/*
    * Copyright 2011 Andres Gomez Casanova
    *
    * Licensed under the Apache License, Version 2.0 (the "License");
    * you may not use this file except in compliance with the License.
    * You may obtain a copy of the License at
    *
    * http://www.apache.org/licenses/LICENSE-2.0
    *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  package net.sf.mgaip;
  
  import java.io.File;
  import java.io.FileInputStream;
  import java.io.FileOutputStream;
  import java.io.IOException;
  import java.io.InputStream;
  import java.io.OutputStreamWriter;
  import java.io.Writer;
  
  import org.jdom.Comment;
  import org.jdom.Document;
  import org.jdom.Element;
  import org.jdom.JDOMException;
  import org.jdom.Namespace;
  import org.jdom.input.SAXBuilder;
  import org.jdom.output.Format;
  import org.jdom.output.XMLOutputter;
  import org.jdom.xpath.XPath;
  
  /**
   * Class that replaces the already existent reports.
   * <p>
   * <b>Control Version</b>
   * <p>
   * <ul>
   * <li>1.0 Class creation.</li>
   * </ul>
   *
   * @author Jose Francisco "Pachito" Saray
   * @author Andres Gomez Casanova <a
   *         href="mailto:a n g o c a at y a h o o dot c o m">(AngocA)</a>
   * @version 1.0 20110529
   * @since 1.0
   */
  public final class Replacer {
  
      /**
       * Internal id for horizontal ad.
       */
      private static final int HORIZONTAL_AD = 2;
      /**
       * Internal id for logo ad.
       */
      private static final int LOGO_AD = 4;
      /**
       * Internal id for unique ad.
       */
      private static final int UNIQUE_AD = 3;
      /**
       * Internal id for vertical ad.
       */
      private static final int VERTICAL_AD = 1;
  
      /**
       * Mojo that calls the replacer.
       */
      private AdInserterMojo report;
  
      /**
       * Instantiates the mojo.
       *
       * @param caller
       *            Mojo containing all parameters.
       */
      Replacer(final AdInserterMojo/* ! */caller) {
          this.report = caller;
      }
  
      /**
       * Replaces an HTML tag with the given type of ad.
       *
       * @param single
       *            XML component that contains the location of the tag to
       *            replace.
       * @param content
       *            Content to insert.
       * @return true because the HTML has been modified and it has to be
       *         rewritten.
       */
      private boolean changeHTMLTag(final Element/* ! */single,
              final String/* ! */content) {
          Element parelement = single.getParentElement();
          single.detach();
         single.removeChild("img");
         Element script = new Element("script");
         script.setAttribute("type", "text/javascript");
         Comment comment = new Comment(content);
         script.addContent(comment);
         parelement.addContent(script);
         Element common = this.getCommon();
         parelement.addContent(common);
         return true;
     }
 
     /**
      * Returns the Google ad according to the requested type.
      *
      * @param type
      *            Type of ad.
      * @return Script to show this ad in html.
      */
     private String/* ! */getAdContent(final int type) {
         // assert type >= 1 && type <=4 : "Unknown ad type";
 
         String ret = "\n";
         ret += "google_ad_client = \"" + report.googleId + "\";\n";
         switch (type) {
         case HORIZONTAL_AD:
             ret += "google_ad_slot = \"" + report.horizontalAdId + "\";\n";
             ret += "google_ad_width = " + report.horizontalAdWidth + ";\n";
             ret += "google_ad_height = " + report.horizontalAdHeight + ";\n";
             break;
         case LOGO_AD:
             ret += "google_ad_slot = \"" + report.logoAdId + "\";\n";
             ret += "google_ad_width = " + report.logoAdWidth + ";\n";
             ret += "google_ad_height = " + report.logoAdHeight + ";\n";
             break;
         case UNIQUE_AD:
             ret += "google_ad_slot = \"" + report.uniqueAdId + "\";\n";
             ret += "google_ad_width = " + report.uniqueAdWidth + ";\n";
             ret += "google_ad_height = " + report.uniqueAdHeight + ";\n";
             break;
         case VERTICAL_AD:
             ret += "google_ad_slot = \"" + report.verticalAdId + "\";\n";
             ret += "google_ad_width = " + report.verticalAdWidth + ";\n";
             ret += "google_ad_height = " + report.verticalAdHeight + ";\n";
             break;
         default:
             this.report.log(2, "No content assigned.");
             break;
         }
         ret += "//";
 
         return ret;
     }
 
     /**
      * @return Returns the common part of Google Ad.
      */
     private Element/* ! */getCommon() {
         Element common = new Element("script");
         common.setAttribute("type", "text/javascript");
         // TODO Delete the namespace from the tag.
         common.setAttribute("src",
                 "http://pagead2.googlesyndication.com/pagead/show_ads.js");
         common.setText("mgaip");
         return common;
     }
 
