import java.util.ArrayList;
import java.util.Iterator;

/**
 * 
 * @author dailin
 * 
 */
public class Paginate {
	int currentPage = 1; // 當前頁

	int totalPages = 0; // 總頁數

	int pageRecorders = 5;// 每頁5條數據

	int totalRows = 0; // 總數據數

	int pageStartRow = 0;// 每頁的起始數

	int pageEndRow = 0; // 每頁顯示數據的終止數

	boolean hasNextPage = false; // 是否有下一頁

	boolean hasPreviousPage = false; // 是否有前一頁

	Iterator it;

	/**
	 * 
	 * @param alllist全部數據
	 * @param nowPage正在看的頁數
	 * @param action用戶請求(上一頁,下一頁)
	 * @return
	 */
	public ArrayList getList(ArrayList alllist, int nowPage, String action) {
		ArrayList list = new ArrayList();
		// 總記錄數
		totalRows = alllist.size();
		hasPreviousPage = false;
		// 總頁數
		if ((totalRows % pageRecorders) == 0) {
			totalPages = totalRows / pageRecorders;
		} else {
			totalPages = totalRows / pageRecorders + 1;
		}
		// 當前要看頁數
		if (action == null || action.equals("null")) { // 第一次讀取數據
			currentPage = 1;
		} else {
			if (action == "nextPage" || action.equals("nextPage")) // 點擊下一頁
			{
				currentPage = nowPage + 1;
			}
			if (action == "previousPage" || action.equals("previousPage")) // 點擊上一頁
			{
				currentPage = nowPage - 1;
			}
		}
		// 判斷有沒有上一頁
		if ((currentPage - 1) > 0) {
			hasPreviousPage = true;
		} else {
			hasPreviousPage = false;
		}
		// 判斷有沒有下一頁
		if (currentPage >= totalPages) {

			hasNextPage = false;
		} else {

			hasNextPage = true;
		}
		// 顯示頁從第幾條到第幾條
		if (currentPage == 1) {
			if (totalRows < pageRecorders) {
				pageStartRow = 0;
				pageEndRow = totalRows;
			} else {
				pageStartRow = 0;
				pageEndRow = pageRecorders;
			}
		}else{
			if (currentPage * pageRecorders < totalRows) {// 判斷是否為最后一頁
				pageEndRow = currentPage * pageRecorders;
				pageStartRow = pageEndRow - pageRecorders;
			} else {
				pageEndRow = totalRows;
				pageStartRow = pageRecorders * (totalPages - 1);
			}
		}
		list = new ArrayList(alllist.subList(pageStartRow, pageEndRow));
		// list=(ArrayList) alllist.subList(pageStartRow, pageEndRow);
		/*
		 * for (int i = pageStartRow; i < pageEndRow; i++) {
		 * 
		 * list.add(alllist.get(i));
		 *  }
		 */
		return list;

	}

	/**
	 * 
	 * @return
	 */
	public int getCurrentPage() {
		return currentPage;
	}

	/**
	 * 
	 * @return
	 */
	public int getTotalRows() {
		return totalRows;
	}

	/**
	 * 
	 * @return
	 */
	public int getTotalPages() {

		return totalPages;
	}

	public boolean isHasNextPage() {
		return hasNextPage;
	}

	public boolean isHasPreviousPage() {
		return hasPreviousPage;
	}
}