package fr.ens.biologie.genomique.eoulsan.util.process;

import fr.ens.biologie.genomique.eoulsan.EoulsanLogger;

import java.io.File;
import java.io.IOException;
import java.util.Arrays;
import java.util.List;
import java.util.Map;

/**
 * This class define how to easily launch a subprocess using the Java Process
 * API.
 * @author Laurent Jourdren
 * @since 2.0
 */
public class SystemSimpleProcess extends AbstractSimpleProcess {

  @Override
  public AdvancedProcess start(final List<String> commandLine,
      final File executionDirectory,
      final Map<String, String> environmentVariables,
      final File temporaryDirectory, final File stdoutFile,
      final File stderrFile, final boolean redirectErrorStream,
      final File... filesUsed) throws IOException {

    EoulsanLogger.getLogger().fine(getClass().getName() + " : commandLine=" + commandLine +
            ", executionDirectory=" + executionDirectory + ", environmentVariables=" + environmentVariables +
            ", temporaryDirectory=" + temporaryDirectory + ", stdoutFile=" + stdoutFile + ", stderrFile=" + stderrFile +
            ", redirectErrorStream="+redirectErrorStream + ", filesUsed" + Arrays.toString(filesUsed));

    final ProcessBuilder pb = new ProcessBuilder(commandLine);
    // Set execution directory
    if (executionDirectory != null) {
      pb.directory(executionDirectory);
    }

    // Set environment variables
    if (environmentVariables != null) {
      pb.environment().putAll(environmentVariables);
    }

    // Set temporary directory
    if (temporaryDirectory != null) {
      pb.environment().put(TMP_DIR_ENV_VARIABLE,
          temporaryDirectory.getAbsolutePath());
    }

    // Redirect stdout
    if (stdoutFile != null) {
      pb.redirectOutput(stdoutFile);
    }

    // Redirect stderr
    if (redirectErrorStream) {
      pb.redirectErrorStream(true);
    } else if (stderrFile != null) {
      pb.redirectError(stderrFile);
    }

    final Process process = pb.start();

    return new AdvancedProcess() {

      @Override
      public int waitFor() throws IOException {

        try {
          return process.waitFor();
        } catch (InterruptedException e) {
          throw new IOException(e);
        }
      }

    };
  }

}