namespace GermanApp.Domain.Entities;

/// <summary>
/// Represents a user's progress through lessons.
/// Tracks completion status and quiz scores.
/// </summary>
public class UserProgress
{
    public int Id { get; private set; }
    public int UserId { get; private set; }
    public int LessonId { get; private set; }
    public bool IsCompleted { get; private set; }
    public int QuizScore { get; private set; }
    public DateTime LastAttemptDate { get; private set; }

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

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

    /// <summary>
    /// Factory method to create a new user progress record.
    /// </summary>
    /// <param name="userId">ID of the user</param>
    /// <param name="lessonId">ID of the lesson</param>
    public static UserProgress Create(int userId, int lessonId)
    {
        return new UserProgress
        {
            UserId = userId,
            LessonId = lessonId,
            IsCompleted = false,
            QuizScore = 0,
            LastAttemptDate = DateTime.UtcNow
        };
    }

    /// <summary>
    /// Marks the lesson as completed.
    /// </summary>
    /// <param name="quizScore">The score achieved on the quiz (0-100)</param>
    public void MarkAsCompleted(int quizScore)
    {
        if (quizScore < 0 || quizScore > 100)
            throw new ArgumentOutOfRangeException(nameof(quizScore), "Score must be between 0 and 100");

        IsCompleted = true;
        QuizScore = quizScore;
        LastAttemptDate = DateTime.UtcNow;
    }

    /// <summary>
    /// Updates the quiz score without marking as completed.
    /// </summary>
    public void UpdateQuizScore(int quizScore)
    {
        if (quizScore < 0 || quizScore > 100)
            throw new ArgumentOutOfRangeException(nameof(quizScore), "Score must be between 0 and 100");

        QuizScore = quizScore;
        LastAttemptDate = DateTime.UtcNow;
    }

    /// <summary>
    /// Resets the progress (e.g., when user wants to redo a lesson).
    /// </summary>
    public void Reset()
    {
        IsCompleted = false;
        QuizScore = 0;
        LastAttemptDate = DateTime.UtcNow;
    }

    /// <summary>
    /// Checks if the user passed the lesson (80% or higher).
    /// </summary>
    public bool HasPassed() => QuizScore >= 80;
}