package com.beetlehand.model.dao;

import org.springframework.transaction.annotation.Transactional;

import javax.persistence.EntityManager;
import javax.persistence.Persistence;
import javax.persistence.Query;
import java.util.List;
import java.util.Map;

public abstract class AbstractDao<T, S> implements AbstractDaoInterface<T, S> {

    protected EntityManager entityManager;

    public EntityManager getEntityManager() {
        if(this.entityManager == null) {
            this.entityManager = Persistence
                .createEntityManagerFactory("NewPersistenceUnit")
                .createEntityManager();
        }

        return this.entityManager;
    }

    // execute native sql or stored procedure queries
    public void exeucte(String sqlQuery, Map<String, Object> params) {
        Query jpaQuery = getEntityManager().createNativeQuery(sqlQuery);

        if(params != null)
            for (String key : params.keySet()) {
                jpaQuery.setParameter(key, params.get(key));
            }

        jpaQuery.executeUpdate();
        getEntityManager().getTransaction().commit();
    }

    // execute native sql or stored procedure queries
    public List<Object> getRow(String sqlQuery, Map<String, Object> params) {
        Query jpaQuery = getEntityManager().createNativeQuery(sqlQuery);

        if(params != null)
            for (String key : params.keySet()) {
                jpaQuery.setParameter(key, params.get(key));
            }

        return jpaQuery.getResultList();
    }

    // execute native sql or stored procedure queries
    public Object getOne(String sqlQuery, Map<String, Object> params) {
        Query jpaQuery = getEntityManager().createNativeQuery(sqlQuery);

        if(params != null)
            for (String key : params.keySet()) {
                jpaQuery.setParameter(key, params.get(key));
            }

        return jpaQuery.getSingleResult();
    }

    @Transactional
    public void saveRow(T entity) {
        getEntityManager().persist(entity);
    }

    @Transactional
    public void deleteRow(T entity) {
        if(getEntityManager().contains(entity)) {
            getEntityManager().remove(entity);
        }
    }

    @Transactional
    public void flush() {
        getEntityManager().flush();
    }

    @Transactional
    public void clear() {
        getEntityManager().clear();
    }

    @Transactional
    public T merge(T entity) {
        T merged = getEntityManager().merge(entity);
        getEntityManager().flush();
        return merged;
    }
}