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

namespace Application.Features.Api.V1.Channels.GetByCode;

internal sealed class Handler(IAppDbContext db) : IQueryHandler<Query, Result<Response>>
{
    public async Task<Result<Response>> Handle(Query request, CancellationToken ct)
    {
        if (string.IsNullOrWhiteSpace(request.Code))
        {
            return Result.Failure<Response>(Error.Problem("Channel.CodeRequired", "후원 코드는 필수입니다."));
        }

        var code = request.Code.Trim().ToUpperInvariant();

        var channel = await db.Channel
            .AsNoTracking()
            .Where(c => c.DonationCode == code)
            .Select(c => new
            {
                c.SID,
                c.Name,
                c.IsActive,
                MemberGone = c.Member.IsWithdraw || c.Member.DeletedAt != null
            })
            .FirstOrDefaultAsync(ct);

        if (channel is null)
        {
            return Result.Failure<Response>(Error.NotFound("Channel.NotFound", "해당 후원 코드의 채널을 찾을 수 없습니다."));
        }

        return Result.Success(new Response(
            channel.SID,
            channel.Name,
            code,
            channel.IsActive && !channel.MemberGone
        ));
    }
}