     /**
      * Replaces the customPoweredBy tag with the given code.
      * <p>
      * TODO this should call an external javascript file that will contain the
      * code and stuff to show here.
      *
      * @param single
      *            Element where the custom code has to be inserted.
      * @return true to indicate that the file has been modified..
      */
     private boolean/* ! */getCustomPoweredBy(final Element/* ! */single) {
         Element parelement = single.getParentElement();
         single.detach();
         single.removeChild("img");
         Element custom = new Element("div");
         // TODO the next line should be inserted as raw, not as text.
         custom.addContent(report.customPoweredBy);
         parelement.addContent(custom);
         return true;
     }
 
     /**
      * Returns the I like Facebook script.
      * <p>
      * <code>
      * &lt;iframe src=
      * "http://www.facebook.com/plugins/like.php?
      * href=https%3A%2F%2Fwww.facebook.com%2Fpages%2FZemucan%2F138284808329
      * &amp;send=false&amp;layout=box_count&amp;width=150&amp;show_faces=false
      * &amp;action=like&amp;colorscheme=light&amp;font&amp;height=90"
      * scrolling="no" frameborder="0"
      * style="border:none; overflow:hidden; width:150px; height:90px;"
      * allowTransparency="true"&gt;&lt;/iframe&gt;
      * </code>
      * <p>
      * The example is for Zemucan, but it is defined in the variable
      * facebookLink. There are two types of links:
      * <ul>
      * <li>
      * In pages, with number:
      * https://www.facebook.com/pages/IBM-InfoSphere-Warehouse/17628877758</li>
      * <li>
      * Direct: https://www.facebook.com/PHP</li>
      * </ul>
      * <p>
      * However the link has to be transformed from
      * <p>
      * <code>https://www.facebook.com/pages/Zemucan/138284808329
      * </code>
      * <p>
      * to
      * <p>
      * <code>https%3A%2F%2Fwww.facebook.com%2Fpages%2FZemucan%2F138284808329
      * </code>
      *
      * @param single
      *            Element where the code has to be inserted.
      * @return true to indicate that the file has been modified.
      */
     private boolean/* ! */getFacebookILike(final Element/* ! */single) {
         String src = "http://www.facebook.com/plugins/like.php";
         src += "?href=" + report.facebookLink + "&";
         src += "send=false&layout=box_count&width=150&";
         src += "show_faces=false&action=like&colorscheme=light&";
         src += "font&height=90";
         String style = "border:none; overflow:hidden; width:150px; "
                 + "height:90px;";
 
         Element parelement = single.getParentElement();
         single.detach();
         single.removeChild("img");
         Element iframe = new Element("iframe");
         iframe.setAttribute("src", src);
         iframe.setAttribute("scrolling", "no");
         iframe.setAttribute("frameborder", "0");
         iframe.setAttribute("style", style);
         iframe.setAttribute("allowTransparency", "true");
         iframe.setText("mgaip");
         parelement.addContent(iframe);
         return true;
     }
 
     /**
      * Adds the google plus one script in the page.
      *
      * @param Element
      *            where the code has to be inserted.
      * @return true to indicate that the file has been modified.
      */
     private boolean getGooglePlusOne(final Element /* ! */single) {
         Element parelement = single.getParentElement();
         single.detach();
         single.removeChild("img");
         Element plusone = new Element("plusone", "g",
                 "http://www.w3.org/1999/xhtml");
         parelement.addContent(plusone);
         plusone.setText("mgaip");
         return true;
     }
 
