using AutoMapper;
using MediatR;
using ExpenseTracker.Application.Common.Exceptions;
using ExpenseTracker.Application.Common.Interfaces;
using ExpenseTracker.Domain.Entities;

namespace ExpenseTracker.Application.Accounts.Commands.Update;

public class UpdateAccountCommandHandler : IRequestHandler<UpdateAccountCommand, AccountDto>
{
    private readonly IMapper _mapper;
    private readonly IUnitOfWork _unitOfWork;

    public UpdateAccountCommandHandler(IMapper mapper, IUnitOfWork unitOfWork)
    {
        _mapper = mapper;
        _unitOfWork = unitOfWork;
    }

    public async Task<AccountDto> Handle(UpdateAccountCommand request, CancellationToken cancellationToken)
    {
        var databaseEntity = _unitOfWork.AccountRepository.Queryable.FirstOrDefault(e => e.Id == request.Id);

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

        // TODO: Add UserId validation. Throw NotFoundException when there is no user with given UserId

        var updatedEntity = new Account()
        {
            Id = request.Id,
            Name = request.Name ?? databaseEntity.Name,
            Description = request.Description,
            UserId = request.UserId
        };

        databaseEntity = await _unitOfWork.AccountRepository.UpdateOneAsync(updatedEntity, cancellationToken);

        await _unitOfWork.SaveAsync(cancellationToken);

        return _mapper.Map<AccountDto>(databaseEntity);
    }
}