/*!
 * jquery oembed plugin
 *
 * Copyright (c) 2009 Richard Chamorro
 * Licensed under the MIT license
 * 
 * Author: Richard Chamorro 
 */
 
(function ($, undefined) {
	$.fn.oembed = function (url, options, embedAction) {

		settings = $.extend(true, $.fn.oembed.defaults, options);		
			
		initializeProviders();
		
		return this.each(function () {		

			var container = $(this),
				resourceURL = (url != null) ? url : container.attr("href"),
				provider;					
			
			if (embedAction) {
				settings.onEmbed = embedAction;
			} else {
				settings.onEmbed = function(oembedData) {			
						$.fn.oembed.insertCode(this, settings.embedMethod, oembedData);
				};
			}

			if (resourceURL != null) {
				provider = getOEmbedProvider(resourceURL);			

				if (provider != null) {
					provider.params = getNormalizedParams(settings[provider.name]) || {};
					provider.maxWidth = settings.maxWidth;
					provider.maxHeight = settings.maxHeight;					
					embedCode(container, resourceURL, provider);
				} else {				
					settings.onProviderNotFound.call(container, resourceURL);
				}
					
				return container;
			}
		});
	
		
	};
	
	var settings, activeProviders = [];

	// Plugin defaults
	$.fn.oembed.defaults = {
		maxWidth: null,
		maxHeight: null,		
		embedMethod: "replace",  	// "auto", "append", "fill"		
		defaultOEmbedProvider: "oohembed", 	// "oohembed", "embed.ly", "none"
		allowedProviders: null,
		disallowedProviders: null,
		customProviders: null,	// [ new $.fn.oembed.OEmbedProvider("customprovider", null, ["customprovider\\.com/watch.+v=[\\w-]+&?"]) ]	
		defaultProvider: null,		
		greedy: true,			
		onProviderNotFound: function() {},
		beforeEmbed: function() {},		
		afterEmbed: function() {},
		onEmbed: function() {},
		ajaxOptions: { }
	};

	/* Private functions */	
	function getRequestUrl (provider, externalUrl) {

		var url = provider.apiendpoint, qs = "", callbackparameter = provider.callbackparameter || "callback", i;

		if (url.indexOf("?") <= 0)
			url = url + "?";
		else
			url = url + "&";		

		if (provider.maxWidth != null && provider.params["maxwidth"] == null)
			provider.params["maxwidth"] = provider.maxWidth;

		if (provider.maxHeight != null && provider.params["maxheight"] == null)
			provider.params["maxheight"] = provider.maxHeight;

		for (i in provider.params) {
			// We don't want them to jack everything up by changing the callback parameter
			if (i == provider.callbackparameter)
				continue;

			// allows the options to be set to null, don't send null values to the server as parameters
			if (provider.params[i] != null)
				qs += "&" + escape(i) + "=" + provider.params[i];
		}	
		
		url += "format=json&url=" + escape(externalUrl) +
					qs +
					"&" + callbackparameter + "=?";
		return url;
	};
	
	function embedCode(container, externalUrl, embedProvider) {
		var requestUrl = getRequestUrl(embedProvider, externalUrl);
		var onSuccess = function (data) {
			var oembedData = $.extend({}, data);			
			switch (oembedData.type) {
				case "photo":
					oembedData.code = $.fn.oembed.getPhotoCode(externalUrl, oembedData);
					break;
				case "video":
					oembedData.code = $.fn.oembed.getVideoCode(externalUrl, oembedData);
					break;
				case "rich":
					oembedData.code = $.fn.oembed.getRichCode(externalUrl, oembedData);
					break;
				default:
					oembedData.code = $.fn.oembed.getGenericCode(externalUrl, oembedData);
					break;
			}
			
			settings.beforeEmbed.call(container, oembedData);
			
			settings.onEmbed.call(container, oembedData);
				
			settings.afterEmbed.call(container, oembedData);			
		};

		var ajaxopts = $.extend({
			url: requestUrl,
			type: 'get',
			dataType: 'json',
			// error: jsonp request doesnt' support error handling
			success:  onSuccess
		}, settings.ajaxOptions || { } );
		$.ajax( ajaxopts );
	};

	function getOEmbedProvider(url) {
		for (var i = 0; i < activeProviders.length; i++) {			
			if (activeProviders[i].matches(url))
				return activeProviders[i];
		}
		return null;
	}
	
	function initializeProviders() {

		activeProviders = [];
		
		var defaultProvider, restrictedProviders = [];
		
		if (!isNullOrEmpty(settings.allowedProviders)) {
			for(i = 0; i < $.fn.oembed.providers.length; i++) {
				if ($.inArray($.fn.oembed.providers[i].name, settings.allowedProviders) >= 0)				
					activeProviders.push($.fn.oembed.providers[i]);
			}
			// If there are allowed providers, jquery-oembed cannot be greedy
			settings.greedy = false;
			
