package dao;

import java.util.*;

import org.hibernate.*;
import factory.*;

public class Pages {
	private int pageSize;// 頁大小

	private int pageCount;// 總頁數

	private int recordSize;// 記錄數

	private String hql;

	public Pages(String hql, int pageSize) {
		this.hql = hql;
		this.pageSize = pageSize;
		this.setPageCount();
	}

	public int getPageCount() {
		return pageCount;
	}

	// 設置總頁數。
	public void setPageCount() {
		Session session = HibernateSessionFactory.getSession();
		Transaction tx = null;
		List list = null;
		try {
			tx = session.beginTransaction();
			Query query = session.createQuery(hql);
			list = query.list();
			tx.commit();
		} catch (Exception e) {
			if (tx != null)
				tx.rollback();
			System.out.print(e);
		} finally {
			session.close();
		}
		// 設置記錄數
		if (list.isEmpty())
			recordSize = 0;
		else
			recordSize = list.size();
		// 計算總頁數
		pageCount = recordSize % pageSize == 0 ? recordSize / pageSize
				: (recordSize / pageSize + 1);
	}

	// 返加記錄
	public List getRecord(int nowPage/* 當前頁數 */) {
		if (nowPage < 0 || nowPage > pageCount)
			System.out.println("頁碼超出范圍");
		Session session = HibernateSessionFactory.getSession();
		Transaction tx = null;
		List list = null;
		try {
			tx = session.beginTransaction();
			Query query = session.createQuery(hql);
			query.setFirstResult((nowPage - 1) * pageSize);
			query.setMaxResults(pageSize);
			list = query.list();
			tx.commit();
		} catch (Exception e) {
			if (tx != null)
				tx.rollback();
			System.out.print(e);
		} finally {
			session.close();
		}
		return list;
	}	
}