define([
	"../_base/array", "../_base/declare", "../_base/kernel", "../_base/lang",
	"../dom", "../dom-construct", "../mouse", "../_base/NodeList", "../on", "../touch", "./common", "./Container"
], function(array, declare, kernel, lang, dom, domConstruct, mouse, NodeList, on, touch, dnd, Container){

// module:
//		dojo/dnd/Selector

/*
	Container item states:
		""			- an item is not selected
		"Selected"	- an item is selected
		"Anchor"	- an item is selected, and is an anchor for a "shift" selection
*/

/*=====
var __SelectorArgs = declare([Container.__ContainerArgs], {
	// singular: Boolean
	//		allows selection of only one element, if true
	singular: false,

	// autoSync: Boolean
	//		autosynchronizes the source with its list of DnD nodes,
	autoSync: false
});
=====*/

var Selector = declare("dojo.dnd.Selector", Container, {
	// summary:
	//		a Selector object, which knows how to select its children

	/*=====
	// selection: Set<String>
	//		The set of id's that are currently selected, such that this.selection[id] == 1
	//		if the node w/that id is selected.  Can iterate over selected node's id's like:
	//	|		for(var id in this.selection)
	selection: {},
	=====*/

	constructor: function(node, params){
		// summary:
		//		constructor of the Selector
		// node: Node||String
		//		node or node's id to build the selector on
		// params: __SelectorArgs?
		//		a dictionary of parameters
		if(!params){ params = {}; }
		this.singular = params.singular;
		this.autoSync = params.autoSync;
		// class-specific variables
		this.selection = {};
		this.anchor = null;
		this.simpleSelection = false;
		// set up events
		this.events.push(
			on(this.node, touch.press, lang.hitch(this, "onMouseDown")),
			on(this.node, touch.release, lang.hitch(this, "onMouseUp"))
		);
	},

	// object attributes (for markup)
	singular: false,	// is singular property

	// methods
	getSelectedNodes: function(){
		// summary:
		//		returns a list (an array) of selected nodes
		var t = new NodeList();
		var e = dnd._empty;
		for(var i in this.selection){
			if(i in e){ continue; }
			t.push(dom.byId(i));
		}
		return t;	// NodeList
	},
	selectNone: function(){
		// summary:
		//		unselects all items
		return this._removeSelection()._removeAnchor();	// self
	},
	selectAll: function(){
		// summary:
		//		selects all items
		this.forInItems(function(data, id){
			this._addItemClass(dom.byId(id), "Selected");
			this.selection[id] = 1;
		}, this);
		return this._removeAnchor();	// self
	},
	deleteSelectedNodes: function(){
		// summary:
		//		deletes all selected items
		var e = dnd._empty;
		for(var i in this.selection){
			if(i in e){ continue; }
			var n = dom.byId(i);
			this.delItem(i);
			domConstruct.destroy(n);
		}
		this.anchor = null;
		this.selection = {};
		return this;	// self
	},
	forInSelectedItems: function(/*Function*/ f, /*Object?*/ o){
		// summary:
		//		iterates over selected items;
		//		see `dojo/dnd/Container.forInItems()` for details
		o = o || kernel.global;
		var s = this.selection, e = dnd._empty;
		for(var i in s){
			if(i in e){ continue; }
			f.call(o, this.getItem(i), i, this);
		}
	},
	sync: function(){
		// summary:
		//		sync up the node list with the data map

		Selector.superclass.sync.call(this);

		// fix the anchor
		if(this.anchor){
			if(!this.getItem(this.anchor.id)){
				this.anchor = null;
			}
		}

		// fix the selection
		var t = [], e = dnd._empty;
		for(var i in this.selection){
			if(i in e){ continue; }
			if(!this.getItem(i)){
				t.push(i);
			}
		}
		array.forEach(t, function(i){
			delete this.selection[i];
		}, this);

		return this;	// self
	},
	insertNodes: function(addSelected, data, before, anchor){
		// summary:
		//		inserts new data items (see `dojo/dnd/Container.insertNodes()` method for details)
		// addSelected: Boolean
		//		all new nodes will be added to selected items, if true, no selection change otherwise
		// data: Array
		//		a list of data items, which should be processed by the creator function
		// before: Boolean
		//		insert before the anchor, if true, and after the anchor otherwise
		// anchor: Node
		//		the anchor node to be used as a point of insertion
		var oldCreator = this._normalizedCreator;
		this._normalizedCreator = function(item, hint){
			var t = oldCreator.call(this, item, hint);
			if(addSelected){
				if(!this.anchor){
					this.anchor = t.node;
					this._removeItemClass(t.node, "Selected");
					this._addItemClass(this.anchor, "Anchor");
				}else if(this.anchor != t.node){
					this._removeItemClass(t.node, "Anchor");
					this._addItemClass(t.node, "Selected");
				}
				this.selection[t.node.id] = 1;
			}else{
				this._removeItemClass(t.node, "Selected");
				this._removeItemClass(t.node, "Anchor");
			}
			return t;
		};
		Selector.superclass.insertNodes.call(this, data, before, anchor);
		this._normalizedCreator = oldCreator;
		return this;	// self
	},
	destroy: function(){
		// summary:
		//		prepares the object to be garbage-collected
		Selector.superclass.destroy.call(this);
		this.selection = this.anchor = null;
	},

