/*!
 * jquery.scrollable 1.0.5 - Scroll your HTML with eye candy.
 * 
 * Copyright (c) 2009 Tero Piirainen
 * http://flowplayer.org/tools/scrollable.html
 *
 * Dual licensed under MIT and GPL 2+ licenses
 * http://www.opensource.org/licenses
 *
 * Launch  : March 2008
 * Date: 2009-06-12 11:02:45 +0000 (Fri, 12 Jun 2009)
 * Revision: 1911 
 */
(function($) {
    
  // static constructs
  $.tools = $.tools || {version: {}};
  
  $.tools.version.scrollable = '1.0.5';
        
  var current = null;    

  
  // constructor
  function Scrollable(root, conf) {   

    // current instance
    var self = this;  
    if (!current) { current = self; }    
    
    // generic binding function
    function bind(name, fn) {
      $(self).bind(name, function(e, args)  {
        if (fn && fn.call(this, args.index) === false && args) {
          args.proceed = false;  
        }  
      });  
      
      return self;
    }
    
    // bind all callbacks from configuration
    $.each(conf, function(name, fn) {
      if ($.isFunction(fn)) { bind(name, fn); }
    });   
    
    
    // horizontal flag
    var horizontal = !conf.vertical;        
    
    // wrap (root elements for items)
    var wrap = $(conf.items, root);        
    
    // current index
    var index = 0;    
    
    function find(query, ctx) {
      return query.indexOf("#") != -1 ? $(query).eq(0) : ctx.siblings(query).eq(0);  
    }    
    
    // get handle to navigational elements
    var navi = find(conf.navi, root);
    var prev = find(conf.prev, root);
    var next = find(conf.next, root);
    var prevPage = find(conf.prevPage, root);
    var nextPage = find(conf.nextPage, root);
    
    
    // methods
    $.extend(self, {
      
      getIndex: function() {
        return index;  
      },
  
      getConf: function() {
        return conf;  
      },
      
      getSize: function() {
        return self.getItems().size();  
      },
  
      getPageAmount: function() {
        return Math.ceil(this.getSize() / conf.size);   
      },
      
      getPageIndex: function() {
        return Math.ceil(index / conf.size);  
      },

      getRoot: function() {
        return root;  
      },
      
      getItemWrap: function() {
        return wrap;  
      },
      
      getItems: function() {
        return wrap.children();  
      },
      
      getVisibleItems: function() {
        return self.getItems().slice(index, index + conf.size);  
      },
      
      /* all seeking functions depend on this */    
      seekTo: function(i, time, fn) {
        
        // default speed
        if (time === undefined) { time = conf.speed; }
        
        // function given as second argument
        if ($.isFunction(time)) {
          fn = time;
          time = conf.speed;
        }
                
        if (i < 0) { i = 0; }        
        if (i > self.getSize() - conf.size) { return self; }         

        var item = self.getItems().eq(i);          
        if (!item.length) { return self; }        
        
        
        // onBeforeSeek
        var p = {index: i, proceed: true};
        $(self).trigger("onBeforeSeek", p);        
        if (!p.proceed) { return self; }
                  
        
        if (horizontal) {
           var left = -item.position().left;          
          wrap.animate({left: left}, time, conf.easing, fn ? function() { fn.call(self); } : null);
          
        } else {
          var top = -item.position().top;                    
          wrap.animate({top: top}, time, conf.easing, fn ? function() { fn.call(self); } : null);              
        }  
        
        
        // navi status update
        if (navi.length) {
          var klass = conf.activeClass;
          var page = Math.ceil(i / conf.size);
          page = Math.min(page, navi.children().length - 1);
          navi.children().removeClass(klass).eq(page).addClass(klass);
        } 
        
        // prev buttons disabled flag
        if (i === 0) {
          prev.add(prevPage).addClass(conf.disabledClass);          
        } else {
          prev.add(prevPage).removeClass(conf.disabledClass);
        }
                
