package com.aptana.ruby.debug.core.launching;

import java.lang.reflect.Field;
import java.util.Map;

import org.eclipse.core.runtime.IStatus;
import org.eclipse.core.runtime.Platform;
import org.eclipse.core.runtime.Status;
import org.eclipse.debug.core.DebugException;
import org.eclipse.debug.core.ILaunch;
import org.eclipse.debug.core.IProcessFactory;
import org.eclipse.debug.core.model.IProcess;
import org.eclipse.debug.core.model.RuntimeProcess;

import com.aptana.core.util.PlatformUtil;
import com.aptana.ruby.debug.core.RubyDebugCorePlugin;

/**
 * When terminating processes generated by this factory, on Mac/Unix we send a SIGINT to the process before doing our
 * normal termination.
 * 
 * @author cwilliams
 */
public class InterruptingProcessFactory implements IProcessFactory
{

	public static final String ID = "com.aptana.ruby.debug.core.interruptingProcessFactory"; //$NON-NLS-1$

	@SuppressWarnings("rawtypes")
	public IProcess newProcess(ILaunch launch, Process process, String label, Map attributes)
	{
		return new RuntimeProcess(launch, process, label, attributes)
		{

			@Override
			public void terminate() throws DebugException
			{
				if (!Platform.getOS().equals(Platform.OS_WIN32))
				{
					killProcess();
				}
				super.terminate();
			}

			private Integer grabPid()
			{
				// FIXME This only works on Unix/Mac Sun JDK and is a nasty hack to grab the underlying process' pid
				try
				{
					Process realProcess = getSystemProcess();

					Field f = realProcess.getClass().getDeclaredField("pid"); //$NON-NLS-1$
					f.setAccessible(true);
					return (Integer) f.get(realProcess);
				}
				catch (Exception e)
				{
					// ignore
				}
				return -1;
			}

			/**
			 * Attempts to send a SIGINT to the underlying process. This is equivalent to Ctrl+C.
			 * 
			 * @return
			 */
			private IStatus killProcess()
			{
				int pid = grabPid();
				if (pid <= 0)
				{
					return new Status(IStatus.ERROR, RubyDebugCorePlugin.getPluginIdentifier(),
							Messages.InterruptingProcessFactory_UnableToGrabPIDMsg);
				}
				PlatformUtil.killProcess(pid, 2); // SIGINT = 2
				return Status.OK_STATUS;
			}

		};
	}

}