package ejbs;

import entities.Document;
import entities.Student;
import exceptions.MyEntityNotFoundException;

import javax.ejb.EJBException;
import javax.ejb.Stateless;
import javax.persistence.EntityManager;
import javax.persistence.PersistenceContext;
import java.util.List;

@Stateless(name = "DocumentEJB")
public class DocumentBean {
    @PersistenceContext
    EntityManager em;

    public void create(
            String username,
            String filepath,
            String fileName)
            throws MyEntityNotFoundException{
        try {
            Student student = em.find(Student.class, username);
            if(student == null){
                throw new MyEntityNotFoundException("Student with username: " + username + " not found");
            }
            Document document = new Document(filepath, fileName, student);
            em.persist(document);
            student.addDocument(document);
        } catch (MyEntityNotFoundException e) {
            throw e;
        } catch (Exception e) {
            throw new EJBException("ERROR_CREATING_DOCUMENT ----> ", e);
        }
    }

    public Document findDocument(int id) {
        try{
            return em.find(Document.class, id);
        } catch (Exception e) {
            throw new EJBException("ERROR_FINDING_DOCUMENT ----> ", e);
        }
    }

    public List<Document> getStudentDocuments(String username) {
        try{
            return em.createNamedQuery("getStudentDocuments", Document.class).setParameter("username", username).getResultList();
        } catch (Exception e) {
            throw new EJBException("ERROR_FINDING_DOCUMENT ----> ", e);
        }
    }


}