ANTOOZA-BACKEND/Application/Features/Api/MyPage/Address/Delete/Handler.cs

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

namespace Application.Features.Api.MyPage.Address.Delete;

public sealed class Handler(IAppDbContext db) : ICommandHandler<Command, Result>
{
    public async Task<Result> Handle(Command request, CancellationToken ct)
    {
        var address = await db.MemberAddress
            .FirstOrDefaultAsync(a => a.ID == request.ID && a.MemberID == request.MemberID, ct);

        if (address is null)
        {
            return Result.Failure(Error.NotFound("Address.NotFound", "주소를 찾을 수 없습니다."));
        }

        var wasDefault = address.IsDefault;

        db.MemberAddress.Remove(address);
        await db.SaveChangesAsync(ct);

        // 기본 주소를 삭제한 경우 — 남아 있는 주소 중 첫 번째를 기본으로 설정
        if (wasDefault)
        {
            var nextDefault = await db.MemberAddress
                .Where(a => a.MemberID == request.MemberID)
                .OrderBy(a => a.ID)
                .FirstOrDefaultAsync(ct);

            if (nextDefault is not null)
            {
                nextDefault.SetAsDefault();
                await db.SaveChangesAsync(ct);
            }
        }

        return Result.Success();
    }
}