     /**
      * Searches the tags to modify the HTML file and call the respective method
      * to insert an ad.
      * <p>
      * Vertical (xpath: html/body/div id="leftColumn"/div id="navcolumn"
      * title="googleAds"):
      * <p>
      * <code>
      * &lt;a href="" title="googleAds" class="poweredBy"&gt;<br>
      * &lt;logo name="googleAds" img="googleAds"/&gt;<br>
      * &lt;/a&gt;
      * </code>
      * <p>
      * Horizontal (xpath: html/body/div id="bodyColumn"/div id="contextBox"/div
      * class="section"):
      * <p>
      * <code>
      * &lt;img src="googleAds" alt="googleAds" /&gt;
      * </code>
      * <p>
      * Unique (xpath: html/body/div id="bodyColumn"/div id="contextBox"/div
      * class="section"/p):
      * <p>
      * <code>
      * &lt;a href="#googleAds"&gt;googleAds&lt;/a&gt;
      * </code>
      * <p>
      * Logo (xpath: html/body/div id="banner"/span id="bannerLeft" |
      * id="bannerRight"):
      * <p>
      * <code>
      * &lt;img src="googleAds" alt="googleAds" /&gt;
      * </code>
      * <p>
      * And then put the publicity:
      * <p>
      * <code>
      * &lt;script type="text/javascript"&gt;&lt;!--<br>
      * google_ad_client = "XXXXX";<br>
      * google_ad_slot = "YYYYY";<br>
      * google_ad_width = 120;<br>
      * google_ad_height = 600;<br>
      * //--&gt;<br>
      * &lt;/script&gt;<br>
      * &lt;script type="text/javascript"<br>
      * src="http://pagead2.googlesyndication.com/pagead/show_ads.js"&gt;<br>
      * &lt;/script&gt;
      * </code>
      * <p>
      * Where XXXXX the google user id, and YYYYY is the ad identifier.
      * <p>
      * Also, it replaces the powered by for facebook (xpath: html/body/div
      * id="leftColumn"/div id="navcolumn" title="facebookILike").
      * <p>
      * <code>
      * &lt;a href="" title="facebookILike" class="poweredBy"&gt;<br>
      * &lt;logo name="facebookILike" img="facebookILike"/&gt;<br>
      * &lt;/a&gt;
      * </code>
      * <p>
      * And a custom code as powered by (xpath: html/body/div id="leftColumn"/div
      * id="navcolumn" title="customPoweredBy").
      * <p>
      * <code>
      * &lt;a href="" title="customPoweredBy" class="poweredBy"&gt;<br>
      * &lt;logo name="customPoweredBy" img="customPoweredBy"/&gt;<br>
      * &lt;/a&gt;
      * </code>
      * <p>
      *
      * @param elem
      *            Root element.
      * @return true if the HTML has been modified and it has to be rewritten,
      *         false otherwise.
      * @throws JDOMException
      *             If there is a problem
      */
     private boolean htmlReplacement(final Element/* ! */elem)
             throws JDOMException {
         boolean modified = false;
 
         Namespace xhtml = Namespace.getNamespace("xhtml",
                 "http://www.w3.org/1999/xhtml");
 
         // FIXME when there are multiple powered by, there is a problem in the
         // order of insertion.
 
         // PoweredBy
         XPath xpath = XPath.newInstance("//xhtml:div[@id='leftColumn']"
                 + "//xhtml:div[@id='navcolumn']//xhtml:a[@class='poweredBy' "
                 + "and @title='googleAds']");
         xpath.addNamespace(xhtml);
         Element single = (Element) xpath.selectSingleNode(elem);
         if (single != null) {
             this.report.log(1, "Powered - Vertical");
             modified = this.changeHTMLTag(single,
                     this.getAdContent(VERTICAL_AD));
         }
 
         // Horizontal
         xpath = XPath.newInstance("//xhtml:div[@id='bodyColumn']"
                 + "/xhtml:div[@id='contentBox']/xhtml:div[@class='section']"
                 + "/xhtml:img[@src='googleAds' and @alt='googleAds']");
         xpath.addNamespace(xhtml);
         single = (Element) xpath.selectSingleNode(elem);
         if (single != null) {
             this.report.log(1, "Horizontal");
             modified = this.changeHTMLTag(single,
                     this.getAdContent(HORIZONTAL_AD));
         }
 
         // Unique
         xpath = XPath.newInstance("//xhtml:div[@id='bodyColumn']"
                 + "/xhtml:div[@id='contentBox']"
                 + "/xhtml:div[@class='section']/xhtml:p"
                 + "/xhtml:a[@href='#googleAds']");
         xpath.addNamespace(xhtml);
         single = (Element) xpath.selectSingleNode(elem);
         if (single != null) {
             this.report.log(1, "Unique");
             modified = this.changeHTMLTag(single, this.getAdContent(UNIQUE_AD));
         }
 
