package com.ankurm.hibernatedemo.naturalid;

import static org.assertj.core.api.Assertions.assertThat;

import com.ankurm.hibernatedemo.HibernateDemoApplication;
import jakarta.persistence.EntityManager;
import jakarta.persistence.EntityManagerFactory;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.stat.Statistics;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;

/**
 * Proves the article's composite-natural-id code sample actually resolves, and captures the
 * real generated SQL: a two-column WHERE clause that includes the FK to Company, not a join
 * on the natural id of Company itself.
 *
 * <p>Docs: docs/06-natural-ids.md, Topic 3.
 */
@SpringBootTest(classes = HibernateDemoApplication.class)
class CompositeNaturalIdTest {

    @Autowired
    private EntityManagerFactory emf;

    private Statistics stats() {
        return emf.unwrap(SessionFactory.class).getStatistics();
    }

    @Test
    void byNaturalId_compositeKey_usingTwoFields_resolvesCorrectRow() {
        EntityManager em = emf.createEntityManager();
        em.getTransaction().begin();
        Company acme = new Company("Acme");
        Company other = new Company("Other Co");
        em.persist(acme);
        em.persist(other);
        // Same deptCode ("ENG-01") at TWO different companies -- proves it's the (company, code)
        // PAIR that is unique, not deptCode alone.
        em.persist(new Department(acme, "ENG-01", "Acme Engineering"));
        em.persist(new Department(other, "ENG-01", "Other Co Engineering"));
        em.getTransaction().commit();
        em.close();

        EntityManager em2 = emf.createEntityManager();
        Session session = em2.unwrap(Session.class);
        stats().clear();

        Department dept = session.byNaturalId(Department.class)
                .using("company", acme)
                .using("deptCode", "ENG-01")
                .load();

        long queries = stats().getPrepareStatementCount();
        em2.close();

        System.out.println("RESULT[composite-naturalid]: byNaturalId(company=Acme, deptCode=ENG-01) resolved to '"
                + dept.getName() + "' in " + queries + " query/queries");

        assertThat(dept).isNotNull();
        assertThat(dept.getName()).isEqualTo("Acme Engineering");
        assertThat(queries).isEqualTo(1);
    }

    @Test
    void byNaturalId_compositeKey_capturesTheGeneratedSql() {
        EntityManager em = emf.createEntityManager();
        em.getTransaction().begin();
        Company acme = new Company("SQL-Capture Co");
        em.persist(acme);
        em.persist(new Department(acme, "OPS-1", "Operations"));
        em.getTransaction().commit();
        em.close();

        EntityManager em2 = emf.createEntityManager();
        Session session = em2.unwrap(Session.class);
        Department dept = session.byNaturalId(Department.class)
                .using("company", acme)
                .using("deptCode", "OPS-1")
                .load();
        em2.close();
        assertThat(dept).isNotNull();
        // The actual SQL is captured in docs/output/naturalid-composite-sql.txt via show_sql
        // logging on this test run -- see that file for the verbatim SELECT.
    }
}