		} else {
			activeProviders = $.fn.oembed.providers;
		}
		
		if (!isNullOrEmpty(settings.disallowedProviders)) {			
			for(i = 0; i < activeProviders.length; i++) {
				if ($.inArray(activeProviders[i].name, settings.disallowedProviders) < 0)				
					restrictedProviders.push(activeProviders[i]);				
			}			
			activeProviders = restrictedProviders;
			
			// If there are allowed providers, jquery-oembed cannot be greedy
			settings.greedy = false;
		}		
		
		if (!isNullOrEmpty(settings.customProviders)) {			
			$.each(settings.customProviders, function(i, customProvider){				
				if (customProvider instanceof $.fn.oembed.OEmbedProvider) {
					activeProviders.push(provider);
				} else {
					provider = new $.fn.oembed.OEmbedProvider();
					if (provider.fromJSON(customProvider))
						activeProviders.push(provider);
				}				
			});			
		}	

		// If in greedy mode, we add the default provider
		defaultProvider = getDefaultOEmbedProvider(settings.defaultOEmbedProvider);		
		if (settings.greedy == true) {			
			activeProviders.push(defaultProvider);
		}
		
		// If any provider has no apiendpoint, we use the default provider endpoint
		$.each(activeProviders, function(i, activeProvider) {
			if (activeProviders[i].apiendpoint == null)
				activeProviders[i].apiendpoint = defaultProvider.apiendpoint;
		});
		
	}	

	function getDefaultOEmbedProvider(defaultOEmbedProvider) {	
		var url = "http://oohembed.com/oohembed/";
		if (defaultOEmbedProvider == "embed.ly")
			url = "http://api.embed.ly/v1/api/oembed?";
		return new $.fn.oembed.OEmbedProvider(defaultOEmbedProvider, null, null, url, "callback");
	}

	function getNormalizedParams(params) {
		if (params == null)
			return null;
		var key, normalizedParams = {};
		for (key in params) {
			if (key != null)
				normalizedParams[key.toLowerCase()] = params[key];
		}
		return normalizedParams;
	}

	function isNullOrEmpty(object) {
		if (typeof object == "undefined")
			return true;
		if (object == null)
			return true;
		if ($.isArray(object) && object.length == 0)
			return true;
		return false;
	}
	
	/* Public functions */
	$.fn.oembed.insertCode = function (container, embedMethod, oembedData) {
		if (oembedData == null)
			return;
			
		switch (embedMethod) {
			case "auto":
				if (container.attr("href") != null) {
					$.fn.oembed.insertCode(container, "append", oembedData);
				}
				else {
					$.fn.oembed.insertCode(container, "replace", oembedData);
				};
				break;
			case "replace":
				container.replaceWith(oembedData.code);
				break;
			case "fill":
				container.html(oembedData.code);
				break;
			case "append":
				var oembedContainer = container.next();
				if (oembedContainer == null || !oembedContainer.hasClass("oembed-container")) {
					oembedContainer = container
						.after('<div class="oembed-container"></div>')
						.next(".oembed-container");
					if (oembedData != null && oembedData.provider_name != null)
						oembedContainer.toggleClass("oembed-container-" + oembedData.provider_name);
				}
				oembedContainer.html(oembedData.code);
				break;
		}
	};

	$.fn.oembed.getPhotoCode = function (url, oembedData) {
		var code, alt = oembedData.title ? oembedData.title : '';
		alt += oembedData.author_name ? ' - ' +oembedData.author_name : '';
		alt += oembedData.provider_name ? ' - ' + oembedData.provider_name : '';
		code = '<div><a href="' + url + '" target=\'_blank\'><img src="' + oembedData.url + '" alt="' + alt + '"/></a></div>';
		if (oembedData.html)
			code += "<div>" + oembedData.html + "</div>";
		return code;
	};

	$.fn.oembed.getVideoCode = function (url, oembedData) {
		var code = oembedData.html;
		
		return code;
	};

