/*
 * Just Another Carousel v1.0
 * http://intrepidstudios.com/projects/jquery-just-another-carousel/
 *
 * Copyright (c) 2009 Kamran Ayub
 * Licensed under the GPL license.
 * http://intrepidstudios.com/projects/jquery-just-another-carousel/#license
 *
 * Last Modified: Feb 2, 2009
 * This file is part of Just Another Carousel.

    Just Another Carousel is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    Just Another Carousel is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with Just Another Carousel.  If not, see <http://www.gnu.org/licenses/>.
*/
(function($) {
  $.fn.jac = function (options) {          
    
    //
    // build main options before element iteration
    //
    var opts = $.extend({}, $.fn.jac.defaults, options);
    
    //
    // iterate and construct the carousel
    //
      return this.each(function() {
      
      // the viwport
      var $vp = $(this);
      var $vpw = Math.round($vp.width()); 
      var $c = $vp.children("ul:only-child");
      
      // Only support one carousel per viewport
      if($c.length > 1) return;
      
      // element specific options
      var settings = $.meta ? $.extend({}, opts, $vp.data()) : opts;
      // selectors
        var sel = {
            carouselSelector: "." + settings.carouselSelector,
            childSelector: "." + settings.childSelector,
            leftArrowSelector: "." + settings.leftArrowSelector,
            rightArrowSelector: "." + settings.rightArrowSelector
        };   
    
      //
      // Setup CSS
      //
        $vp
      .addClass("jac")
      .children("ul")
          .addClass(settings.carouselSelector)
          .children("li")
          .addClass(settings.childSelector);
      // carousel wrapper
           $c.wrapAll(
            $("<div class='carousel-wrapper'></div>")
            .css({
                "overflow":"hidden",
                "width" : $vpw,
                "height" : $vp.height(),
                "position" : "relative"
            })
        );
      $c.css("width", getCarouselWidth() + "px");                                             
      
      // Don't bother letting users move stuff if you can see everything
      if(getCarouselWidth() <= $vpw) return;  
      
      // less processing to store a fixed width
        var childWidth = $c.find(sel.childSelector + ":eq(0)").width();
        var kidsPerView = Math.floor($vpw / childWidth);                  
    
      // 
      // Moves content to center of mouse cursor (where it entered hover)
      //
        $c
        .find(sel.childSelector)    
        .hover(
            function(e) {            
                if(!settings.enableMouse) return;            
      
                // my abs pos to carousel
                var myAbs;

          if(settings.childSizeFixed) {
            myAbs = $c.children().index(this) * childWidth;
          } else {
            myAbs = Math.round($(this).position().left);
          }

                // my rel pos to viewport
                var myRel = myAbs + getCarouselPos();
            
                // my abs pos to carousel - centered
                var myAbsC = myAbs + Math.round($(this).width() / 2);

                // mouse rel to viewport
                var mouseRelV = Math.round(e.pageX) - $vp.offset().left;

                // mouse rel to my center
                var mouseRelC = mouseRelV - myAbsC;

                // new position to move to
                var newPos = myAbsC - mouseRelV;
            
                // new rel position, left
                var newRelPosL = myAbs - newPos;
                var newRelPosR = $(this).width() + myAbs - newPos;
      
          // compensate for $'s -1 off
          if(!settings.childFixedSize) newRelPosR += 1;
      
                // Keep from going outside the viewport
                if (newRelPosL <= 0) newPos = newPos + newRelPosL;
                if (newRelPosR >= $vpw) newPos = newPos + (newRelPosR - $vpw);
      
                // Stop all animations (smoothly)
                $c.stop().animate({
                    "left": -newPos
                }, settings.childSlideSpeed, settings.easingStyle, onMoveFinished);
            },
            function(e) {            
                if(!settings.enableMouse) return;
            
                $c.stop();
            });      
    
      // 
      // Handle navigation
      //
        if(getCarouselWidth() > $vpw) {                                                    
        
        $vp.append("<span class='"+settings.leftArrowSelector+"'></span>");
            $vp.append("<span class='"+settings.rightArrowSelector+"'></span>");
    
