;( function( $, window, document, undefined )
{
  'use strict';

  var cssTransitionSupport = function()
    {
      var s = document.body || document.documentElement, s = s.style;
      if( s.WebkitTransition == '' ) return '-webkit-';
      if( s.MozTransition == '' ) return '-moz-';
      if( s.OTransition == '' ) return '-o-';
      if( s.transition == '' ) return '';
      return false;
    },

    isCssTransitionSupport = cssTransitionSupport() === false ? false : true,

    cssTransitionTranslateX = function( element, positionX, speed )
    {
      var options = {}, prefix = cssTransitionSupport();
      options[ prefix + 'transform' ]  = 'translateX(' + positionX + ')';
      options[ prefix + 'transition' ] = prefix + 'transform ' + speed + 's linear';
      element.css( options );
    },

    hasTouch  = ( 'ontouchstart' in window ),
    hasPointers = window.navigator.pointerEnabled || window.navigator.msPointerEnabled,
    wasTouched  = function( event )
    {
      if( hasTouch )
        return true;

      if( !hasPointers || typeof event === 'undefined' || typeof event.pointerType === 'undefined' )
        return false;

      if( typeof event.MSPOINTER_TYPE_MOUSE !== 'undefined' )
      {
        if( event.MSPOINTER_TYPE_MOUSE != event.pointerType )
          return true;
      }
      else
        if( event.pointerType != 'mouse' )
          return true;

      return false;
    };

  $.fn.imageLightbox = function( options )
  {
    var options    = $.extend(
             {
              selector:   'id="imagelightbox"',
              allowedTypes: 'png|jpg|jpeg|gif',
              animationSpeed: 250,
              preloadNext:  true,
              enableKeyboard: true,
              quitOnEnd:    false,
              quitOnImgClick: false,
              quitOnDocClick: true,
              onStart:    false,
              onEnd:      false,
              onLoadStart:  false,
              onLoadEnd:    false
             },
             options ),

      targets   = $([]),
      target    = $(),
      image   = $(),
      imageWidth  = 0,
      imageHeight = 0,
      swipeDiff = 0,
      inProgress  = false,

      isTargetValid = function( element )
      {
        return $( element ).prop( 'tagName' ).toLowerCase() == 'a' && ( new RegExp( '\.(' + options.allowedTypes + ')$', 'i' ) ).test( $( element ).attr( 'href' ) );
      },

      setImage = function()
      {
        if( !image.length ) return false;

        var screenWidth  = $( window ).width() * 0.8,
          screenHeight = $( window ).height() * 0.9,
          tmpImage   = new Image();

        tmpImage.src  = image.attr( 'src' );
        tmpImage.onload = function()
        {
          imageWidth   = tmpImage.width;
          imageHeight  = tmpImage.height;

          if( imageWidth > screenWidth || imageHeight > screenHeight )
          {
            var ratio  = imageWidth / imageHeight > screenWidth / screenHeight ? imageWidth / screenWidth : imageHeight / screenHeight;
            imageWidth  /= ratio;
            imageHeight /= ratio;
          }

          image.css(
          {
            'width':  imageWidth + 'px',
            'height': imageHeight + 'px',
            'top':    ( $( window ).height() - imageHeight ) / 2 + 'px',
            'left':   ( $( window ).width() - imageWidth ) / 2 + 'px'
          });
        };
      },

      loadImage = function( direction )
      {
        if( inProgress ) return false;

        direction = typeof direction === 'undefined' ? false : direction == 'left' ? 1 : -1;

        if( image.length )
        {
          if( direction !== false && ( targets.length < 2 || ( options.quitOnEnd === true && ( ( direction === -1 && targets.index( target ) == 0 ) || ( direction === 1 && targets.index( target ) == targets.length - 1 ) ) ) ) )
          {
            quitLightbox();
            return false;
          }
          var params = { 'opacity': 0 };
          if( isCssTransitionSupport ) cssTransitionTranslateX( image, ( 100 * direction ) - swipeDiff + 'px', options.animationSpeed / 1000 );
          else params.left = parseInt( image.css( 'left' ) ) + 100 * direction + 'px';
          image.animate( params, options.animationSpeed, function(){ removeImage(); });
          swipeDiff = 0;
        }

        inProgress = true;
        if( options.onLoadStart !== false ) options.onLoadStart();

        setTimeout( function()
        {
          image = $( '<img ' + options.selector + ' />' )
          .attr( 'src', target.attr( 'href' ) )
          .load( function()
          {
            image.appendTo( 'body' );
            setImage();

            var params = { 'opacity': 1 };

            image.css( 'opacity', 0 );
            if( isCssTransitionSupport )
            {
              cssTransitionTranslateX( image, -100 * direction + 'px', 0 );
              setTimeout( function(){ cssTransitionTranslateX( image, 0 + 'px', options.animationSpeed / 1000 ) }, 50 );
            }
            else
            {
              var imagePosLeft = parseInt( image.css( 'left' ) );
              params.left = imagePosLeft + 'px';
              image.css( 'left', imagePosLeft - 100 * direction + 'px' );
            }

