define([
	"dojo/_base/declare", // declare
	"dojo/keys", // keys
	"dojo/_base/lang", // lang.clone lang.hitch
	"dojo/query", // query
	"dojo/string", // string.substitute
	"dojo/when",
	"../registry"	// registry.byId
], function(declare, keys, lang, query, string, when, registry){

	// module:
	//		dijit/form/_SearchMixin


	return declare("dijit.form._SearchMixin", null, {
		// summary:
		//		A mixin that implements the base functionality to search a store based upon user-entered text such as
		//		with `dijit/form/ComboBox` or `dijit/form/FilteringSelect`
		// tags:
		//		protected

		// pageSize: Integer
		//		Argument to data provider.
		//		Specifies maximum number of search results to return per query
		pageSize: Infinity,

		// store: [const] dojo/store/api/Store
		//		Reference to data provider object used by this ComboBox.
		//		The store must accept an object hash of properties for its query. See `query` and `queryExpr` for details.
		store: null,

		// fetchProperties: Object
		//		Mixin to the store's fetch.
		//		For example, to set the sort order of the ComboBox menu, pass:
		//	|	{ sort: [{attribute:"name",descending: true}] }
		//		To override the default queryOptions so that deep=false, do:
		//	|	{ queryOptions: {ignoreCase: true, deep: false} }
		fetchProperties:{},

		// query: Object
		//		A query that can be passed to `store` to initially filter the items.
		//		ComboBox overwrites any reference to the `searchAttr` and sets it to the `queryExpr` with the user's input substituted.
		query: {},

		// list: [const] String
		//		Alternate to specifying a store.  Id of a dijit/form/DataList widget.
		list: "",
		_setListAttr: function(list){
			// Avoid having list applied to the DOM node, since it has native meaning in modern browsers
			this._set("list", list);
		},

		// searchDelay: Integer
		//		Delay in milliseconds between when user types something and we start
		//		searching based on that value
		searchDelay: 200,

		// searchAttr: String
		//		Search for items in the data store where this attribute (in the item)
		//		matches what the user typed
		searchAttr: "name",

		// queryExpr: String
		//		This specifies what query is sent to the data store,
		//		based on what the user has typed.  Changing this expression will modify
		//		whether the results are only exact matches, a "starting with" match,
		//		etc.
		//		`${0}` will be substituted for the user text.
		//		`*` is used for wildcards.
		//		`${0}*` means "starts with", `*${0}*` means "contains", `${0}` means "is"
		queryExpr: "${0}*",

		// ignoreCase: Boolean
		//		Set true if the query should ignore case when matching possible items
		ignoreCase: true,

		_patternToRegExp: function(pattern){
			// summary:
			//		Helper function to convert a simple pattern to a regular expression for matching.
			// description:
			//		Returns a regular expression object that conforms to the defined conversion rules.
			//		For example:
			//
			//		- ca*   -> /^ca.*$/
			//		- *ca*  -> /^.*ca.*$/
			//		- *c\*a*  -> /^.*c\*a.*$/
			//		- *c\*a?*  -> /^.*c\*a..*$/
			//
			//		and so on.
			// pattern: string
			//		A simple matching pattern to convert that follows basic rules:
			//
			//		- * Means match anything, so ca* means match anything starting with ca
			//		- ? Means match single character.  So, b?b will match to bob and bab, and so on.
			//		- \ is an escape character.  So for example, \* means do not treat * as a match, but literal character *.
			//
			//		To use a \ as a character in the string, it must be escaped.  So in the pattern it should be
			//		represented by \\ to be treated as an ordinary \ character instead of an escape.

			return new RegExp("^" + pattern.replace(/(\\.)|(\*)|(\?)|\W/g, function(str, literal, star, question){
				return star ? ".*" : question ? "." : literal ? literal : "\\" + str;
			}) + "$", this.ignoreCase ? "mi" : "m");
		},

		_abortQuery: function(){
			// stop in-progress query
			if(this.searchTimer){
				this.searchTimer = this.searchTimer.remove();
			}
			if(this._queryDeferHandle){
				this._queryDeferHandle = this._queryDeferHandle.remove();
			}
			if(this._fetchHandle){
				if(this._fetchHandle.abort){
					this._cancelingQuery = true;
					this._fetchHandle.abort();
					this._cancelingQuery = false;
				}
				if(this._fetchHandle.cancel){
					this._cancelingQuery = true;
					this._fetchHandle.cancel();
					this._cancelingQuery = false;
				}
				this._fetchHandle = null;
			}
		},

		_processInput: function(/*Event*/ evt){
			// summary:
			//		Handles input (keyboard/paste) events
			if(this.disabled || this.readOnly){ return; }
			var key = evt.charOrCode;

