/**
 * jquery jpages v0.7
 * client side pagination with jquery
 * http://luis-almeida.github.com/jpages
 *
 * licensed under the mit license.
 * copyright 2012 luís almeida
 * https://github.com/luis-almeida
 */

;(function($, window, document, undefined) {

  var name = "jpages",
      instance = null,
      defaults = {
        containerid: "",
        first: false,
        previous: "上一页",
        next: "下一页",
        last: false,
        links: "numeric", // blank || title
        startpage: 1,
        perpage: 6,
        midrange: 5,
        startrange: 1,
        endrange: 1,
        keybrowse: false,
        scrollbrowse: false,
        pause: 0,
        clickstop: false,
        delay: 50,
        direction: "forward", // backwards || auto || random ||
        animation: "", // http://daneden.me/animate/ - any entrance animations
        fallback: 400,
        minheight: false,
        callback: undefined // function( pages, items ) { }
      };


  function plugin(element, options) {
    this.options = $.extend({}, defaults, options);

    this._container = $("#" + this.options.containerid);
    if (!this._container.length) return;

    this.jqwindow = $(window);
    this.jqdocument = $(document);

    this._holder = $(element);
    this._nav = {};

    this._first = $(this.options.first);
    this._previous = $(this.options.previous);
    this._next = $(this.options.next);
    this._last = $(this.options.last);

    /* only visible items! */
    this._items = this._container.children(":visible");
    this._itemsshowing = $([]);
    this._itemshiding = $([]);

    this._numpages = math.ceil(this._items.length / this.options.perpage);
    this._currentpagenum = this.options.startpage;

    this._clicked = false;
    this._cssanimsupport = this.getcssanimationsupport();

    this.init();
  }

  plugin.prototype = {

    constructor : plugin,

    getcssanimationsupport : function() {
      var animation = false,
          animationstring = 'animation',
          keyframeprefix = '',
          domprefixes = 'webkit moz o ms khtml'.split(' '),
          pfx = '',
          elm = this._container.get(0);

      if (elm.style.animationname) animation = true;

      if (animation === false) {
        for (var i = 0; i < domprefixes.length; i++) {
          if (elm.style[domprefixes[i] + 'animationname'] !== undefined) {
            pfx = domprefixes[i];
            animationstring = pfx + 'animation';
            keyframeprefix = '-' + pfx.tolowercase() + '-';
            animation = true;
            break;
          }
        }
      }

      return animation;
    },

    init : function() {
      this.setstyles();
      this.setnav();
      this.paginate(this._currentpagenum);
      this.setminheight();
    },

    setstyles : function() {
      var requiredstyles = "<style>" +
      ".jp-invisible { visibility: hidden !important; } " +
      ".jp-hidden { display: none !important; }" +
      "</style>";

      $(requiredstyles).appendto("head");

      if (this._cssanimsupport && this.options.animation.length)
        this._items.addclass("animated jp-hidden");
      else this._items.hide();

    },

    setnav : function() {
      var navhtml = this.writenav();

      this._holder.each(this.bind(function(index, element) {
        var holder = $(element);
        holder.html(navhtml);
        this.cachenavelements(holder, index);
        this.bindnavhandlers(index);
        this.disablenavselection(element);
      }, this));

      if (this.options.keybrowse) this.bindnavkeybrowse();
      if (this.options.scrollbrowse) this.bindnavscrollbrowse();
    },

    writenav : function() {
      var i = 1, navhtml;
      navhtml = this.writebtn("first") + this.writebtn("previous");

      for (; i <= this._numpages; i++) {
        if (i === 1 && this.options.startrange === 0) navhtml += "<span>...</span>";
        if (i > this.options.startrange && i <= this._numpages - this.options.endrange)
          navhtml += "<a href='#' class='jp-hidden'>";
        else
          navhtml += "<a>";

        switch (this.options.links) {
          case "numeric":
            navhtml += i;
            break;
          case "blank":
            break;
          case "title":
            var title = this._items.eq(i - 1).attr("data-title");
            navhtml += title !== undefined ? title : "";
            break;
        }

        navhtml += "</a>";
        if (i === this.options.startrange || i === this._numpages - this.options.endrange)
          navhtml += "<span>...</span>";
      }
      navhtml += this.writebtn("next") + this.writebtn("last") + "</div>";
      return navhtml;
    },

    writebtn : function(which) {

      return this.options[which] !== false && !$(this["_" + which]).length ?
      "<a class='jp-" + which + "'>" + this.options[which] + "</a>" : "";