         // Logo
         xpath = XPath.newInstance("//xhtml:div[@id='banner']"
                 + "/xhtml:div[@id='bannerRight']"
                 + "/xhtml:img[@src='googleAds' and @alt='googleAds']");
         xpath.addNamespace(xhtml);
         single = (Element) xpath.selectSingleNode(elem);
         if (single != null) {
             this.report.log(1, "Logo right");
             modified = this.changeHTMLTag(single, this.getAdContent(LOGO_AD));
         }
         xpath = XPath.newInstance("//xhtml:div[@id='banner']"
                 + "/xhtml:div[@id='bannerLeft']"
                 + "/xhtml:img[@src='googleAds' and @alt='googleAds']");
         xpath.addNamespace(xhtml);
         single = (Element) xpath.selectSingleNode(elem);
         if (single != null) {
             this.report.log(1, "Logo left");
             modified = this.changeHTMLTag(single, this.getAdContent(LOGO_AD));
         }
 
         // Facebook
         xpath = XPath.newInstance("//xhtml:div[@id='leftColumn']"
                 + "/xhtml:div[@id='navcolumn']/xhtml:a[@class='poweredBy' "
                 + "and @title='facebookILike']");
         xpath.addNamespace(xhtml);
         single = (Element) xpath.selectSingleNode(elem);
         if (single != null) {
             this.report.log(1, "Powered - Facebook");
             modified = this.getFacebookILike(single);
         }
 
         // Plusone
         xpath = XPath.newInstance("//xhtml:div[@id='leftColumn']"
                 + "/xhtml:div[@id='navcolumn']/xhtml:a[@class='poweredBy' "
                 + "and @title='googlePlusOne']");
         xpath.addNamespace(xhtml);
         single = (Element) xpath.selectSingleNode(elem);
         if (single != null) {
             this.report.log(1, "Powered - GooglePlusOne");
             modified = this.getGooglePlusOne(single);
         }
 
         // Custom
         xpath = XPath.newInstance("//xhtml:div[@id='leftColumn']"
                 + "/xhtml:div[@id='navcolumn']/xhtml:a[@class='poweredBy' "
                 + "and @title='customPoweredBy']");
         xpath.addNamespace(xhtml);
         single = (Element) xpath.selectSingleNode(elem);
         if (single != null) {
             this.report.log(1, "Powered - Custom");
             modified = this.getCustomPoweredBy(single);
         }
 
         return modified;
     }
 
     /**
      * Open the file, parses the HTML and the searches the defined tags to
      * replace with other content.
      *
      * @param directory
      *            Directory of the file.
      * @param filename
      *            Name of the file to modify.
      */
     protected void replace(final String/* ! */directory,
             final String/* ! */filename) {
         // assert filename != null && !filename.equals("") : "Invalid filename";
         this.report.log(2, "Processing file " + filename);
         FileOutputStream output = null;
         Writer out = null;
 
         SAXBuilder saxb = new SAXBuilder();
         saxb.setValidation(false);
         saxb.setEntityResolver(new IgnoreEntityResolver());
 
         try {
             InputStream file = new FileInputStream(directory
                     + File.separatorChar + filename);
             Document document = saxb.build(file);
             Element elem = document.getRootElement();
             boolean modified = this.htmlReplacement(elem);
 
             // Writes the new html modified.
             if (modified) {
                 this.report.log(1, "HTML re-written");
                 XMLOutputter xmloutputter = new XMLOutputter(
                         Format.getPrettyFormat());
                 output = new FileOutputStream(directory + File.separatorChar
                         + filename);
                 out = new OutputStreamWriter(output, "ISO-8859-1");
                 xmloutputter.output(document.getDocType(), output);
                 output.write('\n');
                 xmloutputter.output(elem, output);
             }
         } catch (Throwable e) {
             this.report.log(4, "General problem: " + e.getMessage());
             this.report.log(e);
         } finally {
             if (out != null) {
                 try {
                     out.close();
                 } catch (IOException e) {
                     this.report.log(4, "IO Exception: " + e.getMessage());
                     this.report.log(e);
                 }
             }
             if (output != null) {
                 try {
                     output.flush();
                     output.close();
                 } catch (IOException e) {
                     this.report.log(4, "IO Exception: " + e.getMessage());
                     this.report.log(e);
                 }
             }
         }
     }
 }