$.fn.gallery = function(options) { return new Gallery(this.get(0), options); };

function Gallery(context, options) { this.init(context, options); };

Gallery.prototype = {
	options:{},
	init: function (context, options){
		this.options = $.extend({
			infinite: false,								//true = infinite gallery
			duration: 700,									//duration of effect it 1000 = 1sec
			slideElement: 1,								//number of elements for a slide
			autoRotation: false,							//false = option is disabled; 1000 = 1sec
			effect: true,									//false = slide; true = fade
			listOfSlides: 'ul > li',						//elements galleries
			switcher: false,								//false = option is disabled; 'ul > li' = elements switcher
			disableBtn: false,								//false = option is disabled; 'hidden' = class adds an buttons "prev" and "next"
			nextBtn: 'a.link-next, a.btn-next, a.na_next',		//button "next"
			prevBtn: 'a.link-prev, a.btn-prev, a.na_prev',		//button "prev"
			circle: true,									//true = cyclic gallery; false = not cyclic gallery
			direction: false,								//false = horizontal; true = vertical
			event: 'click',									//event for the buttons and switcher
			IE: false,										//forced off effect it "fade" in IE
			autoHeight: false,								//auto height on fade
			width: 500,
			height: 300
		}, options || {});
		var _el = $(context).find(this.options.listOfSlides);
		if (this.options.effect) this.list = _el;
		else this.list = _el.parent();
		if (this.options.width && this.options.height){
			this.list.css({
				width: this.options.width,
				height: this.options.height
			});
			this.list.parent().css({
				width: this.options.width,
				height: this.options.height
			});
			$(context).css({
				width: this.options.width
			});
			$(context).find('.na_title').css({
				width: this.options.width,
				opacity: 0.7
			})
		}
		var t = this;
		this.list.find('img').each(function(){
			var ww = $(this).width();
			var hh = $(this).height();
			$(this).css({ width: t.options.width });
			if ($(this).height() > t.options.height){
				$(this).css({
					width: 'auto',
					height:  t.options.height
				});
			}
			else{
				$(this).css({
					paddingTop: (t.options.height - $(this).height())/2
				});
			}
		});
		this.list.hover(function(){
			$(this).find('.na_title').animate({bottom: 0}, {queue:false, duration: 300});
		}, function(){
			$(this).find('.na_title').animate({bottom: -($(this).find('.na_title').outerHeight()+1)}, {queue:false, duration: 300});
		})
		this.nextBtn = $(context).find(this.options.nextBtn);
		this.prevBtn = $(context).find(this.options.prevBtn);
		this.count = _el.index(_el.filter(':last'));
		if (this.options.switcher){
			var str = '<ul class="'+this.options.switcher+'">';
			for (var i = 0; i < this.count+1; i++){
				str += '<li><a href="#">'+(i+1)+'</a></li>';
			};
			$(context).append($(str+'</ul>'));
		}
		this.switcher = $(context).find('ul.' + this.options.switcher + ' > li');
		
		if (this.options.switcher) this.active = this.switcher.index(this.switcher.filter('.na_active:eq(0)'));
		else this.active = _el.index(_el.filter('.na_active:eq(0)'));
		if (this.active < 0) this.active = 0;
		this.last = this.active;
		
		this.woh = _el.outerWidth(true);
		if (!this.options.direction) this.installDirections(this.list.parent().width());
		else {
			this.woh = _el.outerHeight(true);
			this.installDirections(this.list.parent().height());
		}
		
		if (!this.options.effect) {
			this.rew = this.count - this.wrapHolderW + 1;
			if (!this.options.direction) this.anim = '{marginLeft: -(this.woh * this.active)}';
			else this.anim = '{marginTop: -(this.woh * this.active)}';
			eval('this.list.css('+this.anim+')');
		}
		else {
			this.rew = this.count;
			this.list.css({opacity: 0}).removeClass('na_active').eq(this.active).addClass('na_active').css({opacity: 1}).css('opacity', 'auto');
			this.switcher.removeClass('na_active').eq(this.active).addClass('na_active');
			if(this.options.autoHeight) this.list.parent().css({height: this.list.eq(this.active).outerHeight()});
		}
		this.flag = true;
		if (this.options.infinite){
			this.count++;
			this.active += this.count;
			this.list.append(_el.clone());
			this.list.append(_el.clone());
			eval('this.list.css('+this.anim+')');
		}
		
