/*

  Slidertron 0.1: A flexible slider plugin for jQuery
  By nodethirtythree design | http://nodethirtythree.com/

  Tested on IE6, IE7, IE8, Firefox 3.6, Opera 10.51, Safari 4.0.5, and Chrome 5.0.342.9.
  Dual licensed under the MIT or GPL license.

  //////////////////////////////////////////////////////////////////////////

  MIT license:

  Copyright (c) 2010 nodethirtythree design, http://nodethirtythree.com/

  Permission is hereby granted, free of charge, to any person
  obtaining a copy of this software and associated documentation
  files (the "Software"), to deal in the Software without
  restriction, including without limitation the rights to use,
  copy, modify, merge, publish, distribute, sublicense, and/or sell
  copies of the Software, and to permit persons to whom the
  Software is furnished to do so, subject to the following
  conditions:

  The above copyright notice and this permission notice shall be
  included in all copies or substantial portions of the Software.

  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
  OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
  HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
  WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
  OTHER DEALINGS IN THE SOFTWARE.

  //////////////////////////////////////////////////////////////////////////

  GPL license:

  Copyright (c) 2010 nodethirtythree design, http://nodethirtythree.com/
  
  This program 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.

  This program 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 this program. If not, see <http://www.gnu.org/licenses/>. 

  //////////////////////////////////////////////////////////////////////////

*/

(function($) {

  jQuery.fn.slidertron = function(options) {
    
    var settings = jQuery.extend({
      selectorParent:    jQuery(this)
    }, options);
    
    return jQuery.slidertron(settings);
  }

  jQuery.slidertron = function(options) {

    // Settings
    
      var settings = jQuery.extend({
      
        selectorParent:            null,            // If a jQuery object, all selectors will be restricted to its scope. Otherwise, all selectors will be global.
        
        // Selectors
        
          viewerSelector:          null,            // Viewer selector
          slidesSelector:          null,            // Slides selector
          navNextSelector:        null,            // 'Next' selector
          navPreviousSelector:      null,            // 'Previous' selector
          navFirstSelector:        null,            // 'First' selector
          navLastSelector:        null,            // 'Last' selector
          navStopAdvanceSelector:      null,            // 'Stop Advance' selector
          navPlayAdvanceSelector:      null,            // 'Play Advance' selector

        // General settings

          speed:              'slow',            // Transition speed (0 for instant, 'slow', 'fast', or a custom duration in ms)
          navWrap:            true,            // Wrap navigation when we navigate past the first or last slide
          seamlessWrap:          true,            // Seamlessly wrap slides
          advanceDelay:          10000,              // Time to wait (in ms) before automatically advancing to the next slide (0 disables advancement entirely)
          advanceResume:          0,              // Time to wait (in ms) before resuming advancement after a user interrupts it by manually navigating (0 disables resuming advancement)
          advanceNavActiveClass:      'active'          // Active advancement navigation class

      }, options);
      
    // Variables

      // Operational stuff
    
        var isConfigured = true,
          isLocked = false,
          isAdvancing = false,
          isSeamless = false,
          list = new Array(),
          currentIndex = false,
          timeoutID;

      // jQuery objects

        var __slides,
          __viewer,
          __navFirst,
          __navLast,
          __navNext,
          __navPrevious,
          __navStopAdvance,
          __navPlayAdvance;

    // Functions
      
      function getElement(selector, required)
      {
        var x;
        
        try
        {
          if (selector == null)
            throw 'is undefined';
      
          if (settings.selectorParent)
            x = settings.selectorParent.find(selector);
          else
            x = jQuery(selector);
          
          if (x.length == 0)
            throw 'does not exist';
          
          return x;
        }
        catch (error)
        {
          if (required == true)
          {
            alert('Error: Required selector "' + selector + '" ' + error + '.');
            isConfigured = false;
          }
        }
        
        return null;
      }

      function advance()
      {
        if (settings.advanceDelay == 0)
          return;
      
        if (!isLocked)
          nextSlide();

        timeoutID = window.setTimeout(advance, settings.advanceDelay);
      }

      function initializeAdvance()
      {
        if (settings.advanceDelay == 0)
          return;

        if (__navPlayAdvance)
          __navPlayAdvance.addClass(settings.advanceNavActiveClass);
        
        if (__navStopAdvance)
          __navStopAdvance.removeClass(settings.advanceNavActiveClass);

        isAdvancing = true;
        timeoutID = window.setTimeout(advance, settings.advanceDelay);
      }
      
      function interruptAdvance()
      {
        if (!isAdvancing)
          return;

        if (settings.advanceDelay == 0)
          return;

        window.clearTimeout(timeoutID);

        if (settings.advanceResume == 0)
          return;

        timeoutID = window.setTimeout(advance, settings.advanceResume);
      }
      
      function stopAdvance()
      {
        if (settings.advanceDelay == 0)
          return;

        if (!isAdvancing)
          return;
      
        isAdvancing = false;
        window.clearTimeout(timeoutID);
      }
      
      function playAdvance(skip)
      {
        if (settings.advanceDelay == 0)
          return;

        if (isAdvancing)
          return;

        isAdvancing = true;

