using Application.Abstractions.Data;
using Application.Abstractions.Hub;
using Application.Abstractions.Messaging;
using SharedKernel;
using SharedKernel.Results;
using Domain.Entities.Donations.ValueObject;
using Microsoft.EntityFrameworkCore;

namespace Application.Features.Api.Crew.RemoveMember;

internal sealed class Handler(
    IAppDbContext db,
    ICrewHubBroadcaster crewBroadcaster
) : ICommandHandler<Command, Result>
{
    public async Task<Result> Handle(Command request, CancellationToken ct)
    {
        var member = await db.CrewMember
            .FirstOrDefaultAsync(m => m.ID == request.CrewMemberID, ct);

        if (member is null)
        {
            return Result.Failure(Error.NotFound("Crew.MemberNotFound", "크루원을 찾을 수 없습니다."));
        }

        // 진행 중인 세션이 있으면 삭제 불가
        var hasActiveSession = await db.CrewSession
            .AnyAsync(s => s.CrewID == member.CrewID && s.Status != CrewSessionStatus.Ended, ct);

        if (hasActiveSession)
        {
            return Result.Failure(Error.Conflict("Crew.ActiveSessionExists", "진행 중인 크루 방송이 있어 삭제할 수 없습니다."));
        }

        // EF Remove 후 추적 해제될 수 있으니 broadcast 에 필요한 ID 미리 캐싱
        var crewID = member.CrewID;
        var crewMemberID = member.ID;
        var memberID = member.MemberID;

        db.CrewMember.Remove(member);
        await db.SaveChangesAsync(ct);

        // 운영자 그룹에 삭제 broadcast
        await crewBroadcaster.BroadcastMemberChangeAsync(
            crewID: crewID,
            kind: "removed",
            data: new
            {
                crewMemberID,
                memberID
            },
            ct: ct
        );

        return Result.Success();
    }
}