bitforum-backend/Application/Features/Api/Forum/Post/Create/Handler.cs

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

namespace Application.Features.Api.Forum.Post.Create;

public sealed class Handler(IAppDbContext db) : ICommandHandler<Command, Result<int>>
{
    public async Task<Result<int>> Handle(Command request, CancellationToken ct)
    {
        if (string.IsNullOrWhiteSpace(request.Subject))
        {
            return Result.Failure<int>(Error.Problem("Post.SubjectRequired", "제목을 입력해주세요."));
        }

        var board = await db.Board.AsNoTracking().FirstOrDefaultAsync(x => x.ID == request.BoardID, ct);
        if (board is null)
        {
            return Result.Failure<int>(Error.NotFound("Post.BoardNotFound", "게시판을 찾을 수 없습니다."));
        }

        var member = await db.Member.AsNoTracking().FirstOrDefaultAsync(x => x.ID == request.MemberID, ct);
        if (member is null)
        {
            return Result.Failure<int>(Error.NotFound("Post.MemberNotFound", "회원 정보를 찾을 수 없습니다."));
        }

        var post = new Domain.Entities.Forum.Posts.Post
        {
            BoardID = request.BoardID,
            BoardPrefixID = request.BoardPrefixID,
            MemberID = request.MemberID,
            Subject = request.Subject.Trim(),
            Content = request.Content ?? string.Empty,
            IsSecret = request.IsSecret,
            Name = member.Name,
            SID = member.SID,
            Email = member.Email
        };

        await db.Post.AddAsync(post, ct);
        await db.SaveChangesAsync(ct);

        // Board 게시글 카운트 증가
        var boardEntity = await db.Board.FirstOrDefaultAsync(x => x.ID == request.BoardID, ct);
        if (boardEntity is not null)
        {
            boardEntity.Posts++;
            boardEntity.UpdatedAt = DateTime.UtcNow;

            var boardGroup = await db.BoardGroup.FirstOrDefaultAsync(x => x.ID == boardEntity.BoardGroupID, ct);
            if (boardGroup is not null)
            {
                boardGroup.Posts++;
                boardGroup.UpdatedAt = DateTime.UtcNow;
            }

            // MemberStats 게시글 수 증가
            var memberStats = await db.MemberStats.FirstOrDefaultAsync(x => x.MemberID == request.MemberID, ct);
            if (memberStats is not null)
            {
                memberStats.PostCount++;
            }

            await db.SaveChangesAsync(ct);
        }

        return post.ID;
    }
}