package org.gnu.amSpacks.user;

import java.io.*;
import java.net.*;
import java.lang.reflect.*;
import javax.swing.*;
import java.util.zip.*;

/** This class must be present as part of your package.
 * Your installation must contain the folder "bin".
 * In this folder, it must have the executable .jar
 * archive with this class inside. Then you can
 * easily call this class from any other class, stored in
 * the same archive.
 */


public class Update {

  /** Main demonstrates how to start the update. This the main class
   * in demo.jar .
   *  */
  public static void main(String[] args) {
    try {

      Update autoupdater = new Update();

      URL[] servers =
          new URL[] {
          /** The locations, where the main configuration file can be found. */
          new URL("http://mypage.bluewin.ch/audrius/updates.xml"),
          new URL("http://jsight.sourceforge.net/updates.xml"),
          new URL("http://bioinformatics.org/jSight/updates.xml"),
                     };
      autoupdater.setUpdateFrom(servers);
      autoupdater.proceed();
    }
    catch (MalformedURLException ex) {
      assert false:"Should never happen.";
    }
    };

  /* The rest of the code does not require your attention  */

  private URL[] updateFrom = null;

  /** Starts the update process. */
  public void proceed()
   {
     if (updateFrom==null)
      throw new Error("Set the server list by calling setUpdataFrom(URL[] list)");
     try {
      File f = getBinFolder();
      File dir = getApplicationFolder();

      File autoUpdateJar = new File(f, "autoupdate.jar");

      jarLoader loader = new jarLoader(autoUpdateJar.getAbsolutePath());
      Class c = loader.findClass("org.gnu.amSpacks.AutoUpdate");

      File target = dir;

      Method m = c.getMethod("update", new Class[] { updateFrom.getClass(), File.class });
      m.invoke(null, new Object[] { updateFrom, target });

     }
      catch (Exception ex) {
        ex.printStackTrace();
        JOptionPane.showMessageDialog(null,
        "Sorry, unable to update. Please\n"+
        "download the new version manually.\n"+
        "See Help|About for the download address.", "Error", JOptionPane.ERROR_MESSAGE);
      }
   }

   private String getMainJar()
    {
      return file(getClass().getResource("Update.class"));
    };

   private File getBinFolder() throws Exception
    {
      File f = new File(getMainJar());
      if (!f.exists()) throw new Exception("Unable to loacate the main jar file");
      return f.getParentFile();
    }

   private File getApplicationFolder() throws Exception
    {
      File d = getBinFolder();
      if (!d.getName().equals("bin"))
       throw new Exception("The main parent file must be located in a folder 'bin'");
      return d.getParentFile();
    }

    private static String file(URL _u)
     {
       URL u = _u;
       String up = u.toExternalForm();
       String uab=null;

       boolean jar = up.indexOf(".jar!")>0 || up.startsWith("jar:");
       if (jar)
       // this is a jar file, go to root.
        {
          try {
           u = new URL(u,"/");
           uab = u.getFile();

           if (uab.endsWith("!/"))
            { uab=uab.substring(0, uab.length()-2);
            }
           } catch (Exception exc)
            { exc.printStackTrace(); };
        } else // folder
        {
          uab = up;
        }

        // delete the file: prefix:
        // do not include, but delete also a subsequent char, '/'
        if (uab.startsWith("file:"))
         {
           uab = uab.substring("file:".length()+1);
         };

        String path = uab;

        File library = new File(path);

        /* FIX: folder names with spaces.
        if (!library.exists())
         {
           library = new File("/"+path);
         };
        */
        if (!library.exists())
        {
         try {
           library = new File("/" + URLDecoder.decode(path, "UTF-8"));
         }
         catch (UnsupportedEncodingException ex) {
           library = new File("/" + path, "UTF-8");
         }
        };


        // if not jar, move two folders up:
        if (!jar)
         { library = library.getParentFile().getParentFile().getParentFile();
         };

        if (!library.exists())
         {
           System.out.println("PANIC: no library "+library.getAbsolutePath()+" as from "+_u.toExternalForm());
         };
        return library.getAbsolutePath();
     };

  private void setUpdateFrom(URL[] updateFrom) {
    this.updateFrom = updateFrom;
  }

  private class jarLoader extends ClassLoader {
        final String jar;
        final String subJar;

        private String getJar()
         { return jar; };

        private jarLoader(String _jar, String _subJar)
         {
           super(getSystemClassLoader());
           jar = _jar;
           subJar = _subJar;
         };

        private jarLoader(String _jar)
         {
           super(getSystemClassLoader());
           jar = _jar;
           subJar = null;
         };

        public Class findClass(String name) throws ClassNotFoundException {
          try {
            byte[] b;
             if (subJar!=null) b = loadClassData(jar, subJar, name);
                          else b = loadClassData(jar, name);
            return defineClass(name, b, 0, b.length);
            } catch (Exception exc)
               { //exc.printStackTrace();
                 throw new ClassNotFoundException("Cannot load "+name);
               }
        }

        protected byte[] loadClassData(String jar, String name)
         throws ClassNotFoundException, IOException
         {
          name = name.replace('.','/')+".class";
          //System.out.println("loading "+name+" directly from "+jar);
          ZipInputStream zw;
          ZipEntry ze;

          zw = new ZipInputStream(
           new BufferedInputStream(
             new FileInputStream(jar) ) );

          ze = zw.getNextEntry();
          while (ze!=null && !ze.getName().endsWith(name))
             {
               //System.out.println(ze.getName());
               ze = zw.getNextEntry();
             };

          if (ze==null)
           throw new ClassNotFoundException(name+" not found in "+jar);

          return readContent(zw);
         };

