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

namespace EnvelopeGenerator.Application.EnvelopeReceivers.Queries;

/// <summary>
/// Represents a query for reading an envelope receiver including sensitive fields
/// (access code, phone number) that are excluded from the standard <see cref="ReadEnvelopeReceiverQuery"/>.
/// </summary>
/// <remarks>
/// Returns a single <see cref="EnvelopeReceiverSecretDto"/> matched by UUID and receiver signature.
/// Equivalent to the legacy <c>ReadWithSecretByUuidSignatureAsync</c> service method.
/// </remarks>
public record ReadEnvelopeReceiverSecretQuery
    : EnvelopeReceiverQueryBase<ReadEnvelopeQuery, ReadReceiverQuery>,
      IRequest<EnvelopeReceiverSecretDto?>;

/// <summary>
/// Extension methods for dispatching <see cref="ReadEnvelopeReceiverSecretQuery"/> via <see cref="IMediator"/>.
/// </summary>
public static class ReadEnvelopeReceiverSecretQueryExtensions
{
    /// <summary>
    /// Sends a <see cref="ReadEnvelopeReceiverSecretQuery"/> using the composite key (uuid::signature).
    /// </summary>
    /// <param name="mediator">The mediator instance.</param>
    /// <param name="key">Composite key in the format <c>uuid::signature</c>.</param>
    /// <param name="cancel">Cancellation token.</param>
    /// <returns>The matching <see cref="EnvelopeReceiverSecretDto"/>, or <c>null</c> if not found.</returns>
    public static Task<EnvelopeReceiverSecretDto?> ReadEnvelopeReceiverSecretAsync(
        this IMediator mediator,
        string key,
        CancellationToken cancel = default)
        => mediator.Send(new ReadEnvelopeReceiverSecretQuery { Key = key }, cancel);

    /// <summary>
    /// Sends a <see cref="ReadEnvelopeReceiverSecretQuery"/> using UUID and receiver signature.
    /// </summary>
    /// <param name="mediator">The mediator instance.</param>
    /// <param name="uuid">Envelope UUID.</param>
    /// <param name="signature">Receiver signature.</param>
    /// <param name="cancel">Cancellation token.</param>
    /// <returns>The matching <see cref="EnvelopeReceiverSecretDto"/>, or <c>null</c> if not found.</returns>
    public static Task<EnvelopeReceiverSecretDto?> ReadEnvelopeReceiverSecretAsync(
        this IMediator mediator,
        string uuid,
        string signature,
        CancellationToken cancel = default)
    {
        var q = new ReadEnvelopeReceiverSecretQuery();
        q.Envelope.Uuid = uuid;
        q.Receiver.Signature = signature;
        return mediator.Send(q, cancel);
    }

    /// <summary>
    /// Handles <see cref="ReadEnvelopeReceiverSecretQuery"/> and returns a
    /// <see cref="EnvelopeReceiverSecretDto"/> containing sensitive fields.
    /// </summary>
    public class ReadEnvelopeReceiverSecretQueryHandler
        : IRequestHandler<ReadEnvelopeReceiverSecretQuery, EnvelopeReceiverSecretDto?>
    {
        private readonly IRepository<EnvelopeReceiver> _repo;
        private readonly IRepository<Receiver> _rcvRepo;
        private readonly IMapper _mapper;

        /// <summary>
        /// Initializes a new instance of <see cref="ReadEnvelopeReceiverSecretQueryHandler"/>.
        /// </summary>
        /// <param name="envelopeReceiver">Repository for <see cref="EnvelopeReceiver"/>.</param>
        /// <param name="rcvRepo">Repository for <see cref="Receiver"/>.</param>
        /// <param name="mapper">AutoMapper instance.</param>
        public ReadEnvelopeReceiverSecretQueryHandler(
            IRepository<EnvelopeReceiver> envelopeReceiver,
            IRepository<Receiver> rcvRepo,
            IMapper mapper)
        {
            _repo = envelopeReceiver;
            _rcvRepo = rcvRepo;
            _mapper = mapper;
        }

        /// <summary>
        /// Handles the query and returns the matching <see cref="EnvelopeReceiverSecretDto"/>.
        /// </summary>
        /// <param name="request">The query containing filter criteria.</param>
        /// <param name="cancel">Cancellation token.</param>
        /// <returns>
        /// The matched <see cref="EnvelopeReceiverSecretDto"/>, or <c>null</c> if no record is found.
        /// </returns>
        public async Task<EnvelopeReceiverSecretDto?> Handle(
            ReadEnvelopeReceiverSecretQuery request,
            CancellationToken cancel)
        {
            var q = _repo.Query.Where(request, notnull: false);

            var envRcvs = await q
                .Include(er => er.Envelope).ThenInclude(e => e!.Documents!).ThenInclude(d => d.Elements)
                .Include(er => er.Envelope).ThenInclude(e => e!.Histories)
                .Include(er => er.Envelope).ThenInclude(e => e!.User)
                .Include(er => er.Receiver)
                .ToListAsync(cancel);

            if (request.Receiver.HasAnyCriteria && envRcvs.Count != 0)
            {
                var receiver = await _rcvRepo.Query.Where(request.Receiver).FirstAsync(cancel);

                foreach (var item in envRcvs)
                    item.Envelope?.Documents?.FirstOrDefault()?.Elements?.RemoveAll(s => s.ReceiverId != receiver.Id);
            }

            var envRcv = envRcvs.FirstOrDefault();
            if (envRcv is null)
                return null;

            return _mapper.Map<EnvelopeReceiverSecretDto>(envRcv);
        }
    }
}