/*
 * Copyright (C) The Apache Software Foundation. All rights reserved.
 *
 * This software is published under the terms of the Apache Software License
 * version 1.1, a copy of which has been included with this distribution in
 * the LICENSE file.
 */
package server.ftp;

import java.util.Date;
import java.util.List; 
import java.util.Collection;
import java.util.Iterator;
import java.util.StringTokenizer;
import java.text.SimpleDateFormat;
import java.lang.reflect.Method;

import util.StringUtils;
import server.IpRestrictor;
import server.ftp.usermanager.User;
import server.ftp.usermanager.UserManager;

/**
 * Handle ftp site command.
 *
 * @author <a href="mailto:rana_b@yahoo.com">Rana Bhattacharyya</a>
 */
public
class SiteCommandHandler {
    
    // as SimpleDateFormat is not thread-safe we have to use ThreadLocal
    private final static ThreadLocal DATE_FMT = new ThreadLocal() {
        protected Object initialValue() {
            return new SimpleDateFormat("MM/dd HH:mm:ss"); 
        }
    };
    
    protected final static Class[] INPUT_SIG = new Class[] {String[].class, FtpRequest.class};
    
    private FtpConfig mConfig;
    private FtpUser mUser;
    
    
    /**
     * Constructor - set the configuration object
     */
    public SiteCommandHandler(FtpConfig cfg, FtpUser user) {
        mConfig = cfg;
        mUser = user;
    }
    
    
    /**
     * Handle site.
     */
    public String getResponse(FtpRequest request) {
        String argArray[] = parseArg(request.getArgument());
        
        String response = "";
        if (hasPermission(argArray)) {
            if ((argArray != null) && (argArray.length != 0)) {
                try {
                    String metName = "do" + argArray[0].toUpperCase();
                    Method actionMet = getClass().getDeclaredMethod(metName, INPUT_SIG);
                    response = (String)actionMet.invoke(this, new Object[] {argArray, request});
                }
                catch(Throwable th) {
                    mConfig.getLogger().warn(th);
                    response = mConfig.getStatus().getResponse(530, request, mUser, null);
                }
            }
            else {
                response = mConfig.getStatus().getResponse(200, request, mUser, null);
            }
        }
        else {
            response = mConfig.getStatus().getResponse(530, request, mUser, null);
        }
        
        return response;
    }
    
    
    /**
     * Parse all the tokens.
     */
    private String[] parseArg(String arg) {
        if (arg == null) {
            return null;
        }
        
        StringTokenizer st = new StringTokenizer(arg, " ");
        String[] args = new String[st.countTokens()]; 
        for(int i=0; i<args.length; i++) {
            args[i] = st.nextToken();
        }
        
        return args;
    }
    
    
    /**
     * Has permission
     */
    private boolean hasPermission(String args[]) {
        UserManager userManager = mConfig.getUserManager();
        String adminName = userManager.getAdminName();
        if ( args == null || mUser.getName().equals(adminName) ) {
            return true;
        }
        return ( (args.length > 0) && "HELP".equalsIgnoreCase(args[0]) );
    }
     
     
    ////////////////////////////////////////////////////////////////////////////   
    ////////////////////////  All site command handlers //////////////////////// 
    /**
     * Add banned IP
     */
     public String doADDIP(String[] args, FtpRequest cmd) {
         if (args.length != 2) {
             return mConfig.getStatus().getResponse(501, cmd, mUser, null);
         }
         
         String response = "";
         try {
             IpRestrictor ipRestrictor = mConfig.getIpRestrictor();
             ipRestrictor.add(args[1]);
             ipRestrictor.writeFile();
             response = mConfig.getStatus().getResponse(200, cmd, mUser, null);
         }
         catch(Exception ex) {
             mConfig.getLogger().warn(ex);
             response = mConfig.getStatus().getResponse(451, cmd, mUser, null);
         }
         return response;
     } 


    /**
     * Add user
     */
     public String doADDUSER(String[] args, FtpRequest cmd) {
         if (args.length != 2) {
             return mConfig.getStatus().getResponse(501, cmd, mUser, null);
         }
         
         String response = "";
         try {
             String userName = args[1];
             UserManager userManager = mConfig.getUserManager(); 
             
             if( !userManager.doesExist(userName) ) {
                 User user = new User();
                 user.setName(userName);
                 user.setPassword("");
                 user.setEnabled(false);
                 user.getVirtualDirectory().setWritePermission(false);
                 user.setMaxUploadRate(0);
                 user.setMaxDownloadRate(0);
                 user.getVirtualDirectory().setRootDirectory(mConfig.getDefaultRoot());
                 user.setMaxIdleTime(mConfig.getDefaultIdleTime());
                 mConfig.getUserManager().save(user);
             }
             response = mConfig.getStatus().getResponse(200, cmd, mUser, null);
         }
         catch(Exception ex) {
             mConfig.getLogger().warn(ex);
             response = mConfig.getStatus().getResponse(451, cmd, mUser, null);
         }
         return response;
     } 

     
     /**
      * Add banned IP
      */
     public String doDELIP(String[] args, FtpRequest cmd) {
          if (args.length != 2) {
              return mConfig.getStatus().getResponse(501, cmd, mUser, null);
          }
          
          String response = "";
          try {
              IpRestrictor ipRestrictor = mConfig.getIpRestrictor();
              if (ipRestrictor.remove(args[1])) {
                ipRestrictor.writeFile();
              }
              response = mConfig.getStatus().getResponse(200, cmd, mUser, null);
          }
          catch(Exception ex) {
              mConfig.getLogger().warn(ex);
              response = mConfig.getStatus().getResponse(451, cmd, mUser, null);
          }
          return response;
    } 
      
           
    /**
     * Delete user from repository.
     */
    public String doDELUSER(String[] args, FtpRequest cmd) {
        if (args.length != 2) {
            return mConfig.getStatus().getResponse(501, cmd, mUser, null);
        }
        
        String response = "";
        try {
            mConfig.getUserManager().delete(args[1]);
            response = mConfig.getStatus().getResponse(200, cmd, mUser, null);
        }
        catch(Exception ex) {
            mConfig.getLogger().warn(ex);
            response = mConfig.getStatus().getResponse(451, cmd, mUser, null);
        }