using System.Threading;
using System.Threading.Tasks;
using MediatR;
using Microsoft.EntityFrameworkCore;
using Mirea.Api.DataAccess.Application.Common.Exceptions;
using Mirea.Api.DataAccess.Application.Interfaces.DbContexts.Schedule;

namespace Mirea.Api.DataAccess.Application.Cqrs.Professor.Commands.CreateProfessor;

public class CreateProfessorCommandHandler(IProfessorDbContext dbContext) : IRequestHandler<CreateProfessorCommand, int>
{
    public async Task<int> Handle(CreateProfessorCommand request, CancellationToken cancellationToken)
    {
        var entity = await dbContext.Professors.FirstOrDefaultAsync(p => p.Name == request.Name, cancellationToken: cancellationToken);

        if (entity != null)
            throw new RecordExistException(typeof(Domain.Schedule.Professor), nameof(Domain.Schedule.Professor.Name), entity.Id);

        var professor = new Domain.Schedule.Professor()
        {
            Name = request.Name,
            AltName = request.AltName
        };

        var result = await dbContext.Professors.AddAsync(professor, cancellationToken);
        await dbContext.SaveChangesAsync(cancellationToken);

        return result.Entity.Id;
    }
}