/*
 * Copyright 2011 Gildas Lormeau
 * contact : gildas.lormeau <at> gmail.com
 * 
 * This file is part of SingleFile Core.
 *
 *   SingleFile Core is free software: you can redistribute it and/or modify
 *   it under the terms of the GNU Lesser General Public License as published by
 *   the Free Software Foundation, either version 3 of the License, or
 *   (at your option) any later version.
 *
 *   SingleFile Core is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *   GNU Lesser General Public License for more details.
 *
 *   You should have received a copy of the GNU Lesser General Public License
 *   along with SingleFile Core.  If not, see <http://www.gnu.org/licenses/>.
 */

(function() {

	var IMPORT_URL_VALUE_EXP = /(url\s*\(\s*(?:'|")?\s*([^('|"|\))]*)\s*(?:'|")?\s*\))|(@import\s*\(?\s*(?:'|")?\s*([^('|"|\))]*)\s*(?:'|")?\s*(?:\)|;))/i;
	var URL_VALUE_EXP = /url\s*\(\s*(?:'|")?\s*([^('|"|\))]*)\s*(?:'|")?\s*\)/i;
	var IMPORT_VALUE_ALT_EXP = /@import\s*\(?\s*(?:'|")?\s*([^('|"|\))]*)\s*(?:'|")?\s*(?:\)|;)/i;
	var URL_EXP = /url\s*\(([^\)]*)\)/gi;
	var IMPORT_EXP = /(@import\s*url\s*\([^\)]*\)\s*;?)|(@import\s*('|")?\s*[^\(|;|'|"]*\s*('|")?\s*;)/gi;
	var IMPORT_ALT_EXP = /@import\s*('|")?\s*[^\(|;|'|"]*\s*('|")?\s*;/gi;
	var EMPTY_PIXEL_DATA = "data:image/gif;base64,R0lGODlhAQABAIAAAP///////yH5BAEKAAEALAAAAAABAAEAAAICTAEAOw==";

	function decodeDataURI(dataURI) {
		var content = dataURI.indexOf(","), meta = dataURI.substr(5, content).toLowerCase()
		// 'data:'.length == 5
		, data = decodeURIComponent(dataURI.substr(content + 1));

		if (/;\s*base64\s*[;,]/.test(meta)) {
			data = atob(data); // decode base64
		}
		if (/;\s*charset=[uU][tT][fF]-?8\s*[;,]/.test(meta)) {
			data = decodeURIComponent(escape(data)); // decode UTF-8
		}

		return data;
	}
	;

	function formatURL(link, host) {
		var i, newlinkparts, hparts, lparts;
		if (!link)
			return "";

		lparts = link.split('/');
		host = host.split("#")[0].split("?")[0];
		if (/http:|https:|ftp:|data:|javascript:/i.test(lparts[0]))
			return link.trim();
		hparts = host.split('/');
		newlinkparts = [];
		if (hparts.length > 3)
			hparts.pop();
		if (lparts[0] == '') {
			if (lparts[1] == '')
				host = hparts[0] + '//' + lparts[2];
			else
				host = hparts[0] + '//' + hparts[2];
			hparts = host.split('/');
			delete lparts[0];
			if (lparts[1] == '') {
				delete lparts[1];
				delete lparts[2];
			}
		}
		for (i = 0; i < lparts.length; i++) {
			if (lparts[i] == '..') {
				if (lparts[i - 1])
					delete lparts[i - 1];
				else if (hparts.length > 3)
					hparts.pop();
				delete lparts[i];
			}
			if (lparts[i] == '.')
				delete lparts[i];
		}
		for (i = 0; i < lparts.length; i++)
			if (lparts[i])
				newlinkparts[newlinkparts.length] = lparts[i];
		return (hparts.join('/') + '/' + newlinkparts.join('/')).trim();
	}

	function resolveURLs(content, host) {
		var ret = content.replace(URL_EXP, function(value) {
			var result = value.match(URL_VALUE_EXP);
			if (result)
				if (result[1].indexOf("data:") != 0)
					return value.replace(result[1], formatURL(result[1], host));
			return value;
		});
		return ret.replace(IMPORT_ALT_EXP, function(value) {
			var result = value.match(IMPORT_VALUE_ALT_EXP);
			if (result)
				if (result[1].indexOf("data:") != 0)
					return "@import \"" + formatURL(result[1], host) + "\";";
			return value;
		});
	}

