import java.io.File;
import java.io.IOException;
import java.util.Vector;

import org.apache.commons.io.FileUtils;
import org.apache.tools.ant.BuildException;
import org.apache.tools.ant.taskdefs.Java;
import org.apache.tools.ant.types.CommandlineJava;

/**
 * An ant task that writes a bourne script for launching interactive JRuby
 * shells.  Extends the <java> task to take advantage of classpath handling
 * and java argument assembly, and overrides execute() to write the JVM
 * launch command-line to a file instead of executing it.
 * <p>
 * The ProjectShell is intended for exploratory programming, ad-hoc testing of
 * the project's API, and assembling test data.
 * <p>
 * @author dacc
 */
public class ProjectShellAntTask extends Java
{
  private String outputScriptPath;
  private String initScriptPath;

  /**
   * @see Java#init()
   */
  @Override
  public void init() throws BuildException
  {
    this.setClassname("org.jruby.Main");
    this.setFork(true);
    super.init();
  }

  /**
   * @see Java#execute()
   */
  @Override
  public void execute() throws BuildException
  {
    CommandlineJava commandLine = getCommandLine();

    String arguments
      = String.format("%s --readline -r irb/completion", initScriptPath);

    commandLine.createArgument().setLine(arguments);

    File scriptFile = new File(outputScriptPath);

    Vector<String> lines = new Vector<String>(2);
    lines.add("#!/usr/bin/env sh");
    lines.add(commandLine.toString());

    try {
      FileUtils.writeLines(scriptFile, lines);
    }
    catch ( IOException e ) {
      throw new BuildException(e);
    }
    
    log("Wrote project shell bourne script to " + outputScriptPath);
  }
  
  public String getInitScriptPath()
  {
    return initScriptPath;
  }

  /**
   * Set the path to a Ruby initialization script that should be run when the
   * shell starts up.
   * 
   * @param initScriptPath
   *   Filesystem path relative to the project root including file name.
   */
  public void setInitScriptPath(String initScriptPath)
  {
    this.initScriptPath = initScriptPath;
  }

  public String getOutputScriptPath()
  {
    return outputScriptPath;
  }

  /**
   * Set the path of the bourne script to be written.
   * 
   * @param outputScriptPath
   *   Filesystem path relative to the project root including file name.
   */
  public void setOutputScriptPath(String outputScriptPath)
  {
    this.outputScriptPath = outputScriptPath;
  }
}