ANTOOZA-BACKEND/Application/Features/Api/Channel/GetByCode/Handler.cs

using Application.Abstractions.Data;
using Application.Abstractions.Messaging;
using Microsoft.EntityFrameworkCore;
using SharedKernel.Results;

namespace Application.Features.Api.Channel.GetByCode;

public sealed class Handler(IAppDbContext db) : IQueryHandler<Query, Result<Response>>
{
    public async Task<Result<Response>> Handle(Query request, CancellationToken ct)
    {
        if (string.IsNullOrWhiteSpace(request.Code))
        {
            return Result.Failure<Response>(Error.NotFound("Channel.CodeRequired", "후원 코드를 입력해 주세요."));
        }

        // 후원 코드 정규화 (uppercase). SearchForOrder 와 동일 규약.
        var normalized = request.Code.Trim().ToUpperInvariant();

        var channel = await db.Channel.AsNoTracking()
            .Where(c => c.IsActive && c.MemberID != request.MemberID && c.DonationCode == normalized)
            .Select(c => new Response(
                c.ID,
                c.SID,
                c.Name,
                c.Handle,
                c.ThumbnailUrl,
                c.SubscriberCount,
                c.IsVerified,
                c.DonationCode
            ))
            .FirstOrDefaultAsync(ct);

        if (channel is null)
        {
            return Result.Failure<Response>(Error.NotFound("Channel.NotFound", "해당 후원 코드의 채널을 찾을 수 없습니다."));
        }

        return Result.Success(channel);
    }
}