	function getDataURI(data, defaultURL, woURL) {
		if (data.content)
			return (woURL ? "" : "url(") + "data:" + data.mediaType + ";" + data.mediaTypeParam + "," + data.content + (woURL ? "" : ")");
		else
			return woURL ? defaultURL : "url(" + defaultURL + ")";
	}

	function removeComments(content) {
		var start, end;
		do {
			start = content.indexOf("/*");
			end = content.indexOf("*/", start);
			if (start != -1 && end != -1)
				content = content.substring(0, start) + content.substr(end + 2);
		} while (start != -1 && end != -1);
		return content;
	}

	function replaceURLs(content, host, requestManager, callback) {
		var i, url, result, values = removeComments(content).match(URL_EXP), requestMax = 0, requestIndex = 0;

		function sendRequest(origUrl) {
			requestMax++;
			requestManager.send(url, function(data) {
				requestIndex++;
				if (content.indexOf(origUrl) != -1) {
					data.mediaType = data.mediaType ? data.mediaType.split(";")[0] : null;
					content = content.replace(new RegExp(origUrl.replace(/([{}\(\)\^$&.\*\?\/\+\|\[\\\\]|\]|\-)/g, "\\$1"), "gi"), getDataURI(data,
							EMPTY_PIXEL_DATA, true));
				}
				if (requestIndex == requestMax)
					callback(content);
			}, null, "base64");
		}

		if (values)
			for (i = 0; i < values.length; i++) {
				result = values[i].match(URL_VALUE_EXP);
				if (result && result[1]) {
					url = formatURL(result[1], host);
					if (url.indexOf("data:") != 0)
						sendRequest(result[1]);
				}
			}
	}

	// ----------------------------------------------------------------------------------------------

	function processStylesheets(doc, docElement, baseURI, requestManager) {
		Array.prototype.forEach.call(docElement.querySelectorAll('link[href][rel*="stylesheet"]'), function(node) {
			var href = node.getAttribute("href"), url = formatURL(href, baseURI);

			function createStyleNode(content) {
				var i, newNode, commentNode;
				newNode = doc.createElement("style");
				for (i = 0; i < node.attributes.length; i++)
					if (node.attributes[i].value)
						newNode.setAttribute(node.attributes[i].name, node.attributes[i].value);
				newNode._baseURI = url;
				newNode.removeAttribute("href");
				newNode.textContent = resolveURLs(content, url);
				if (node.disabled) {
					commentNode = doc.createComment();
					commentNode.textContent = newNode.outerHTML.replace(/</g, "&lt;").replace(/>/g, "&gt;").replace(/--/g, "&minus;&minus;");
					node.parentElement.replaceChild(commentNode, node);
				} else
					node.parentElement.replaceChild(newNode, node);
			}

			if (href.indexOf("data:") != 0)
				requestManager.send(url, function(data) {
					if (data.status >= 400) {
						node.parentElement.removeChild(node);
					} else {
						createStyleNode(data.content || "");
					}
				});
			else
				createStyleNode(decodeDataURI(href));
		});
	}

	function processImports(docElement, baseURI, characterSet, requestManager) {
		var ret = true;
		Array.prototype.forEach.call(docElement.querySelectorAll("style"), function(styleSheet) {
			var imports = removeComments(styleSheet.textContent).match(IMPORT_EXP);

			function insertStylesheet(imp, content, url) {
				styleSheet.textContent = styleSheet.textContent.replace(imp, resolveURLs(content, url));
			}
			if (imports)
				imports.forEach(function(imp) {
					var url, result = imp.match(IMPORT_URL_VALUE_EXP);
					if (result && (result[2] || result[4])) {
						url = formatURL(result[2] || result[4], styleSheet._baseURI || baseURI);
						if (url.indexOf("data:") != 0) {
							requestManager.send(url, function(data) {
								insertStylesheet(imp, data.status < 400 && data.content ? data.content : "", url);
							}, null, characterSet);
						} else {
							insertStylesheet(imports[i], decodeDataURI(url), url);
						}
						ret = false;
					}
				});
		});
		return ret;
	}

	function processStyleAttributes(docElement, baseURI, requestManager) {
		Array.prototype.forEach.call(docElement.querySelectorAll("*[style]"), function(node) {
			replaceURLs(node.getAttribute("style"), baseURI, requestManager, function(style) {
				node.setAttribute("style", style);
			});
		});
	}

