dojo.provide("dojox.data.GoogleSearchStore");
dojo.provide("dojox.data.GoogleWebSearchStore");
dojo.provide("dojox.data.GoogleBlogSearchStore");
dojo.provide("dojox.data.GoogleLocalSearchStore");
dojo.provide("dojox.data.GoogleVideoSearchStore");
dojo.provide("dojox.data.GoogleNewsSearchStore");
dojo.provide("dojox.data.GoogleBookSearchStore");
dojo.provide("dojox.data.GoogleImageSearchStore");

dojo.require("dojo.io.script");

dojo.experimental("dojox.data.GoogleSearchStore");

dojo.declare("dojox.data.GoogleSearchStore",null,{
	// summary:
	//	A data store for retrieving search results from Google.
	//  This data store acts as a base class for Google searches,
	//  and has a number of child data stores that implement different
	//  searches. This store defaults to searching the web, and is functionally
	//  identical to the dojox.data.GoogleWebSearchStore object.
	//	The following attributes are supported on each item:
	//		<ul>
	//			<li>url - The URL for the item</li>
	//			<li>unescapedUrl - The URL for the item, with URL escaping. This is often more readable</li>
	//			<li>visibleUrl - The URL with no protocol specified.
	//			<li>cacheUrl - The URL to the copy of the document cached by Google
	//			<li>title - The page title in HTML format.</li>
	//			<li>titleNoFormatting - The page title in plain text</li>
	//			<li>content - A snippet of information about the page</li>
	//		</ul>
	//	The query accepts one parameter: text - The string to search for
	constructor: function(/*Object*/args){
		//	summary:
		//		Initializer for the GoogleSearchStore store.
		//	description:
		//		The GoogleSearchStore is a Datastore interface to
		//      the Google search service. The constructor accepts the following arguments:
		//		<ul>
		//			<li>label - the label attribute to use. Defaults to titleNoFormatting</li>
		//			<li>key - The API key to use. This is optional</li>
		//			<li>lang - The language locale to use. Defaults to the browser locale</li>
		//		</ul>

		if(args){
			if(args.label){
				this.label = args.label;
			}
			if(args.key){
				this._key = args.key;
			}
			if(args.lang){
				this._lang = args.lang;
			}
		}
		this._id = dojox.data.GoogleSearchStore.prototype._id++;
	},

	// _id: Integer
	// A unique identifier for this store.
	_id: 0,

	// _requestCount: Integer
	// A counter for the number of requests made. This is used to define
	// the callback function that GoogleSearchStore will use.
	_requestCount: 0,

	// _googleUrl: String
	// The URL to Googles search web service.
	_googleUrl: "http://ajax.googleapis.com/ajax/services/search/",

	// _storeRef: String
	// The internal reference added to each item pointing at the store which owns it.
	_storeRef: "_S",

	// _attributes: Array
	// The list of attributes that this store supports
	_attributes: ["unescapedUrl", "url", "visibleUrl", "cacheUrl", "title", "titleNoFormatting", "content"],

	// label: String
	// The default attribute which acts as a label for each item.
	label: "titleNoFormatting",

	// type: String
	// The type of search. Valid values are "web", "local", "video", "blogs", "news", "books", "images".
	// This should not be set directly. Instead use one of the child classes.
	_type: "web",

	_queryAttr: "text",

	_assertIsItem: function(/* item */ item){
		//	summary:
		//      This function tests whether the item passed in is indeed an item in the store.
		//	item:
		//		The item to test for being contained by the store.
		if(!this.isItem(item)){
			throw new Error("dojox.data.GoogleSearchStore: a function was passed an item argument that was not an item");
		}
	},

