ANTOOZA-BACKEND/Domain/Entities/Members/BroadcastSession.cs

using System.ComponentModel.DataAnnotations;
using System.ComponentModel.DataAnnotations.Schema;
using Domain.Entities.Members.ValueObject;

namespace Domain.Entities.Members;

/// <summary>
/// 1회 방송 세션 (라이브 시작~종료) — YouTube 라이브 지표 수집 단위
/// </summary>
public sealed class BroadcastSession
{
    [ForeignKey(nameof(ChannelID))]
    public Channel Channel { get; private set; } = null!;

    [Key]
    public int ID { get; private set; }

    public int ChannelID { get; private set; }

    public BroadcastPlatform Platform { get; private set; } = BroadcastPlatform.YouTube;

    public string VideoID { get; private set; } = default!;

    public string? Title { get; private set; }

    public DateTime? StartAt { get; private set; }

    public DateTime? EndAt { get; private set; }

    public int DurationSec { get; private set; }

    public long FinalViews { get; private set; }

    public long FinalLikes { get; private set; }

    public bool IsFinalized { get; private set; }

    public DateTime? UpdatedAt { get; private set; }

    public DateTime CreatedAt { get; private set; } = DateTime.UtcNow;

    private BroadcastSession() { }

    private BroadcastSession(int channelID, BroadcastPlatform platform, string videoID)
    {
        if (channelID <= 0)
        {
            throw new ArgumentOutOfRangeException(nameof(channelID));
        }

        if (string.IsNullOrWhiteSpace(videoID))
        {
            throw new ArgumentException("VideoID is required.", nameof(videoID));
        }

        ChannelID = channelID;
        Platform = platform;
        VideoID = videoID;
    }

    public static BroadcastSession Create(int channelID, BroadcastPlatform platform, string videoID)
    {
        return new(channelID, platform, videoID);
    }

    public void UpdateStats(
        string? title,
        DateTime? startAt,
        DateTime? endAt,
        long finalViews,
        long finalLikes
    ) {
        Title = title;
        StartAt = startAt;
        EndAt = endAt;

        if (startAt.HasValue && endAt.HasValue && endAt.Value > startAt.Value)
        {
            DurationSec = (int)(endAt.Value - startAt.Value).TotalSeconds;
        }

        FinalViews = finalViews;
        FinalLikes = finalLikes;
        UpdatedAt = DateTime.UtcNow;
    }

    public void MarkFinalized()
    {
        IsFinalized = true;
        UpdatedAt = DateTime.UtcNow;
    }
}