package com.example;

import static org.junit.Assert.assertNull;

import jakarta.persistence.EntityManager;
import jakarta.persistence.EntityManagerFactory;
import jakarta.persistence.EntityTransaction;
import jakarta.persistence.Query;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;

public class TestParentChildRelationship {
  private EntityManagerFactory emf;
  private EntityManager em;

  @Before
  public void setup() {
    emf = JpaConfig.getEntityManagerFactory();
    em = emf.createEntityManager();
  }

  @After
  public void tearDown() {
    if (em != null) {
      em.close();
    }
    if (emf != null) {
      emf.close();
    }
  }

  @Test
  public void testParentChildRelationship() {
    EntityTransaction transaction = em.getTransaction();
    transaction.begin();
    // Create Parent entity 1
    ParentEntity parentEntity1 = new ParentEntity();
    parentEntity1.setId(1);
    parentEntity1.setName("parent entity 1");
    ChildEntity childEntity1 = new ChildEntity();
    childEntity1.setId(1);
    childEntity1.setName("Child of parent entity 1");
    parentEntity1.setChildEntity(childEntity1);
    em.persist(parentEntity1);

    // Create Parent entity 2
    ParentEntity parentEntity2 = new ParentEntity();
    parentEntity2.setId(2);
    parentEntity2.setName("parent entity 2");
    ChildEntity childEntity2 = new ChildEntity();
    childEntity2.setId(2);
    childEntity2.setName("Child of parent entity 2");
    parentEntity2.setChildEntity(childEntity2);
    em.persist(parentEntity2);
    transaction.commit();

    // Delete using EM
    int parentId = parentEntity1.getId();
    transaction.begin();
    ParentEntity retrievedParent = em.find(ParentEntity.class, parentId);
    em.remove(retrievedParent);
    transaction.commit();

    // Delete using HQL
    parentId = parentEntity2.getId();
    transaction = em.getTransaction();
    transaction.begin();
    // Use HQL to delete the parent .... with cascade all, the child should be deleted.
    Query query = em.createQuery("DELETE FROM ParentEntity WHERE id = :parentId");
    query.setParameter("parentId", parentId);
    query.executeUpdate();
    transaction.commit();
    assertNull(
        "Parent entity  1 should be deleted", em.find(ParentEntity.class, parentEntity1.getId()));
    assertNull(
        "Parent entity  2 should be deleted", em.find(ParentEntity.class, parentEntity2.getId()));
    assertNull(
        "Child entity 1 should be deleted along with the parent",
        em.find(ChildEntity.class, childEntity1.getId()));
    assertNull(
        "Child entity 2 should be deleted along with the parent",
        em.find(ChildEntity.class, childEntity2.getId()));
  }
}