	_assertIsAttribute: function(/* attribute-name-string */ attribute){
		//	summary:
		//		This function tests whether the item passed in is indeed a valid 'attribute' like type for the store.
		//	attribute:
		//		The attribute to test for being contained by the store.
		if(typeof attribute !== "string"){
			throw new Error("dojox.data.GoogleSearchStore: a function was passed an attribute argument that was not an attribute name string");
		}
	},

	getFeatures: function(){
		//	summary:
		//      See dojo.data.api.Read.getFeatures()
		return {
			'dojo.data.api.Read': true
		};
	},

	getValue: function(item, attribute, defaultValue){
		//	summary:
		//      See dojo.data.api.Read.getValue()
		var values = this.getValues(item, attribute);
		if(values && values.length > 0){
			return values[0];
		}
		return defaultValue;
	},

	getAttributes: function(item){
		//	summary:
		//      See dojo.data.api.Read.getAttributes()
		return this._attributes;
	},

	hasAttribute: function(item, attribute){
		//	summary:
		//      See dojo.data.api.Read.hasAttributes()
		if(this.getValue(item,attribute)){
			return true;
		}
		return false;
	},

	isItemLoaded: function(item){
		 //	summary:
		 //      See dojo.data.api.Read.isItemLoaded()
		 return this.isItem(item);
	},

	loadItem: function(keywordArgs){
		//	summary:
		//      See dojo.data.api.Read.loadItem()
	},

	getLabel: function(item){
		//	summary:
		//      See dojo.data.api.Read.getLabel()
		return this.getValue(item,this.label);
	},

	getLabelAttributes: function(item){
		//	summary:
		//      See dojo.data.api.Read.getLabelAttributes()
		return [this.label];
	},

	containsValue: function(item, attribute, value){
		//	summary:
		//      See dojo.data.api.Read.containsValue()
		var values = this.getValues(item,attribute);
		for(var i = 0; i < values.length; i++){
			if(values[i] === value){
				return true;
			}
		}
		return false;
	},

	getValues: function(item, attribute){
		//	summary:
		//      See dojo.data.api.Read.getValue()
		this._assertIsItem(item);
		this._assertIsAttribute(attribute);
		var val = item[attribute];
		if(dojo.isArray(val)) {
			return val;
		}else if(val !== undefined){
			return [val];
		}else{
			return [];
		}
	},

	isItem: function(item){
		//	summary:
		//      See dojo.data.api.Read.isItem()
		if(item && item[this._storeRef] === this){
			return true;
		}
		return false;
	},

	close: function(request){
		//	summary:
		//      See dojo.data.api.Read.close()
	},

	_format: function(item, name){
		return item;//base implementation does not format any items
	},

	fetch: function(request){
		//	summary:
		//		Fetch Google search items that match to a query
		//	request:
		//		A request object
		//	fetchHandler:
		//		A function to call for fetched items
		//	errorHandler:
		//		A function to call on error
		request = request || {};

		var scope = request.scope || dojo.global;

		if(!request.query || !request.query[this._queryAttr]){
			if(request.onError){
				request.onError.call(scope, new Error(this.declaredClass +
					": A query must be specified, with a '" + [this._queryAttr] + "' parameter."));
				return;
			}
		}
		//Make a copy of the request object, in case it is
		//modified outside the store in the middle of a request
		var query = request.query[this._queryAttr];
		request = {
			query: {
			},
			onComplete: request.onComplete,
			onError: request.onError,
			onItem: request.onItem,
			onBegin: request.onBegin,
			start: request.start,
			count: request.count
		};
		request.query[this._queryAttr] = query;

        //Google's web api will only return a max of 8 results per page.
		var pageSize = 8;

		//Generate a unique function to be called back
		var callbackFn = "GoogleSearchStoreCallback_" + this._id + "_" + (++this._requestCount);

		//Build up the content to send the request for.
		//rsz is the result size, "large" gives 8 results each time
		var content = this._createContent(query, callbackFn, request);

		var firstRequest;

		if(typeof(request.start) === "undefined" || request.start === null){
			request.start = 0;
		}

		if(!request.count){
			request.count = pageSize;
		}
		firstRequest = {start: request.start - request.start % pageSize};

		var _this = this;
		var handle = null;
		var searchUrl = this._googleUrl + this._type;

		var getArgs = {
			url: searchUrl,
			preventCache: true,
			content: content
		};

		var items = [];
		var successfulReq = 0;
		var finished = false;
		var lastOnItem = request.start -1;
		var numRequests = 0;

		// Performs the remote request.
		function doRequest(req){
			//Record how many requests have been made.
			numRequests ++;
			getArgs.content.context = getArgs.content.start = req.start;

			var deferred = dojo.io.script.get(getArgs);

