using GermanApp.Domain.Entities;

namespace GermanApp.Application.DTOs;

/// <summary>
/// Data Transfer Object for QuizQuestion - used for API responses.
/// This is a read-only representation of a QuizQuestion entity.
/// </summary>
public record QuizQuestionDto(
    int Id,
    int LessonId,
    string LessonTitle,
    string QuestionText,
    QuestionType Type,
    string? CorrectAnswer,
    int Difficulty,
    int Order,
    bool IsActive,
    DateTime CreatedAt,
    DateTime? UpdatedAt,
    IReadOnlyList<QuizOptionDto> Options);

/// <summary>
/// Data Transfer Object for creating a new QuizQuestion.
/// </summary>
public record CreateQuizQuestionDto(
    int LessonId,
    string QuestionText,
    QuestionType Type,
    string? CorrectAnswer,
    int Difficulty,
    int Order,
    IReadOnlyList<CreateQuizOptionDto>? Options);

/// <summary>
/// Data Transfer Object for updating an existing QuizQuestion.
/// </summary>
public record UpdateQuizQuestionDto(
    int LessonId,
    string QuestionText,
    QuestionType Type,
    string? CorrectAnswer,
    int Difficulty,
    int Order,
    bool IsActive,
    IReadOnlyList<UpdateQuizOptionDto>? Options);

/// <summary>
/// Data Transfer Object for QuizOption - used for API responses.
/// </summary>
public record QuizOptionDto(
    int Id,
    int QuizQuestionId,
    string Text,
    bool IsCorrect,
    int Order);

/// <summary>
/// Data Transfer Object for creating a new QuizOption.
/// </summary>
public record CreateQuizOptionDto(
    string Text,
    bool IsCorrect,
    int Order);

/// <summary>
/// Data Transfer Object for updating an existing QuizOption.
/// </summary>
public record UpdateQuizOptionDto(
    int Id,
    string Text,
    bool IsCorrect,
    int Order);

/// <summary>
/// Data Transfer Object for quiz question with user's answer.
/// </summary>
public record QuizQuestionWithAnswerDto(
    int QuizQuestionId,
    int LessonId,
    string QuestionText,
    QuestionType Type,
    IReadOnlyList<QuizOptionDto> Options,
    string? UserAnswer,
    bool IsCorrect);

/// <summary>
/// Data Transfer Object for submitting quiz answers.
/// </summary>
public record SubmitQuizAnswersDto(
    int LessonId,
    IReadOnlyList<QuizAnswerDto> Answers);

/// <summary>
/// Data Transfer Object for a single quiz answer submission.
/// </summary>
public record QuizAnswerDto(
    int QuizQuestionId,
    string? AnswerText,
    int[]? SelectedOptionIds);

/// <summary>
/// Data Transfer Object for quiz result.
/// </summary>
public record QuizResultDto(
    int LessonId,
    int TotalQuestions,
    int CorrectAnswers,
    double ScorePercentage,
    bool Passed,
    TimeSpan TimeTaken,
    IReadOnlyList<QuizQuestionResultDto> QuestionResults);

/// <summary>
/// Data Transfer Object for individual question result.
/// </summary>
public record QuizQuestionResultDto(
    int QuizQuestionId,
    string QuestionText,
    QuestionType Type,
    bool IsCorrect,
    string? CorrectAnswer,
    string? UserAnswer);

/// <summary>
/// Extension methods for mapping between QuizQuestion entity and DTOs.
/// </summary>
public static class QuizQuestionDtoExtensions
{
    public static QuizQuestionDto ToDto(this QuizQuestion quizQuestion) => new(
        quizQuestion.Id,
        quizQuestion.LessonId,
        quizQuestion.Lesson?.Title ?? "Unknown",
        quizQuestion.QuestionText,
        quizQuestion.Type,
        quizQuestion.CorrectAnswer,
        quizQuestion.Difficulty,
        quizQuestion.Order,
        quizQuestion.IsActive,
        quizQuestion.CreatedAt,
        quizQuestion.UpdatedAt,
        quizQuestion.Options?.OrderBy(o => o.Order).Select(o => o.ToDto()).ToList() ?? new List<QuizOptionDto>());

    public static QuizQuestion ToEntity(this CreateQuizQuestionDto dto) =>
        QuizQuestion.Create(
            dto.LessonId,
            dto.QuestionText,
            dto.Type,
            dto.CorrectAnswer ?? string.Empty,
            dto.Difficulty,
            dto.Order);

    public static void UpdateFromDto(this QuizQuestion quizQuestion, UpdateQuizQuestionDto dto)
    {
        quizQuestion.UpdateLesson(dto.LessonId);
        quizQuestion.UpdateQuestionText(dto.QuestionText);
        quizQuestion.UpdateType(dto.Type);
        quizQuestion.UpdateCorrectAnswer(dto.CorrectAnswer ?? string.Empty);
        quizQuestion.UpdateDifficulty(dto.Difficulty);
        quizQuestion.UpdateOrder(dto.Order);
        
        if (dto.IsActive != quizQuestion.IsActive)
        {
            if (dto.IsActive)
                quizQuestion.Activate();
            else
                quizQuestion.Deactivate();
        }
    }

    public static QuizOptionDto ToDto(this QuizOption quizOption) => new(
        quizOption.Id,
        quizOption.QuizQuestionId,
        quizOption.Text,
        quizOption.IsCorrect,
        quizOption.Order);

    public static QuizOption ToEntity(this CreateQuizOptionDto dto, int quizQuestionId) =>
        QuizOption.Create(
            quizQuestionId,
            dto.Text,
            dto.IsCorrect,
            dto.Order);

    public static void UpdateFromDto(this QuizOption quizOption, UpdateQuizOptionDto dto)
    {
        quizOption.UpdateText(dto.Text);
        quizOption.UpdateIsCorrect(dto.IsCorrect);
        quizOption.UpdateOrder(dto.Order);
    }
}