/*******************************************************************************
 * Copyright (c) 2013 Boeing.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     Boeing - initial API and implementation
 *******************************************************************************/
package org.eclipse.osee.framework.ui.workspacebundleloader;

import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.net.URISyntaxException;
import java.net.URL;
import java.security.NoSuchAlgorithmException;
import java.util.jar.JarFile;
import java.util.jar.Manifest;
import java.util.logging.Level;

import org.eclipse.osee.framework.jdk.core.util.ChecksumUtil;
import org.eclipse.osee.framework.logging.OseeLog;
import org.osgi.framework.Bundle;
import org.osgi.framework.BundleContext;
import org.osgi.framework.BundleException;

public class BundleInfoLite {

   private final String symbolicName;
   private final String version;
   private final URL systemLocation;
   private final File file;
   private final Manifest manifest;
   private byte[] md5Digest;
   private Bundle bundle;

   
   public BundleInfoLite(URL systemLocation) throws IOException {
      File tmpFile;
      try {
         tmpFile = new File(systemLocation.toURI());
      } catch (URISyntaxException ex) {
         tmpFile = new File(systemLocation.getPath());
      }
      this.file = tmpFile;

      JarFile jarFile = new JarFile(file);
      this.manifest = jarFile.getManifest();
      this.symbolicName = generateBundleName(manifest);
      this.version = manifest.getMainAttributes().getValue("Bundle-Version");

      this.systemLocation = systemLocation;
      this.md5Digest = null;
   }

   /**
    * @return the name of the bundle
    */
   private String generateBundleName(Manifest jarManifest) {
      String nameEntry = jarManifest.getMainAttributes().getValue("Bundle-SymbolicName");
	  if(nameEntry == null){
	     return "unknown";
	  }
      // Sometimes there's a semicolon then extra info - ignore this
      int index = nameEntry.indexOf(';');
      if (index != -1) {
         nameEntry = nameEntry.substring(0, index);
      }

      return nameEntry;
   }

   /**
    * @return the symbolicName
    */
   public String getSymbolicName() {
      return symbolicName;
   }

   /**
    * @return the version
    */
   public String getVersion() {
      return version;
   }

   /**
    * @return the location
    */
   public URL getSystemLocation() {
      return systemLocation;
   }

   @Override
   public String toString() {
      return getSymbolicName() + ":" + getVersion();
   }

   /**
    * @return the md5Digest
    */
   public byte[] getMd5Digest() {
      // Do lazy calculation of this since it can be costly
      // and does not get read for all bundle info's
      if (md5Digest == null) {
         try {
            InputStream in = systemLocation.openStream();

            md5Digest = ChecksumUtil.createChecksum(in, "MD5");

            in.close();
         } catch (NoSuchAlgorithmException ex) {
            throw new IllegalStateException("Always expect MD5 to be available", ex);
         } catch (IOException ex) {
            throw new IllegalStateException("Always expect local jar file to be available", ex);
         }
      }
      return md5Digest;
   }
   
   public void install(BundleContext context) throws BundleException, IOException{
	   bundle = context.installBundle("reference:" + this.getSystemLocation().toExternalForm());
   }
   
   public Bundle uninstall() throws BundleException{
	   if(isInstalled()){
		   bundle.uninstall();
	   }
	   return bundle;
   }
   
   public boolean isInstalled() {
	   if(bundle == null){
		   return false;
	   } else {
		   int state = bundle.getState();
		   return state != Bundle.UNINSTALLED;
	   }
   }
   
   public boolean isStarted() {
	   if(isInstalled()){
		   int state = bundle.getState();
		   return state == Bundle.ACTIVE || state == Bundle.STARTING;
	   } else {
		   return false;
	   }
   }
   
   public void start(BundleContext context) throws BundleException{
	   if(bundle == null){
		  for(Bundle findit:context.getBundles()){
			  if(findit.getSymbolicName().equals(getSymbolicName())){
				  findit.start();
				  return;
			  }
		  }
	      OseeLog.log(BundleInfoLite.class, Level.WARNING, String.format("Tried to start bundle [%s] that is not installed.", getSymbolicName()));  
	   } else if (bundle.getState() == Bundle.INSTALLED || bundle.getState() == Bundle.RESOLVED){
		   bundle.start();
	   } 
   }
   
}