/**
    * This file Copyright (c) 2003-2010 Magnolia International
    * Ltd.  (http://www.magnolia-cms.com). All rights reserved.
    *
    *
    * This file is dual-licensed under both the Magnolia
    * Network Agreement and the GNU General Public License.
    * You may elect to use one or the other of these licenses.
    *
   * This file is distributed in the hope that it will be
   * useful, but AS-IS and WITHOUT ANY WARRANTY; without even the
   * implied warranty of MERCHANTABILITY or FITNESS FOR A
   * PARTICULAR PURPOSE, TITLE, or NONINFRINGEMENT.
   * Redistribution, except as permitted by whichever of the GPL
   * or MNA you select, is prohibited.
   *
   * 1. For the GPL license (GPL), you can redistribute and/or
   * modify this file under the terms of the GNU General
   * Public License, Version 3, as published by the Free Software
   * Foundation.  You should have received a copy of the GNU
   * General Public License, Version 3 along with this program;
   * if not, write to the Free Software Foundation, Inc., 51
   * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
   *
   * 2. For the Magnolia Network Agreement (MNA), this file
   * and the accompanying materials are made available under the
   * terms of the MNA which accompanies this distribution, and
   * is available at http://www.magnolia-cms.com/mna.html
   *
   * Any modifications to this file must keep this entire header
   * intact.
   *
   */
  package info.magnolia.module.mail.templates.impl;
  
  import freemarker.template.Template;
  import info.magnolia.cms.core.Path;
  import info.magnolia.cms.security.User;
  import info.magnolia.context.MgnlContext;
  import info.magnolia.module.mail.MailTemplate;
  import info.magnolia.module.mail.templates.MailAttachment;
  
  import org.apache.commons.httpclient.HttpClient;
  import org.apache.commons.httpclient.NameValuePair;
  import org.apache.commons.httpclient.cookie.CookiePolicy;
  import org.apache.commons.httpclient.methods.GetMethod;
  import org.apache.commons.httpclient.methods.PostMethod;
  import org.apache.commons.lang.StringUtils;
  import org.jdom.Attribute;
  import org.jdom.Document;
  import org.jdom.Element;
  import org.jdom.filter.Filter;
  import org.jdom.input.SAXBuilder;
  import org.jdom.output.Format;
  import org.jdom.output.XMLOutputter;
  import org.xml.sax.EntityResolver;
  import org.xml.sax.InputSource;
  import org.xml.sax.SAXException;
  
  import java.io.BufferedInputStream;
  import java.io.File;
  import java.io.FileOutputStream;
  import java.io.IOException;
  import java.io.InputStream;
  import java.io.StringReader;
  import java.io.StringWriter;
  import java.net.MalformedURLException;
  import java.net.URL;
  import java.util.ArrayList;
  import java.util.HashMap;
  import java.util.Iterator;
  import java.util.Map;
  
  
  /**
   * MgnlPageEmail.
   * Date: Apr 6, 2006 Time: 9:24:29 PM
   * @author <a href="mailto:niko@macnica.com">Nicolas Modrzyk</a>
   *
   */
  public class MgnlPageEmail extends FreemarkerEmail {
  
      public static final String SUFFIX = "?mgnlIntercept=PREVIEW&mgnlPreview=true&mail=draw";
  
      private HttpClient client;
  
      private int cid = 0;
  
      private static final String UTF_8 = "UTF-8";
  
      private static final String MAGNOLIA = "magnolia";
  
      private static final String IMG = "img";
  
      private static final String SRC = "src";
  
      private static final String CID = "cid:";
  
      private static final String LINK = "link";
 
     private static final String HREF = "href";
 
     private static final String STYLE = "style";
 
     private static final String REL = "rel";
 
     private static final String ACTION = "action";
 
     private static final String LOGIN = "login";
 
     private static final String URL = "url";
 
     private static final String MGNL_USER_ID = "mgnlUserId";
 
     private static final String MGNL_USER_PSWD = "mgnlUserPSWD";
 
     private static final String SLASH = "/";
 
     private static final String HTTP = "http://";
 
     private static final String A_LINK = "a";
 
     private static final String FORM = "form";
 
     private static final String BODY = "body";
 
     private static final String FORM_ACTION = "action";
 
     private static final String DEFAULT_FORM_ACTION = "#";
 
 
     public MgnlPageEmail(MailTemplate template) {
         super(template);
     }
 
     public void setBodyFromResourceFile() throws Exception {
         String resourceFile = this.getTemplate().getTemplateFile();
 
         if(!StringUtils.contains(resourceFile, "http") ) {
             String oriurl = MgnlContext.getAggregationState().getOriginalURL();
             String temp = StringUtils.substring(oriurl, 0, StringUtils.indexOf(oriurl, MgnlContext.getContextPath()));
             resourceFile = temp + MgnlContext.getContextPath() + resourceFile;
         }
 
