using AutoMapper;
using DigitalData.Core.Abstraction.Application.Repository;
using DigitalData.Core.Exceptions;
using EnvelopeGenerator.Application.Common.Dto.EnvelopeHistory;
using EnvelopeGenerator.Application.Extensions;
using EnvelopeGenerator.Application.Model;
using EnvelopeGenerator.Domain.Constants;
using EnvelopeGenerator.Domain.Entities;
using MediatR;
using Microsoft.EntityFrameworkCore;

namespace EnvelopeGenerator.Application.Histories.Commands;

/// <summary>
/// 
/// </summary>
public record CreateHistoryCommand : EnvelopeReceiverQueryBase, IRequest<EnvelopeHistoryDto?>
{
    /// <summary>
    /// 
    /// </summary>
    public int? EnvelopeId { get; set; }

    /// <summary>
    /// 
    /// </summary>
    public string? UserReference { get; set; }

    /// <summary>
    /// 
    /// </summary>
    public EnvelopeStatus Status { get; set; }

    /// <summary>
    /// 
    /// </summary>
    public DateTime AddedWhen { get; } = DateTime.Now;

    /// <summary>
    /// 
    /// </summary>
    public DateTime ActionDate => AddedWhen;

    /// <summary>
    /// 
    /// </summary>
    public string? Comment { get; set; }
}

/// <summary>
/// 
/// </summary>
public class CreateHistoryCommandHandler : IRequestHandler<CreateHistoryCommand, EnvelopeHistoryDto?>
{
    private readonly IRepository<EnvelopeHistory> _repo;

    private readonly IRepository<EnvelopeReceiver> _erRepo;

    private readonly IMapper _mapper;

    /// <summary>
    /// 
    /// </summary>
    /// <param name="repo"></param>
    /// <param name="erRepo"></param>
    /// <param name="mapper"></param>
    public CreateHistoryCommandHandler(IRepository<EnvelopeHistory> repo, IRepository<EnvelopeReceiver> erRepo, IMapper mapper)
    {
        _repo = repo;
        _erRepo = erRepo;
        _mapper = mapper;
    }

    /// <summary>
    /// 
    /// </summary>
    /// <param name="request"></param>
    /// <param name="cancel"></param>
    /// <returns></returns>
    public async Task<EnvelopeHistoryDto?> Handle(CreateHistoryCommand request, CancellationToken cancel)
    {
        if(request.UserReference is null)
        {
            var receivers = await _erRepo
                .ReadOnly()
                .Where(request)
                .Include(er => er.Receiver)
                .ToListAsync(cancel);

            if (receivers.Count != 1)
                throw new BadRequestException(
                    receivers.Count > 1
                        ? "Multiple receivers found for the given envelope and receiver criteria."
                        : "No receiver found for the given envelope and receiver criteria."
                );

            var receiver = receivers.Single().Receiver
                           ?? throw new BadRequestException("No receiver found for the given envelope and receiver criteria.");

            request.UserReference = receiver.EmailAddress;
        }

        // create entitiy
        var hist = await _repo.CreateAsync(request, cancel);
        
        return _mapper.Map<EnvelopeHistoryDto>(hist);
    }
}