dojo.provide("demos.skew.src.Image");

dojo.require("dojo.parser");
dojo.require("dijit._Widget");
dojo.require("dijit._Templated");
dojo.require("dijit.focus");
dojo.require("dojo.fx");
dojo.require("dojo.fx.easing");

dojo.declare("image.Skewed",
	[dijit._Widget, dijit._Templated],{
	// a node on the surface
	
	imgUrl: "", // dojo.moduleUrl("dojo", "resources/blank.gif"),
	// filterUrl: String
	//		Endpoint to get valid image data. This url is passed query params
	//		of 'src' (the original filename) and dir 1 || 0 (left of right skew)
	//		The default [supplied] implementation uses PHP-5 and required the GD
	//		library.
	filterUrl:"imageReflect.php",

	// Selected: Boolean
	//		Is image initially selected
	selected:"",
	// value: String
	//		Each Item has a value associated with it's image.
	value:"",

	reflectSpacing: 5,
	angle: 25,

	templateString:
		'<div class="anImage"><div dojoAttachPoint="holder" class="imageInner">'+
			'<img dojoAttachPoint="leftImage" class="imageNodeLeft" src="${imgUrl}" alt="${value}" />'+
			'<img dojoAttachPoint="imageNode" class="imageNodeCenter" src="${imgUrl}" alt="${value}" />'+
			'<img dojoAttachPoint="rightImage" class="imageNodeRight" src="${imgUrl}" alt="${value}" />'+
		'</div></div>',
		
	postCreate: function(){
		// summary:
		//		start the widget, and fetch the filtered images.
		this.inherited(arguments);
		this.imageNode.src = this.filterUrl + "?greyscale=1&src=" + this.imgUrl + "&spacing=" + this.reflectSpacing;
		this.leftImage.src = this.filterUrl + "?greyscale=1&src=" + this.imgUrl + "&skew=left&angle=" + this.angle + "&spacing=" + this.reflectSpacing;
		this.rightImage.src = this.filterUrl + "?greyscale=1&src=" + this.imgUrl + "&skew=right&angle=" + this.angle + "&spacing=" + this.reflectSpacing;
		this.connect(this.domNode,"onfocus","center");
	},
	
	startup: function(){
		if(!this._started){
			this.inherited(arguments);
			if(this.selected){
				this.center();
			}
		}
	},
	
	center: function(e){
		// summary:
		//		public function to center a particular image
		var p = dijit.getEnclosingWidget(this.domNode.parentNode);
		p._center(this.domNode);
	}
	
});

dojo.declare("image.Container",
	[dijit._Widget,dijit._Templated],
	{

	// loop: Boolean
	//		If true, Images will loop when continuing on beyond end or before beginning
	loop:false,
	// useWheel: Boolean
	//		Disable/enable mouse wheel listener
	useWheel: true,
	// useDrag: Boolean
	//		Experimental: NOT WORKING, toggles dragging a direction on the pane as
	//		a method of reordering
	useDrag: false,
	// spacing: Integer
	//		The relative offset of each image from it's immediate siblings
	spacing: 50,
	_spacing: 50, // an additional param for offset from center
	
	
	// only use even numbers:
	visibleItems: 15,
	
	// offOpacity: Float
	//		An opacity value to set to the images that do not have focus
	offOpacity: 0.75,
	
	// easing: String|Function
	//		An easing function [name] to use
	easing:"dojo.fx.easing.easeOut",
	
	templateString:
		'<div tabIndex="0"><div class="imageContainer" dojoAttachPoint="containerWrapper,containerNode">'+
		'</div></div>',
		
	postCreate:function(){
		
		this.inherited(arguments);
		this.threshold = (this.visibleItems + (this.visibleItems % 2)) / 2;

		var node = this.domNode;
		dojo.style(this.containerWrapper,"position","relative");
		this.easing = (dojo.isString(this.easing) ? dojo.getObject(this.easing) : this.easing);

		if(dojo.isIE){
			// FIXME: can move to css with .dj_ie prefix
			dojo.style(this.containerNode,"overflow","hidden");
		}

		this.connect(node,"onclick","_click");
		this.connect(node,"onkeypress","_handleKey");
		if(this.useWheel){
			this.connect(node, (!dojo.isMozilla ? "onmousewheel" : "DOMMouseScroll"), "_scroll");
		}

	},
	
	startup:function(){
		
		// sets this.nl
		if(this._started) return;
		this.inherited(arguments);
		var sel = Math.floor(this._getChildren().length / 2);
		// FIXME: if no children, this throws an error
		this._center(this.nl[sel].firstChild);
		
	},
	
	_getChildren: function(){
		this.nl = dojo.query(".anImage",this.domNode);
		return this.nl;
	},
	