         URL url = new URL(resourceFile);
         // retrieve the html content
         String _content = retrieveContentFromMagnolia(resourceFile);
         StringReader reader = new StringReader(_content);
 
         // filter the images
         String urlBasePath = url.getProtocol() + "://" + url.getHost() + (url.getPort() > -1? ":" + url.getPort() : "" + "/");
         String tmp = filterImages(urlBasePath, reader, url.toString());
 
         tmp = StringUtils.remove(tmp, "&#xD;");
         super.setBody(tmp);
     }
 
     // TODO : this is not used !
     public void setBodyFromTemplate(Template template, Map _map) throws Exception {
         final StringWriter writer = new StringWriter();
         template.process(_map, writer);
         writer.flush();
         setBody(writer.toString());
     }
 
 
     private String filterImages(String urlBasePath, StringReader reader, String pageUrl) throws Exception {
         log.info("Filtering images");
         SAXBuilder parser = new SAXBuilder();
         parser.setEntityResolver(new EntityResolver() {
 
             public InputSource resolveEntity(String publicId, String systemId) throws SAXException, IOException {
                 return new InputSource(new java.io.ByteArrayInputStream(new byte[0]));
             }
 
         });
         Document doc = parser.build(reader);
         ArrayList toremove = new ArrayList();
         ArrayList toadd = new ArrayList();
         Element body = null;
         // Filter content
         Iterator iter = doc.getDescendants(new ContentFilter());
         while (iter.hasNext()) {
             Element elem = (Element) iter.next();
             String name = elem.getName();
             if (name.equalsIgnoreCase(IMG)) {
                 // stream image and attach it to the email
                 Attribute att = elem.getAttribute(SRC);
                 if (log.isDebugEnabled()) {
                     log.debug("Found new img:" + att.toString());
                 }
                 String value = att.getValue();
                 this.cid++;
                 att.setValue(CID + (this.cid));
                 String url = getUrl(pageUrl, value);
 
                 if (log.isDebugEnabled()) {
                     log.debug("Url is:" + url);
                 }
                 this.getTemplate().addAttachment(new MailAttachment(getAttachmentFile(url).toURL(), String.valueOf(this.cid)));
             }
             else if (name.equalsIgnoreCase(LINK)) {
                 // stream the css and put the content into a <style> tag and add to body tag
                 Attribute att = elem.getAttribute(HREF);
                 Element el = (Element) elem.clone();
                 //Element el = elem;
                 if (log.isDebugEnabled()) {
                     log.debug("Found new css:" + att.toString());
                 }
                 String url = getUrl(pageUrl, att.getValue());
                 el.setName(STYLE);
                 el.removeAttribute(HREF);
                 el.removeAttribute(REL);
                 GetMethod streamCss = new GetMethod(url);
                 getHttpClient(url).executeMethod(streamCss);
                 String tmp = streamCss.getResponseBodyAsString();
                 tmp = processUrls(tmp, url);
                 el.setText(tmp);
                 toremove.add(elem);
                 toadd.add(el);
 
             } else if(name.equalsIgnoreCase(A_LINK)) {
                 Attribute att = elem.getAttribute(HREF);
 
                 String url = getUrl(pageUrl, att.getValue());
                 if(!att.getValue().startsWith(DEFAULT_FORM_ACTION)) {
                     att.setValue(url);
                 }
 
             } else if(name.equalsIgnoreCase(FORM)) {
                 Attribute att = elem.getAttribute(FORM_ACTION);
                 String url = att.getValue();
                 if(att.getValue().equals(DEFAULT_FORM_ACTION)) {
                     url = pageUrl;
                 }
                 att.setValue(url);
 
             } else if(name.equalsIgnoreCase(BODY)) {
                 body = elem;
             }
         }
 
         // this is ugly but is there to
         // avoid concurrent modification exception on the Document
         for (int i = 0; i < toremove.size(); i++) {
             Element elem = (Element) toremove.get(i);
             Element parent = elem.getParentElement();
 
             body.addContent(0, (Element) toadd.get(i));
             parent.removeContent(elem);
 
         }
 
         // create the return string reader with new document content
         Format format = Format.getRawFormat();
         format.setExpandEmptyElements(true);
 
 
         XMLOutputter outputter = new XMLOutputter(format);
         StringWriter writer = new StringWriter();
         return outputter.outputString(doc);
     }
 
 
     private String getUrl(String currentPagePath, String path) {
         String urlBasePath = currentPagePath.substring(0, currentPagePath.indexOf(MgnlContext.getContextPath()) );
         if(!StringUtils.contains(path, HTTP) && !StringUtils.contains(path, MgnlContext.getContextPath())) {
             return currentPagePath.substring(0, currentPagePath.lastIndexOf("/") + 1) + path;
         } else if(!StringUtils.contains(path, HTTP)) {
             return urlBasePath + path;
         }
         return path;
     }
 
     private String processUrls(String responseBodyAsString, String cssPath) throws MalformedURLException, Exception {
         String tmp = "";
         Map<String, String> map = new HashMap<String, String>();
 
         int urlIndex = 0;
         int closeIndex = 0;
         int begin = 0;
         int cid;
 
