package org.jfw.util;

import java.util.Collections;
import java.util.LinkedList;
import java.util.List;

public class PageQueryResult<T> {
	private int total;
	private int pageNo = 1;
	private int pageSize;

	public int getTotal() {
		return total;
	}

	public void setTotal(int total) {
		this.total = total;
	}

	public int getPageNo() {
		return pageNo;
	}

	public void setPageNo(int pageNo) {
		this.pageNo = pageNo;
	}

	public int getPageSize() {
		return pageSize;
	}

	public void setPageSize(int pageSize) {
		this.pageSize = pageSize;
	}

	public List<T> getData() {
		return data;
	}

	public void setData(List<T> data) {
		this.data = data;
	}

	private List<T> data;

	public static <T> PageQueryResult<T> build(List<T> list, int pageSize, int pageNo) {
		PageQueryResult<T> ret = new PageQueryResult<T>();
		ret.setTotal(list.size());
		pageSize = Math.max(1, pageSize);
		pageNo = Math.max(1, pageNo);
		if (list.isEmpty()) {
			ret.setData(list);
			ret.setPageNo(pageNo);
			ret.setPageSize(1);
		} else if (pageNo == 1) {
			ret.setPageNo(pageNo);
			ret.setPageSize(pageSize);
			ret.setData(list.subList(0,Math.min(list.size(), pageSize)));
		} else {
			int tps = list.size() / pageSize;
			if (list.size() % pageSize != 0) {
				++tps;
			}
			if (pageNo > tps) {
				pageNo = tps;
			}
			ret.setPageNo(pageNo);
			ret.setPageSize(pageSize);
			int begin = pageNo * pageSize - pageSize;
			ret.setData(list.subList(begin,Math.min(list.size(), begin + pageSize)));
		}
		return ret;
	}

	public static void main(String[] args) {
		List<String> list = new LinkedList<String>();
		for(int i = 0 ; i < 14;++i) list.add("a");
		PageQueryResult.build(list,10,2);

		new PageQueryResult<String>().setData(Collections.<String> emptyList());

	}
}