            image.animate( params, options.animationSpeed, function()
            {
              inProgress = false;
              if( options.onLoadEnd !== false ) options.onLoadEnd();
            });
            if( options.preloadNext )
            {
              var nextTarget = targets.eq( targets.index( target ) + 1 );
              if( !nextTarget.length ) nextTarget = targets.eq( 0 );
              $( '<img />' ).attr( 'src', nextTarget.attr( 'href' ) ).load();
            }
          })
          .error( function()
          {
            if( options.onLoadEnd !== false ) options.onLoadEnd();
          })

          var swipeStart   = 0,
            swipeEnd   = 0,
            imagePosLeft = 0;

          image.on( hasPointers ? 'pointerup MSPointerUp' : 'click', function( e )
          {
            e.preventDefault();
            if( options.quitOnImgClick )
            {
              quitLightbox();
              return false;
            }
            if( wasTouched( e.originalEvent ) ) return true;
              var posX = ( e.pageX || e.originalEvent.pageX ) - e.target.offsetLeft;
            target = targets.eq( targets.index( target ) - ( imageWidth / 2 > posX ? 1 : -1 ) );
            if( !target.length ) target = targets.eq( imageWidth / 2 > posX ? targets.length : 0 );
            loadImage( imageWidth / 2 > posX ? 'left' : 'right' );
          })
          .on( 'touchstart pointerdown MSPointerDown', function( e )
          {
            if( !wasTouched( e.originalEvent ) || options.quitOnImgClick ) return true;
            if( isCssTransitionSupport ) imagePosLeft = parseInt( image.css( 'left' ) );
            swipeStart = e.originalEvent.pageX || e.originalEvent.touches[ 0 ].pageX;
          })
          .on( 'touchmove pointermove MSPointerMove', function( e )
          {
            if( !wasTouched( e.originalEvent ) || options.quitOnImgClick ) return true;
            e.preventDefault();
            swipeEnd = e.originalEvent.pageX || e.originalEvent.touches[ 0 ].pageX;
            swipeDiff = swipeStart - swipeEnd;
            if( isCssTransitionSupport ) cssTransitionTranslateX( image, -swipeDiff + 'px', 0 );
            else image.css( 'left', imagePosLeft - swipeDiff + 'px' );
          })
          .on( 'touchend touchcancel pointerup MSPointerUp', function( e )
          {
            if( !wasTouched( e.originalEvent ) || options.quitOnImgClick ) return true;
            if( Math.abs( swipeDiff ) > 50 )
            {
              target = targets.eq( targets.index( target ) - ( swipeDiff < 0 ? 1 : -1 ) );
              if( !target.length ) target = targets.eq( swipeDiff < 0 ? targets.length : 0 );
              loadImage( swipeDiff > 0 ? 'right' : 'left' );
            }
            else
            {
              if( isCssTransitionSupport ) cssTransitionTranslateX( image, 0 + 'px', options.animationSpeed / 1000 );
              else image.animate({ 'left': imagePosLeft + 'px' }, options.animationSpeed / 2 );
            }
          });

        }, options.animationSpeed + 100 );
      },

      removeImage = function()
      {
        if( !image.length ) return false;
        image.remove();
        image = $();
      },

      quitLightbox = function()
      {
        if( !image.length ) return false;
        image.animate({ 'opacity': 0 }, options.animationSpeed, function()
        {
          removeImage();
          inProgress = false;
          if( options.onEnd !== false ) options.onEnd();
        });
      };

    $( window ).on( 'resize', setImage );

    if( options.quitOnDocClick )
    {
      $( document ).on( hasTouch ? 'touchend' : 'click', function( e )
      {
        if( image.length && !$( e.target ).is( image ) ) quitLightbox();
      })
    }

    if( options.enableKeyboard )
    {
      $( document ).on( 'keyup', function( e )
      {
        if( !image.length ) return true;
        e.preventDefault();
        if( e.keyCode == 27 ) quitLightbox();
        if( e.keyCode == 37 || e.keyCode == 39 )
        {
          target = targets.eq( targets.index( target ) - ( e.keyCode == 37 ? 1 : -1 ) );
          if( !target.length ) target = targets.eq( e.keyCode == 37 ? targets.length : 0 );
          loadImage( e.keyCode == 37 ? 'left' : 'right' );
        }
      });
    }

    $( document ).on( 'click', this.selector, function( e )
    {
      if( !isTargetValid( this ) ) return true;
      e.preventDefault();
      if( inProgress ) return false;
      inProgress = false;
      if( options.onStart !== false ) options.onStart();
      target = $( this );
      loadImage();
    });

    this.each( function()
    {
      if( !isTargetValid( this ) ) return true;
      targets = targets.add( $( this ) );
    });

    this.switchImageLightbox = function( index )
    {
      var tmpTarget = targets.eq( index );
      if( tmpTarget.length )
      {
        var currentIndex = targets.index( target );
        target = tmpTarget;
        loadImage( index < currentIndex ? 'left' : 'right' );
      }
      return this;
    };

    this.quitImageLightbox = function()
    {
      quitLightbox();
      return this;
    };

    return this;
  };
})( jQuery, window, document );