	function processBgAttributes(docElement, baseURI, requestManager) {
		var backgrounds = docElement.querySelectorAll("*[background]");
		Array.prototype.forEach.call(backgrounds, function(node) {
			var url, value = node.getAttribute("background");
			if (value.indexOf(".") != -1) {
				url = formatURL(value, baseURI);
				if (url.indexOf("data:") != 0)
					requestManager.send(url, function(data) {
						node.setAttribute("background", getDataURI(data, EMPTY_PIXEL_DATA, true));
					}, null, "base64");
			}
		});
	}

	function insertDefaultFavico(doc, docElement, baseURI) {
		var node, docHead = docElement.querySelector("html > head"), favIcon = docElement
				.querySelector('link[href][rel="shortcut icon"], link[href][rel="apple-touch-icon"], link[href][rel="icon"]');
		if (!favIcon && docHead) {
			node = doc.createElement("link");
			node.setAttribute("type", "image/x-icon");
			node.setAttribute("rel", "shortcut icon");
			node.setAttribute("href", formatURL("/favicon.ico", baseURI));
			docHead.appendChild(node);
		}
	}

	function processImages(docElement, baseURI, requestManager) {
		var images;

		function process(attributeName) {
			Array.prototype.forEach.call(images, function(node) {
				var url = formatURL(node.getAttribute(attributeName), baseURI);
				if (url.indexOf("data:") != 0)
					requestManager.send(url, function(data) {
						node.setAttribute(attributeName, getDataURI(data, EMPTY_PIXEL_DATA, true));
					}, null, "base64");
			});
		}

		images = docElement.querySelectorAll('link[href][rel="shortcut icon"], link[href][rel="apple-touch-icon"], link[href][rel="icon"]');
		process("href");
		images = docElement.querySelectorAll('img[src], input[src][type="image"]');
		process("src");
		images = docElement.querySelectorAll('video[poster]');
		process("poster");

	}

	function processSVGs(docElement, baseURI, requestManager) {
		var images = docElement.querySelectorAll('object[type="image/svg+xml"], object[type="image/svg-xml"], embed[src*=".svg"]');
		Array.prototype.forEach.call(images, function(node) {
			var data = node.getAttribute("data"), src = node.getAttribute("src"), url = formatURL(data || src, baseURI);
			if (url.indexOf("data:") != 0)
				requestManager.send(url, function(data) {
					node.setAttribute(data ? "data" : "src", getDataURI(data, "data:text/xml,<svg></svg>", true));
				}, null, null);
		});
	}

	function processStyles(docElement, baseURI, requestManager) {
		Array.prototype.forEach.call(docElement.querySelectorAll("style"), function(styleSheet) {
			replaceURLs(styleSheet.textContent, styleSheet._baseURI || baseURI, requestManager, function(textContent) {
				styleSheet.textContent = textContent;
			});
		});
	}

	function processScripts(docElement, baseURI, characterSet, requestManager) {
		Array.prototype.forEach.call(docElement.querySelectorAll("script[src]"), function(node) {
			var src = node.getAttribute("src");
			if (src.indexOf("data:") != 0)
				requestManager.send(formatURL(src, baseURI), function(data) {
					if (data.status < 400) {
						data.content = data.content.replace(/"([^"]*)<\/\s*script\s*>([^"]*)"/gi, '"$1<"+"/script>$2"');
						data.content = data.content.replace(/'([^']*)<\/\s*script\s*>([^']*)'/gi, "'$1<'+'/script>$2'");
						node.textContent = "\n" + data.content + "\n";
					}
					node.removeAttribute("src");
				}, characterSet);
		});
	}

	function processCanvas(doc, docElement, canvasData) {
		var index = 0;
		Array.prototype.forEach.call(docElement.querySelectorAll("canvas"), function(node) {
			var i, data = canvasData[index], newNode = doc.createElement("img");
			if (data) {
				newNode.setAttribute("src", data);
				for (i = 0; i < node.attributes.length; i++)
					if (node.attributes[i].value)
						newNode.setAttribute(node.attributes[i].name, node.attributes[i].value);
				if (!newNode.width)
					newNode.style.pixelWidth = node.clientWidth;
				if (!newNode.height)
					newNode.style.pixelHeight = node.clientHeight;
				node.parentElement.replaceChild(newNode, node);
			}
			index++;
		});
	}

	function removeScripts(docElement) {
		Array.prototype.forEach.call(docElement.querySelectorAll("script"), function(node) {
			node.parentElement.removeChild(node);
		});
		Array.prototype.forEach.call(docElement.querySelectorAll("*[onload]"), function(node) {
			node.removeAttribute("onload");
		});
	}