            // left arrow    
            $vp.find(sel.leftArrowSelector)
            .html("<a href='javascript:void(0)' title='"+settings.leftText+"'>"+settings.leftText+"</a>")
            .css("opacity", 0.7)
            .find("a")
            .hover(function() { $(this).parent().fadeTo(settings.fadeSpeed,1); }, function(){ $(this).parent().fadeTo(settings.fadeSpeed,0.7); })                    
            .click(function() {
                var movePos, newPos;
                newPos = getCarouselPos() + $vpw;
            
                if(checkReachedEdge("left")) {onMoveFinished(); return;}
            
                if(!settings.enableMouse && settings.childSizeFixed) {
            // move so we show equal amounts of kids at once
            // if the mouse is enabled, this wouldn't make sense
                    movePos = kidsPerView * childWidth;
                } else {
            // children are variable, so move viewport width
                    movePos = $vpw;
                }                    
              
                if (newPos > 0) {        
                    movePos = -getCarouselPos();
                }

            movePos = movePos + getCarouselPos();

                $c.stop();
                $c.animate({
                    "left": movePos
                }, settings.parentSlideSpeed, settings.easingStyle, onMoveFinished);
            }); // left
        
            // right arrow
            $vp.find(sel.rightArrowSelector)
            .html("<a href='javascript:void(0)' title='"+settings.rightText+"'>"+settings.rightText+"</a>")
            .css("opacity", 0.7)
            .find("a")       
            .hover(function() { $(this).parent().fadeTo(settings.fadeSpeed,1); }, function(){ $(this).parent().fadeTo(settings.fadeSpeed,0.7); })             
            .click(function() {
                var movePos, newPos;
                newPos = -getCarouselPos() + $vpw;

                if(!settings.enableMouse && settings.childSizeFixed) {
                    movePos = kidsPerView * childWidth;
                } else {
                    movePos = $vpw;
                }

      
                if (newPos >= getCarouselWidth() - $vpw) {
                    movePos = (getCarouselWidth() - $vpw) + getCarouselPos();
                }      
      
          movePos = movePos - getCarouselPos();
      
                $c.stop();
                $c.animate({
                    "left": -movePos
                }, settings.parentSlideSpeed, settings.easingStyle, onMoveFinished);                
            }); // next

        // In case its decided that the carousel has a different
        // initial pos
        if(checkReachedEdge("left")) {
          $vp.find(sel.leftArrowSelector).hide();
        }
    
        if(checkReachedEdge("right")) {
          $vp.find(sel.rightArrowSelector).hide();
        }
        
        } // navigation
    
      // Get the carousel width
      function getCarouselWidth() {
        var w = 0;

        // Get carousel width
        if(settings.childFixedSize) {
          w = $c.find(sel.childSelector).length * childWidth;
        } else {

          $c.find(sel.childSelector).each(function() {
            w += $(this).width();
          });

        }
        return w;
      }
  
      // When animation finishes, checks to see if carousel reached edge,
      // and hides/shows arrows
      function onMoveFinished() {
    
        if(checkReachedEdge("left")) {
          $vp.find(sel.leftArrowSelector).hide("normal");
        } else {
          $vp.find(sel.leftArrowSelector).show("normal");
        }
    
        if(checkReachedEdge("right")) {
          $vp.find(sel.rightArrowSelector).hide("normal");
        } else {
          $vp.find(sel.rightArrowSelector).show("normal");
        }
      }
  
      // Checks to see if the carousel
      // has reached an edge
      function checkReachedEdge(side) {
        switch(side) {
          case "left":
            if(Math.round(getCarouselPos()) >= 0) return true;        
            break;
          case "right":
            var rightEdge = Math.round((getCarouselWidth() - $vpw) + getCarouselPos());

            if(rightEdge <= 0) return true;  
              
            break;      
        }
    
        return false;
      }      
  
      // For some reason, $'s position().left
      // is off by 1 pixel. So we get it from the CSS instead since that's
      // what we're manipulating.
      function getCarouselPos() {
        return getCssPos($c);
      }
    
      }); // return this.each
  
  }; // jac
  
  //
  // Returns a number for the CSS left position
  //
  function getCssPos(el) {
    var cssPos = $(el).css("left");

    return Math.round(parseInt(cssPos.replace("px","")));
  }
  
  //
  // plugin defaults
  //
  $.fn.jac.defaults = {
        carouselSelector: "carousel",
        childSelector: "jac-content",
        leftArrowSelector: "arrow-left",
        rightArrowSelector: "arrow-right",
        easingStyle: "swing",
       rightText: "Next",
    leftText: "Previous",
       childSizeFixed: true,
        childSlideSpeed: 300,        
        parentSlideSpeed: 600,
        fadeSpeed: 300,
        enableMouse: false
    }; // defaults
  
//
// end of closure
//
})(jQuery);