/*
 * author:chao.yang@foxmail.com
 * 
 * 参数 
 * ------------------------------------------------------------------
 * pgerId						//唯一标识
 * pg_size  					//每页显示记录数
 * pg_count 					//当前页数
 * pg_total_count 				//总记录数
 * pg_nav_count     			//显示多少个导航数
 * pg_prev_name     			//上一页按钮名称
 * pg_next_name     			//下一页按钮名称
 * pg_call_fun(page_count)      //回调函数，点击按钮执行
 * */
(function ($) {
    $.fn.cypager = function (options) {
        var defaults = {
            id: "cy_pager",
            pg_size: 10,
            pg_total_count: 0,
            pg_cur_count: 1,
            pg_nav_count: 7,
            pg_prev_name: "上一页",
            pg_next_name: "下一页",
            pg_call_fun: $.noop
        };
        var options = $.extend(defaults, options);
        var pager = {};
        $this = $(this);
        pager.pagerId = options["id"];
        pager.pgSize = options["pg_size"];
        pager.pgCurCount = options["pg_cur_count"];
        pager.pgTotalCount = options["pg_total_count"];
        pager.pgNavCount = options["pg_nav_count"];
        pager.pgPrevName = options["pg_prev_name"];
        pager.pgNextName = options["pg_next_name"];
        pager.pgCallFun = options.pg_call_fun;
        pager.pgCount = parseInt(pager.pgTotalCount / pager.pgSize);
        if (pager.pgTotalCount % pager.pgSize > 0) {
            pager.pgCount++
        }
        if (pager.pgCount == 0) {
            pager.pgCount = 1
        }
        var html = genHtml(pager);
        $this.html(html);
        renderedPageBtn(pager, $this);
        $this.find("li").click(function () {
            var $id = $(this).attr("id");
            var $page = $(this).attr("page");
            if ("prev" == $id) {
                $page = parseInt(pager.pgCurCount) > 1 ? parseInt(pager.pgCurCount) - 1 : parseInt(pager.pgCurCount);
                pager.pgCurCount = $page;
                renderedPageBtn(pager, $this);
                options.pg_call_fun($page)
            } else {
                if ("next" == $id) {
                    $page = parseInt(pager.pgCurCount) < parseInt(pager.pgCount) ? parseInt(pager.pgCurCount) + 1 : parseInt(pager.pgCurCount);
                    pager.pgCurCount = $page;
                    renderedPageBtn(pager, $this);
                    options.pg_call_fun($page)
                } else {
                    if (options.pg_call_fun) {
                        $page = $(this).attr("page");
                        pager.pgCurCount = $page;
                        renderedPageBtn(pager, $this);
                        options.pg_call_fun($page)
                    }
                }
            }
        })
    };
    function genHtml(pager) {
        var allPage=Math.ceil(pager.pgTotalCount/pager.pgSize);
        var html = "<ul class='page-ul'><li page='1' class='pg-showpage'>首页</li></ul><ul class='pager' id='" + pager.pagerId + "'>";
        html += "<li class='pg-prev' id='prev'>" + pager.pgPrevName + "</li>";
        for (var i = 0; i < pager.pgCount; i++) {
            var page = (i + 1);
            if (i < pager.pgNavCount) {
                html += "<li page='" + page + "' class='pg-showpage'>" + page + "</li>"
            } else {
                html += "<li page='" + page + "' class='pg-hidepage'>" + page + "</li>"
            }
        }
        html += "<li class='pg-next' id='next'>" + pager.pgNextName + "</li>";
        html += "</ul><ul class='page-ul'><li page='"+allPage+"' class='pg-showpage'>尾页</li></ul>";
        return html
    }

    function renderedPageBtn(pager, obj) {
        if (pager.pgCurCount == 1) {
            obj.find("#prev").addClass("pg-dislabel")
        } else {
            obj.find("#prev").removeClass("pg-dislabel")
        }
        var lrNode = parseInt(pager.pgNavCount / 2);
        var leftNode = (parseInt(pager.pgCurCount) > lrNode) ? parseInt(pager.pgCurCount) - lrNode + 1 : 1;
        var rightNode = (parseInt(pager.pgCurCount) > lrNode) ? parseInt(pager.pgCurCount) + lrNode + 1 : parseInt(pager.pgNavCount);
        if (parseInt(pager.pgCurCount) <= lrNode) {
            leftNode = 1;
            rightNode = parseInt(pager.pgNavCount) + 1
        }
        if ((parseInt(pager.pgCurCount) + lrNode) > parseInt(pager.pgCount)) {
            leftNode = parseInt(pager.pgCount) - parseInt(pager.pgNavCount) + 1;
            rightNode = parseInt(pager.pgCount) + 1
        }
        obj.find("li").removeClass("pg-showpage").removeClass("pg-selected").addClass("pg-hidepage");
        obj.find("#prev").removeClass("pg-hidepage");
        obj.find("#next").removeClass("pg-hidepage");
        for (var i = leftNode; i < rightNode; i++) {
            if (i == pager.pgCurCount) {
                obj.find("li[page='" + i + "']").removeClass("pg-hidepage").addClass("pg-showpage").addClass("pg-selected")
            } else {
                obj.find("li[page='" + i + "']").removeClass("pg-hidepage").addClass("pg-showpage")
            }
        }
        if (pager.pgCurCount == pager.pgCount) {
            obj.find("#next").addClass("pg-dislabel")
        } else {
            obj.find("#next").removeClass("pg-dislabel")
        }
    }
})(jQuery);