/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (the "License").  You may not use this file except in compliance
 * with the License.
 *
 * You can obtain a copy of the license at
 * trunk/opends/resource/legal-notices/OpenDS.LICENSE
 * or https://OpenDS.dev.java.net/OpenDS.LICENSE.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at
 * trunk/opends/resource/legal-notices/OpenDS.LICENSE.  If applicable,
 * add the following below this CDDL HEADER, with the fields enclosed
 * by brackets "[]" replaced with your own identifying information:
 *      Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 *
 *
 *      Copyright 2008 Sun Microsystems, Inc.
 */

package org.opends.server.admin;



import java.io.BufferedInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.HashMap;
import java.util.Map;
import java.util.MissingResourceException;
import java.util.Properties;



/**
 * A class for retrieving non-internationalized resource properties
 * associated with a managed object definition.
 * <p>
 * Resource properties are not available for the {@link TopCfgDefn}.
 */
public final class ManagedObjectDefinitionResource {

  // Mapping from definition to property tables.
  private final Map<AbstractManagedObjectDefinition<?, ?>,
      Properties> properties;

  // The resource name prefix.
  private final String prefix;



  /**
   * Creates a new resource instance for the named profile.
   *
   * @param profile
   *          The name of the profile.
   * @return Returns the resource instance for the named profile.
   */
  public static ManagedObjectDefinitionResource createForProfile(
      String profile) {
    return new ManagedObjectDefinitionResource("admin.profiles."
        + profile);
  }



  // Private constructor.
  private ManagedObjectDefinitionResource(String prefix) {
    this.properties =
      new HashMap<AbstractManagedObjectDefinition<?, ?>, Properties>();
    this.prefix = prefix;
  }



  /**
   * Get the resource value associated with the specified key.
   *
   * @param d
   *          The managed object definition.
   * @param key
   *          The resource key.
   * @return Returns the resource value associated with the specified
   *         key.
   * @throws MissingResourceException
   *           If the key was not found.
   * @throws UnsupportedOperationException
   *           If the provided managed object definition was the
   *           {@link TopCfgDefn}.
   */
  public String getString(AbstractManagedObjectDefinition<?, ?> d, String key)
      throws MissingResourceException, UnsupportedOperationException {
    if (d.isTop()) {
      throw new UnsupportedOperationException(
          "Profile resources are not available for the "
              + "Top configuration definition");
    }

    Properties p = getProperties(d);
    String result = p.getProperty(key);

    if (result == null) {
      String baseName = prefix + "." + d.getClass().getName();
      String path = baseName.replace('.', '/') + ".properties";

      throw new MissingResourceException("Can't find resource "
          + path + ", key " + key, baseName, key);
    }

    return result;
  }



  // Retrieve the properties table associated with a managed object,
  // lazily loading it if necessary.
  private synchronized Properties getProperties(
      AbstractManagedObjectDefinition<?, ?> d)
      throws MissingResourceException {
    Properties p = properties.get(d);

    if (p == null) {
      // Load the resource file.
      String baseName = prefix + "." + d.getClass().getName();
      String path = baseName.replace('.', '/') + ".properties";
      InputStream stream = ClassLoaderProvider.getInstance()
          .getClassLoader().getResourceAsStream(path);

      if (stream == null) {
        throw new MissingResourceException("Can't find resource "
            + path, baseName, "");
      }

      p = new Properties();
      try {
        p.load(new BufferedInputStream(stream));
      } catch (IOException e) {
        throw new MissingResourceException("Can't load resource "
            + path + " due to IO exception: " + e.getMessage(),
            baseName, "");
      }

      // Cache the resource.
      properties.put(d, p);
    }

    return p;
  }
}