/**
    * This file Copyright (c) 2003-2013 Magnolia International
    * Ltd.  (http://www.magnolia-cms.com). All rights reserved.
    *
    *
    * This file is dual-licensed under both the Magnolia
    * Network Agreement and the GNU General Public License.
    * You may elect to use one or the other of these licenses.
    *
   * This file is distributed in the hope that it will be
   * useful, but AS-IS and WITHOUT ANY WARRANTY; without even the
   * implied warranty of MERCHANTABILITY or FITNESS FOR A
   * PARTICULAR PURPOSE, TITLE, or NONINFRINGEMENT.
   * Redistribution, except as permitted by whichever of the GPL
   * or MNA you select, is prohibited.
   *
   * 1. For the GPL license (GPL), you can redistribute and/or
   * modify this file under the terms of the GNU General
   * Public License, Version 3, as published by the Free Software
   * Foundation.  You should have received a copy of the GNU
   * General Public License, Version 3 along with this program;
   * if not, write to the Free Software Foundation, Inc., 51
   * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
   *
   * 2. For the Magnolia Network Agreement (MNA), this file
   * and the accompanying materials are made available under the
   * terms of the MNA which accompanies this distribution, and
   * is available at http://www.magnolia-cms.com/mna.html
   *
   * Any modifications to this file must keep this entire header
   * intact.
   *
   */
  package info.magnolia.commands;
  
  import info.magnolia.cms.beans.config.ObservedManager;
  import info.magnolia.cms.core.Content;
  import info.magnolia.commands.chain.Catalog;
  import info.magnolia.commands.chain.Command;
  import info.magnolia.commands.chain.Context;
  import info.magnolia.context.SimpleContext;
  import info.magnolia.jcr.node2bean.Node2BeanException;
  import info.magnolia.jcr.node2bean.Node2BeanProcessor;
  import info.magnolia.jcr.util.NodeTypes;
  import info.magnolia.objectfactory.Components;
  
  import java.util.HashMap;
  import java.util.Iterator;
  import java.util.Map;
  
  import javax.inject.Inject;
  import javax.inject.Singleton;
  import javax.jcr.RepositoryException;
  
  import org.apache.commons.lang.StringUtils;
  
  
  /**
   * Manages the Commands and Catalogs.
   *
   */
  @Singleton
  public class CommandsManager extends ObservedManager {
  
      public static final String DEFAULT_CATALOG = "default";
  
      public static final String COMMAND_DELIM = "-";
  
      private final CommandTransformer commandTransformer;
  
      private final Node2BeanProcessor nodeToBean;
  
      private Map<String, MgnlCatalog> catalogs;
  
      @Inject
      public CommandsManager(Node2BeanProcessor nodeToBean) {
          this.nodeToBean = nodeToBean;
          this.commandTransformer = new CommandTransformer();
          this.catalogs = new HashMap<String, MgnlCatalog>();
      }
  
      /**
       * Register observation for command catalogs.
       */
      @Override
      protected void onRegister(Content node) {
          // is this a catalog or a collection of catalogs?
          if (node.getChildren(NodeTypes.Content.NAME).size() == 0) {
              registerCatalog(node);
          }
          else{
              for (Iterator iter = node.getChildren(NodeTypes.Content.NAME).iterator(); iter.hasNext();) {
                  onRegister((Content) iter.next());
              }
          }
      }
  