        if (skip)
          timeoutID = window.setTimeout(advance, settings.advanceDelay);
        else
          advance();
      }
      
      function firstSlide()
      {
        switchSlide((isSeamless ? 1 : 0));
      }
      
      function lastSlide()
      {
        switchSlide((isSeamless ? list.length - 2 : list.length - 1));
      }

      function nextSlide()
      {
        if (currentIndex < list.length - 1)
          switchSlide(currentIndex + 1);
        else if (settings.navWrap || isAdvancing)
          switchSlide(0);
      }
      
      function previousSlide()
      {
        if (currentIndex > 0)
          switchSlide(currentIndex - 1);
        else if (settings.navWrap)
          switchSlide(list.length - 1);
      }

      function switchSlide(index)
      {
        // Check locking status (so another switch can't be initiated while another is in progress)

        if (isLocked)
          return false;
          
        isLocked = true;

        if (currentIndex === false)
        {
          currentIndex = index;
          __reel.css('left', -1 * list[currentIndex].x);
          isLocked = false;
        }
        else
        {
          var diff, currentX, newX;
          
          currentX = list[currentIndex].x;
          newX = list[index].x;
          diff = currentX - newX;

          __reel.animate({ left: '+=' + diff }, settings.speed, 'swing', function() {
            currentIndex = index;

            if (list[currentIndex].realIndex !== false)
            {
              currentIndex = list[currentIndex].realIndex;
              __reel.css('left', -1 * list[currentIndex].x);
            }

            isLocked = false;
          });
        }
      }

      function initialize()
      {
        // Slides, viewer, reel

          __viewer = getElement(settings.viewerSelector, true);
          __reel = getElement(settings.reelSelector, true);
          __slides = getElement(settings.slidesSelector, true);

        // Navigation

          __navFirst = getElement(settings.navFirstSelector);
          __navLast = getElement(settings.navLastSelector);
          __navNext = getElement(settings.navNextSelector);
          __navPrevious = getElement(settings.navPreviousSelector);
          __navStopAdvance = getElement(settings.navStopAdvanceSelector);
          __navPlayAdvance = getElement(settings.navPlayAdvanceSelector);

        // Check configuration status
        
          if (isConfigured == false)
          {
            alert('Error: One or more configuration errors detected. Aborting.');
            return;
          }

        // Set up

          // Viewer
          
            __viewer.css('position', 'relative');
            __viewer.css('overflow', 'hidden');

          // Reel
          
            __reel.css('position', 'absolute');
            __reel.css('left', 0);
            __reel.css('top', 0);

          // Slides
        
            var cx = 0, length = __slides.length;
        
            if (length > 2 && settings.seamlessWrap)
            {
              isSeamless = true;

              var first = __slides.first();
              var last = __slides.last();
              
              last.clone().insertBefore(first);
              first.clone().insertAfter(last);

              __slides = getElement(settings.slidesSelector, true);
            }
            
            __slides.each(function(index) {

              var y = jQuery(this);

              list[index] = {
                object:    y,
                x:      cx,
                realIndex:  false
              };
              
              y.css('position', 'absolute');
              y.css('left', cx);
              y.css('top', 0);
              
              cx += y.width();
            });

            if (isSeamless)
            {
              list[0].realIndex = length; // second to last
              list[length + 1].realIndex = 1; // second
            }
            
          // Navigation

            if (__navFirst)
              __navFirst.click(function(event) {
                event.preventDefault();

                if (isLocked)
                  return false;

                if (isAdvancing)
                  interruptAdvance();
                
                firstSlide();
              });

            if (__navLast)
              __navLast.click(function(event) {
                event.preventDefault();

                if (isLocked)
                  return false;

                if (isAdvancing)
                  interruptAdvance();

                lastSlide();
              });

            if (__navNext)
              __navNext.click(function(event) {
                event.preventDefault();

                if (isLocked)
                  return false;

                if (isAdvancing)
                  interruptAdvance();

                nextSlide();
              });

            if (__navPrevious)
              __navPrevious.click(function(event) {
                event.preventDefault();

                if (isLocked)
                  return false;
              
                if (isAdvancing)
                  interruptAdvance();

                previousSlide();
              });

            if (__navStopAdvance)
              __navStopAdvance.click(function(event) {
                event.preventDefault();

                if (isLocked)
                  return false;

                if (!isAdvancing)
                  return false;

                __navStopAdvance.addClass(settings.advanceNavActiveClass);
                
                if (__navPlayAdvance)
                  __navPlayAdvance.removeClass(settings.advanceNavActiveClass);

                stopAdvance();
              });

            if (__navPlayAdvance)
              __navPlayAdvance.click(function(event) {
                event.preventDefault();

                if (isLocked)
                  return false;
                  
                if (isAdvancing)
                  return false;

                __navPlayAdvance.addClass(settings.advanceNavActiveClass);
                
                if (__navStopAdvance)
                  __navStopAdvance.removeClass(settings.advanceNavActiveClass);

                playAdvance();
              });

      }

      // Ready

        jQuery().ready(function() {
          initialize();
          initializeAdvance();
          firstSlide();
        });
  };

})(jQuery);