/*
 * Copyright 2005-2008 Werner Guttmann
 *
 * Licensed 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.
 */
package org.exolab.castor.builder.printing;

import java.util.HashMap;
import java.util.Map;

import org.apache.commons.lang3.StringUtils;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.exolab.castor.builder.BuilderConfiguration;

/**
 * Registry for {@link JClassPrinterFactory} implementations obtained from the Castor XML code
 * generator property file and used by the XML code generator during its operation.
 * 
 * @author <a href="mailto:Werner.Guttmann@morganstanley.com">Werner Guttmann</a>
 * @version $Revision: 7134 $ $Date: 2006-04-08 08:58:10 -0600 (Sat, 08 Apr 2006) $
 * @since 1.2.1
 */
public class JClassPrinterFactoryRegistry {

  /**
   * The <a href="http://jakarta.apache.org/commons/logging/">Jakarta Commons Logging</a> instance
   * used for all logging.
   */
  private final Log _log = LogFactory.getLog(JClassPrinterFactoryRegistry.class);

  /** Association between name of implementation and JClassPrinterFactory instance. */
  private Map<String, JClassPrinterFactory> _factories =
      new HashMap<String, JClassPrinterFactory>();

  /**
   * Construct an instance of JClassPrinterFactoryRegistry that loads the
   * {@link JClassPrinterFactory} implementations specified in the given Configuration.
   * 
   * @param config The LocalConfiguration.
   */
  public JClassPrinterFactoryRegistry(final BuilderConfiguration config) {
    String jClassPrinterFactories = config.getJClassPrinterFactories();
    String[] factoryClassNames = StringUtils.split(jClassPrinterFactories, ',');

    for (String factoryClassName : factoryClassNames) {
      JClassPrinterFactory factory;
      try {
        factory = (JClassPrinterFactory) Class.forName(factoryClassName).newInstance();
      } catch (InstantiationException | IllegalAccessException | ClassNotFoundException e) {
        throw new IllegalStateException("Property entry '" + factoryClassName + "' does"
            + " not represent a valid class name.");
      }
      _factories.put(factory.getName(), factory);
    }
  }

  /**
   * Returns the names of all the configured {@link JClassPrinterFactory} implementations. A
   * {@link JClassPrinterFactory} instance can be obtained by the {@link #getJClassPrinterFactory}
   * method.
   *
   * @return Names of {@link JClassPrinterFactory} implementations
   */
  public String[] getJClassPrinterFactoryNames() {
    String[] names = new String[_factories.size()];
    return _factories.keySet().toArray(names);
  }

  /**
   * Returns a {@link JClassPrinterFactory} with the specified name. Returns null if the named
   * factory is not supported.
   *
   * @param name The name of the JClassPrinterFactory.
   * @return The {@link JClassPrinterFactory} or null if none exists.
   */
  public JClassPrinterFactory getJClassPrinterFactory(final String name) {
    Object factory = _factories.get(name);
    if (factory == null) {
      String msg = "The JClassPrinterFactory '" + name + "' "
          + "does not exist in the Castor XML code generator properties file "
          + "and is therefore not supported.";
      _log.error(msg);
      throw new IllegalArgumentException(msg);
    }

    if (_log.isDebugEnabled()) {
      _log.debug("Returning JClassPrinterFactory with name " + name);
    }
    return (JClassPrinterFactory) factory;
  }

}
