( function( $ ) {

    if($.browser.msie && $.browser.version <= "6.0") {
        // vergiss es...
    } else {
    
        var $background = $( '<img />' ).addClass( 'vegas-background' ),
            $overlay    = $( '<div />' ).addClass( 'vegas-overlay' ),
            $loading    = $( '<div />' ).addClass( 'vegas-loading' ),
            $current    = $(),
            paused = null,
            backgrounds = [],
            step = 0,
            timer,
            methods = {

            // Init plugin
            init : function( settings ) {

                var options = {
                    src: getBackground(),
                    align: 'center',
                    valign: 'center',
                    fade: 0,
                    loading: false,
                    load: function() {},
                    complete: function() {}
                }
                $.extend( options, $.vegas.defaults.background, settings );

                if ( options.loading ) {
                    loading();
                }

                $new = $background.clone();
                $new.css( {
                    'position': 'fixed',
                    'left': '0px',
                    'top': '0px'
                })
                .load( function() {
                    $( window ).bind( 'resize.vegas', function( e ) {
                        resize( $new, options );
                    });

                    if ( $current.is( 'img' ) ) {

                        $current.stop();

                        $new.hide()
                            .insertAfter( $current )
                            .fadeIn( options.fade, function() {
                                $('.vegas-background')
                                    .not(this)
                                        .remove();
                                $( 'body' ).trigger( 'vegascomplete', [ this, step - 1 ] );
                                options.complete.apply( $new, [ step - 1 ] );
                            });
                    } else {
                        $new.hide()
                            .prependTo( 'body' )
                            .fadeIn( options.fade, function() {
                                $( 'body' ).trigger( 'vegascomplete', [ this, step - 1 ] );
                                options.complete.apply( this, [ step - 1 ] );
                            });
                    }

                    $current = $new;

                    resize( $current, options );

                    if ( options.loading ) {
                        loaded();
                    }

                    $( 'body' ).trigger( 'vegasload', [ $current.get(0), step - 1 ] );
                    options.load.apply( $current.get(0), [ step - 1 ] );

                    if ( step ) {
                        $( 'body' ).trigger( 'vegaswalk', [ $current.get(0), step - 1 ] );
                        options.walk.apply( $current.get(0), [ step - 1 ] );
                    }
                })
                .attr( 'src', options.src );

                return $.vegas;
            },

            // Destroy background and/or overlay
            destroy: function( what ) {
                if ( !what || what == 'background') {
                    $( '.vegas-background, .vegas-loading' ).remove();
                    $( window ).unbind( 'resize.vegas' );
                    $current = null;
                }

                if ( what == 'overlay') {
                    $( '.vegas-overlay' ).remove();
                }

                return $.vegas;
            },

            // Display the pattern overlay
            overlay: function( settings ) {
                var options = {
                    src: null,
                    opacity: null
                };
                $.extend( options, $.vegas.defaults.overlay, settings );

                $overlay.remove();

                $overlay
                    .css( {
                        'margin': '0',
                        'padding': '0',
                        'position': 'fixed',
                        'left': '0px',
                        'top': '0px',
                        'width': '100%',
                        'height': '100%'
                });

                if ( options.src ) {
                    $overlay.css( 'backgroundImage', 'url(' + options.src + ')' );
                }

                if ( options.opacity ) {
                    $overlay.css( 'opacity', options.opacity );
                }

                $overlay.prependTo( 'body' );

                return $.vegas;
            },

            // Start/restart slideshow
            slideshow: function( settings, keepPause ) {
                var options = {
                    step: step,
                    delay: 5000,
                    preload: false,
                    backgrounds: backgrounds,
                    walk: function() {}
                };
                options = $.extend( {}, $.vegas.defaults.slideshow, options, settings );

                if ( options.backgrounds != backgrounds ) {
                    if ( !settings.step ) {
                        options.step = 0;
                    }

                    if ( options.preload ) {
                        $.vegas( 'preload', options.backgrounds )
                    }
                }

                backgrounds = options.backgrounds;
                step = options.step;

                clearInterval( timer );

                if ( !backgrounds.length ) {
                    return $.vegas;
                }

                var doSlideshow = function() {
                    if ( step < 0 ) {
                        step = backgrounds.length - 1;
                    }

                    if ( step >= backgrounds.length || !backgrounds[ step - 1 ] ) {
                        step = 0;
                    }

                    var settings = backgrounds[ step++ ];
                    settings.walk = options.walk;

                    $.vegas( settings );
                }
                doSlideshow();

                if ( !keepPause ) {
                    paused = false;

                    $( 'body' ).trigger( 'vegasstart', [ $current.get(0), step - 1 ] );
                }

                if ( !paused ) {
                    timer = setInterval( doSlideshow, options.delay );
                }

                return $.vegas;
            },

            // Jump to the next background in the current slideshow
            next: function() {
                var from = step;

                if ( step ) {
                    $.vegas( 'slideshow', { step: step }, true );

