/*
    * $Id: Fingerprint.java,v 1.1.1.1 2005/02/17 18:37:35 mch Exp $
    *
    * (C) Copyright Astrogrid...
    */
   
   package org.astrogrid.webapp;
   
   import java.io.File;
  import java.io.IOException;
  import java.util.Date;
  import javax.servlet.jsp.JspWriter;
  
  /***
   * Methods used by JSPs to show details of the sites configuration
   * <p>
   * @author M Hill, from N Winstanley's fingerprint.jsp page from Brian Ewis
   */
  
  public class Fingerprint
  {
  
      /***
       * Returns an HTML details on theIdentify the version of a jar file. This uses a properties file
       * containing known names and sizes in the format
       * 'name(size)=version'. Version strings should be like 'xerces-1.4'
       * ie they should include the name of the library.
       */
      public String getFileVersion(File file) throws IOException {
          String key="<td>"+file.getName()+"</td>";
          key+= "<td>"+file.length()+"</td>";
          Date timestamp=new Date(file.lastModified());
          key+= "<td>"+timestamp.toString()+"</td>";
          return key;
  
          /* TODO: implement
          String value=versionProps.getProperty(key);
          if (value==null) {
              // make it possible to have jars without version nos
              value=versionProps.getProperty(file.getName());
          }
          if (value==null) {
              // fall back on something obvious
              value=key;
              Date timestamp=new Date(file.lastModified());
              value+=" / "+timestamp.toString();
          }
          return value;
          */
      }
  
      /***
       * Split up a classpath-like variable. Returns a list of files.
       * TODO: this can't cope with relative paths. I think theres code in BCEL that
       * can be used for this?
       */
      private File[] splitClasspath(String path) throws IOException {
          java.util.StringTokenizer st=
              new java.util.StringTokenizer(path,
                              System.getProperty("path.separator"));
          int toks=st.countTokens();
          File[] files=new File[toks];
          for(int i=0;i<toks;i++) {
              files[i]=new File(st.nextToken());
          }
          return files;
      }
  
      /*** given a list of files, return a list of jars which actually exist */
      File[] scanFiles(File[] files) throws IOException {
          File[] jars=new File[files.length];
          int found=0;
          for (int i=0; i<files.length; i++) {
              if (files[i].getName().toLowerCase().endsWith(".jar")
                      && files[i].exists()) {
                  jars[found]=files[i];
                  found++;
              }
          }
          if (found<files.length) {
              File[] temp=new File[found];
              System.arraycopy(jars,0,temp,0,found);
              jars=temp;
          }
          return jars;
      }
  
      private static final File[] NO_FILES=new File[0];
  
      /*** scan a directory for jars */
      public File[] scanDir(String dir) throws IOException
          {
          return scanDir(new File(dir));
          }
          
      public File[] scanDir(File dir) throws IOException {
          if (!dir.exists() || !dir.isDirectory()) {
              return NO_FILES;
          }
         return scanFiles(dir.listFiles());
     }
 
     /*** scan a classpath for jars */
     public File[] scanClasspath(String path) throws IOException {
         if (path==null) {
             return NO_FILES;
         }
         return scanFiles(splitClasspath(path));
     }
 
     /***
      * scan a 'dirpath' (like the java.ext.dirs system property) for jars
      */
     public File[] scanDirpath(String path) throws IOException {
         if (path==null) {
             return NO_FILES;
         }
         File[] current=new File[0];
         File[] dirs=splitClasspath(path);
         for(int i=0; i<dirs.length; i++) {
             File[] jars=scanDir(dirs[i]);
             File[] temp=new File[current.length+jars.length];
             System.arraycopy(current,0,temp,0,current.length);
             System.arraycopy(jars,0,temp,current.length,jars.length);
             current=temp;
         }
         return scanFiles(current);
     }
 
     /*** print out the jar versions for a directory */
     public void listDirectory(String title, JspWriter out,String dir, String comment) throws IOException {
         listVersions(title, out,scanDir(dir), comment);
     }
 
     /*** print out the jar versions for a directory-like system property */
     public void listDirProperty(String title, JspWriter out,String key, String comment) throws IOException {
         listVersions(title, out,scanDir(System.getProperty(key)), comment);
     }
 
     /*** print out the jar versions for a classpath-like system property */
     public void listClasspathProperty(String title, JspWriter out,String key, String comment) throws IOException {
         listVersions(title, out,scanClasspath(System.getProperty(key)), comment);
     }
 
     /*** print out the jar versions for a 'java.ext.dirs'-like system property */
     public void listDirpathProperty(String title, JspWriter out,String key, String comment) throws IOException {
         listVersions(title, out,scanDirpath(System.getProperty(key)), comment);
     }
 
     /*** print out the jar versions for a given list of files */
     public void listVersions(String title, JspWriter out,File[] jars, String comment) throws IOException {
         out.print("<h2>");
         out.print(title);
         out.println("</h2>");
         out.println("<table>");
         for (int i=0; i<jars.length; i++) {
             out.println("<tr>"+getFileVersion(jars[i])+"</tr>");
         }
         out.println("</table>");
         if(comment!=null && comment.length()>0) {
             out.println("<p>");
             out.println(comment);
             out.println("<p>");
         }
     }
 
  }