			//We only set up the errback, because the callback isn't ever really used because we have
			//to link to the jsonp callback function....
			deferred.addErrback(function(error){
				if(request.onError){
					request.onError.call(scope, error, request);
				}
			});
		}

		// Function to handle returned data.
		var myHandler = function(start, data){
			if(finished){return;}
			var results = _this._getItems(data);
			var cursor = data ? data['cursor']: null;
			if(results){
				//Process the results, adding the store reference to them
				for(var i = 0; i < results.length && i + start < request.count + request.start; i++) {
					_this._processItem(results[i], data);
					items[i + start] = results[i];
				}
				successfulReq ++;
				if(successfulReq == 1){
					// After the first request, we know how many results exist.
					// So perform any follow up requests to retrieve more data.
					var pages = cursor ? cursor.pages : null;
					var firstStart = pages ? Number(pages[pages.length - 1].start) : 0;

					//Call the onBegin method if it exists
					if (request.onBegin){
						var est = cursor ? cursor.estimatedResultCount : results.length;
						var total =  est ? Math.min(est, firstStart + results.length) : firstStart + results.length;
						request.onBegin.call(scope, total, request);
					}

					// Request the next pages.
					var nextPage = (request.start - request.start % pageSize) + pageSize;
					var page = 1;
					while(pages){
						if(!pages[page] || Number(pages[page].start) >= request.start + request.count){
							break;
						}
						if(Number(pages[page].start) >= nextPage) {
							doRequest({start: pages[page].start});
						}
						page++;
					}
				}

				// Call the onItem function on all retrieved items.
				if(request.onItem && items[lastOnItem + 1]){
					do{
						lastOnItem++;
						request.onItem.call(scope, items[lastOnItem], request);
					}while(items[lastOnItem + 1] && lastOnItem < request.start + request.count);
				}

				//If this is the last request, call final fetch handler.
				if(successfulReq == numRequests){
					//Process the items...
					finished = true;
					//Clean up the function, it should never be called again
					dojo.global[callbackFn] = null;
					if(request.onItem){
						request.onComplete.call(scope, null, request);
					}else{
						items = items.slice(request.start, request.start + request.count);
						request.onComplete.call(scope, items, request);
					}

				}
			}
		};

		var callbacks = [];
		var lastCallback = firstRequest.start - 1;

		var sortFn = function(a,b){
			if(a.start < b.start){return -1;}
			if(b.start < a.start){return 1;}
			return 0;
		};

		// Attach a callback function to the global namespace, where Google can call it.
		dojo.global[callbackFn] = function(start, data, responseCode, errorMsg){
			try {
				if(responseCode != 200){
					if(request.onError){
						request.onError.call(scope, new Error("Response from Google was: " + responseCode), request);
					}
					dojo.global[callbackFn] = function(){};//an error occurred, do not return anything else.
					return;
				}
	
				if(start == lastCallback + 1){
					myHandler(Number(start), data);
					lastCallback += pageSize;
	
					//make sure that the callbacks happen in the correct sequence
					if(callbacks.length > 0){
						callbacks.sort(sortFn);
						//In case the requsts do not come back in order, sort the returned results.
						while(callbacks.length > 0 && callbacks[0].start == lastCallback + 1){
							myHandler(Number(callbacks[0].start), callbacks[0].data);
							callbacks.splice(0,1);
							lastCallback += pageSize;
						}
					}
				}else{
					callbacks.push({start:start, data: data});
				}
			} catch (e) {
				request.onError.call(scope, e, request);
			}
		};

		// Perform the first request. When this has finished
		// we will have a list of pages, which can then be
		// gone through
		doRequest(firstRequest);
	},