		this.initEvent(this, this.nextBtn, true);
		this.initEvent(this, this.prevBtn, false);
		if (this.options.disableBtn) this.initDisableBtn();
		if (this.options.autoRotation) this.runTimer(this);
		if (this.options.switcher) this.initEventSwitcher(this, this.switcher);
	},
	initDisableBtn: function(){
		this.prevBtn.removeClass('na_prev-'+this.options.disableBtn);
		this.nextBtn.removeClass('na_next-'+this.options.disableBtn);
		if (this.active == 0 || this.count+1 == this.wrapHolderW) this.prevBtn.addClass('na_prev-'+this.options.disableBtn);
		if (this.active == 0 && this.count == 1 || this.count+1 <= this.wrapHolderW) this.nextBtn.addClass('na_next-'+this.options.disableBtn);
		if (this.active == this.rew) this.nextBtn.addClass('na_next-'+this.options.disableBtn);
	},
	installDirections: function(temp){
		this.wrapHolderW = Math.ceil(temp / this.woh);
		if (((this.wrapHolderW - 1) * this.woh + this.woh / 2) > temp) this.wrapHolderW--;
	},
	fadeElement: function(){
		if ($.browser.msie && this.options.IE){
			this.list.eq(this.last).css({opacity:0});
			this.list.removeClass('na_active').eq(this.active).addClass('na_active').css({opacity:'auto'});
		}
		else{
			this.list.eq(this.last).animate({opacity:0}, {queue:false, duration: this.options.duration});
			this.list.removeClass('na_active').eq(this.active).addClass('na_active').animate({
				opacity:1
			}, {queue:false, duration: this.options.duration, complete: function(){
				$(this).css('opacity','auto');
			}});
		}
		if(this.options.autoHeight) this.list.parent().animate({height: this.list.eq(this.active).outerHeight()}, {queue:false, duration: this.options.duration});
		if (this.options.switcher) this.switcher.removeClass('na_active').eq(this.active).addClass('na_active');
		this.last = this.active;
	},
	scrollElement: function($this){
		if (!$this.options.infinite) eval('$this.list.animate('+$this.anim+', {queue:false, duration: $this.options.duration});');
		else eval('$this.list.animate('+$this.anim+', $this.options.duration, function(){ $this.flag = true });');
		if ($this.options.switcher) $this.switcher.removeClass('na_active').eq($this.active / $this.options.slideElement).addClass('na_active');
	},
	runTimer: function($this){
		if($this._t) clearTimeout($this._t);
		$this._t = setInterval(function(){
			if ($this.options.infinite) $this.flag = false;
			$this.toPrepare($this, true);
		}, this.options.autoRotation);
	},
	initEventSwitcher: function($this, el){
		el.bind($this.options.event, function(){
			$this.active = $this.switcher.index($(this)) * $this.options.slideElement;
			if($this._t) clearTimeout($this._t);
			if ($this.options.disableBtn) $this.initDisableBtn();
			if (!$this.options.effect) $this.scrollElement($this);
			else $this.fadeElement();
			if ($this.options.autoRotation) $this.runTimer($this);
			return false;
		});
	},
	initEvent: function($this, addEventEl, dir){
		addEventEl.bind($this.options.event, function(){
			if ($this.flag){
				if ($this.options.infinite) $this.flag = false;
				if($this._t) clearTimeout($this._t);
				$this.toPrepare($this, dir);
				if ($this.options.autoRotation) $this.runTimer($this);
			}
			return false;
		});
	},
	toPrepare: function($this, side){
		if (!$this.options.infinite){
			if (($this.active == $this.rew) && $this.options.circle && side) $this.active = -$this.options.slideElement;
			if (($this.active == 0) && $this.options.circle && !side) $this.active = $this.rew + $this.options.slideElement;
			for (var i = 0; i < $this.options.slideElement; i++){
				if (side) { if ($this.active + 1 <= $this.rew) $this.active++; }
				else { if ($this.active - 1 >= 0) $this.active--; }
			};
		}
		else{
			if ($this.active >= $this.count + $this.count && side) $this.active -= $this.count;
			if ($this.active <= $this.count-1 && !side) $this.active += $this.count;
			eval('$this.list.css('+$this.anim+')');
			if (side) $this.active += $this.options.slideElement;
			else $this.active -= $this.options.slideElement;
		}
		if (this.options.disableBtn) this.initDisableBtn();
		if (!$this.options.effect) $this.scrollElement($this);
		else $this.fadeElement();
	},
	stop: function(){
		if (this._t) clearTimeout(this._t);
	},
	play: function(){
		if (this._t) clearTimeout(this._t);
		if (this.options.autoRotation) this.runTimer(this);
	}
}