priorityPoints,
          equals(10 + config.priorityIncreaseOnIncorrect));
    });

    test('decreases priority on correct answer', () {
      final question = Question(
        id: 'q1',
        prompt: 'Test',
        answers: ['A', 'B'],
        correctAnswerIndices: [0],
        priorityPoints: 10,
      );

      final updated = PriorityManager.applyAnswerResult(
        question: question,
        isCorrect: true,
        config: config,
      );

      expect(updated.priorityPoints,
          equals(10 - config.priorityDecreaseOnCorrect));
    });

    test('priority cannot go below 0', () {
      final question = Question(
        id: 'q1',
        prompt: 'Test',
        answers: ['A', 'B'],
        correctAnswerIndices: [0],
        priorityPoints: 1,
      );

      final updated = PriorityManager.applyAnswerResult(
        question: question,
        isCorrect: true,
        config: config,
      );

      expect(updated.priorityPoints, equals(0));
    });

    test('resetPriority sets priority to 0', () {
      final question = Question(
        id: 'q1',
        prompt: 'Test',
        answers: ['A', 'B'],
        correctAnswerIndices: [0],
        priorityPoints: 100,
      );

      final updated = PriorityManager.resetPriority(question);

      expect(updated.priorityPoints, equals(0));
    });

    test('withPriorityPoints enforces non-negative priority', () {
      final question = Question(
        id: 'q1',
        prompt: 'Test',
        answers: ['A', 'B'],
        correctAnswerIndices: [0],
        priorityPoints: 10,
      );

      final updated = question.withPriorityPoints(-5);

      expect(updated.priorityPoints, equals(0));
    });
  });
}