        // next buttons disabled flag
        if (i >= self.getSize() - conf.size) {
          next.add(nextPage).addClass(conf.disabledClass);
        } else {
          next.add(nextPage).removeClass(conf.disabledClass);
        }        
        
        current = self;
        index = i;        
        
        // onSeek after index being updated
        $(self).trigger("onSeek", {index: i});        
        return self; 
      },      
      
        
      move: function(offset, time, fn) {
        var to = index + offset;
        if (conf.loop && to > (self.getSize() - conf.size)) {
          to = 0;  
        }
        return this.seekTo(to, time, fn);
      },
      
      next: function(time, fn) {
        return this.move(1, time, fn);  
      },
      
      prev: function(time, fn) {
        return this.move(-1, time, fn);  
      },
      
      movePage: function(offset, time, fn) {
        return this.move(conf.size * offset, time, fn);    
      },
      
      setPage: function(page, time, fn) {
        var size = conf.size;
        var index = size * page;
        var lastPage = index + size >= this.getSize(); 
        if (lastPage) {
          index = this.getSize() - conf.size;
        }
        return this.seekTo(index, time, fn);
      },
      
      prevPage: function(time, fn) {
        return this.setPage(this.getPageIndex() - 1, time, fn);
      },  
  
      nextPage: function(time, fn) {
        return this.setPage(this.getPageIndex() + 1, time, fn);
      }, 
      
      begin: function(time, fn) {
        return this.seekTo(0, time, fn);  
      },
      
      end: function(time, fn) {
        return this.seekTo(this.getSize() - conf.size, time, fn);  
      },
      
      reload: function() {
        return load();  
      },
      
      click: function(index, time, fn) {
        
        var item = self.getItems().eq(index);
        var klass = conf.activeClass;      
        
        // check that index is sane
        if (index < 0 || index >= this.getSize()) { return self; }
          
        
        // special case with two items
        if (conf.size == 2) {
          if (index == self.getIndex()) { index--; }
          self.getItems().removeClass(klass);
          item.addClass(klass);          
          return this.seekTo(index, time, fn);
        }
        

        if (!item.hasClass(klass)) {        
          self.getItems().removeClass(klass);
          item.addClass(klass);
          var delta = Math.floor(conf.size / 2);
          var to = index - delta;

          // next to last item must work
          if (to > self.getSize() - conf.size) { 
            to = self.getSize() - conf.size; 
          }
          
          if (to !== index) {
            return this.seekTo(to, time, fn);    
          }         
        }
        
        return self;
      },

      // callback functions
      onBeforeSeek: function(fn) {
        return bind("onBeforeSeek", fn);     
      },
      
      onSeek: function(fn) {
        return bind("onSeek", fn);     
      }
      
    });
  
    
    // mousewheel
    if ($.isFunction($.fn.mousewheel)) { 
      root.bind("mousewheel.scrollable", function(e, delta)  {
        // opera goes to opposite direction
        var step = $.browser.opera ? 1 : -1;
        
        self.move(delta > 0 ? step : -step, 50);
        return false;
      });
    }  
    
    // prev button    
    prev.addClass(conf.disabledClass).click(function() { 
      self.prev(); 
    });
    

    // next button
    next.click(function() { 
      self.next(); 
    });
    
    // prev page button
    nextPage.click(function() { 
      self.nextPage(); 
    });
    

    // next page button
    prevPage.addClass(conf.disabledClass).click(function() { 
      self.prevPage(); 
    });    

    
    // keyboard
    if (conf.keyboard) {      

      // keyboard works on one instance at the time. thus we need to unbind first
      $(document).unbind("keydown.scrollable").bind("keydown.scrollable", function(evt) {
        
        var el = current;  
        if (!el || evt.altKey || evt.ctrlKey) { return; }
          
        if (horizontal && (evt.keyCode == 37 || evt.keyCode == 39)) {          
          el.move(evt.keyCode == 37 ? -1 : 1);
          return evt.preventDefault();
        }  
        
        if (!horizontal && (evt.keyCode == 38 || evt.keyCode == 40)) {
          el.move(evt.keyCode == 38 ? -1 : 1);
          return evt.preventDefault();
        }
        
        return true;
        