                    $( 'body' ).trigger( 'vegasnext', [ $current.get(0), step - 1, from - 1 ] );
                }

                return $.vegas;
            },

            // Jump to the previous background in the current slideshow
            previous: function() {
                var from = step;

                if ( step ) {
                    $.vegas( 'slideshow', { step: step - 2 }, true );

                    $( 'body' ).trigger( 'vegasprevious', [ $current.get(0), step - 1, from - 1 ] );
                }

                return $.vegas;
            },

            // Jump to a specific background in the current slideshow
            jump: function( s ) {
                var from = step;

                if ( step ) {
                    $.vegas( 'slideshow', { step: s }, true );

                    $( 'body' ).trigger( 'vegasjump', [ $current.get(0), step - 1, from - 1 ] );
                }

                return $.vegas;
            },

            // Stop slideshow
            stop: function() {
                var from = step;
                step = 0;
                paused = null;
                clearInterval( timer );

                $( 'body' ).trigger( 'vegasstop', [ $current.get(0), from - 1 ] );

                return $.vegas;
            },

            // Pause slideShow
            pause: function() {
                paused = true;
                clearInterval( timer );

                $( 'body' ).trigger( 'vegaspause', [ $current.get(0), step - 1 ] );

                return $.vegas;
            },

            // Get some useful values or objects
            get: function( what ) {
                if ( what == null || what == 'background' ) {
                    return $current.get(0);
                }

                if ( what == 'overlay' ) {
                    return $overlay.get(0);
                }

                if ( what == 'step' ) {
                    return step - 1;
                }

                if ( what == 'paused' ) {
                    return paused;
                }
            },

            // Preload an array of backgrounds
            preload: function( backgrounds ) {
                for( var i in backgrounds ) {
                    if ( backgrounds[ i ].src ) {
                        $('<img src="' + backgrounds[ i ].src + '">');
                    }
                }

                return $.vegas;
            }
        }

        // Resize the background
        function resize( $img, settings ) {
            var options =  {
                align: 'center',
                valign: 'center'
            }
            $.extend( options, settings );

            var ww = $( window ).width(),
                wh = $( window ).height(),
                iw = $img.width(),
                ih = $img.height(),
                rw = wh / ww,
                ri = ih / iw,
                newWidth, newHeight,
                newLeft, newTop,
                properties;

            if ( rw > ri ) {
                newWidth = wh / ri;
                newHeight = wh;
            } else {
                newWidth = ww;
                newHeight = ww * ri;
            }

            properties = {
                'width': newWidth + 'px',
                'height': newHeight + 'px',
                'top': 'auto',
                'bottom': 'auto',
                'left': 'auto',
                'right': 'auto'
            }

            if ( !isNaN( parseInt( options.valign ) ) ) {
                properties[ 'top' ] = ( 0 - ( newHeight - wh ) / 100 * parseInt( options.valign ) ) + 'px';
            } else if ( options.valign == 'top' ) {
                properties[ 'top' ] = 0;
            } else if ( options.valign == 'bottom' ) {
                properties[ 'bottom' ] = 0;
            } else {
                properties[ 'top' ] = ( wh - newHeight ) / 2;
            }

            if ( !isNaN( parseInt( options.align ) ) ) {
                properties[ 'left' ] = ( 0 - ( newWidth - ww ) / 100 * parseInt( options.align ) ) + 'px';
            } else if ( options.align == 'left' ) {
                properties[ 'left' ] = 0;
            } else if ( options.align == 'right' ) {
                properties[ 'right' ] = 0;
            } else {
                properties[ 'left' ] = ( ww - newWidth ) / 2 ;
            }

            $img.css( properties );
        }

        // Display the loading indicator
        function loading() {
            $loading.prependTo( 'body' ).fadeIn();
        }

        // Hide the loading indicator
        function loaded() {
            $loading.fadeOut( 'fast', function() {
                $( this ).remove();
            });
        }

        // Get the background image from the body
        function getBackground() {
            if ( $( 'body' ).css( 'backgroundImage' ) ) {
                return $( 'body' ).css( 'backgroundImage' ).replace( /url\("?(.*?)"?\)/i, '$1' );
            }
        }

        // The plugin
        $.vegas = function( method ) {
            if ( methods[ method ] ) {
                return methods[ method ].apply( this, Array.prototype.slice.call( arguments, 1 ) );
            } else if ( typeof method === 'object' || !method ) {
                return methods.init.apply( this, arguments );
            } else {
                $.error( 'Method ' +  method + ' does not exist' );
            }
        };

        // Global parameters
        $.vegas.defaults = {
            background: {
                // src:         string
                // align:       string/int
                // valign:      string/int
                // fade:        int
                // loading      bool
                // load:        function
                // complete:    function
            },
            slideshow: {
                // step:        int
                // delay:       int
                // backgrounds: array
                // preload:     bool
                // walk:        function
            },
            overlay: {
                // src:         string
                // opacity:     float
            }
        }
    }

})( jQuery );