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

namespace EnvelopeGenerator.Application.DocStatus.Commands;

/// <summary>
/// Represents a command to save the status of a document, either by creating a new status or updating an existing one based on the provided envelope and receiver identifiers.
/// It returns the identifier of the saved document status.
/// </summary>
public record SaveDocStatusCommand : ModifyDocStatusCommandBase, IRequest<DocumentStatusDto?>;

/// <summary>
/// 
/// </summary>
public class SaveDocStatusCommandHandler : IRequestHandler<SaveDocStatusCommand, DocumentStatusDto?>
{
    private readonly IMapper _mapper;

    private readonly IRepository<DocumentStatus> _repo;

    private readonly IRepository<Envelope> _envRepo;

    private readonly IRepository<Receiver> _rcvRepo;

    /// <summary>
    /// 
    /// </summary>
    /// <param name="mapper"></param>
    /// <param name="repo"></param>
    /// <param name="rcvRepo"></param>
    /// <param name="envRepo"></param>
    public SaveDocStatusCommandHandler(IMapper mapper, IRepository<DocumentStatus> repo, IRepository<Receiver> rcvRepo, IRepository<Envelope> envRepo)
    {
        _mapper = mapper;
        _repo = repo;
        _rcvRepo = rcvRepo;
        _envRepo = envRepo;
    }

    /// <summary>
    /// 
    /// </summary>
    /// <param name="request"></param>
    /// <param name="cancel"></param>
    /// <returns></returns>
    public async Task<DocumentStatusDto?> Handle(SaveDocStatusCommand request, CancellationToken cancel)
    {
        // ceck if exists
        bool isExists = await _repo.ReadOnly().Where(request).AnyAsync(cancel);

        var env = await _envRepo.ReadOnly().Where(request.Envelope).FirstAsync(cancel);
        var rcv = await _rcvRepo.ReadOnly().Where(request.Receiver).FirstAsync(cancel);

        request.Envelope.Id = env.Id;
        request.Receiver.Id = rcv.Id;

        if (isExists)
        {
            var uReq = request.To<UpdateDocStatusCommand>();
            await _repo.UpdateAsync(uReq, q => q.Where(request), cancel);
        }
        else
        {
            var cReq = request.To<CreateDocStatusCommand>();
            await _repo.CreateAsync(cReq, cancel);
        }

        var docStatus = await _repo.ReadOnly().Where(request).SingleOrDefaultAsync(cancel);
        
        return _mapper.Map<DocumentStatusDto>(docStatus);
    }
}