      });   
    }

    // navi       
    function load() {      
  
      // generate new entries
      if (navi.is(":empty") || navi.data("me") == self) {
        
        navi.empty();
        navi.data("me", self);
        
        for (var i = 0; i < self.getPageAmount(); i++) {    
          
          var item = $("<" + conf.naviItem + "/>").attr("href", i).click(function(e) {              
            var el = $(this);
            el.parent().children().removeClass(conf.activeClass);
            el.addClass(conf.activeClass);
            self.setPage(el.attr("href"));
            return e.preventDefault();
          });
          
          if (i === 0) { item.addClass(conf.activeClass); }
          navi.append(item);          
        }
        
      // assign onClick events to existing entries
      } else {
        
        // find a entries first -> syntaxically correct
        var els = navi.children(); 
        
        els.each(function(i)  {
          var item = $(this);
          item.attr("href", i);
          if (i === 0) { item.addClass(conf.activeClass); }
          
          item.click(function() {
            navi.find("." + conf.activeClass).removeClass(conf.activeClass);
            item.addClass(conf.activeClass);
            self.setPage(item.attr("href"));
          });
          
        });
      }
      
      
      // item.click()
      if (conf.clickable) {
        self.getItems().each(function(index, arg) {
          var el = $(this);
          if (!el.data("set")) {
            el.bind("click.scrollable", function() {
              self.click(index);    
            });
            el.data("set", true);
          }
        });        
      }
      
      
      // hover
      if (conf.hoverClass) {
        self.getItems().hover(function()  {
          $(this).addClass(conf.hoverClass);    
        }, function() {
          $(this).removeClass(conf.hoverClass);  
        });
      }      
      
      return self;
    }
    
    load();
    
    
    // interval stuff
    var timer = null;

    function setTimer() {

      // do not start additional timer if already exists
      if (timer) { return; }
      
      // construct new timer
      timer = setInterval(function()  {
          
        // check if interval is being changed dynamically during runtime
        if (conf.interval === 0) {          
          clearInterval(timer);
          timer = 0;
          return;
        }      
        
        self.next();        
      }, conf.interval);
    }  
    
    if (conf.interval > 0) {      
      
      // when mouse enters, autoscroll stops
      root.hover(function() {      
        clearInterval(timer);    
        timer = 0;
        
      }, function() {    
        setTimer();  
      });
      
      setTimer();  
    }
    
  } 

    
  // jQuery plugin implementation
  $.fn.scrollable = function(conf) { 
      
    // already constructed --> return API
    var el = this.eq(typeof conf == 'number' ? conf : 0).data("scrollable");
    if (el) { return el; }    
    
 
    var opts = {
      
      // basics
      size: 5,
      vertical:false,      
      clickable: true,
      loop: false,
      interval: 0,      
      speed: 400,
      keyboard: true,      
      
      // other
      activeClass:'active',
      disabledClass: 'disabled',
      hoverClass: null,      
      easing: 'swing',
      
      // navigational elements
      items: '.items',
      prev: '.prev',
      next: '.next',
      prevPage: '.prevPage',
      nextPage: '.nextPage',      
      navi: '.navi',
      naviItem: 'a',
      api:false,

      
      // callbacks
      onBeforeSeek: null,
      onSeek: null
      
    }; 
    
    
    $.extend(opts, conf);    
    
    this.each(function() {      
      el = new Scrollable($(this), opts);
      $(this).data("scrollable", el);  
    });
    
    return opts.api ? el: this; 
    
  };
      
  
})(jQuery);