			// except for cutting/pasting case - ctrl + x/v
			if("type" in evt && evt.type.substring(0,3) == "key" && (evt.altKey || ((evt.ctrlKey || evt.metaKey) && (key != 'x' && key != 'v')) || key == keys.SHIFT)){
				return; // throw out weird key combinations and spurious events
			}

			var doSearch = false;
			this._prev_key_backspace = false;

			switch(key){
				case keys.DELETE:
				case keys.BACKSPACE:
					this._prev_key_backspace = true;
					this._maskValidSubsetError = true;
					doSearch = true;
					break;

				default:
					// Non char keys (F1-F12 etc..) shouldn't start a search..
					// Ascii characters and IME input (Chinese, Japanese etc.) should.
					//IME input produces keycode == 229.
					doSearch = typeof key == 'string' || key == 229;
			}
			if(doSearch){
				// need to wait a tad before start search so that the event
				// bubbles through DOM and we have value visible
				if(!this.store){
					this.onSearch();
				}else{
					this.searchTimer = this.defer("_startSearchFromInput", 1);
				}
			}
		},

		onSearch: function(/*===== results, query, options =====*/){
			// summary:
			//		Callback when a search completes.
			//
			// results: Object
			//		An array of items from the originating _SearchMixin's store.
			//
			// query: Object
			//		A copy of the originating _SearchMixin's query property.
			//
			// options: Object
			//		The additional parameters sent to the originating _SearchMixin's store, including: start, count, queryOptions.
			//
			// tags:
			//		callback
		},

		_startSearchFromInput: function(){
			this._startSearch(this.focusNode.value);
		},

		_startSearch: function(/*String*/ text){
			// summary:
			//		Starts a search for elements matching text (text=="" means to return all items),
			//		and calls onSearch(...) when the search completes, to display the results.

			this._abortQuery();
			var
				_this = this,
				// Setup parameters to be passed to store.query().
				// Create a new query to prevent accidentally querying for a hidden
				// value from FilteringSelect's keyField
				query = lang.clone(this.query), // #5970
				options = {
					start: 0,
					count: this.pageSize,
					queryOptions: {		// remove for 2.0
						ignoreCase: this.ignoreCase,
						deep: true
					}
				},
				qs = string.substitute(this.queryExpr, [text.replace(/([\\\*\?])/g, "\\$1")]),
				q,
				startQuery = function(){
					var resPromise = _this._fetchHandle = _this.store.query(query, options);
					if(_this.disabled || _this.readOnly || (q !== _this._lastQuery)){
						return;
					} // avoid getting unwanted notify
					when(resPromise, function(res){
						_this._fetchHandle = null;
						if(!_this.disabled && !_this.readOnly && (q === _this._lastQuery)){ // avoid getting unwanted notify
							when(resPromise.total, function(total){
								res.total = total;
								var pageSize = _this.pageSize;
								if(isNaN(pageSize) || pageSize > res.total){ pageSize = res.total; }
								// Setup method to fetching the next page of results
								res.nextPage = function(direction){
									//	tell callback the direction of the paging so the screen
									//	reader knows which menu option to shout
									options.direction = direction = direction !== false;
									options.count = pageSize;
									if(direction){
										options.start += res.length;
										if(options.start >= res.total){
											options.count = 0;
										}
									}else{
										options.start -= pageSize;
										if(options.start < 0){
											options.count = Math.max(pageSize + options.start, 0);
											options.start = 0;
										}
									}
									if(options.count <= 0){
										res.length = 0;
										_this.onSearch(res, query, options);
									}else{
										startQuery();
									}
								};
								_this.onSearch(res, query, options);
							});
						}
					}, function(err){
						_this._fetchHandle = null;
						if(!_this._cancelingQuery){	// don't treat canceled query as an error
							console.error(_this.declaredClass + ' ' + err.toString());
						}
					});
				};

			lang.mixin(options, this.fetchProperties);

			// Generate query
			if(this.store._oldAPI){
				// remove this branch for 2.0
				q = qs;
			}else{
				// Query on searchAttr is a regex for benefit of dojo/store/Memory,
				// but with a toString() method to help dojo/store/JsonRest.
				// Search string like "Co*" converted to regex like /^Co.*$/i.
				q = this._patternToRegExp(qs);
				q.toString = function(){ return qs; };
			}

			// set _lastQuery, *then* start the timeout
			// otherwise, if the user types and the last query returns before the timeout,
			// _lastQuery won't be set and their input gets rewritten
			this._lastQuery = query[this.searchAttr] = q;
			this._queryDeferHandle = this.defer(startQuery, this.searchDelay);
		},

		//////////// INITIALIZATION METHODS ///////////////////////////////////////

		constructor: function(){
			this.query={};
			this.fetchProperties={};
		},

		postMixInProperties: function(){
			if(!this.store){
				var list = this.list;
				if(list){
					this.store = registry.byId(list);
				}
			}
			this.inherited(arguments);
		}
	});
});
