DeutschLernen/GermanApp/Domain/Entities/StoryProgress.cs

namespace GermanApp.Domain.Entities;

/// <summary>
/// Tracks a user's progress through story segments.
/// A user unlocks story segments by completing lessons.
/// </summary>
public class StoryProgress
{
    public int Id { get; private set; }

    /// <summary>
    /// The user ID who owns this progress.
    /// </summary>
    public int UserId { get; private set; }

    /// <summary>
    /// The level ID this progress is for.
    /// </summary>
    public int LevelId { get; private set; }

    /// <summary>
    /// The story segment ID that was unlocked.
    /// </summary>
    public int StorySegmentId { get; private set; }

    /// <summary>
    /// Whether the user has read/listened to this segment.
    /// </summary>
    public bool IsCompleted { get; private set; }

    /// <summary>
    /// When the segment was unlocked.
    /// </summary>
    public DateTime UnlockedAt { get; private set; }

    /// <summary>
    /// When the segment was completed (read/listened to).
    /// </summary>
    public DateTime? CompletedAt { get; private set; }

    /// <summary>
    /// Timestamp when the progress record was created.
    /// </summary>
    public DateTime CreatedAt { get; private set; }

    /// <summary>
    /// Timestamp when the progress record was last updated.
    /// </summary>
    public DateTime? UpdatedAt { get; private set; }

    // Navigation properties
    public virtual User? User { get; private set; }
    public virtual Level? Level { get; private set; }
    public virtual StorySegment? StorySegment { get; private set; }

    /// <summary>
    /// Constructor for EF Core deserialization.
    /// </summary>
    private StoryProgress() { }

    /// <summary>
    /// Factory method to create a new story progress record.
    /// </summary>
    /// <param name="userId">The user ID</param>
    /// <param name="levelId">The level ID</param>
    /// <param name="storySegmentId">The story segment ID</param>
    /// <returns>New StoryProgress instance</returns>
    public static StoryProgress Create(int userId, int levelId, int storySegmentId)
    {
        return new StoryProgress
        {
            UserId = userId,
            LevelId = levelId,
            StorySegmentId = storySegmentId,
            IsCompleted = false,
            UnlockedAt = DateTime.UtcNow,
            CreatedAt = DateTime.UtcNow
        };
    }

    /// <summary>
    /// Marks this story segment as completed (read/listened to).
    /// </summary>
    public void MarkAsCompleted()
    {
        if (!IsCompleted)
        {
            IsCompleted = true;
            CompletedAt = DateTime.UtcNow;
            UpdatedAt = DateTime.UtcNow;
        }
    }

    /// <summary>
    /// Marks this story segment as not completed.
    /// </summary>
    public void MarkAsIncomplete()
    {
        if (IsCompleted)
        {
            IsCompleted = false;
            CompletedAt = null;
            UpdatedAt = DateTime.UtcNow;
        }
    }
}