//
   //  ========================================================================
   //  Copyright (c) 1995-2016 Mort Bay Consulting Pty. Ltd.
   //  ------------------------------------------------------------------------
   //  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.opensource.org/licenses/apache2.0.php
  //
  //  You may elect to redistribute this code under either of these licenses.
  //  ========================================================================
  //
  
  package org.eclipse.jetty.security;
  
  import java.io.File;
  import java.io.IOException;
  import java.nio.file.Path;
  import java.security.Principal;
  import java.util.ArrayList;
  import java.util.HashMap;
  import java.util.HashSet;
  import java.util.Iterator;
  import java.util.List;
  import java.util.Map;
  import java.util.Properties;
  import java.util.Set;
  
  import javax.security.auth.Subject;
  
  import org.eclipse.jetty.security.MappedLoginService.KnownUser;
  import org.eclipse.jetty.security.MappedLoginService.RolePrincipal;
  import org.eclipse.jetty.server.UserIdentity;
  import org.eclipse.jetty.util.PathWatcher;
  import org.eclipse.jetty.util.PathWatcher.PathWatchEvent;
  import org.eclipse.jetty.util.StringUtil;
  import org.eclipse.jetty.util.component.AbstractLifeCycle;
  import org.eclipse.jetty.util.log.Log;
  import org.eclipse.jetty.util.log.Logger;
  import org.eclipse.jetty.util.resource.PathResource;
  import org.eclipse.jetty.util.resource.Resource;
  import org.eclipse.jetty.util.security.Credential;
  
  /**
   * PropertyUserStore
   * <p>
   * This class monitors a property file of the format mentioned below and notifies registered listeners of the changes to the the given file.
   *
   * <pre>
   *  username: password [,rolename ...]
   * </pre>
   *
   * Passwords may be clear text, obfuscated or checksummed. The class com.eclipse.Util.Password should be used to generate obfuscated passwords or password
   * checksums.
   *
   * If DIGEST Authentication is used, the password must be in a recoverable format, either plain text or OBF:.
   */
  public class PropertyUserStore extends AbstractLifeCycle implements PathWatcher.Listener
  {
      private static final Logger LOG = Log.getLogger(PropertyUserStore.class);
  
      private Path _configPath;
      private Resource _configResource;
      
      private PathWatcher pathWatcher;
      private boolean hotReload = false; // default is not to reload
  
      private IdentityService _identityService = new DefaultIdentityService();
      private boolean _firstLoad = true; // true if first load, false from that point on
      private final List<String> _knownUsers = new ArrayList<String>();
      private final Map<String, UserIdentity> _knownUserIdentities = new HashMap<String, UserIdentity>();
      private List<UserListener> _listeners;
  
      /**
       * Get the config (as a string)
       * @return the config path as a string
       * @deprecated use {@link #getConfigPath()} instead
       */
      @Deprecated
      public String getConfig()
      {
          return _configPath.toString();
      }
  
      /**
       * Set the Config Path from a String reference to a file
       * @param configFile the config file
       * @deprecated use {@link #setConfigPath(String)} instead
       */
      @Deprecated
      public void setConfig(String configFile)
      {
          setConfigPath(configFile);
      }
     
     /**
      * Get the Config {@link Path} reference.
      * @return the config path
      */
     public Path getConfigPath()
     {
         return _configPath;
     }
 
     /**
      * Set the Config Path from a String reference to a file
      * @param configFile the config file
      */
     public void setConfigPath(String configFile)
     {
         if (configFile == null)
         {
             _configPath = null;
         }
         else
         {
             _configPath = new File(configFile).toPath();
         }
     }
 
     /**
      * Set the Config Path from a {@link File} reference
      * @param configFile the config file
      */
     public void setConfigPath(File configFile)
     {
         _configPath = configFile.toPath();
     }
 
     /**
      * Set the Config Path
      * @param configPath the config path
      */
     public void setConfigPath(Path configPath)
     {
         _configPath = configPath;
     }
     
     /* ------------------------------------------------------------ */
     public UserIdentity getUserIdentity(String userName)
     {
         return _knownUserIdentities.get(userName);
     }
 
     /* ------------------------------------------------------------ */
     /**
      * @return the resource associated with the configured properties file, creating it if necessary
      * @throws IOException if unable to get the resource
      */
     public Resource getConfigResource() throws IOException
     {
         if (_configResource == null)
         {
             _configResource = new PathResource(_configPath);
         }
 
         return _configResource;
     }
     
     /**
      * Is hot reload enabled on this user store
      * 
      * @return true if hot reload was enabled before startup
      */
     public boolean isHotReload()
     {
         return hotReload;
     }
 
     /**
      * Enable Hot Reload of the Property File
      * 
      * @param enable true to enable, false to disable
      */
     public void setHotReload(boolean enable)
     {
         if (isRunning())
         {
             throw new IllegalStateException("Cannot set hot reload while user store is running");
         }
         this.hotReload = enable;
     }
 
     /* ------------------------------------------------------------ */
     /**
      * sets the refresh interval (in seconds)
      * @param sec the refresh interval
      * @deprecated use {@link #setHotReload(boolean)} instead
      */
     @Deprecated
     public void setRefreshInterval(int sec)
     {
     }
 
     /* ------------------------------------------------------------ */
     /**
      * @return refresh interval in seconds for how often the properties file should be checked for changes
      * @deprecated use {@link #isHotReload()} instead
      */
     @Deprecated
     public int getRefreshInterval()
     {
         return (hotReload)?1:0;
     }
     
