/*
    * Copyright 2011 SOFTEC sa. All rights reserved.
    *
    * This source code is licensed under the Creative Commons
    * Attribution-NonCommercial-NoDerivs 3.0 Luxembourg
    * License.
    *
    * To view a copy of this license, visit
    * http://creativecommons.org/licenses/by-nc-nd/3.0/lu/
   * or send a letter to Creative Commons, 171 Second Street,
   * Suite 300, San Francisco, California, 94105, USA.
   */
  
  package org.codehaus.mojo.javascript;
  
  import org.apache.maven.plugin.logging.Log;
  
  import java.io.BufferedReader;
  import java.io.IOException;
  import java.io.InputStreamReader;
  import java.io.PrintStream;
  
  /**
   * Utitlity class to manage the android emulator Thread.
   */
  public class AndroidEmulatorThread extends Thread {
      /**
       * The process builder containing the command to launch to execute the emulator.
       */
      private ProcessBuilder processBuilder;
  
      /**
       * The maven logger.
       */
      private Log log;
  
      /**
       * The emulator process.
       */
      private Process process;
  
      /**
       * Create a new instance.
       * @param processBuilder The ProcessBuilder to use to execute the emulator.
       * @param log The maven logger.
       */
      public AndroidEmulatorThread(ProcessBuilder processBuilder, Log log) {
          this.processBuilder = processBuilder;
          this.log = log;
      }
  
      @Override
      public void run() {
          try {
              //processBuilder.redirectErrorStream(true);
              process = processBuilder.start();
          } catch (IOException e) {
              log.error("Error while starting thread", e);
              process = null;
          }
  
          if (process != null) {
              outputProcessLog();
          }
  
          System.out.println("process execution finished");
      }
  
      /**
       * Check if the emulator process is running.
       * @return true if the emulator process is running,
       * false otherwise.
       */
      public boolean isRunning() {
          if (process == null) {
              return false;
          }
          try {
              process.exitValue();
              return false;
          } catch (IllegalThreadStateException ise) {
              return true;
          }
      }
  
      /**
       * Output the emulator process log.
       */
      private void outputProcessLog() {
          BufferedReader outReader = new BufferedReader(new InputStreamReader(process.getInputStream()));
          BufferedReader errReader = new BufferedReader(new InputStreamReader(process.getErrorStream()));
  
          while (isRunning()) {
              try {
                  fetchRow(outReader, System.out);
                  fetchRow(errReader, System.err);
              } catch (IOException e) {
                  System.err.println("Error while reading process input");
              }
         }
 
         try {
             fetchRow(outReader, System.out);
             fetchRow(errReader, System.err);
         } catch (IOException e) {
             System.err.println("Error while reading process input");
         }
     }
 
     /**
      * Fetch a row from a stream and
      * output it to the specified output.
      * @param reader The reader from which to read a row.
      * @param outStream The output stream.
      * @throws IOException If an I/O exception occurs.
      */
     private void fetchRow(BufferedReader reader, PrintStream outStream) throws IOException {
         if (reader.ready()) {
             String line = reader.readLine();
             if (line != null) {
                 outStream.println(line);
             }
         }
     }
 }