	_click: function(e){
		if(!dojo.isIE){
			dijit.focus(this.domNode);
		}
		var n = e.target;
		if(n !== this.domNode && n !== this.containerNode){
			this._center(n);
		}
	},

	resize: function(){
		this._size = {
			w: this.domNode.clientWidth,
			h: this.domNode.clientHeight
		};
		if(dojo.isIE){
			dojo.marginBox(this.containerNode,dojo.mixin(this._size,{ t: 0, l:0 }));
		}
		if(this.selectedChild){
			this._center(this.selectedChild.domNode);
		}
	},
	
	_center: function(/* DomNode */node){
		// summary:
		//		Main function used to arrage the images based on a selected node
		var w = dijit.getEnclosingWidget(node);
		if(this._centering){
			this.selectedChild = w;
			return;
		}
		this._centering = true;
		var _anims = [];
		
		var currentIdx = null;
		if(this.selectedChild){
			currentIdx = this.nl.indexOf(this.selectedChild.domNode);
		}
							
		this.selectedChild = w;
		var x = this.nl.indexOf(w.domNode);
		
		// fire our stub functions
		this[(x === currentIdx ? "onSelected" : "onShow")](this.selectedChild);
		
		if(!this._size){ this.resize(); }
		var centerL = Math.floor(this._size.w / 2);
		
		// FIXME: we can use just a slice around +/- x for long lists! (alex?)
		var _delay = 10;
		var _diff = this._spacing;
		var thresh = this.threshold;
		var some = this.nl.map(function(n,i){
			var dist = Math.abs(i - x);
			dojo.style(n, "display", (Math.abs(i - x) > thresh ? "none" : ""));
			
		});
		
		this.nl
			.forEach(function(n,i){
	
				var isNextRight = (i === x + 1);
				var isNextLeft = (i === x - 1);
				var _mix = {
					opacity: this.offOpacity,
					zIndex:69
				};

				var c;
				if(i > x){
					c = "alignRight";
					// stagger z-index downward from center on
					_mix.zIndex = isNextRight ? 45 : 40 - i;
				}else if(i < x){
					c = "alignLeft";
					// left z-indexes are fine, they go in order of markup
					_mix.zIndex = isNextLeft ? 45 : 40;
				}else{
					// center should be on top always
					c = "alignCenter";
					_mix.opacity = 1;
				}
				dojo.style(n, _mix);
				dojo.forEach(["alignLeft","alignRight","alignCenter"],function(cl){
					dojo.removeClass(n,cl);
				});
				dojo.addClass(n,c);
				
				// need to make dynamic, this is "half the size of a single image"
				var _half = 50;
				
				if(currentIdx || currentIdx === 0){
					// figure out where our left edge will be: magically,
					// this centers and seems to subtly get further from
					// center. need maff master here:
					var d = i - x;
					var _off = (d === 0 ? 0 : _diff) * (d < 0 ? -1 : 1);
					var lef = centerL - _half + (d * this.spacing) + _off;

					// create another animation for this node:
					_anims.push(
						dojo.animateProperty({
							duration:150,
							node:n,
							properties: { left: lef },
							delay: parseInt(_delay),
							easing: this.easing
						})
					);
					// oh so slightly, or less if going away from node:
					_delay += (d < 0 ? 15 : -15);
				}

			}, this) // forEach
		;
		
		// don't use onEnd here, but might ought to stop()?
		// seems like it handles the new animations okay?
		this._anim && this._anim.stop && this._anim.stop();
		
		this._anim = dojo.fx.combine(_anims);
		this._anim.play();
		this._centering = false;
		
	},
	
	onShow: function(widget){
		// summary:
		//		stub fired when a user triggers a recenter
		//		this could happen very often!
	},
	
	onSelected: function(widget){
		// summary:
		//		stub fired when a user explicitly clicks the already displayed value
	},
	
	_handleKey: function(e){
		// summary:
		//		keyboard handling code
		var dk = dojo.keys,
			cur = this.nl.indexOf(this.selectedChild.domNode || this.nl[0]),
			ni
		;
		
		switch(e.charOrCode){
			
			case dk.RIGHT_ARROW:
				// goto next item or stop if loop='false' and at end
				ni = cur + 1;
				if(ni >= this.nl.length){ ni = (this.loop ? 0 : cur); }
				if(ni !== cur){ this._center(this.nl[ni]);	}
				break;

			case dk.LEFT_ARROW:
				// ditto, but left.
				ni = cur - 1;
				if(ni < 0){ ni = (this.loop ? this.nl.length - 1 : cur); }
				if(ni !== cur){ this._center(this.nl[ni]); }
				break;
			
			case dk.ENTER:
				// just like clicking a selected image
				this.onSelected(this.selectedChild);
				break;
		}
		
	},
	
	_scroll: function(e){
		// summary:
		//		handle mouse wheel event, and duck type a fake event to pass
		//		along to _handleKey
		dojo.stopEvent(e);
		var scroll = e[(!dojo.isMozilla ? "wheelDelta" : "detail")] * (!dojo.isMozilla ? 1 : -1);
		this._handleKey({
			charOrCode: dojo.keys[(scroll > 0 ? "LEFT_ARROW" : "RIGHT_ARROW")]
		});
		
	}
	
});

