using AutoMapper;
using DigitalData.Core.Abstraction.Application.Repository;
using EnvelopeGenerator.Application.Common.Dto.EnvelopeReceiver;
using EnvelopeGenerator.Application.Common.Extensions;
using EnvelopeGenerator.Application.Common.Query;
using EnvelopeGenerator.Application.Envelopes.Queries;
using EnvelopeGenerator.Application.Receivers.Queries;
using EnvelopeGenerator.Domain.Entities;
using MediatR;
using Microsoft.EntityFrameworkCore;

namespace EnvelopeGenerator.Application.EnvelopeReceivers.Queries;

/// <summary>
/// Leichte Variante von <see cref="ReadEnvelopeReceiverQuery"/>:
/// Lädt NUR Envelope (mit Histories + User) und Receiver.
/// Lädt NICHT Documents/Elements.
/// 
/// Verwendung: Status-Prüfungen wo keine Dokument-Daten benötigt werden
/// (z.B. ReceiverAuthController.GetStatus).
/// </summary>
public record ReadEnvelopeReceiverLightQuery
    : EnvelopeReceiverQueryBase<ReadEnvelopeQuery, ReadReceiverQuery>, IRequest<EnvelopeReceiverDto?>;

/// <summary>
/// Handler für <see cref="ReadEnvelopeReceiverLightQuery"/>.
/// </summary>
public class ReadEnvelopeReceiverLightQueryHandler
    : IRequestHandler<ReadEnvelopeReceiverLightQuery, EnvelopeReceiverDto?>
{
    private readonly IRepository<EnvelopeReceiver> _repo;
    private readonly IMapper _mapper;

    /// <summary>
    /// Konstruktor.
    /// </summary>
    /// <param name="repo">EnvelopeReceiver-Repository</param>
    /// <param name="mapper">AutoMapper</param>
    public ReadEnvelopeReceiverLightQueryHandler(IRepository<EnvelopeReceiver> repo, IMapper mapper)
    {
        _repo = repo;
        _mapper = mapper;
    }

    /// <summary>
    /// Lädt einen EnvelopeReceiver ohne Documents/Elements.
    /// </summary>
    public async Task<EnvelopeReceiverDto?> Handle(ReadEnvelopeReceiverLightQuery request, CancellationToken cancel)
    {
        var envRcv = await _repo.Query
            .Where(request, notnull: false)
            .AsNoTracking()
            .Include(er => er.Envelope).ThenInclude(e => e!.Histories)
            .Include(er => er.Envelope).ThenInclude(e => e!.User)
            .Include(er => er.Receiver)
            .FirstOrDefaultAsync(cancel);

        return envRcv is null ? null : _mapper.Map<EnvelopeReceiverDto>(envRcv);
    }
}