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

namespace Application.Features.Api.MyPage.UpdateChatSettings;

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

        if (approve is null)
        {
            var exists = await db.Member.AsNoTracking().AnyAsync(m => m.ID == request.MemberID, ct);
            if (!exists)
            {
                return Result.Failure(Error.NotFound("MyPage.MemberNotFound", "회원 정보를 찾을 수 없습니다."));
            }

            approve = MemberApprove.Create(request.MemberID);
            await db.MemberApprove.AddAsync(approve, ct);
        }

        approve.IsChatAllowInvite = request.AllowInvite;
        approve.IsChatAllowWhisper = request.AllowWhisper;
        approve.IsChatShowFollowingOnline = request.ShowFollowingOnline;

        try
        {
            await db.SaveChangesAsync(ct);
        }
        catch (DbUpdateException)
        {
            // 최초 저장 동시 요청 경합 — 다른 요청이 이미 MemberApprove 를 생성함(MemberID PK 충돌).
            // 재시도 시 갱신 경로로 성공한다.
            return Result.Failure(Error.Conflict("MyPage.ChatSettingsConflict", "설정 저장이 지연되었습니다. 다시 시도해 주세요."));
        }

        return Result.Success();
    }
}