ANTOOZA-BACKEND/Application/Features/Api/V1/Purchases/Get/Handler.cs

using Application.Abstractions.Data;
using Application.Abstractions.Messaging;
using Domain.Entities.Developers.ValueObject;
using Microsoft.EntityFrameworkCore;
using SharedKernel.Results;

namespace Application.Features.Api.V1.Purchases.Get;

internal sealed class Handler(IAppDbContext db) : IQueryHandler<Query, Result<Response>>
{
    public async Task<Result<Response>> Handle(Query request, CancellationToken ct)
    {
        if (string.IsNullOrWhiteSpace(request.OrderID))
        {
            return Result.Failure<Response>(Error.Problem("Purchase.OrderIDRequired", "orderID 는 필수입니다."));
        }

        if (request.Marketplace.HasValue && !Enum.IsDefined(typeof(ApiPurchaseMarketplace), request.Marketplace.Value))
        {
            return Result.Failure<Response>(Error.Problem("Purchase.MarketplaceInvalid", "marketplace 는 1(구글)~6(기타) 값이어야 합니다."));
        }

        var orderID = request.OrderID.Trim();

        var query = db.ApiPurchase.AsNoTracking().Where(c => c.OrderID == orderID);

        // 호출 주체 범위 제한 — OAuth2: 해당 앱 / PAT: 본인 소유 앱 전체
        if (request.ApplicationID.HasValue)
        {
            query = query.Where(c => c.ApplicationID == request.ApplicationID.Value);
        }
        else if (request.OwnerMemberID.HasValue)
        {
            query = query.Where(c => c.Application!.OwnerMemberID == request.OwnerMemberID.Value);
        }
        else
        {
            return Result.Failure<Response>(Error.Unauthorized("Purchase.CallerUnknown", "호출 주체를 식별할 수 없습니다."));
        }

        if (request.Marketplace.HasValue)
        {
            var marketplace = (ApiPurchaseMarketplace)request.Marketplace.Value;
            query = query.Where(c => c.Marketplace == marketplace);
        }

        var rows = await query
            .Select(c => new Response(
                c.ID,
                c.OrderID,
                (int)c.Marketplace,
                c.Channel!.DonationCode,
                c.Channel!.SID,
                c.Game!.Code ?? string.Empty,
                c.ProductID,
                c.SubID,
                c.OrderPrice,
                c.CommissionRate,
                c.CommissionAmount,
                c.Status.ToString(),
                c.ConfirmDueAt,
                c.ConfirmedAt,
                c.CanceledAt,
                c.CreatedAt
            ))
            .ToListAsync(ct);

        if (rows.Count == 0)
        {
            return Result.Failure<Response>(Error.NotFound("Purchase.NotFound", "등록된 주문을 찾을 수 없습니다."));
        }

        if (rows.Count > 1)
        {
            return Result.Failure<Response>(Error.Problem("Purchase.AmbiguousOrderID", "여러 건이 조회되었습니다. marketplace 를 지정하세요."));
        }

        return Result.Success(rows[0]);
    }
}