package com.atlassian.plugin.osgi.loader.transform;
   
   import aQute.lib.osgi.Analyzer;
   import aQute.lib.osgi.Builder;
   import aQute.lib.osgi.Jar;
   import com.atlassian.plugin.PluginInformation;
   import com.atlassian.plugin.PluginManager;
   import com.atlassian.plugin.PluginParseException;
   import com.atlassian.plugin.osgi.hostcomponents.HostComponentRegistration;
  import com.atlassian.plugin.osgi.util.OsgiHeaderUtil;
  import com.atlassian.plugin.parsers.XmlDescriptorParser;
  import org.apache.log4j.Level;
  import org.apache.log4j.Logger;
  import org.dom4j.*;
  import org.dom4j.io.OutputFormat;
  import org.dom4j.io.SAXReader;
  import org.dom4j.io.XMLWriter;
  import org.osgi.framework.Constants;
  
  import java.io.*;
  import java.net.URL;
  import java.net.URLClassLoader;
  import java.util.*;
  import java.util.jar.JarEntry;
  import java.util.jar.JarFile;
  import java.util.zip.ZipEntry;
  import java.util.zip.ZipInputStream;
  import java.util.zip.ZipOutputStream;
  
  /**
   * Default implementation of plugin transformation that uses BND to generate the manifest and manually creates the
   * spring configuration file.
   */
  public class DefaultPluginTransformer implements PluginTransformer
  {
      // The spring configuration containing exported components and imported host components
      static final String ATLASSIAN_PLUGIN_SPRING_XML = "META-INF/spring/atlassian-plugins-spring.xml";
  
      private static final Logger log = Logger.getLogger(DefaultPluginTransformer.class);
  
      /**
       * Transforms the file into an OSGi bundle
       * @param pluginJar The plugin jar
       * @param regs The list of registered host components
       * @return The new OSGi-enabled plugin jar
       * @throws PluginTransformationException If anything goes wrong
       */
      public File transform(File pluginJar, List<HostComponentRegistration> regs) throws PluginTransformationException
      {
          log.setLevel(Level.DEBUG);
          final JarFile jar;
          try
          {
              jar = new JarFile(pluginJar);
          }
          catch (IOException e)
          {
              throw new PluginTransformationException("Plugin is not a valid jar file", e);
          }
  
          // List of all files to add/override in the new jar
          Map<String,byte[]> filesToAdd = new HashMap<String, byte[]>();
  
          // Try to generate a manifest if none available
          URL atlassianPluginsXmlUrl = null;
          try
          {
              final ClassLoader cl = new URLClassLoader(new URL[]{pluginJar.toURL()}, null);
              atlassianPluginsXmlUrl = cl.getResource(PluginManager.PLUGIN_DESCRIPTOR_FILENAME);
              if (atlassianPluginsXmlUrl == null)
                  throw new IllegalStateException("Cannot find atlassian-plugins.xml in jar");
  
              log.info("Generating the manifest for plugin "+pluginJar.getName());
              filesToAdd.put("META-INF/MANIFEST.MF", generateManifest(atlassianPluginsXmlUrl.openStream(), pluginJar, regs));
          } catch (PluginParseException e)
          {
              throw new PluginTransformationException("Unable to generate manifest", e);
          } catch (IOException e)
          {
              throw new PluginTransformationException("Unable to read existing plugin jar manifest", e);
          }
  
          // Try to generate the spring config that pulls in host components and exports plugin components
          if (jar.getEntry(ATLASSIAN_PLUGIN_SPRING_XML) == null) {
              try
              {
                  log.info("Generating "+ATLASSIAN_PLUGIN_SPRING_XML + " for plugin "+pluginJar.getName());
                  filesToAdd.put(ATLASSIAN_PLUGIN_SPRING_XML, generateSpringXml(atlassianPluginsXmlUrl.openStream(), regs));
              } catch (DocumentException e)
              {
                  throw new PluginTransformationException("Unable to generate host component spring XML", e);
              } catch (IOException e)
              {
                  throw new PluginTransformationException("Unable to open atlassian-plugins.xml", e);
              }
          }
  
          // Create a new jar by overriding the specified files
          try
         {
             if (log.isDebugEnabled())
             {
                 StringBuilder sb = new StringBuilder();
                 sb.append("Overriding files in ").append(pluginJar.getName()).append(":\n");
                 for (Map.Entry<String,byte[]> entry : filesToAdd.entrySet())
                 {
                     sb.append("==").append(entry.getKey()).append("==\n");
                     sb.append(new String(entry.getValue()));
                 }
                 log.debug(sb.toString());
             }
             return addFilesToExistingZip(pluginJar, filesToAdd);
         } catch (IOException e)
         {
             throw new PluginTransformationException("Unable to add files to plugin jar");
         }
 