    },

    cachenavelements : function(holder, index) {
      this._nav[index] = {};
      this._nav[index].holder = holder;
      this._nav[index].first = this._first.length ? this._first : this._nav[index].holder.find("a.jp-first");
      this._nav[index].previous = this._previous.length ? this._previous : this._nav[index].holder.find("a.jp-previous");
      this._nav[index].next = this._next.length ? this._next : this._nav[index].holder.find("a.jp-next");
      this._nav[index].last = this._last.length ? this._last : this._nav[index].holder.find("a.jp-last");
      this._nav[index].fstbreak = this._nav[index].holder.find("span:first");
      this._nav[index].lstbreak = this._nav[index].holder.find("span:last");
      this._nav[index].pages = this._nav[index].holder.find("a").not(".jp-first, .jp-previous, .jp-next, .jp-last");
      this._nav[index].permpages =
        this._nav[index].pages.slice(0, this.options.startrange)
          .add(this._nav[index].pages.slice(this._numpages - this.options.endrange, this._numpages));
      this._nav[index].pagesshowing = $([]);
      this._nav[index].currentpage = $([]);
    },

    bindnavhandlers : function(index) {
      var nav = this._nav[index];

      // default nav
      nav.holder.bind("click.jpages", this.bind(function(evt) {
        var newpage = this.getnewpage(nav, $(evt.target));
        if (this.validnewpage(newpage)) {
          this._clicked = true;
          this.paginate(newpage);
        }
        evt.preventdefault();
      }, this));

      // custom first
      if (this._first.length) {
        this._first.bind("click.jpages", this.bind(function() {
          if (this.validnewpage(1)) {
            this._clicked = true;
            this.paginate(1);
          }
        }, this));
      }

      // custom previous
      if (this._previous.length) {
        this._previous.bind("click.jpages", this.bind(function() {
          var newpage = this._currentpagenum - 1;
          if (this.validnewpage(newpage)) {
            this._clicked = true;
            this.paginate(newpage);
          }
        }, this));
      }

      // custom next
      if (this._next.length) {
        this._next.bind("click.jpages", this.bind(function() {
          var newpage = this._currentpagenum + 1;
          if (this.validnewpage(newpage)) {
            this._clicked = true;
            this.paginate(newpage);
          }
        }, this));
      }

      // custom last
      if (this._last.length) {
        this._last.bind("click.jpages", this.bind(function() {
          if (this.validnewpage(this._numpages)) {
            this._clicked = true;
            this.paginate(this._numpages);
          }
        }, this));
      }

    },

    disablenavselection : function(element) {
      if (typeof element.onselectstart != "undefined")
        element.onselectstart = function() {
          return false;
        };
      else if (typeof element.style.mozuserselect != "undefined")
        element.style.mozuserselect = "none";
      else
        element.onmousedown = function() {
          return false;
        };
    },

    bindnavkeybrowse : function() {
      this.jqdocument.bind("keydown.jpages", this.bind(function(evt) {
        var target = evt.target.nodename.tolowercase();
        if (this.elemscrolledintoview() && target !== "input" && target != "textarea") {
          var newpage = this._currentpagenum;

          if (evt.which == 37) newpage = this._currentpagenum - 1;
          if (evt.which == 39) newpage = this._currentpagenum + 1;

          if (this.validnewpage(newpage)) {
            this._clicked = true;
            this.paginate(newpage);
          }
        }
      }, this));
    },

    elemscrolledintoview : function() {
      var docviewtop, docviewbottom, elemtop, elembottom;
      docviewtop = this.jqwindow.scrolltop();
      docviewbottom = docviewtop + this.jqwindow.height();
      elemtop = this._container.offset().top;
      elembottom = elemtop + this._container.height();
      return ((elembottom >= docviewtop) && (elemtop <= docviewbottom));