       //  List urls = new Array
         while(StringUtils.indexOf(responseBodyAsString, "url(", begin) >= 0) {
             urlIndex = StringUtils.indexOf(responseBodyAsString, "url(", begin) + "url(".length();
             closeIndex = StringUtils.indexOf(responseBodyAsString, ")", urlIndex) ;
 
             String url = StringUtils.substring(responseBodyAsString, urlIndex, closeIndex);
             url = getUrl(cssPath, url).replaceAll("\"", "");
             url = "\"" + url + "\"";
             if(!StringUtils.isEmpty(url) && !map.containsKey(url)) {
                 map.put(url, url);
 
             } else if (map.containsKey(url)) {
                 url = map.get(url);
 
             }
             tmp += StringUtils.substring(responseBodyAsString, begin, urlIndex) + url;
             begin = closeIndex;
 
         }
 
         tmp += StringUtils.substring(responseBodyAsString, closeIndex);
         return tmp;
     }
 
 
     private File getAttachmentFile(String url) throws Exception {
         log.info("Streaming content of url:" + url + " to a temporary file");
 
         // Execute an http get on the url
         GetMethod redirect = new GetMethod(url);
         getHttpClient(url).executeMethod(redirect);
 
         URL _url = new URL(url);
         String file = _url.getFile();
 
         // create file in temp dir, with just the file name.
         File tempFile = new File(Path.getTempDirectoryPath()
             + File.separator
             + file.substring(file.lastIndexOf(SLASH) + 1));
         // if same file and same size, return, do not process
         if (tempFile.exists() && redirect.getResponseContentLength() == tempFile.length()) {
             redirect.releaseConnection();
             return tempFile;
         }
 
         // stream the content to the temp file
         FileOutputStream out = new FileOutputStream(tempFile);
         final int BUFFER_SIZE = 1 << 10 << 3; // 8KiB buffer
         byte[] buffer = new byte[BUFFER_SIZE];
         int bytesRead;
         InputStream in = new BufferedInputStream(redirect.getResponseBodyAsStream());
         while (true) {
             bytesRead = in.read(buffer);
             if (bytesRead > -1) {
                 out.write(buffer, 0, bytesRead);
             }
             else {
                 break;
             }
         }
 
         // cleanup
         in.close();
         out.close();
         redirect.releaseConnection();
 
         return tempFile;
     }
 
 
     private HttpClient getHttpClient(String baseURL) throws Exception {
         if (this.client == null) {
             URL location = new URL(baseURL);
             User user = MgnlContext.getUser();
             this.client = getHttpClientForUser(location, user);
         }
         return this.client;
     }
 
 
     private HttpClient getHttpClientForUser(URL location, User _user) throws IOException {
         HttpClient _client = new HttpClient();
         _client.getHostConfiguration().setHost(location.getHost(), location.getPort(), location.getProtocol());
         _client.getParams().setCookiePolicy(CookiePolicy.BROWSER_COMPATIBILITY);
         String user = _user.getName();
         String pass = _user.getPassword();
         log.info("Creating http client for user:" + user);
         // login using the id and password of the current user
         PostMethod authpost = new PostMethod(location.getPath());
         NameValuePair action = new NameValuePair(ACTION, LOGIN);
         NameValuePair url = new NameValuePair(URL, location.getPath());
         NameValuePair userid = new NameValuePair(MGNL_USER_ID, user);
         NameValuePair password = new NameValuePair(MGNL_USER_PSWD, pass);
         authpost.setRequestBody(new NameValuePair[]{action, url, userid, password});
         _client.executeMethod(authpost);
         authpost.releaseConnection();
         return _client;
     }
 
     private String retrieveContentFromMagnolia(String _url) throws Exception {
         log.info("Retrieving content from magnolia:" + _url);
         GetMethod redirect = new GetMethod(_url + SUFFIX);
         getHttpClient(_url).executeMethod(redirect);
         String response = redirect.getResponseBodyAsString();
         redirect.releaseConnection();
         return response;
     }
 
     /**
      * Content filter.
      *
      */
     static class ContentFilter implements Filter {
 
 
         private static final long serialVersionUID = 1L;
 
         public boolean matches(Object object) {
             if (object instanceof Element) {
                 Element e = (Element) object;
                 return e.getName().equalsIgnoreCase(LINK) || e.getName().equalsIgnoreCase(IMG)
                 || e.getName().equalsIgnoreCase(A_LINK) || e.getName().equalsIgnoreCase(FORM)
                 || e.getName().equalsIgnoreCase(BODY);
             }
 
             return false;
 
         }
     }
 }