using System.ComponentModel.DataAnnotations;

namespace Domain.Entities.Chat;

/// <summary>
/// 채팅방 설정 (개미투자 D2) — RoomKey: main | stock:{code}.
/// main 은 row 없이도 기본 오픈, 종목방은 row 존재 + IsActive 일 때만 오픈(상위 N 종목 단계 오픈 — d0 §5-④).
/// </summary>
public class ChatRoomConfig
{
    /// <summary>룸 키 (PK) — main, stock:005930 형식</summary>
    [Key]
    public string RoomKey { get; private set; } = default!;

    /// <summary>활성 여부 — 종목방 단계 오픈 게이트</summary>
    public bool IsActive { get; private set; } = true;

    /// <summary>슬로우 모드 (초) — 0 이면 전역 rate limit 만 적용</summary>
    public short SlowModeSeconds { get; private set; }

    /// <summary>상단 고정 공지 (선택)</summary>
    public string? Notice { get; private set; }

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

    private ChatRoomConfig() { }

    public static ChatRoomConfig Create(string roomKey, bool isActive = true, short slowModeSeconds = 0, string? notice = null)
    {
        if (string.IsNullOrWhiteSpace(roomKey) || roomKey.Length > 20)
        {
            throw new ArgumentException("roomKey must be 1~20 chars", nameof(roomKey));
        }

        if (slowModeSeconds < 0)
        {
            throw new ArgumentOutOfRangeException(nameof(slowModeSeconds));
        }

        return new ChatRoomConfig
        {
            RoomKey = roomKey.Trim(),
            IsActive = isActive,
            SlowModeSeconds = slowModeSeconds,
            Notice = string.IsNullOrWhiteSpace(notice) ? null : notice.Trim()
        };
    }

    public void Update(bool isActive, short slowModeSeconds, string? notice)
    {
        if (slowModeSeconds < 0)
        {
            throw new ArgumentOutOfRangeException(nameof(slowModeSeconds));
        }

        IsActive = isActive;
        SlowModeSeconds = slowModeSeconds;
        Notice = string.IsNullOrWhiteSpace(notice) ? null : notice.Trim();
        UpdatedAt = DateTime.UtcNow;
    }
}