      // comment above and uncomment below if you want keybrowse to happen
      // only when container is completely visible in the page
      /*return ((elembottom >= docviewtop) && (elemtop <= docviewbottom) &&
                (elembottom <= docviewbottom) &&  (elemtop >= docviewtop) );*/
    },

    bindnavscrollbrowse : function() {
      this._container.bind("mousewheel.jpages dommousescroll.jpages", this.bind(function(evt) {
        var newpage = (evt.originalevent.wheeldelta || -evt.originalevent.detail) > 0 ?
        (this._currentpagenum - 1) : (this._currentpagenum + 1);
        if (this.validnewpage(newpage)) {
          this._clicked = true;
          this.paginate(newpage);
        }
        evt.preventdefault();
        return false;
      }, this));
    },

    getnewpage : function(nav, target) {
      if (target.is(nav.currentpage)) return this._currentpagenum;
      if (target.is(nav.pages)) return nav.pages.index(target) + 1;
      if (target.is(nav.first)) return 1;
      if (target.is(nav.last)) return this._numpages;
      if (target.is(nav.previous)) return nav.pages.index(nav.currentpage);
      if (target.is(nav.next)) return nav.pages.index(nav.currentpage) + 2;
    },

    validnewpage : function(newpage) {
      return newpage !== this._currentpagenum && newpage > 0 && newpage <= this._numpages;
    },

    paginate : function(page) {
      var itemrange, pageinterval;
      itemrange = this.updateitems(page);
      pageinterval = this.updatepages(page);
      this._currentpagenum = page;
      if ($.isfunction(this.options.callback))
        this.callback(page, itemrange, pageinterval);

      this.updatepause();
    },

    updateitems : function(page) {
      var range = this.getitemrange(page);
      this._itemshiding = this._itemsshowing;
      this._itemsshowing = this._items.slice(range.start, range.end);
      if (this._cssanimsupport && this.options.animation.length) this.cssanimations(page);
      else this.jqanimations(page);
      return range;
    },

    getitemrange : function(page) {
      var range = {};
      range.start = (page - 1) * this.options.perpage;
      range.end = range.start + this.options.perpage;
      if (range.end > this._items.length) range.end = this._items.length;
      return range;
    },

    cssanimations : function(page) {
      clearinterval(this._delay);

      this._itemshiding
        .removeclass(this.options.animation + " jp-invisible")
        .addclass("jp-hidden");

      this._itemsshowing
        .removeclass("jp-hidden")
        .addclass("jp-invisible");

      this._itemsoriented = this.getdirecteditems(page);
      this._index = 0;

      this._delay = setinterval(this.bind(function() {
        if (this._index === this._itemsoriented.length) clearinterval(this._delay);
        else {
          this._itemsoriented
          .eq(this._index)
          .removeclass("jp-invisible")
          .addclass(this.options.animation);
        }
        this._index = this._index + 1;
      }, this), this.options.delay);
    },

    jqanimations : function(page) {
      clearinterval(this._delay);
      this._itemshiding.addclass("jp-hidden");
      this._itemsshowing.fadeto(0, 0).removeclass("jp-hidden");
      this._itemsoriented = this.getdirecteditems(page);
      this._index = 0;
      this._delay = setinterval(this.bind(function() {
        if (this._index === this._itemsoriented.length) clearinterval(this._delay);
        else {
          this._itemsoriented
          .eq(this._index)
          .fadeto(this.options.fallback, 1);
        }
        this._index = this._index + 1;
      }, this), this.options.delay);
    },

    getdirecteditems : function(page) {
      var itemstoshow;

      switch (this.options.direction) {
        case "backwards":
          itemstoshow = $(this._itemsshowing.get().reverse());
          break;
        case "random":
          itemstoshow = $(this._itemsshowing.get().sort(function() {
            return (math.round(math.random()) - 0.5);
          }));
          break;
        case "auto":
          itemstoshow = page >= this._currentpagenum ?
          this._itemsshowing : $(this._itemsshowing.get().reverse());
          break;
        default:
          itemstoshow = this._itemsshowing;
      }

      return itemstoshow;
    },

    updatepages : function(page) {
      var interval, index, nav;
      interval = this.getinterval(page);
      for (index in this._nav) {
        if (this._nav.hasownproperty(index)) {
          nav = this._nav[index];
          this.updatebtns(nav, page);
          this.updatecurrentpage(nav, page);
          this.updatepagesshowing(nav, interval);
          this.updatebreaks(nav, interval);
        }
      }
      return interval;
    },

