package com.ankurm.hibernatedemo.datetime;

import jakarta.persistence.EntityManager;
import jakarta.persistence.EntityManagerFactory;
import java.time.Instant;
import java.time.LocalDateTime;
import org.junit.jupiter.api.Test;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;

/**
 * Backs ankurm.com post 4876, docs/13-date-and-time-mapping.md chapter "Second-precision / truncation".
 * Default (H2) profile here; see {@link NanosecondTruncationHsqldbTest} for the HSQLDB variant.
 */
@SpringBootTest
class NanosecondTruncationTest {

    private static final Logger DEMO = LoggerFactory.getLogger("DEMO");

    @Autowired
    private EntityManagerFactory emf;

    @Test
    void nanosecondsOnH2() {
        LocalDateTime withNanos = LocalDateTime.of(2026, 1, 1, 12, 0, 0, 123_456_789);
        Instant instantWithNanos = Instant.ofEpochSecond(1_800_000_000L, 123_456_789);

        EntityManager em = emf.createEntityManager();
        em.getTransaction().begin();
        NanoPrecisionEntity e = new NanoPrecisionEntity();
        e.setPlainLocalDateTime(withNanos);
        e.setHighPrecisionLocalDateTime(withNanos);
        e.setPlainInstant(instantWithNanos);
        em.persist(e);
        em.getTransaction().commit();
        Long id = e.getId();
        em.close();

        EntityManager em2 = emf.createEntityManager();
        NanoPrecisionEntity loaded = em2.find(NanoPrecisionEntity.class, id);

        DEMO.info("H2 2.4.240: original LocalDateTime nanos          = {}", withNanos.getNano());
        DEMO.info("H2 2.4.240: plain column (precision default) nanos = {} (value={})",
                loaded.getPlainLocalDateTime().getNano(), loaded.getPlainLocalDateTime());
        DEMO.info("H2 2.4.240: @Column(precision=9) column nanos      = {} (value={})",
                loaded.getHighPrecisionLocalDateTime().getNano(), loaded.getHighPrecisionLocalDateTime());
        DEMO.info("H2 2.4.240: original Instant nanos                 = {}", instantWithNanos.getNano());
        DEMO.info("H2 2.4.240: plain Instant column nanos             = {} (value={})",
                loaded.getPlainInstant().getNano(), loaded.getPlainInstant());
        em2.close();
    }
}