ANTOOZA-BACKEND/Application/Features/Api/Auth/ForgotPassword/Handler.cs

using Application.Abstractions.Data;
using Application.Abstractions.Messaging;
using Application.Abstractions.Messaging.Email;
using Application.Common;
using Domain.Entities.EmailVerification;
using Domain.Entities.EmailVerification.ValueObject;
using SharedKernel.Results;
using Microsoft.EntityFrameworkCore;

namespace Application.Features.Api.Auth.ForgotPassword;

internal sealed class Handler(
    IAppDbContext db,
    IMailService mailService
) : ICommandHandler<Command, Result>
{
    public async Task<Result> Handle(Command request, CancellationToken ct)
    {
        // 이메일 유효성 검사
        if (string.IsNullOrWhiteSpace(request.Email))
        {
            return Result.Failure(Error.Problem("Auth.EmailRequired", "이메일은 필수입니다."));
        }

        var email = request.Email.Trim().ToLower();

        // 회원 조회
        var member = await db.Member.FirstOrDefaultAsync(m => m.Email == email, ct);
        if (member is null)
        {
            return Result.Failure(Error.NotFound("Auth.MemberNotFound", "등록된 회원 정보를 찾을 수 없습니다."));
        }

        // 탈퇴 회원 거부
        if (member.IsWithdraw)
        {
            return Result.Failure(Error.Problem("Auth.MemberWithdrawn", "탈퇴한 회원은 이용할 수 없습니다."));
        }

        // 차단 회원 거부
        if (member.IsDenied)
        {
            return Result.Failure(Error.Problem("Auth.MemberDenied", "차단된 회원이므로 이용할 수 없습니다."));
        }

        // 기존 미인증 코드 삭제
        var existing = await db.EmailVerifyNumber.Where(e => e.Email == email && e.Type == VerificationType.ForgotPassword && !e.IsVerified).ToListAsync(ct);

        db.EmailVerifyNumber.RemoveRange(existing);

        // 6자리 랜덤 숫자 코드 생성
        var code = Random.Shared.Next(100000, 999999).ToString();
        var verifyNumber = EmailVerifyNumber.Create(
            VerificationType.ForgotPassword,
            email,
            code,
            DateTime.UtcNow.AddMinutes(10)
        );

        await db.EmailVerifyNumber.AddAsync(verifyNumber, ct);
        await db.SaveChangesAsync(ct);

        // 인증번호 이메일 발송
        var emailTpl = (await db.Config.AsNoTracking().FirstOrDefaultAsync(ct))?.EmailTemplate;
        var subject = string.IsNullOrWhiteSpace(emailTpl?.ResetPasswordEmailFormTitle)
            ? "비밀번호 재설정 인증번호"
            : emailTpl!.ResetPasswordEmailFormTitle!;
        var content = string.IsNullOrWhiteSpace(emailTpl?.ResetPasswordEmailFormContent)
            ? $"<p>비밀번호 재설정 인증번호입니다.</p><p><strong>{code}</strong></p><p>이 코드는 10분간 유효합니다.</p>"
            : emailTpl!.ResetPasswordEmailFormContent!.Render(("Code", code), ("Email", email));
        await mailService.SendAsync(new SendData(email, subject, content), ct);

        return Result.Success();
    }
}