	$.fn.oembed.getRichCode = function (url, oembedData) {
		var code = oembedData.html;
		return code;
	};

	$.fn.oembed.getGenericCode = function (url, oembedData) {
		var title = (oembedData.title != null) ? oembedData.title : url,
			code = '<a href="' + url + '">' + title + '</a>';
		if (oembedData.html)
			code += "<div>" + oembedData.html + "</div>";
		return code;
	};

	$.fn.oembed.isProviderAvailable = function (url) {
		var provider = getOEmbedProvider(url);
		return (provider != null);
	};

	$.fn.oembed.OEmbedProvider = function(name, type, urlschemes, apiendpoint, callbackparameter) {
		this.name = name;
		this.type = type; // "photo", "video", "link", "rich", null
		this.urlschemes = getUrlSchemes(urlschemes);
		this.apiendpoint = apiendpoint;
		this.callbackparameter = callbackparameter;
		this.maxWidth = 500;
		this.maxHeight = 400;		
		var i, property, regExp;

		this.matches = function (externalUrl) {
			for (i = 0; i < this.urlschemes.length; i++) {
				regExp = new RegExp(this.urlschemes[i], "i");
				if (externalUrl.match(regExp) != null)
					return true;
			}
			return false;
		};
		
		this.fromJSON = function(json) {
			for(property in json){
				if (property != "urlschemes")				
	        		this[property] = json[property];
				else
					this[property] = getUrlSchemes(json[property])
    		}		
			return true; 	
		};
		
		function getUrlSchemes(urls) {
			if (isNullOrEmpty(urls))
				return ["."];
			if ($.isArray(urls))
				return urls;
			return urls.split(";");			
		}
	}
	
	/* Native & common providers */
	$.fn.oembed.providers =	[	
		new $.fn.oembed.OEmbedProvider("youtube", "video", ["youtube\\.com/watch.+v=[\\w-]+&?"]), // "http://www.youtube.com/oembed"	(no jsonp)
		new $.fn.oembed.OEmbedProvider("flickr",  "photo", ["flickr\\.com/photos/[-.\\w@]+/\\d+/?"], "http://flickr.com/services/oembed", "jsoncallback"),		
		new $.fn.oembed.OEmbedProvider("viddler", "video", ["viddler\.com"]), // "http://lab.viddler.com/services/oembed/" (no jsonp)
		new $.fn.oembed.OEmbedProvider("blip", "video", ["blip\\.tv/.+"], "http://blip.tv/oembed/"),
		new $.fn.oembed.OEmbedProvider("hulu", "video", ["hulu\\.com/watch/.*"], "http://www.hulu.com/api/oembed.json"),
		new $.fn.oembed.OEmbedProvider("vimeo", "video", ["http:\/\/www\.vimeo\.com\/groups\/.*\/videos\/.*", "http:\/\/www\.vimeo\.com\/.*", "http:\/\/vimeo\.com\/groups\/.*\/videos\/.*", "http:\/\/vimeo\.com\/.*"], "http://vimeo.com/api/oembed.json"),				
		new $.fn.oembed.OEmbedProvider("dailymotion", "video", ["dailymotion\\.com/.+"]), // "http://www.dailymotion.com/api/oembed/" (callback parameter does not return jsonp)
		new $.fn.oembed.OEmbedProvider("scribd", "rich", ["scribd\\.com/.+"]), // ", "http://www.scribd.com/services/oembed"" (no jsonp)		
		new $.fn.oembed.OEmbedProvider("slideshare", "rich", ["slideshare\.net"], "http://www.slideshare.net/api/oembed/1"),
		new $.fn.oembed.OEmbedProvider("photobucket", "photo", ["photobucket\\.com/(albums|groups)/.*"], "http://photobucket.com/oembed/")
		// new $.fn.oembed.OEmbedProvider("vids.myspace.com", "video", ["vids\.myspace\.com"]), // "http://vids.myspace.com/index.cfm?fuseaction=oembed" (not working)
		// new $.fn.oembed.OEmbedProvider("screenr", "rich", ["screenr\.com"], "http://screenr.com/api/oembed.json") (error)		
		// new $.fn.oembed.OEmbedProvider("qik", "video", ["qik\\.com/\\w+"], "http://qik.com/api/oembed.json"),		
		// new $.fn.oembed.OEmbedProvider("revision3", "video", ["revision3\.com"], "http://revision3.com/api/oembed/"),
		
	];
})(jQuery);