	_processItem: function(item, data) {
		item[this._storeRef] = this;
	},

	_getItems: function(data){
		return data['results'] || data;
	},

	_createContent: function(query, callback, request){
		return {
				q: query,
				v:"1.0",
				rsz:"large",
				callback: callback,
				key:this._key,
				hl: this._lang
			};
	}
});

dojo.declare("dojox.data.GoogleWebSearchStore", dojox.data.GoogleSearchStore,{
	// summary:
	//	A data store for retrieving search results from Google.
	//	The following attributes are supported on each item:
	//		<ul>
	//			<li>title - The page title in HTML format.</li>
	//			<li>titleNoFormatting - The page title in plain text</li>
	//			<li>content - A snippet of information about the page</li>
	//			<li>url - The URL for the item</li>
	//			<li>unescapedUrl - The URL for the item, with URL escaping. This is often more readable</li>
	//			<li>visibleUrl - The URL with no protocol specified.</li>
	//			<li>cacheUrl - The URL to the copy of the document cached by Google</li>
	//		</ul>
	//	The query accepts one parameter: text - The string to search for
});

dojo.declare("dojox.data.GoogleBlogSearchStore", dojox.data.GoogleSearchStore,{
	// summary:
	//	A data store for retrieving search results from Google.
	//	The following attributes are supported on each item:
	//		<ul>
	//			<li>title - The blog post title in HTML format.</li>
	//			<li>titleNoFormatting - The  blog post title in plain text</li>
	//			<li>content - A snippet of information about the blog post</li>
	//			<li>blogUrl - The URL for the blog</li>
	//			<li>postUrl - The URL for the a single blog post</li>
	//			<li>visibleUrl - The URL with no protocol specified.
	//			<li>cacheUrl - The URL to the copy of the document cached by Google
	//			<li>author - The author of the blog post</li>
	//			<li>publishedDate - The published date, in RFC-822 format</li>
	//		</ul>
	//	The query accepts one parameter: text - The string to search for
	_type: "blogs",
	_attributes: ["blogUrl", "postUrl", "title", "titleNoFormatting", "content", "author", "publishedDate"]
});


dojo.declare("dojox.data.GoogleLocalSearchStore", dojox.data.GoogleSearchStore,{
	// summary:
	//	A data store for retrieving search results from Google.
	//	The following attributes are supported on each item:
	//		<ul>
	//			<li>title - The blog post title in HTML format.</li>
	//			<li>titleNoFormatting - The  blog post title in plain text</li>
	//			<li>content - A snippet of information about the blog post</li>
	//			<li>url - The URL for the item</li>
	//			<li>lat - The latitude.</li>
	//			<li>lng - The longtitude.</li>
	//			<li>streetAddress - The street address</li>
	//			<li>city - The city</li>
	//			<li>region - The region</li>
	//			<li>country - The country</li>
	//			<li>phoneNumbers - Phone numbers associated with this address. Can be one or more.</li>
	//			<li>ddUrl - A URL that can be used to provide driving directions from the center of the search results to this search results</li>
	//			<li>ddUrlToHere - A URL that can be used to provide driving directions from this search result to a user specified location</li>
	//			<li>staticMapUrl - The published date, in RFC-822 format</li>
	//		</ul>
	//	The query accepts one parameter: text - The string to search for
	_type: "local",
	_attributes: ["title", "titleNoFormatting", "url", "lat", "lng", "streetAddress",
					"city", "region", "country", "phoneNumbers", "ddUrl", "ddUrlToHere",
					"ddUrlFromHere", "staticMapUrl"]
});

dojo.declare("dojox.data.GoogleVideoSearchStore", dojox.data.GoogleSearchStore,{
	// summary:
	//	A data store for retrieving search results from Google.
	//	The following attributes are supported on each item:
	//		<ul>
	//			<li>title - The blog post title in HTML format.</li>
	//			<li>titleNoFormatting - The  blog post title in plain text</li>
	//			<li>content - A snippet of information about the blog post</li>
	//			<li>url - The URL for the item</li>
	//			<li>published - The published date, in RFC-822 format.</li>
	//			<li>publisher - The name of the publisher.</li>
	//			<li>duration - The approximate duration, in seconds, of the video.</li>
	//			<li>tbWidth - The width in pixels of the video.</li>
	//			<li>tbHeight - The height in pixels of the video</li>
	//			<li>tbUrl - The URL to a thumbnail representation of the video.</li>
	//			<li>playUrl - If present, supplies the url of the flash version of the video that can be played inline on your page. To play this video simply create and <embed> element on your page using this value as the src attribute and using application/x-shockwave-flash as the type attribute. If you want the video to play right away, make sure to append &autoPlay=true to the url..</li>
	//		</ul>
	//	The query accepts one parameter: text - The string to search for
	_type: "video",
	_attributes: ["title", "titleNoFormatting", "content", "url", "published", "publisher",
					"duration", "tbWidth", "tbHeight", "tbUrl", "playUrl"]
});