  
      protected void registerCatalog(Content node) {
         log.debug("Registering commands at {}...", node.getHandle());
         try {
             MgnlCatalog catalog = (MgnlCatalog) nodeToBean.toBean(node.getJCRNode(), true, commandTransformer, Components.getComponentProvider());
             MgnlCatalog current = catalogs.get(catalog.getName());
             if (current == null) {
                 catalogs.put(catalog.getName(), catalog);
                 log.info("Catalog [{}] registered: {}", catalog.getName(), catalog);
             } else {
                 for (String commandName : catalog.getNames()) {
                     Command command = current.getCommand(commandName);
                     if (command != null) {
                         log.warn(String.format("Command [%s] found at [%s] already exists in the catalog [%s], skipping...", commandName, node.getHandle(), current.getName()));
                     } else {
                         log.info("Adding new command [{}] to already registered catalog [{}]...", commandName, current.getName());
                         current.addCommand(commandName, catalog.getCommand(commandName));
                     }
                 }
             }
         }
         catch (RepositoryException e) {
             log.error("Can't read catalog [" + node + "]", e);
         }
         catch (Node2BeanException e) {
             log.error("Can't create catalog [" + node  + "]", e);
         }
     }
 
     /**
      * Clear all catalogs.
      */
     @Override
     protected void onClear() {
         catalogs.clear();
     }
 
     /**
      * Get the command.
      * @param catalogName the catalog containing the command
      * @param commandName the name of the command
      * @return the command to execute
      */
     public Command getCommand(String catalogName, String commandName) {
         // if empty catalog name, use default catalog
         MgnlCatalog catalog = catalogs.get(StringUtils.isNotEmpty(catalogName) ? catalogName : DEFAULT_CATALOG);
         if (catalog != null) {
             Command command = catalog.getCommand(commandName);
             if (command != null) {
                 Command copy = command.copy(command);
                 if (copy != null) {
                     return copy;
                 }
                 log.warn("Cannot create copy of command [" + commandName + "] from catalog [" + catalogName + "].");
             }
         }
 
         return null;
     }
 
     /**
      * Use a delimiter to separate the catalog and command name.
      */
     public Command getCommand(String commandName) {
         String catalogName = DEFAULT_CATALOG;
         if (StringUtils.contains(commandName, COMMAND_DELIM)) {
             catalogName = StringUtils.substringBefore(commandName, COMMAND_DELIM);
             commandName = StringUtils.substringAfter(commandName, COMMAND_DELIM);
         }
 
         Command command = getCommand(catalogName, commandName);
         if (command == null) {
             command = getCommand(DEFAULT_CATALOG, commandName);
         }
         return command;
     }
 
     /**
      * @return Returns the instance.
      * @deprecated since 4.5, use IoC !
      */
     @Deprecated
     public static CommandsManager getInstance() {
         return Components.getComponent(CommandsManager.class);
     }
 
     /**
      * Executes the given command at the given catalog with the given
      * parameters.
      * 
      * @throws Exception
      * if an error occurs during command execution or if the command
      * could not be found in any catalog.
      */
     public boolean executeCommand(final String catalogName, final String commandName, final Map<String, Object> params) throws Exception {
         final Command command = getCommand(catalogName, commandName);
         if (command == null) {
             throw new Exception(String.format("Command [%s] could not be found in catalog [%s]", commandName, catalogName));
         }
         log.debug("Executing command [{}] from catalog [{}] and params [{}]...", new Object[] { commandName, catalogName, params });
         return executeCommand(command, params);
     }
 
     /**
      * Executes the given command by first looking in the default catalog.
      * Should the command not be found, it will try to look in all other
      * catalogs.
      * 
      * @see CommandsManager#executeCommand(String, String, Map)
      */
     public boolean executeCommand(final String commandName, final Map<String, Object> params) throws Exception {
         return executeCommand(DEFAULT_CATALOG, commandName, params);
     }
 
     /**
      * Executes the given command.
      * 
      * @see CommandsManager#executeCommand(String, Map)
      */
     public boolean executeCommand(final Command command, final Map<String, Object> params) throws Exception {
         return executeCommand(command, params, new SimpleContext());
     }
 
     /**
      * Executes the given command with given context.
      *
      * @see CommandsManager#executeCommand(String, Map)
      */
     public boolean executeCommand(final Command command, final Map<String, Object> params, Context context) throws Exception {
         if (params != null) {
             context.putAll(params);
         }
         return command.execute(context);
     }
 
     Catalog getCatalogByName(String name) {
         return catalogs.get(name);
     }
 
 }