    getinterval : function(page) {
      var nehalf, upperlimit, start, end;
      nehalf = math.ceil(this.options.midrange / 2);
      upperlimit = this._numpages - this.options.midrange;
      start = page > nehalf ? math.max(math.min(page - nehalf, upperlimit), 0) : 0;
      end = page > nehalf ?
        math.min(page + nehalf - (this.options.midrange % 2 > 0 ? 1 : 0), this._numpages) :
        math.min(this.options.midrange, this._numpages);
      return {start: start,end: end};
    },

    updatebtns : function(nav, page) {
      if (page === 1) {
        nav.first.addclass("jp-disabled");
        nav.previous.addclass("jp-disabled");
      }
      if (page === this._numpages) {
        nav.next.addclass("jp-disabled");
        nav.last.addclass("jp-disabled");
      }
      if (this._currentpagenum === 1 && page > 1) {
        nav.first.removeclass("jp-disabled");
        nav.previous.removeclass("jp-disabled");
      }
      if (this._currentpagenum === this._numpages && page < this._numpages) {
        nav.next.removeclass("jp-disabled");
        nav.last.removeclass("jp-disabled");
      }
    },

    updatecurrentpage : function(nav, page) {
      nav.currentpage.removeclass("jp-current current");
      nav.currentpage = nav.pages.eq(page - 1).addclass("jp-current current");
    },

    updatepagesshowing : function(nav, interval) {
      var newrange = nav.pages.slice(interval.start, interval.end).not(nav.permpages);
      nav.pagesshowing.not(newrange).addclass("jp-hidden");
      newrange.not(nav.pagesshowing).removeclass("jp-hidden");
      nav.pagesshowing = newrange;
    },

    updatebreaks : function(nav, interval) {
      if (
        interval.start > this.options.startrange ||
        (this.options.startrange === 0 && interval.start > 0)
      ) nav.fstbreak.removeclass("jp-hidden");
      else nav.fstbreak.addclass("jp-hidden");

      if (interval.end < this._numpages - this.options.endrange) nav.lstbreak.removeclass("jp-hidden");
      else nav.lstbreak.addclass("jp-hidden");
    },

    callback : function(page, itemrange, pageinterval) {
      var pages = {
            current: page,
            interval: pageinterval,
            count: this._numpages
          },
          items = {
            showing: this._itemsshowing,
            oncoming: this._items.slice(itemrange.start + this.options.perpage, itemrange.end + this.options.perpage),
            range: itemrange,
            count: this._items.length
          };

      pages.interval.start = pages.interval.start + 1;
      items.range.start = items.range.start + 1;
      this.options.callback(pages, items);
    },

    updatepause : function() {
      if (this.options.pause && this._numpages > 1) {
        cleartimeout(this._pause);
        if (this.options.clickstop && this._clicked) return;
        else {
          this._pause = settimeout(this.bind(function() {
            this.paginate(this._currentpagenum !== this._numpages ? this._currentpagenum + 1 : 1);
          }, this), this.options.pause);
        }
      }
    },

    setminheight : function() {
      if (this.options.minheight && !this._container.is("table, tbody")) {
        settimeout(this.bind(function() {
          this._container.css({ "min-height": this._container.css("height") });
        }, this), 1000);
      }
    },

    bind : function(fn, me) {
      return function() {
        return fn.apply(me, arguments);
      };
    },

    destroy : function() {
      this.jqdocument.unbind("keydown.jpages");
      this._container.unbind("mousewheel.jpages dommousescroll.jpages");

      if (this.options.minheight) this._container.css("min-height", "");
      if (this._cssanimsupport && this.options.animation.length)
        this._items.removeclass("animated jp-hidden jp-invisible " + this.options.animation);
      else this._items.removeclass("jp-hidden").fadeto(0, 1);
      this._holder.unbind("click.jpages").empty();
    }

  };

  $.fn[name] = function(arg) {
    var type = $.type(arg);

    if (type === "object") {
      if (this.length && !$.data(this, name)) {
        instance = new plugin(this, arg);
        this.each(function() {
          $.data(this, name, instance);
        });
      }
      return this;
    }

    if (type === "string" && arg === "destroy") {
      instance.destroy();
      this.each(function() {
        $.removedata(this, name);
      });
      return this;
    }

    if (type === 'number' && arg % 1 === 0) {
      if (instance.validnewpage(arg)) instance.paginate(arg);
      return this;
    }

    return this;
  };

})(jquery, window, document);