     @Override
     public String toString()
     {
         StringBuilder s = new StringBuilder();
         s.append(this.getClass().getName());
         s.append("[");
         s.append("users.count=").append(this._knownUsers.size());
         s.append("identityService=").append(this._identityService);
         s.append("]");
         return s.toString();
     }
 
     /* ------------------------------------------------------------ */
     private void loadUsers() throws IOException
     {
         if (_configPath == null)
             return;
 
         if (LOG.isDebugEnabled())
         {
             LOG.debug("Loading " + this + " from " + _configPath);
         }
         
         Properties properties = new Properties();
         if (getConfigResource().exists())
             properties.load(getConfigResource().getInputStream());
         
         Set<String> known = new HashSet<String>();
 
         for (Map.Entry<Object, Object> entry : properties.entrySet())
         {
             String username = ((String)entry.getKey()).trim();
             String credentials = ((String)entry.getValue()).trim();
             String roles = null;
             int c = credentials.indexOf(',');
             if (c > 0)
             {
                 roles = credentials.substring(c + 1).trim();
                 credentials = credentials.substring(0,c).trim();
             }
 
             if (username != null && username.length() > 0 && credentials != null && credentials.length() > 0)
             {
                 String[] roleArray = IdentityService.NO_ROLES;
                 if (roles != null && roles.length() > 0)
                 {
                     roleArray = StringUtil.csvSplit(roles);
                 }
                 known.add(username);
                 Credential credential = Credential.getCredential(credentials);
 
                 Principal userPrincipal = new KnownUser(username,credential);
                 Subject subject = new Subject();
                 subject.getPrincipals().add(userPrincipal);
                 subject.getPrivateCredentials().add(credential);
 
                 if (roles != null)
                 {
                     for (String role : roleArray)
                     {
                         subject.getPrincipals().add(new RolePrincipal(role));
                     }
                 }
 
                 subject.setReadOnly();
 
                 _knownUserIdentities.put(username,_identityService.newUserIdentity(subject,userPrincipal,roleArray));
                 notifyUpdate(username,credential,roleArray);
             }
         }
 
         synchronized (_knownUsers)
         {
             /*
              * if its not the initial load then we want to process removed users
              */
             if (!_firstLoad)
             {
                 Iterator<String> users = _knownUsers.iterator();
                 while (users.hasNext())
                 {
                     String user = users.next();
                     if (!known.contains(user))
                     {
                         _knownUserIdentities.remove(user);
                         notifyRemove(user);
                     }
                 }
             }
 
             /*
              * reset the tracked _users list to the known users we just processed
              */
 
             _knownUsers.clear();
             _knownUsers.addAll(known);
 
         }
 
         /*
          * set initial load to false as there should be no more initial loads
          */
         _firstLoad = false;
         
         if (LOG.isDebugEnabled())
         {
             LOG.debug("Loaded " + this + " from " + _configPath);
         }
     }
     
     /* ------------------------------------------------------------ */
     /**
      * Depending on the value of the refresh interval, this method will either start up a scanner thread that will monitor the properties file for changes after
      * it has initially loaded it. Otherwise the users will be loaded and there will be no active monitoring thread so changes will not be detected.
      *
      *
      * @see org.eclipse.jetty.util.component.AbstractLifeCycle#doStart()
      */
     protected void doStart() throws Exception
     {
         super.doStart();
 
         loadUsers();
         if ( isHotReload() && (_configPath != null) )
         {
             this.pathWatcher = new PathWatcher();
             this.pathWatcher.watch(_configPath);
             this.pathWatcher.addListener(this);
             this.pathWatcher.setNotifyExistingOnStart(false);
             this.pathWatcher.start();
         }
        
     }
     
     @Override
     public void onPathWatchEvent(PathWatchEvent event)
     {
         try
         {
             loadUsers();
         }
         catch (IOException e)
         {
             LOG.warn(e);
         }
     }
 
     /* ------------------------------------------------------------ */
     /**
      * @see org.eclipse.jetty.util.component.AbstractLifeCycle#doStop()
      */
     protected void doStop() throws Exception
     {
         super.doStop();
         if (this.pathWatcher != null)
             this.pathWatcher.stop();
         this.pathWatcher = null;
     }
 
     /**
      * Notifies the registered listeners of potential updates to a user
      *
      * @param username
      * @param credential
      * @param roleArray
      */
     private void notifyUpdate(String username, Credential credential, String[] roleArray)
     {
         if (_listeners != null)
         {
             for (Iterator<UserListener> i = _listeners.iterator(); i.hasNext();)
             {
                 i.next().update(username,credential,roleArray);
             }
         }
     }
 
     /**
      * notifies the registered listeners that a user has been removed.
      *
      * @param username
      */
     private void notifyRemove(String username)
     {
         if (_listeners != null)
         {
             for (Iterator<UserListener> i = _listeners.iterator(); i.hasNext();)
             {
                 i.next().remove(username);
             }
         }
     }
 
     /**
      * registers a listener to be notified of the contents of the property file
      * @param listener the user listener
      */
     public void registerUserListener(UserListener listener)
     {
         if (_listeners == null)
         {
             _listeners = new ArrayList<UserListener>();
         }
         _listeners.add(listener);
     }
 
     /**
      * UserListener
      */
     public interface UserListener
     {
         public void update(String username, Credential credential, String[] roleArray);
 
         public void remove(String username);
     }
 }