using GermanApp.Domain.Entities;

namespace GermanApp.Application.DTOs;

/// <summary>
/// Data Transfer Object for Lesson - used for API responses.
/// This is a read-only representation of a Lesson entity.
/// </summary>
public record LessonDto(
    int Id,
    string Title,
    string Description,
    int LevelId,
    string LevelName,
    string LevelCode,
    int Order,
    string Topic,
    DateTime CreatedAt,
    DateTime? UpdatedAt);

/// <summary>
/// Data Transfer Object for creating a new Lesson.
/// </summary>
public record CreateLessonDto(
    string Title,
    string Description,
    int LevelId,
    int Order,
    string Topic);

/// <summary>
/// Data Transfer Object for updating an existing Lesson.
/// </summary>
public record UpdateLessonDto(
    string Title,
    string Description,
    int LevelId,
    int Order,
    string Topic);

/// <summary>
/// Extension methods for mapping between Lesson entity and DTOs.
/// </summary>
public static class LessonDtoExtensions
{
    public static LessonDto ToDto(this Lesson lesson) => new(
        lesson.Id,
        lesson.Title,
        lesson.Description,
        lesson.LevelId,
        lesson.Level?.Name ?? "Unknown",
        lesson.Level?.Code ?? "??",
        lesson.Order,
        lesson.Topic,
        lesson.CreatedAt,
        lesson.UpdatedAt);

    public static Lesson ToEntity(this CreateLessonDto dto) =>
        Lesson.Create(dto.LevelId, dto.Title, dto.Order, dto.Topic, dto.Description);

    public static void UpdateFromDto(this Lesson lesson, UpdateLessonDto dto)
    {
        lesson.UpdateTitle(dto.Title);
        lesson.UpdateDescription(dto.Description);
        lesson.UpdateLevel(dto.LevelId);
        lesson.UpdateOrder(dto.Order);
        lesson.UpdateTopic(dto.Topic);
    }
}