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

namespace Domain.Entities.Store;

/// <summary>
/// 게임사 월별 정산 큐. 매월 1일 새벽 HostedService 가 전월 Order 들의 GameRevenueAmount 를 GameID 별로 집계.
/// UNIQUE (GameID, Year, Month). Admin 이 다운로드 후 수동 송금하고 Settled 마킹.
/// </summary>
public class GameSettlement
{
    [ForeignKey(nameof(GameID))]
    public virtual Game? Game { get; private set; }

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

    public int GameID { get; private set; }

    public int Year { get; private set; }

    public int Month { get; private set; }

    /// <summary>해당 월 누적 게임사 몫 (= Σ Order.GameRevenueAmount).</summary>
    public int TotalRevenueAmount { get; private set; }

    /// <summary>해당 월 주문 건수.</summary>
    public int OrderCount { get; private set; }

    public GameSettlementStatus Status { get; private set; } = GameSettlementStatus.Pending;

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

    public DateTime? SettledAt { get; private set; }

    /// <summary>처리 관리자 (ASP.NET Identity ApplicationUser.Id).</summary>
    public string? SettledByAdminUserId { get; private set; }

    /// <summary>처리 관리자 Email 스냅샷 (표시용).</summary>
    public string? SettledByAdminEmail { get; private set; }

    public string? AdminMemo { get; private set; }

    private GameSettlement() { }

    public static GameSettlement Create(int gameID, int year, int month)
    {
        if (gameID <= 0)
        {
            throw new ArgumentOutOfRangeException(nameof(gameID));
        }

        if (year < 2000 || year > 9999)
        {
            throw new ArgumentOutOfRangeException(nameof(year));
        }

        if (month < 1 || month > 12)
        {
            throw new ArgumentOutOfRangeException(nameof(month));
        }

        return new GameSettlement
        {
            GameID = gameID,
            Year = year,
            Month = month
        };
    }

    /// <summary>월간 집계 시 row 가 이미 있으면 누적. HostedService 에서 멱등 처리용.</summary>
    public void AddRevenue(int revenueAmount, int orderCount = 1)
    {
        if (revenueAmount < 0)
        {
            throw new ArgumentOutOfRangeException(nameof(revenueAmount));
        }

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

        if (Status != GameSettlementStatus.Pending)
        {
            throw new InvalidOperationException("이미 정산된 row 에는 추가 적재 불가.");
        }

        TotalRevenueAmount += revenueAmount;
        OrderCount += orderCount;
    }

    /// <summary>환불 시 비례 차감.</summary>
    public void SubtractRevenue(int revenueAmount)
    {
        if (revenueAmount <= 0)
        {
            throw new ArgumentOutOfRangeException(nameof(revenueAmount));
        }

        if (Status != GameSettlementStatus.Pending)
        {
            throw new InvalidOperationException("이미 정산된 row 에는 환불 차감 불가. 별도 정정 정산 row 필요.");
        }

        TotalRevenueAmount = Math.Max(0, TotalRevenueAmount - revenueAmount);
    }

    public void MarkSettled(string adminUserId, string? adminEmail, string? adminMemo = null)
    {
        if (Status != GameSettlementStatus.Pending)
        {
            throw new InvalidOperationException($"Cannot mark settled from status {Status}.");
        }

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

        Status = GameSettlementStatus.Settled;
        SettledByAdminUserId = adminUserId;
        SettledByAdminEmail = adminEmail;
        SettledAt = DateTime.UtcNow;
        AdminMemo = adminMemo;
    }
}