/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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.apache.ranger.authentication;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.net.Socket;
import java.util.List;

import org.apache.log4j.Logger;

public class PasswordValidator implements Runnable {

	private static final Logger LOG = Logger.getLogger(PasswordValidator.class);
	
	private static String validatorProgram = null;

	private static List<String> adminUserList;

	private static String adminRoleNames;

	private Socket client;
	
	public PasswordValidator(Socket client) {
		this.client = client;
	}

	@Override
	public void run() {
		BufferedReader reader = null;
		PrintWriter writer = null;

		String userName = null;

		try {
			reader = new BufferedReader(new InputStreamReader(client.getInputStream()));
			writer = new PrintWriter(new OutputStreamWriter(client.getOutputStream()));
			String request = reader.readLine();
			
			if (request.startsWith("LOGIN:")) {
				String line = request.substring(6).trim();
				int passwordAt = line.indexOf(' ');
				if (passwordAt != -1) {
					userName = line.substring(0,passwordAt).trim();
				}
			}

			if (validatorProgram == null) {
				String res = "FAILED: Unable to validate credentials.";
				writer.println(res);
				writer.flush();
				LOG.error("Response [" + res + "] for user: " + userName + " as ValidatorProgram is not defined in configuration.");

			}
			else {
				
				BufferedReader pReader = null;
				PrintWriter pWriter = null;
				Process p =  null;
				
				try {
					p = Runtime.getRuntime().exec(validatorProgram);
					
					pReader = new BufferedReader(new InputStreamReader(p.getInputStream()));
					
					pWriter = new PrintWriter(new OutputStreamWriter(p.getOutputStream()));
					
					pWriter.println(request); pWriter.flush();
	
					String res = pReader.readLine();


					if (res != null && res.startsWith("OK")) {
						if (adminRoleNames != null && adminUserList != null) {
							if (adminUserList.contains(userName)) {
								res = res + " " + adminRoleNames;
							}
						}
					}

					LOG.info("Response [" + res + "] for user: " + userName);
					
					writer.println(res); writer.flush();
				}
				finally {
					if (p != null) {
						p.destroy();
					}
				}
			}
			
		}
		catch(Throwable t) {
			if (userName != null && writer != null ) {
                                String res = "FAILED: unable to validate due to error " + t.getMessage();
				writer.println(res);
                                LOG.error("Response [" + res + "] for user: " + userName+", "+ t.getMessage());
			}
		}
		finally {
			try {
				if (client != null) {
					client.close();
				}
			}
			catch(IOException ioe){
				LOG.debug("Close socket failure. Detail: \n", ioe);
			}
			finally {
				client = null;
			}
		}
	}
	
	
	public static String getValidatorProgram() {
		return validatorProgram;
	}

	public static void setValidatorProgram(String validatorProgram) {
		PasswordValidator.validatorProgram = validatorProgram;
	}

	public static List<String> getAdminUserList() {
		return adminUserList;
	}

	public static void setAdminUserList(List<String> adminUserList) {
		PasswordValidator.adminUserList = adminUserList;
	}

	public static String getAdminRoleNames() {
		return adminRoleNames;
	}

	public static void setAdminRoleNames(String adminRoleNames) {
		PasswordValidator.adminRoleNames = adminRoleNames;
	}

}