        /** Load class from jar of subJar in that jar. Jar and subJar names must not be
         *  identical. */
        protected byte[] loadClassData(String jar, String subJar, String name) throws Exception {

          if (subJar==null) return loadClassData(jar, name);

          if (!subJar.startsWith("/")) subJar = "/"+subJar;
          name = name.replace('.','/')+".class";
          //System.out.println("loading "+name+" from "+jar+" : "+subJar);
          ZipInputStream zw;
          ZipEntry ze;

          if (jar.endsWith(subJar))
           { //System.out.println("Direct library specified.");
             zw = new ZipInputStream(
              new BufferedInputStream(
               new FileInputStream(jar) ) );
            } else
            { //System.out.println("Looking for "+subJar+" inside archive.");
              ZipInputStream zi = new ZipInputStream(
               new BufferedInputStream(
                new FileInputStream(jar) ) );

              ze = zi.getNextEntry();
              while (ze!=null && !ze.getName().endsWith(subJar))
               {
                 ze = zi.getNextEntry();
               };
              if (ze==null)
               throw new ClassNotFoundException(subJar+" not found in "+jar);
              zw = new ZipInputStream(zi);
            };

            System.out.println(subJar+" found and opened.");
            ze = zw.getNextEntry();
            while (ze!=null && !ze.getName().endsWith(name))
             {
               //System.out.println(ze.getName());
               ze = zw.getNextEntry();
             };

            if (ze==null)
             throw new ClassNotFoundException(name+" not found in "+jar+"/"+subJar);

            return readContent(zw);
        }

        private ZipInputStream getJarInputStream()
         throws Exception
         {
          if (subJar==null)
           return
           new ZipInputStream(
           new BufferedInputStream(
             new FileInputStream(jar) ) );

          //System.out.println("loading "+name+" from "+jar+" : "+subJar);
          ZipEntry ze;

          if (jar.endsWith(subJar))
           {
             return new ZipInputStream(
              new BufferedInputStream(
               new FileInputStream(jar) ) );
            } else
            { //System.out.println("Looking for "+subJar+" inside archive.");
              ZipInputStream zi = new ZipInputStream(
               new BufferedInputStream(
                new FileInputStream(jar) ) );

              ze = zi.getNextEntry();
              while (ze!=null && !ze.getName().endsWith(subJar))
               {
                 ze = zi.getNextEntry();
               };
              if (ze==null)
               throw new ClassNotFoundException(subJar+" not found in "+jar);

              return new ZipInputStream(zi);
            }
         }

        private byte[] readContent(InputStream zw)
         throws IOException
         {
            ByteArrayOutputStream bu = new ByteArrayOutputStream(2000);
            int x;
            while ( (x = zw.read())!=-1)
             bu.write(x);
            return bu.toByteArray();
         };

        public String toString()
         { return "jarLoader "+jar+" - "+subJar; }

        public InputStream getResourceAsStream(String name)
         {
          try {
          ZipInputStream zw;
          ZipEntry ze;

          zw = new ZipInputStream(
           new BufferedInputStream(
             new FileInputStream(jar) ) );

          ze = zw.getNextEntry();
          while (ze!=null && !ze.getName().endsWith(name))
             {

               ze = zw.getNextEntry();
             };

          if (ze==null)
           {
             return super.getResourceAsStream(name);
           };

          return zw;
          } catch (Exception exc)
            {
              exc.printStackTrace();
              exc.printStackTrace();
              return super.getResourceAsStream(name);
            }
         };

         private InputStream getResourceAsStreamExclusive(String name)
          {
           try {
           ZipInputStream zw;
           ZipEntry ze;

           zw = new ZipInputStream(
            new BufferedInputStream(
              new FileInputStream(jar) ) );

           ze = zw.getNextEntry();
           while (ze!=null && !ze.getName().endsWith(name))
              {

                ze = zw.getNextEntry();
              };

           if (ze==null) return null;

           return zw;
           } catch (Exception exc)
             {
               exc.printStackTrace();
               return null;
             }
          };



       public URL getResource(String name) {
         try {
         if (getResourceAsStream(name)!=null)
          return new URL("jar:file:/"+jar+"!/"+name);
          } catch (Exception exc)
            {
            };

         return super.getResource(name);
       }


     }


}