$(function(){
	$(".pagination").pagination({
		pageSize : 12,
		pageNum : 4	
	});
});


/* 
pagination 0.91 分页插件已实现图片延时加载
Copyright (c) 2014 ZhibinPu
Date: 2014-11-13
jquery-1.12.4.min.js
*/ 

(function($){ 
	$.fn.pagination = function(options){

		var defaults = {
			pageSize : 12,		//每页几条
			pageNum : 4			//页码显示个数，使用双数
		}

		var options = $.extend(defaults, options);


		var $this = this;	//整个列表对象
		var $row = $this.find("li");	//数据行对象

		var pageSize = options.pageSize;				//每页条数
		var pageNow = 1;								//当前页码
		var rowCount = $row.length;						//数据总条数
		var pageCount = Math.ceil(rowCount/pageSize);	//总页数

		var pageNum = options.pageNum;					//页码显示个数

		var startItem = (pageNow-1)*pageSize;			//数据显示开始处
		var endItem = startItem+pageSize;				//数据显示结束处

		var pageNoStart;								//页码开始处
		var pageNoEnd;									//页码结束处

		var imgSrc = new Array();						//存储图片路径
		for(i=0; i<$row.length; i++){
			imgSrc[i] = $row.eq(i).find("img").attr("src");
		}

		init();	//初始化

		//初始化
		function init(){

			//显示分页项目
			showItem();

			//设置页码开始结尾
			setPageStartEnd();

			//写入导航加载页码
			$this.after("<div class='pageNav'></div>");
			showFirstPage();
			showPageNum();
			showLastPage();
			//加载点击事件
			clickPageNo();

			//加载页面跳转
			showPageJump();

			//加载页面统计
			showStatistics();

			//加载每页记录数选择
			showPageSizeSet();

			//数据测试
			console.log("startItem = "+startItem);
			console.log("endItem = "+endItem);
			console.log("pageNoStart = "+pageNoStart);
			console.log("pageNoEnd = "+pageNoEnd);
			console.log("pageNow = "+pageNow);
			console.log("pageNum = "+pageNum);
			console.log("pageCount = "+pageCount);
			console.log("imgSrc = "+imgSrc);
		}
		

		//显示当前页数据
		function showItem(){
			startItem = (pageNow-1)*pageSize;
			endItem = startItem + pageSize;
			$row.find("img").attr("src", "");
			$row.hide();
			for(i=0; i<$row.length; i++){
				if(i>=startItem && i<endItem){
					$row.eq(i).find("img").attr("src", imgSrc[i]);
					$row.eq(i).show();
				}
			}
		}

		//设置页码的开始和结尾
		function setPageStartEnd(){

			pageNoStart = pageNow-pageNum/2;
			pageNoEnd = pageNoStart+pageNum;

			if(pageCount<pageNum){
				pageNoStart = 1;
				pageNoEnd = pageCount;
				return;
			}

			if(pageNoStart < 1){
				pageNoStart = 1;
				pageNoEnd = pageNoStart+pageNum > pageCount ? pageCount : pageNoStart+pageNum;
				return;
			}

			if(pageNoEnd > pageCount){
				pageNoEnd = pageCount;
				pageNoStart = pageNoEnd-pageNum < 1 ? 1 : pageNoEnd-pageNum;
				return;
			}

		}

		//显示页码
		function showPageNum(){
			if(pageCount <= 1){
				return;
			}
			$(".pageNav").append(function(){
				var str = "";
				for(i=pageNoStart; i<=pageNoEnd; i++){
					if(i==pageNow){
						str += "<span class='p"+i+" now'>"+i+"</span>";
					}else{
						str += "<span class='p"+i+"'>"+i+"</span>";
					}
				}
				return str;
			});
		}

		//显示首页
		function showFirstPage(){
			if(pageNoStart<2){
				return;
			}
			if(pageNow - pageNum/2 == 2 ){
				$(".pageNav").append("<span>1</span>");
				return;
			}
			$(".pageNav").append("<span>1</span> ... ");
		}

		//显示尾页
		function showLastPage(){
			if(pageNoEnd > pageCount - 1){
				return;
			}
			if( parseInt(pageNow) + parseInt(pageNum)/2 == (pageCount - 1) ){
				$(".pageNav").append("<span>"+pageCount+"</span>");
				return;
			}
			$(".pageNav").append(" ... <span>"+pageCount+"</span>");
		}

		//点击页码动作
		function clickPageNo(){
			$(".pageNav span").click(function(){

				//设置当前页
				if( $(this).text() == "首页" ){
					pageNow = 1;
				}else if( $(this).text() == "尾页" ){
					pageNow = pageCount;
				}else{
					pageNow = $(this).text();
				}

				//重新初始化
				$(".pageNav").remove();
				init();
			});
		}

		//页面统计
		function showStatistics(){
			$(".pageNav").append(" | 当前第"+pageNow+"页/共"+pageCount+"页/共"+rowCount+"条记录");
		}

		//直接跳转
		function showPageJump(){
			if(pageCount <= 1){
				return;
			}
			$(".pageNav").append(function(){
				var str = " | 跳转到：<select class='pageSelect'>";
				for(i=1; i<=pageCount; i++){
					if(i==pageNow){
						str += "<option selected='selected'>第"+i+"页</option>";
					}else{
						str += "<option value="+i+">第"+i+"页</option>";
					}
				}
				str += "</select>"
				return str;
			});

			$(".pageSelect").change(function () {
				$(this).find("option:selected").each(function () {
					pageNow = $(this).val();
				});

				//重新初始化
				$(".pageNav").remove();
				init();
			})
		}

		//选择每页几条
		function showPageSizeSet(){
			var arr = new Array(12,24);

			$(".pageNav").append(function(){
				var str = " | 每页<select class='pageSizeSelect'>";
				for(i=0; i<arr.length; i++){
					if(arr[i]==pageSize){
						str += "<option selected='selected'>"+arr[i]+"</option>";
					}else{
						str += "<option value="+arr[i]+">"+arr[i]+"</option>";
					}
				}
				str += "</select>条记录"
				return str;
			});

			$(".pageSizeSelect").change(function () {
				$(this).find("option:selected").each(function () {
					pageSize = parseInt($(this).val());
				});

				//重新设置以下参数
				pageNow = 1;
				pageCount = Math.ceil(rowCount/pageSize);	//总页数
				startItem = (pageNow-1)*pageSize;			//数据显示开始处
				endItem = startItem+pageSize;				//数据显示结束处

				//重新初始化
				$(".pageNav").remove();
				init();
			})
		}

	};
})(jQuery);