     }
 
     /**
      * Generate the spring xml by processing the atlassian-plugins.xml file
      * @param in The stream of the atlassian-plugins.xml file
      * @param regs The list of registered host components
      * @return The new spring xml in bytes
      * @throws DocumentException If there are any errors processing the atlassian-plugins.xml document
      */
     byte[] generateSpringXml(InputStream in, List<HostComponentRegistration> regs) throws DocumentException
     {
         Document springDoc = DocumentHelper.createDocument();
         Element root = springDoc.addElement("beans");
 
         root.addNamespace("beans", "http://www.springframework.org/schema/beans");
         root.addNamespace("osgi", "http://www.springframework.org/schema/osgi");
         root.addNamespace("xsi", "http://www.w3.org/2001/XMLSchema-instance");
         root.addAttribute(new QName("schemaLocation", new Namespace("xsi", "http://www.w3.org/2001/XMLSchema-instance")),
                 "http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.5.xsd\n" +
                 "http://www.springframework.org/schema/osgi http://www.springframework.org/schema/osgi/spring-osgi.xsd");
         root.setName("beans:beans");
         root.addAttribute("default-autowire", "autodetect");
 
         // Write plugin components
         SAXReader reader = new SAXReader();
         Document pluginDoc = reader.read(in);
         List<Element> elements = pluginDoc.getRootElement().elements("component");
         for (Element component : elements)
         {
             Element bean = root.addElement("beans:bean");
             bean.addAttribute("id", component.attributeValue("key"));
             bean.addAttribute("alias", component.attributeValue("alias"));
             bean.addAttribute("class", component.attributeValue("class"));
             if ("true".equalsIgnoreCase(component.attributeValue("public")))
             {
                 Element osgiService = root.addElement("osgi:service");
                 osgiService.addAttribute("id", component.attributeValue("key")+"_osgiService");
                 osgiService.addAttribute("ref", component.attributeValue("key"));
 
                 List<String> interfaceNames = new ArrayList<String>();
                 List<Element> compInterfaces = component.elements("interface");
                 for (Element inf : compInterfaces)
                     interfaceNames.add(inf.getTextTrim());
 
                 Element interfaces = osgiService.addElement("osgi:interfaces");
                 for (String name : interfaceNames)
                 {
                     Element e = interfaces.addElement("beans:value");
                     e.setText(name);
                 }
             }
         }
 
         // Write plugin component imports
         elements = pluginDoc.getRootElement().elements("component-import");
         for (Element component : elements)
         {
             Element osgiReference = root.addElement("osgi:reference");
             osgiReference.addAttribute("id", component.attributeValue("key"));
             String infName = component.attributeValue("interface");
             if (infName != null)
                 osgiReference.addAttribute("interface", infName);
 
 
             List<Element> compInterfaces = component.elements("interface");
             if (compInterfaces.size() > 0)
             {
                 List<String> interfaceNames = new ArrayList<String>();
                 for (Element inf : compInterfaces)
                     interfaceNames.add(inf.getTextTrim());
 
                 Element interfaces = osgiReference.addElement("osgi:interfaces");
                 for (String name : interfaceNames)
                 {
                     Element e = interfaces.addElement("beans:value");
                     e.setText(name);
                 }
             }
         }
 
         // write host components
         if (regs != null)
         {
             for (int x=0; x<regs.size(); x++)
             {
                 HostComponentRegistration reg = regs.get(x);
                 String beanName = reg.getProperties().get("bean-name");
                 String id = beanName;
                 if (id == null)
                     id = "bean"+x;
 
                 id = id.replaceAll("#", "LB");
                 Element osgiService = root.addElement("osgi:reference");
                 osgiService.addAttribute("id", id);
                 osgiService.addAttribute("context-class-loader", "service-provider");
                 if (beanName != null)
                     osgiService.addAttribute("filter", "(bean-name="+beanName+")");
 
                 Element interfaces = osgiService.addElement("osgi:interfaces");
                 for (String name : reg.getMainInterfaces())
                 {
                     Element e = interfaces.addElement("beans:value");
                     e.setText(name);
                 }
             }
         }
 
         ByteArrayOutputStream bout = new ByteArrayOutputStream();
         OutputFormat format = OutputFormat.createPrettyPrint();
 
         try
         {
             XMLWriter writer = new XMLWriter(bout, format );
             writer.write(springDoc );
         } catch (IOException e)
         {
             throw new PluginTransformationException("Unable to print generated Spring XML", e);
         }
 
         return bout.toByteArray();
     }
 
     /**
      * Generates a new manifest file
      *
      * @param descriptorStream The existing manifest
      * @param file The jar
      * @return The new manifest file in bytes
      * @throws PluginParseException If there is any problems parsing atlassian-plugin.xml
      */
     byte[] generateManifest(InputStream descriptorStream, File file, List<HostComponentRegistration> regs) throws PluginParseException, IOException
     {
 
         Builder builder = new Builder();
         try
         {
             builder.setJar(file);
             String referrers = OsgiHeaderUtil.findReferredPackages(regs);
             if (builder.getJar().getManifest().getMainAttributes().getValue(Constants.BUNDLE_SYMBOLICNAME) != null)
             {
                 String imports = builder.getJar().getManifest().getMainAttributes().getValue(Constants.IMPORT_PACKAGE);
                 if (imports != null && imports.length() > 0)
                     imports = referrers + imports;
                 else
                     imports = referrers.substring(0, referrers.length() - 1);
                 builder.setProperty(Constants.IMPORT_PACKAGE, imports);
                 builder.mergeManifest(builder.getJar().getManifest());
             } else
             {
                 PluginInformationDescriptorParser parser = new PluginInformationDescriptorParser(descriptorStream);
                 PluginInformation info = parser.getPluginInformation();
 
