/*
    * Copyright (C) 2014 The Android Open Source Project
    *
    * Licensed 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 com.simpligility.maven.plugins.android;
  
  import com.android.annotations.NonNull;
  import com.android.ide.common.process.JavaProcessExecutor;
  import com.android.ide.common.process.JavaProcessInfo;
  import com.android.ide.common.process.ProcessException;
  import com.android.ide.common.process.ProcessOutput;
  import com.android.ide.common.process.ProcessOutputHandler;
  import com.android.ide.common.process.ProcessResult;
  import com.android.utils.ILogger;
  import com.google.common.base.Joiner;
  import com.google.common.collect.Lists;
  import com.google.common.io.ByteStreams;
  import com.google.common.io.Closeables;
  import java.io.IOException;
  import java.io.InputStream;
  import java.io.OutputStream;
  import java.util.List;
  import java.util.Map;
  /**
   * Simple implementation of ProcessExecutor, using the standard Java Process(Builder) API.
   */
  public class DefaultJavaProcessExecutor implements JavaProcessExecutor
  {
      private final ILogger mLogger;
      public DefaultJavaProcessExecutor( ILogger logger )
      {
          mLogger = logger;
      }
      @NonNull
      @Override
      public ProcessResult execute(
              @NonNull JavaProcessInfo processInfo,
              @NonNull ProcessOutputHandler processOutputHandler )
      {
          List<String> command = Lists.newArrayList();
          command.add( processInfo.getExecutable() );
          command.addAll( processInfo.getArgs() );
          String commandString = Joiner.on( ' ' ).join( command );
          mLogger.info( "command: " + commandString );
          try
          {
              // launch the command line process
              ProcessBuilder processBuilder = new ProcessBuilder( command );
              Map<String, Object> envVariableMap = processInfo.getEnvironment();
              if ( !envVariableMap.isEmpty() )
              {
                  Map<String, String> env = processBuilder.environment();
                  for ( Map.Entry<String, Object> entry : envVariableMap.entrySet() )
                  {
                      env.put( entry.getKey(), entry.getValue().toString() );
                  }
              }
              // start the process
              Process process = processBuilder.start();
              // and grab the output, and the exit code
              ProcessOutput output = processOutputHandler.createOutput();
              int exitCode = grabProcessOutput( process, output );
              processOutputHandler.handleOutput( output );
              return new ProcessResultImplCopy( commandString, exitCode );
          }
          catch ( IOException e )
          {
              return new ProcessResultImplCopy( commandString, e );
          }
          catch ( InterruptedException e )
          {
              // Restore the interrupted status
              Thread.currentThread().interrupt();
              return new ProcessResultImplCopy( commandString, e );
          }
          catch ( ProcessException e )
          {
              return new ProcessResultImplCopy( commandString, e );
          }
      }
      /**
       * Get the stderr/stdout outputs of a process and return when the process is done.
       * Both <b>must</b> be read or the process will block on windows.
       *
       * @param process The process to get the output from.
       * @param output The processOutput containing where to send the output.
       *      Note that on Windows capturing the output is not optional. If output is null
       *      the stdout/stderr will be captured and discarded.
      * @return the process return code.
      * @throws InterruptedException if {@link Process#waitFor()} was interrupted.
      */
     private static int grabProcessOutput(
             @NonNull final Process process,
             @NonNull final ProcessOutput output ) throws InterruptedException
     {
         Thread threadErr = new Thread( "stderr" )
         {
             @Override
             public void run()
             {
                 InputStream stderr = process.getErrorStream();
                 OutputStream stream = output.getErrorOutput();
                 try
                 {
                     ByteStreams.copy( stderr, stream );
                     stream.flush();
                 }
                 catch ( IOException e )
                 {
                     // ignore?
                 }
                 finally
                 {
                     try
                     {
                         Closeables.close( stderr, true /* swallowIOException */ );
                     }
                     catch ( IOException e )
                     {
                         // cannot happen
                     }
                     try
                     {
                         Closeables.close( stream, true /* swallowIOException */ );
                     }
                     catch ( IOException e )
                     {
                         // cannot happen
                     }
                 }
             }
         };
         Thread threadOut = new Thread( "stdout" )
         {
             @Override
             public void run()
             {
                 InputStream stdout = process.getInputStream();
                 OutputStream stream = output.getStandardOutput();
                 try
                 {
                     ByteStreams.copy( stdout, stream );
                     stream.flush();
                 }
                 catch ( IOException e )
                 {
                     // ignore?
                 }
                 finally
                 {
                     try
                     {
                         Closeables.close( stdout, true /* swallowIOException */ );
                     }
                     catch ( IOException e )
                     {
                         // cannot happen
                     }
                     try
                     {
                         Closeables.close( stream, true /* swallowIOException */ );
                     }
                     catch ( IOException e )
                     {
                         // cannot happen
                     }
                 }
             }
         };
         threadErr.start();
         threadOut.start();
         // it looks like on windows process#waitFor() can return
         // before the thread have filled the arrays, so we wait for both threads and the
         // process itself.
         threadErr.join();
         threadOut.join();
         // get the return code from the process
         return process.waitFor();
     }
 }