using MediatR;
using cuqmbr.TravelGuide.Application.Common.Interfaces.Persistence;
using AutoMapper;
using cuqmbr.TravelGuide.Application.Common.Exceptions;

namespace cuqmbr.TravelGuide.Application.Buses.Commands.UpdateBus;

public class UpdateBusCommandHandler : 
    IRequestHandler<UpdateBusCommand, BusDto>
{
    private readonly UnitOfWork _unitOfWork;
    private readonly IMapper _mapper;

    public UpdateBusCommandHandler(
        UnitOfWork unitOfWork,
        IMapper mapper)
    {
        _unitOfWork = unitOfWork;
        _mapper = mapper;
    }

    public async Task<BusDto> Handle(
        UpdateBusCommand request,
        CancellationToken cancellationToken)
    {
        var entity = await _unitOfWork.BusRepository.GetOneAsync(
            e => e.Guid == request.Guid, cancellationToken);

        if (entity == null)
        {
            throw new NotFoundException();
        }

        var duplicateEntity = await _unitOfWork.BusRepository.GetOneAsync(
            e => e.Number == request.Number && e.Guid != request.Guid,
            cancellationToken);

        if (duplicateEntity != null)
        {
            throw new DuplicateEntityException(
                "Bus with given number already exists.");
        }

        var parentEntity = await _unitOfWork.CompanyRepository.GetOneAsync(
            e => e.Guid == request.CompanyGuid, cancellationToken);

        if (parentEntity == null)
        {
            throw new NotFoundException(
                $"Parent entity with Guid: {request.CompanyGuid} not found.");
        }

        entity.Number = request.Number;
        entity.Model = request.Model;
        entity.Capacity = request.Capacity;
        entity.CompanyId = parentEntity.Id;
        entity.Company = parentEntity;

        entity = await _unitOfWork.BusRepository.UpdateOneAsync(
            entity, cancellationToken);

        await _unitOfWork.SaveAsync(cancellationToken);
        _unitOfWork.Dispose();

        return _mapper.Map<BusDto>(entity);
    }
}