package com.zyp.dao.impl;

import java.util.List;
import javax.persistence.EntityManager;
import javax.persistence.PersistenceContext;
import javax.persistence.Query;
import com.zyp.dao.IDao;

public class DaoImpl implements IDao {

	@PersistenceContext
	private EntityManager em;

	public void setEntityManager(EntityManager em) {
		this.em = em;
	}

	public <T> void add(T t) throws Exception {
		em.persist(t);
	}

	public <T> void delete(Class<T> clazz, int id) throws Exception {
		em.remove(em.getReference(clazz, id));
	}

	public <T> void update(T t) throws Exception {
		em.merge(t);
	}

	public <T> T get(Class<T> clazz, int id) throws Exception {
		return em.find(clazz, id);
	}

	public <T> List<T> getList(Class<T> clazz) throws Exception {
		String className = clazz.getSimpleName();
		Query query = em.createQuery("SELECT o FROM " + className + " o");
		List<T> list = query.getResultList();
		return list;
	}

	public <T> List<T> getList(Class<T> clazz, int start, int limit) throws Exception {
		String className = clazz.getSimpleName();
		Query query = em.createQuery("SELECT o FROM " + className + " o");
		query.setFirstResult(start).setMaxResults(limit);
		List<T> list = query.getResultList();
		return list;
	}

	public <T> List<T> getList(Class<T> clazz, String field, String keyword, int start, int limit) throws Exception {
		keyword = keyword.trim();
		String className = clazz.getSimpleName();
		Query query = em.createQuery("SELECT o FROM " + className + " o WHERE UPPER(o." + field + ") like UPPER('%" + keyword + "%')");
		query.setFirstResult(start).setMaxResults(limit);
		List<T> list = query.getResultList();
		return list;
	}
}