dojo.declare("dojox.data.GoogleNewsSearchStore", dojox.data.GoogleSearchStore,{
	// summary:
	//	A data store for retrieving search results from Google.
	//	The following attributes are supported on each item:
	//		<ul>
	//			<li>title - The news story title in HTML format.</li>
	//			<li>titleNoFormatting - The news story title in plain text</li>
	//			<li>content - A snippet of information about the news story</li>
	//			<li>url - The URL for the item</li>
	//			<li>unescapedUrl - The URL for the item, with URL escaping. This is often more readable</li>
	//			<li>publisher - The name of the publisher</li>
	//			<li>clusterUrl - A URL pointing to a page listing related storied.</li>
	//			<li>location - The location of the news story.</li>
	//			<li>publishedDate - The date of publication, in RFC-822 format.</li>
	//			<li>relatedStories - An optional array of objects specifying related stories.
	//				Each object has the following subset of properties:
	//				"title", "titleNoFormatting", "url", "unescapedUrl", "publisher", "location", "publishedDate".
	//			</li>
	//		</ul>
	//	The query accepts one parameter: text - The string to search for
	_type: "news",
	_attributes: ["title", "titleNoFormatting", "content", "url", "unescapedUrl", "publisher",
					"clusterUrl", "location", "publishedDate", "relatedStories" ]
});

dojo.declare("dojox.data.GoogleBookSearchStore", dojox.data.GoogleSearchStore,{
	// summary:
	//	A data store for retrieving search results from Google.
	//	The following attributes are supported on each item:
	//		<ul>
	//			<li>title - The book title in HTML format.</li>
	//			<li>titleNoFormatting - The book title in plain text</li>
	//			<li>authors - An array of authors</li>
	//			<li>url - The URL for the item</li>
	//			<li>unescapedUrl - The URL for the item, with URL escaping. This is often more readable</li>
	//			<li>bookId - An identifier for the book, usually an ISBN.</li>
	//			<li>pageCount - The number of pages in the book.</li>
	//			<li>publishedYear - The year of publication.</li>
	//		</ul>
	//	The query accepts one parameter: text - The string to search for
	_type: "books",
	_attributes: ["title", "titleNoFormatting", "authors", "url", "unescapedUrl", "bookId",
					"pageCount", "publishedYear"]
});

dojo.declare("dojox.data.GoogleImageSearchStore", dojox.data.GoogleSearchStore,{
	// summary:
	//	A data store for retrieving search results from Google.
	//	The following attributes are supported on each item:
	//		<ul>
	//			<li>title - The image title in HTML format.</li>
	//			<li>titleNoFormatting - The image title in plain text</li>
	//			<li>url - The URL for the image</li>
	//			<li>unescapedUrl - The URL for the image, with URL escaping. This is often more readable</li>
	//			<li>tbUrl - The URL for the image thumbnail</li>
	//			<li>visibleUrl - A shortened version of the URL associated with the result, stripped of a protocol and path</li>
	//			<li>originalContextUrl - The URL of the page containing the image.</li>
	//			<li>width - The width of the image in pixels.</li>
	//			<li>height - The height of the image in pixels.</li>
	//			<li>tbWidth - The width of the image thumbnail in pixels.</li>
	//			<li>tbHeight - The height of the image thumbnail in pixels.</li>
	//			<li>content - A snippet of information about the image, in HTML format</li>
	//			<li>contentNoFormatting - A snippet of information about the image, in plain text</li>
	//		</ul>
	//	The query accepts one parameter: text - The string to search for
	_type: "images",
	_attributes: ["title", "titleNoFormatting", "visibleUrl", "url", "unescapedUrl", "originalContextUrl",
					"width", "height", "tbWidth", "tbHeight", "tbUrl", "content", "contentNoFormatting"]
});