	function removeObjects(docElement) {
		var objects = docElement.querySelectorAll('applet, object:not([type="image/svg+xml"]):not([type="image/svg-xml"]), embed:not([src*=".svg"])');
		Array.prototype.forEach.call(objects, function(node) {
			node.parentElement.removeChild(node);
		});
		objects = docElement.querySelectorAll('audio[src], video[src]');
		Array.prototype.forEach.call(objects, function(node) {
			node.removeAttribute("src");
		});
	}

	function removeBlockquotesCite(docElement) {
		Array.prototype.forEach.call(docElement.querySelectorAll("blockquote[cite]"), function(node) {
			node.removeAttribute("cite");
		});
	}

	function removeFrames(docElement) {
		Array.prototype.forEach.call(docElement.querySelectorAll("iframe, frame"), function(node) {
			node.parentElement.removeChild(node);
		});
	}

	function removeMetaRefresh(docElement) {
		Array.prototype.forEach.call(docElement.querySelectorAll("meta[http-equiv=refresh]"), function(node) {
			node.parentElement.removeChild(node);
		});
	}

	function resetFrames(docElement, baseURI) {
		Array.prototype.forEach.call(docElement.querySelectorAll("iframe, frame"), function(node) {
			var src = formatURL(node.getAttribute("src"), baseURI);
			if (src.indexOf("data:") != 0)
				node.setAttribute("src", "about:blank");
		});
	}

	function setAbsoluteLinks(docElement, baseURI) {
		Array.prototype.forEach.call(docElement.querySelectorAll("a:not([href^='#'])"), function(link) {
			var fullHref = formatURL(link.getAttribute("href"), baseURI);
			if (fullHref && (!(fullHref.indexOf(baseURI.split("#")[0]) == 0) || fullHref.indexOf("#") == -1))
				link.setAttribute("href", fullHref);
		});
	}

	// ----------------------------------------------------------------------------------------------

	singlefile.initProcess = function(doc, docElement, addDefaultFavico, baseURI, characterSet, config, canvasData, requestManager, onInit, onProgress, onEnd) {
		var initManager = new RequestManager(), manager = new RequestManager(onProgress);

		function RequestManager(onProgress) {
			var that = this, currentCount = 0, requests = [];
			this.requestCount = 0;
			this.send = function(url, responseHandler, characterSet, mediaTypeParam) {
				this.requestCount++;
				requests.push({
					url : url,
					responseHandler : responseHandler,
					characterSet : characterSet,
					mediaTypeParam : mediaTypeParam
				});
			};
			this.doSend = function() {
				requests.forEach(function(request) {
					requestManager.send(request.url, function(response) {
						request.responseHandler(response);
						currentCount++;
						if (onProgress)
							onProgress(currentCount, that.requestCount);
						if (currentCount == that.requestCount) {
							that.requestCount = 0;
							currentCount = 0;
							if (that.onEnd)
								that.onEnd();
						}
					}, request.characterSet, request.mediaTypeParam);
				});
				requests = [];
			};
		}

		function cbImports() {
			if (config.removeScripts)
				removeScripts(docElement);
			if (config.removeObjects)
				removeObjects(docElement);
			if (config.removeFrames || config.getRawDoc)
				removeFrames(docElement);
			resetFrames(docElement, baseURI);
			removeBlockquotesCite(docElement);
			removeMetaRefresh(docElement);
			setAbsoluteLinks(docElement, baseURI);
			if (addDefaultFavico)
				insertDefaultFavico(doc, docElement, baseURI);
			processStyleAttributes(docElement, baseURI, manager);
			processBgAttributes(docElement, baseURI, manager);
			processImages(docElement, baseURI, manager);
			processSVGs(docElement, baseURI, manager);
			processStyles(docElement, baseURI, manager);
			processScripts(docElement, baseURI, characterSet, manager);
			processCanvas(doc, docElement, canvasData);
			if (onInit)
				setTimeout(function() {
					onInit(manager.requestCount);
				}, 1);
		}

		function cbStylesheets() {
			initManager.onEnd = function(noRequests) {
				if (noRequests)
					cbImports();
				else
					cbStylesheets();
			};
			processImports(docElement, baseURI, characterSet, initManager);
			initManager.doSend();
			if (initManager.requestCount == 0)
				cbImports();
		}

		manager.onEnd = onEnd;
		processStylesheets(doc, docElement, baseURI, initManager);
		initManager.onEnd = cbStylesheets;
		initManager.doSend();
		if (initManager.requestCount == 0)
			initManager.onEnd();
		return function() {
			manager.doSend();
			if (manager.onEnd && manager.requestCount == 0)
				manager.onEnd();
		};
	};

})();