                 Properties properties = new Properties();
 
                 // Setup defaults
                 properties.put("Spring-Context", "*;create-asynchronously:=false");
                 properties.put(Analyzer.BUNDLE_SYMBOLICNAME, parser.getKey());
                 properties.put(Analyzer.IMPORT_PACKAGE, referrers+"*");
                 properties.put(Analyzer.EXPORT_PACKAGE, "*");
                 properties.put(Analyzer.BUNDLE_VERSION, info.getVersion());
 
                 // remove the verbose Include-Resource entry from generated manifest
                 properties.put(Analyzer.REMOVE_HEADERS, Analyzer.INCLUDE_RESOURCE);
 
                 header(properties, Analyzer.BUNDLE_DESCRIPTION, info.getDescription());
                 header(properties, Analyzer.BUNDLE_NAME, parser.getKey());
                 header(properties, Analyzer.BUNDLE_VENDOR, info.getVendorName());
                 header(properties, Analyzer.BUNDLE_DOCURL, info.getVendorUrl());
 
                 // Scan for embedded jars
                 StringBuilder classpath = new StringBuilder();
                 classpath.append(".");
                 JarFile jarfile = new JarFile(file);
                 for (Enumeration<JarEntry> e = jarfile.entries(); e.hasMoreElements(); )
                 {
                     JarEntry entry = e.nextElement();
                     if (entry.getName().startsWith("META-INF/lib/") && entry.getName().endsWith(".jar"))
                         classpath.append(",").append(entry.getName());
                 }
                 header(properties, Analyzer.BUNDLE_CLASSPATH, classpath.toString());
 
                 builder.setProperties(properties);
             }
 
             // Not sure if this is the best incantation of bnd, but as I don't have the source, it'll have to do
             builder.calcManifest();
             Jar jar = builder.build();
             ByteArrayOutputStream bout = new ByteArrayOutputStream();
             jar.writeManifest(bout);
             return bout.toByteArray();
 
         } catch (Exception t)
         {
             throw new PluginParseException("Unable to process plugin to generate OSGi manifest", t);
         }
     }
 
     /**
      * Creates a new jar by overriding the specified files in the existing one
      *
      * @param zipFile The existing zip file
      * @param files The files to override
      * @return The new zip
      * @throws IOException If there are any problems processing the streams
      */
     static File addFilesToExistingZip(File zipFile,
 			 Map<String,byte[]> files) throws IOException {
                 // get a temp file
 		File tempFile = File.createTempFile(zipFile.getName(), null);
                 // delete it, otherwise you cannot rename your existing zip to it.
 		byte[] buf = new byte[1024];
 
 		ZipInputStream zin = new ZipInputStream(new FileInputStream(zipFile));
 		ZipOutputStream out = new ZipOutputStream(new FileOutputStream(tempFile));
 
 		ZipEntry entry = zin.getNextEntry();
 		while (entry != null) {
 			String name = entry.getName();
 			if (!files.containsKey(name))
             {
 				// Add ZIP entry to output stream.
 				out.putNextEntry(new ZipEntry(name));
 				// Transfer bytes from the ZIP file to the output file
 				int len;
 				while ((len = zin.read(buf)) > 0) {
 					out.write(buf, 0, len);
 				}
 			}
 			entry = zin.getNextEntry();
 		}
 		// Close the streams
 		zin.close();
 		// Compress the files
 		for (Map.Entry<String,byte[]> fentry : files.entrySet())
         {
             InputStream in = new ByteArrayInputStream(fentry.getValue());
 			// Add ZIP entry to output stream.
 			out.putNextEntry(new ZipEntry(fentry.getKey()));
 			// Transfer bytes from the file to the ZIP file
 			int len;
 			while ((len = in.read(buf)) > 0) {
 				out.write(buf, 0, len);
 			}
 			// Complete the entry
 			out.closeEntry();
 			in.close();
 		}
 		// Complete the ZIP file
 		out.close();
         return tempFile;
     }
 
 
     private static void header(Properties properties, String key, Object value)
     {
         if (value == null)
             return;
 
         if (value instanceof Collection && ((Collection) value).isEmpty())
             return;
 
         properties.put(key, value.toString().replaceAll("[\r\n]", ""));
     }
 
     /**
      * Descriptor parser that exposes the PluginInformation object directly
      */
     static class PluginInformationDescriptorParser extends XmlDescriptorParser
     {
         /**
          * @throws com.atlassian.plugin.PluginParseException
          *          if there is a problem reading the descriptor from the XML {@link java.io.InputStream}.
          */
         public PluginInformationDescriptorParser(InputStream source) throws PluginParseException
         {
             super(source);
         }
 
         public PluginInformation getPluginInformation()
         {
             return createPluginInformation(getDocument().getRootElement().element("plugin-info"));
         }
     }
 }