package org.apache.torque.generator.configuration;
   
   /*
    * Licensed to the Apache Software Foundation (ASF) under one
    * or more contributor license agreements.  See the NOTICE file
    * distributed with this work for additional information
    * regarding copyright ownership.  The ASF licenses this file
    * to you 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.
   */
  
  import java.io.BufferedInputStream;
  import java.io.IOException;
  import java.io.InputStream;
  import java.util.ArrayList;
  import java.util.Collection;
  import java.util.Enumeration;
  import java.util.List;
  import java.util.jar.JarEntry;
  import java.util.jar.JarFile;
  
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  import org.apache.torque.generator.configuration.paths.ProjectPaths;
  import org.apache.torque.generator.configuration.paths.TorqueGeneratorPaths;
  
  /**
   * Provides InputStreams to read a configuration of a unit of generation from a
   * jar file.
   */
  public class JarConfigurationProvider implements ConfigurationProvider
  {
      /** The logger. */
      private static Log log
              = LogFactory.getLog(JarConfigurationProvider.class);
  
      /**
       * The paths needed to interact with the enclosing project, not null.
       */
      private ProjectPaths projectPaths;
  
      /**
       * The internal directory structure of the generator configuration files,
       * not null.
       */
      private TorqueGeneratorPaths configurationPaths;
  
      /**
       * The jar file from which the configuration should be read, not null.
       */
      private JarFile jarFile;
  
      /**
       * Constructor.
       * @param projectPaths the paths needed to interact with the enclosing
       *         project, not null.
       * @param configurationPaths The internal directory structure of the
       *         generator configuration files, not null.
       *
       * @throws NullPointerException if projectPaths or configurationPaths
       *          are null.
       * @throws ConfigurationException if the jar file can not be accessed.
       */
      public JarConfigurationProvider(
              ProjectPaths projectPaths,
              TorqueGeneratorPaths configurationPaths)
          throws ConfigurationException
      {
          if (projectPaths == null)
          {
              throw new NullPointerException("projectPaths is null");
          }
          if (configurationPaths == null)
          {
              throw new NullPointerException("configurationPaths is null");
          }
          this.projectPaths = projectPaths;
          this.configurationPaths = configurationPaths;
  
          try
          {
              jarFile = new JarFile(projectPaths.getConfigurationPath());
          }
          catch (IOException e)
          {
              log.error("Could not open jar File "
                      + projectPaths.getConfigurationPath()
                          .getAbsolutePath());
              throw new ConfigurationException(e);
         }
     }
 
     public InputStream getControlConfigurationInputStream()
             throws ConfigurationException
     {
         return getInputStream(
                 configurationPaths.getControlConfigurationFile(),
                 configurationPaths.getConfigurationDirectory(),
                 "configuration");
     }
 
 
     public String getControlConfigurationLocation()
             throws ConfigurationException
     {
         return projectPaths.getConfigurationPath() + ":"
             + configurationPaths.getConfigurationDirectory() + "/"
             + configurationPaths.getControlConfigurationFile();
     }
 
     public InputStream getTemplateInputStream(String name)
             throws ConfigurationException
     {
         return getInputStream(
                 name,
                 configurationPaths.getTemplateDirectory(),
                 "template");
     }
 
     public InputStream getOutletConfigurationInputStream(String name)
             throws ConfigurationException
     {
         return getInputStream(
                 name,
                 configurationPaths.getOutletDirectory(),
                 "outlet configuration");
    }
 
     public InputStream getResourceInputStream(String name)
             throws ConfigurationException
     {
         return getInputStream(
                 name,
                 configurationPaths.getResourceDirectory(),
                 "resource");
     }
 
     public InputStream getOptionsInputStream(String name)
             throws ConfigurationException
     {
         return getInputStream(
                 name,
                 configurationPaths.getConfigurationDirectory(),
                 "option");
     }
 
     private InputStream getInputStream(
                String name,
                String directory,
                String description)
             throws ConfigurationException
     {
         String fileName = directory + "/" + name;
 
         InputStream inputStream = null;
         try
         {
             JarEntry jarEntry = jarFile.getJarEntry(fileName);
             inputStream = jarFile.getInputStream(jarEntry);
         }
         catch (IOException e)
         {
             throw new ConfigurationException(
                     "Could not read " + description + " file "
                         + fileName
                         + " in jar file "
                         + projectPaths.getConfigurationPath(),
                     e);
         }
         BufferedInputStream bis = new BufferedInputStream(inputStream);
         if (log.isDebugEnabled())
         {
             log.debug("Reading " + description + " file: '"
                     + projectPaths.getConfigurationPath()
                     + "' in jar file "
                     + projectPaths.getConfigurationPath());
         }
         return bis;
     }
 
     public Collection<String> getOutletConfigurationNames()
         throws ConfigurationException
     {
         return getOutletConfigurationNames(
                 jarFile,
                 configurationPaths.getOutletDirectory());
     }
 
     /**
      * Extracts the outlet configuration files from a jar file.
      * @param jarFile the jar file to process, not null.
      * @param outletConfigurationDirectory the name of the directory
      *        which contains the outlet configuration files. Cannot be
      *        a composite path like parent/child.
      * @return a set with the names of all outlet configuration files
      *         contained in the jar file.
      * @throws NullPointerException if jarFile
      *         or outletConfigurationDirectory is null
      */
     static Collection<String> getOutletConfigurationNames(
             JarFile jarFile,
             String outletConfigurationDirectory)
     {
         if (log.isDebugEnabled())
         {
             log.debug("Analyzing jar file " + jarFile.getName()
                     +  " seeking Directory " + outletConfigurationDirectory);
         }
 
         List<String> result = new ArrayList<String>();
 
         Enumeration<JarEntry> entries = jarFile.entries();
         while (entries.hasMoreElements())
         {
             JarEntry jarEntry = entries.nextElement();
             if (jarEntry.isDirectory())
             {
                 continue;
             }
             String rawName = jarEntry.getName();
             if (!rawName.startsWith(outletConfigurationDirectory))
             {
                 continue;
             }
             String name = rawName.substring(rawName.lastIndexOf('/') + 1);
 
             int expectedRawNameLength
                     = outletConfigurationDirectory.length()
                         + name.length()
                         + 1;
             if (rawName.length() != expectedRawNameLength)
             {
                 // file is in a subdirectory of outletConfigurationSubdir,
                 // we only consider files directly in
                 // outletConfigurationSubdir
                 continue;
             }
             result.add(name);
         }
         if (log.isDebugEnabled())
         {
             log.debug("Found the following outlet configuration files "
                     + result);
         }
         return result;
     }
 }