using AutoMapper;
using DigitalData.Core.Abstraction.Application.Repository;
using DigitalData.Core.Exceptions;
using EnvelopeGenerator.Application.Common.Dto;
using EnvelopeGenerator.Application.DocReceiverElements.Commands;
using EnvelopeGenerator.Domain.Entities;
using MediatR;
using Microsoft.EntityFrameworkCore;

namespace EnvelopeGenerator.Application.DocReceiverElements.Behaviors;

/// <summary>
/// Pipeline behavior that creates document status.
/// Executes second in the signing process.
/// </summary>
public class SaveSignatureBehavior : IPipelineBehavior<SigningCommand, Unit>
{
    private readonly ISender _sender;

    private readonly IRepository<DocReceiverElement> _elementRepo;

    private readonly IMapper _mapper;

    /// <summary>
    /// 
    /// </summary>
    /// <param name="sender"></param>
    /// <param name="elementRepo"></param>
    /// <param name="mapper"></param>
    public SaveSignatureBehavior(ISender sender, IRepository<DocReceiverElement> elementRepo, IMapper mapper)
    {
        _sender = sender;
        _elementRepo = elementRepo;
        _elementRepo = elementRepo;
        _mapper = mapper;
    }

    /// <summary>
    /// 
    /// </summary>
    /// <param name="request"></param>
    /// <param name="next"></param>
    /// <param name="cancel"></param>
    /// <returns></returns>
    public async Task<Unit> Handle(SigningCommand request, RequestHandlerDelegate<Unit> next, CancellationToken cancel)
    {
        if (request.ReceiverAppType == ReceiverAppType.LegacyWeb)
            return await next(cancel);
        else if(request.Signatures is not IEnumerable<Signature> signatures)
            throw new BadRequestException($"Signatures are required for saving signature behavior.");

        var elements = await _elementRepo
            .Where(e => e.Document.EnvelopeId == request.Envelope.Id)
            .Where(e => e.ReceiverId == request.Receiver.Id)
            .ToListAsync(cancel);

        foreach (var element in elements)
        {
            var signatures = request.Signatures.Where(s => s.Id == element.Id).ToList();
            if(signatures.Count == 0)
                throw new BadRequestException("No signature found for element with id {element.Id}.");
            else if(signatures.Count > 1)
                throw new BadRequestException("Multiple signatures found for element with id {element.Id}.");
            
            await _elementRepo.UpdateAsync(signatures.First(), e => e.Id == element.Id, cancel);
        }

        return await next(cancel);
    }
}