	// mouse events
	onMouseDown: function(e){
		// summary:
		//		event processor for onmousedown
		// e: Event
		//		mouse event
		if(this.autoSync){ this.sync(); }
		if(!this.current){ return; }
		if(!this.singular && !dnd.getCopyKeyState(e) && !e.shiftKey && (this.current.id in this.selection)){
			this.simpleSelection = true;
			if(mouse.isLeft(e)){
				// Accept the left button and stop the event.   Stopping the event prevents text selection while
				// dragging.   However, don't stop the event on mobile because that prevents a click event,
				// and also prevents scroll (see #15838).
				// For IE we don't stop event when multiple buttons are pressed.
				e.stopPropagation();
				e.preventDefault();
			}
			return;
		}
		if(!this.singular && e.shiftKey){
			if(!dnd.getCopyKeyState(e)){
				this._removeSelection();
			}
			var c = this.getAllNodes();
			if(c.length){
				if(!this.anchor){
					this.anchor = c[0];
					this._addItemClass(this.anchor, "Anchor");
				}
				this.selection[this.anchor.id] = 1;
				if(this.anchor != this.current){
					var i = 0, node;
					for(; i < c.length; ++i){
						node = c[i];
						if(node == this.anchor || node == this.current){ break; }
					}
					for(++i; i < c.length; ++i){
						node = c[i];
						if(node == this.anchor || node == this.current){ break; }
						this._addItemClass(node, "Selected");
						this.selection[node.id] = 1;
					}
					this._addItemClass(this.current, "Selected");
					this.selection[this.current.id] = 1;
				}
			}
		}else{
			if(this.singular){
				if(this.anchor == this.current){
					if(dnd.getCopyKeyState(e)){
						this.selectNone();
					}
				}else{
					this.selectNone();
					this.anchor = this.current;
					this._addItemClass(this.anchor, "Anchor");
					this.selection[this.current.id] = 1;
				}
			}else{
				if(dnd.getCopyKeyState(e)){
					if(this.anchor == this.current){
						delete this.selection[this.anchor.id];
						this._removeAnchor();
					}else{
						if(this.current.id in this.selection){
							this._removeItemClass(this.current, "Selected");
							delete this.selection[this.current.id];
						}else{
							if(this.anchor){
								this._removeItemClass(this.anchor, "Anchor");
								this._addItemClass(this.anchor, "Selected");
							}
							this.anchor = this.current;
							this._addItemClass(this.current, "Anchor");
							this.selection[this.current.id] = 1;
						}
					}
				}else{
					if(!(this.current.id in this.selection)){
						this.selectNone();
						this.anchor = this.current;
						this._addItemClass(this.current, "Anchor");
						this.selection[this.current.id] = 1;
					}
				}
			}
		}
		e.stopPropagation();
		e.preventDefault();
	},
	onMouseUp: function(/*===== e =====*/){
		// summary:
		//		event processor for onmouseup
		// e: Event
		//		mouse event
		if(!this.simpleSelection){ return; }
		this.simpleSelection = false;
		this.selectNone();
		if(this.current){
			this.anchor = this.current;
			this._addItemClass(this.anchor, "Anchor");
			this.selection[this.current.id] = 1;
		}
	},
	onMouseMove: function(/*===== e =====*/){
		// summary:
		//		event processor for onmousemove
		// e: Event
		//		mouse event
		this.simpleSelection = false;
	},

	// utilities
	onOverEvent: function(){
		// summary:
		//		this function is called once, when mouse is over our container
		this.onmousemoveEvent = on(this.node, touch.move, lang.hitch(this, "onMouseMove"));
	},
	onOutEvent: function(){
		// summary:
		//		this function is called once, when mouse is out of our container
		if(this.onmousemoveEvent){
			this.onmousemoveEvent.remove();
			delete this.onmousemoveEvent;
		}
	},
	_removeSelection: function(){
		// summary:
		//		unselects all items
		var e = dnd._empty;
		for(var i in this.selection){
			if(i in e){ continue; }
			var node = dom.byId(i);
			if(node){ this._removeItemClass(node, "Selected"); }
		}
		this.selection = {};
		return this;	// self
	},
	_removeAnchor: function(){
		if(this.anchor){
			this._removeItemClass(this.anchor, "Anchor");
			this.anchor = null;
		}
		return this;	// self
	}
});

return Selector;

});