// ========================================================================
   // Copyright (c) Webtide LLC
   // ------------------------------------------------------------------------
   // All rights reserved. This program and the accompanying materials
   // are made available under the terms of the Eclipse Public License v1.0
   // and Apache License v2.0 which accompanies this distribution.
   //
   // The Eclipse Public License is available at 
   // http://www.eclipse.org/legal/epl-v10.html
  //
  // The Apache License v2.0 is available at
  // http://www.apache.org/licenses/LICENSE-2.0.txt
  //
  // You may elect to redistribute this code under either of these licenses. 
  // ========================================================================
  package org.eclipse.jetty.deploy;
  
  import java.util.ArrayList;
  import java.util.HashMap;
  import java.util.HashSet;
  import java.util.List;
  import java.util.Map;
  import java.util.Set;
  
  import org.eclipse.jetty.deploy.graph.Graph;
  import org.eclipse.jetty.deploy.graph.Node;
  import org.eclipse.jetty.util.log.Log;
  import org.eclipse.jetty.util.log.Logger;
  
  /**
   * The lifecycle of an App in the {@link DeploymentManager}.
   * 
   * Setups a the default {@link Graph}, and manages the bindings to the life cycle via the {@link AppLifeCycle.Binding}
   * annotation.
   * <p>
   * <img src="doc-files/AppLifeCycle.png">
   */
  public class AppLifeCycle extends Graph
  {
      private static final Logger LOG = Log.getLogger(AppLifeCycle.class);
  
      private static final String ALL_NODES = "*";
  
      public static interface Binding
      {
          /**
           * Get a list of targets that this implementation should bind to.
           * 
           * @return the array of String node names to bind to. (use <code>"*"</code> to bind to all known node names)
           */
          String[] getBindingTargets();
  
          /**
           * Event called to process a {@link AppLifeCycle} binding.
           * 
           * @param node
           *            the node being processed
           * @param app
           *            the app being processed
           * @throws Exception
           *             if any problem severe enough to halt the AppLifeCycle processing
           */
          void processBinding(Node node, App app) throws Exception;
      }
  
      // Well known existing lifecycle Nodes
      public static final String UNDEPLOYED = "undeployed";
      public static final String DEPLOYING = "deploying";
      public static final String DEPLOYED = "deployed";
      public static final String STARTING = "starting";
      public static final String STARTED = "started";
      public static final String STOPPING = "stopping";
      public static final String UNDEPLOYING = "undeploying";
      
      
      private Map<String, List<Binding>> lifecyclebindings = new HashMap<String, List<Binding>>();
  
      public AppLifeCycle()
      {
          // Define Default Graph
  
          // undeployed -> deployed
          addEdge(UNDEPLOYED,DEPLOYING);
          addEdge(DEPLOYING,DEPLOYED);
  
          // deployed -> started
          addEdge(DEPLOYED,STARTING);
          addEdge(STARTING,STARTED);
  
          // started -> deployed
          addEdge(STARTED,STOPPING);
          addEdge(STOPPING,DEPLOYED);
  
          // deployed -> undeployed
          addEdge(DEPLOYED,UNDEPLOYING);
          addEdge(UNDEPLOYING,UNDEPLOYED);
      }
  
      public void addBinding(AppLifeCycle.Binding binding)
     {
         for (String nodeName : binding.getBindingTargets())
         {
             List<Binding> bindings = lifecyclebindings.get(nodeName);
             if (bindings == null)
             {
                 bindings = new ArrayList<Binding>();
             }
             bindings.add(binding);
 
             lifecyclebindings.put(nodeName,bindings);
         }
     }
     
     public void removeBinding(AppLifeCycle.Binding binding)
     {
         for (String nodeName : binding.getBindingTargets())
         {
             List<Binding> bindings = lifecyclebindings.get(nodeName);
             if (bindings != null)
                 bindings.remove(binding);
         }
     }
 
     /**
      * Get all {@link Node} bound objects.
      * 
      * @return Set of Object(s) for all lifecycle bindings. never null.
      */
     public Set<AppLifeCycle.Binding> getBindings()
     {
         Set<Binding> boundset = new HashSet<Binding>();
 
         for (List<Binding> bindings : lifecyclebindings.values())
         {
             boundset.addAll(bindings);
         }
 
         return boundset;
     }
 
     /**
      * Get all objects bound to a specific {@link Node}
      * 
      * @return Set of Object(s) for specific lifecycle bindings. never null.
      */
     public Set<AppLifeCycle.Binding> getBindings(Node node)
     {
         return getBindings(node.getName());
     }
 
     /**
      * Get all objects bound to a specific {@link Node}
      * 
      * @return Set of Object(s) for specific lifecycle bindings. never null.
      */
     public Set<AppLifeCycle.Binding> getBindings(String nodeName)
     {
         Set<Binding> boundset = new HashSet<Binding>();
 
         // Specific node binding
         List<Binding> bindings = lifecyclebindings.get(nodeName);
         if (bindings != null)
         {
             boundset.addAll(bindings);
         }
 
         // Special 'all nodes' binding
         bindings = lifecyclebindings.get(ALL_NODES);
         if (bindings != null)
         {
             boundset.addAll(bindings);
         }
 
         return boundset;
     }
 
     public void runBindings(Node node, App app, DeploymentManager deploymentManager) throws Throwable
     {
         for (Binding binding : getBindings(node))
         {
             if (LOG.isDebugEnabled())
                 LOG.debug("Calling " + binding.getClass().getName()+" for "+app);
             binding.processBinding(node,app);
         }
     }
 }