package cn.gov.csdn.base.dao.impl;

import java.lang.reflect.ParameterizedType;
import java.util.ArrayList;
import java.util.List;

import javax.annotation.Resource;

import org.hibernate.Criteria;
import org.hibernate.Query;
import org.hibernate.SQLQuery;
import org.hibernate.SessionFactory;
import org.hibernate.criterion.Criterion;
import org.hibernate.criterion.Order;
import org.hibernate.criterion.Projections;
import org.hibernate.criterion.Restrictions;

import cn.gov.csdn.base.dao.BaseDao;
import cn.gov.csdn.base.util.ValidateUtil;
import cn.gov.csdn.base.vo.Paginater;

/**
*
* File:    BaseDaoImpl抽象类
* Author:  admin
* Version: 1.0
* Date:    2014/01/02 15:33
* Modify:
* Description:用于继承
* Copyright csdn
 */
public abstract class BaseDaoImpl<T> implements BaseDao<T> {

	private Class clazz;

	/* 注入SessionFactory */
	@Resource
	private SessionFactory sf;

	public BaseDaoImpl() {
		ParameterizedType type = (ParameterizedType) this.getClass()
				.getGenericSuperclass();
		clazz = (Class) type.getActualTypeArguments()[0];
	}

	public void saveEntity(T t) {
		sf.getCurrentSession().save(t);
	}

	public void saveOrUpdateEntity(T t) {
		sf.getCurrentSession().saveOrUpdate(t);
	}

	public void updateEntity(T t) {
		sf.getCurrentSession().update(t);
	}

	public void deleteEntity(T t) {
		sf.getCurrentSession().delete(t);
	}

	public SessionFactory getSf() {
		return sf;
	}

	public void setSf(SessionFactory sf) {
		this.sf = sf;
	}

	/**
	 * 按照hql语句批量写操作
	 */
	public void batchEntityByHQL(String hql, Object... objects) {
		Query q = sf.getCurrentSession().createQuery(hql);
		for (int i = 0; i < objects.length; i++) {
			q.setParameter(i, objects[i]);
		}
		q.executeUpdate();
	}

	public T loadEntity(Integer id) {
		return (T) sf.getCurrentSession().load(clazz, id);
	}

	public T getEntity(Integer id) {
		return (T) sf.getCurrentSession().get(clazz, id);
	}

	public List<T> findAllEntities() {
		String hql = "from " + clazz.getSimpleName();
		return findEntityByHQL(hql);
	}

	// 执行原生sql语句
	protected void executeSQL(String sql, Object... objects) {
		SQLQuery q = sf.getCurrentSession().createSQLQuery(sql);
		for (int i = 0; i < objects.length; i++) {
			q.setParameter(i, objects[i]);
		}
		q.executeUpdate();
	}

	protected List<T> findEntityByHQL(String hql, Object... objects) {
		Query q = sf.getCurrentSession().createQuery(hql);
		for (int i = 0; i < objects.length; i++) {
			q.setParameter(i, objects[i]);
		}
		return q.list();
	}

	// 按照sql查询
	protected List<T> findObjectBySQL(String sql, Object... objects) {
		SQLQuery q = sf.getCurrentSession().createSQLQuery(sql);
		for (int i = 0; i < objects.length; i++) {
			q.setParameter(i, objects[i]);
		}
		// 给查询添加实体
		q.addEntity(clazz);
		return q.list();
	}

	// 单值检索,查询结果有且仅有一条记录
	protected Object uniqueResult(String hql, Object... objects) {
		Query q = sf.getCurrentSession().createQuery(hql);
		for (int i = 0; i < objects.length; i++) {
			q.setParameter(i, objects[i]);
		}
		return q.uniqueResult();
	}

	/**
	 * 开启hibernate二级缓存的查询缓存版本 hibernate二级缓存共有四部分,除了用于缓存hql的查询缓存
	 * 剩下三部分是：类缓存，集合缓存，更新时间戳缓存
	 */
	@SuppressWarnings("rawtypes")
	protected List batchEntityByHQLCacheable(String hql, Object... objects) {
		Query q = getSf().getCurrentSession().createQuery(hql);
		for (int i = 0; i < objects.length; i++) {
			q.setParameter(i, objects[i]);
		}
		q.setCacheable(true);
		return q.list();
	}

	// 解决hibernate的a different object with the same identifier
	// value was already associated with the session问题
	// saveOrUpdate之前先clear();
	public void saveOrUpClearFirst(T t) {
		sf.getCurrentSession().clear();
		sf.getCurrentSession().saveOrUpdate(t);
	}

	/**
	 * 分页，模糊查询目前版本没有实现。等下个版本。
	 */
	public Paginater findPaging(int pageNo, int pageSize, Object... objects) {
		if (objects == null) {
			return findPaging(pageNo, pageSize, null, null);
		} else {
			List<Criterion> lst = new ArrayList<Criterion>();
			Criterion criterion = Restrictions.eq(objects[0].toString(),
					objects[1]);
			lst.add(criterion);
			return findPaging(pageNo, pageSize, lst, null);
		}

	}

	protected Paginater findPaging(int pageNo, int pageSize,
			List<Criterion> crits, List<Order> orders) {
		Criteria criteria = sf.getCurrentSession().createCriteria(clazz);
		if (ValidateUtil.isValid(crits)) {
			// 拼装查询条件
			for (int i = 0; i < crits.size(); i++) {
				criteria.add(crits.get(i));
			}
		}

		if (ValidateUtil.isValid(orders)) {
			// 拼装排序条件
			for (int i = 0; i < orders.size(); i++) {
				criteria.addOrder(orders.get(i));
			}

		} else {
			criteria.addOrder(Order.desc("id"));
		}

		int currentPage = pageNo == 0 ? 1 : pageNo;

		// 获取根据条件分页查询的总行数
		int count = ((Long) criteria.setProjection(Projections.rowCount())
				.uniqueResult()).intValue();
		// 查完条数记得清空Projection
		criteria.setProjection(null);

		int totalPage = count % pageSize == 0 ? count / pageSize : count
				/ pageSize + 1;

		int start = (currentPage - 1) * pageSize;
		// 进行查库
		List<T> list = criteria.setFirstResult(start).setMaxResults(pageSize)
				.list();

		// 封装分页对象
		Paginater paginater = new Paginater();
		paginater.setPageSize(pageSize);
		paginater.setCurrentPage(currentPage);
		paginater.setTotalNum(count);
		paginater.setTotalPage(totalPage);
		paginater.setRoot(list);
		if (currentPage == 1) {
			paginater.setFirstPage(true);
			paginater.setHasPreviousPage(false);
		} else {
			paginater.setFirstPage(false);
			paginater.setHasPreviousPage(true);
		}
		if (currentPage == totalPage) {
			paginater.setHasNextPage(false);
		} else {
			paginater.setHasNextPage(true);
		}

		if (totalPage < currentPage) {
			paginater.setHasPreviousPage(true);
		} else {
			paginater.setHasNextPage(false);
		}
		return paginater;
	}
}