/*******************************************************************************
 * Copyright (c) 2007 Chase Technology Ltd - http://www.chasetechnology.co.uk
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     Doug Satchwell (Chase Technology Ltd) - initial API and implementation
 *******************************************************************************/
package org.eclipse.wst.xsl.launching.config;

import java.io.ByteArrayInputStream;
import java.io.File;
import java.io.IOException;
import java.net.MalformedURLException;
import java.net.ServerSocket;
import java.net.URL;

import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IPath;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.core.runtime.Path;
import org.eclipse.core.runtime.Status;
import org.eclipse.core.variables.VariablesPlugin;
import org.eclipse.debug.core.ILaunchConfiguration;
import org.eclipse.wst.xsl.internal.launching.LaunchingPlugin;
import org.eclipse.wst.xsl.launching.XSLLaunchConfigurationConstants;
import org.eclipse.wst.xsl.launching.XSLTRuntime;

/**
 * @since 1.0
 */
public class BaseLaunchHelper
{
	private final URL source;
	private final File target;
	protected final LaunchPipeline pipeline;
	private int requestPort = -1;
	private int eventPort = -1;
	private int generatePort = -1;
	private final boolean openFileOnCompletion;
	private final boolean formatFileOnCompletion;

	public BaseLaunchHelper(ILaunchConfiguration configuration) throws CoreException
	{
		source = hydrateSourceFileURL(configuration);
		target = hydrateOutputFile(configuration);
		pipeline = hydratePipeline(configuration);
		openFileOnCompletion = configuration.getAttribute(XSLLaunchConfigurationConstants.ATTR_OPEN_FILE, true);
		formatFileOnCompletion = configuration.getAttribute(XSLLaunchConfigurationConstants.ATTR_FORMAT_FILE, false);
	}

	public int getRequestPort()
	{
		if (requestPort == -1)
			requestPort = findFreePort();
		return requestPort;
	}

	public int getEventPort()
	{
		if (eventPort == -1)
			eventPort = findFreePort();
		return eventPort;
	}

	public int getGeneratePort()
	{
		if (generatePort == -1)
			generatePort = findFreePort();
		return generatePort;
	}

	public LaunchPipeline getPipeline()
	{
		return pipeline;
	}

	public URL getSource()
	{
		return source;
	}

	public File getTarget()
	{
		return target;
	}

	private static LaunchPipeline hydratePipeline(ILaunchConfiguration configuration) throws CoreException
	{
		LaunchPipeline pipeline = null;
		String s = configuration.getAttribute(XSLLaunchConfigurationConstants.ATTR_PIPELINE, (String) null);
		if (s != null && s.length() > 0)
		{
			ByteArrayInputStream inputStream = new ByteArrayInputStream(s.getBytes());
			pipeline = LaunchPipeline.fromXML(inputStream);
		}
		return pipeline;
	}

	public static URL hydrateSourceFileURL(ILaunchConfiguration configuration) throws CoreException
	{
		IPath sourceFile = hydrateSourceFile(configuration);
		return pathToURL(sourceFile);
	}
	
	private static IPath hydrateSourceFile(ILaunchConfiguration configuration) throws CoreException
	{
		String sourceFileExpr = configuration.getAttribute(XSLLaunchConfigurationConstants.ATTR_INPUT_FILE, (String) null);
		return getSubstitutedPath(sourceFileExpr);
	}

	protected static URL pathToURL(IPath sourceFile) throws CoreException
	{
		URL url = null;
		try
		{
			url = sourceFile.toFile().toURL();
		}
		catch (MalformedURLException e)
		{
			throw new CoreException(new Status(IStatus.ERROR, LaunchingPlugin.PLUGIN_ID, IStatus.ERROR, sourceFile.toString(), e));
		}
		return url;
	}

	public static File hydrateOutputFile(ILaunchConfiguration configuration) throws CoreException
	{
		IPath outputFile = null;
		boolean useDefaultOutputFile = configuration.getAttribute(XSLLaunchConfigurationConstants.ATTR_USE_DEFAULT_OUTPUT_FILE, true);
		if (!useDefaultOutputFile)
		{
			String outputFileName = configuration.getAttribute(XSLLaunchConfigurationConstants.ATTR_OUTPUT_FILENAME, (String) null);
			String outputFolderExpr = configuration.getAttribute(XSLLaunchConfigurationConstants.ATTR_OUTPUT_FOLDER, (String) null);
			outputFile = getSubstitutedPath(outputFolderExpr).append(outputFileName);
		}
		else
		{
			outputFile = XSLTRuntime.defaultOutputFileForInputFile(configuration.getAttribute(XSLLaunchConfigurationConstants.ATTR_INPUT_FILE, (String) null));
		}
		return outputFile.toFile();
	}

	private static IPath getSubstitutedPath(String path) throws CoreException
	{
		if (path != null)
		{
			path = VariablesPlugin.getDefault().getStringVariableManager().performStringSubstitution(path);
			return new Path(path);
		}
		return null;
	}

	/**
	 * Returns a free port number on localhost, or -1 if unable to find a free
	 * port.
	 * 
	 * @return a free port number on localhost, or -1 if unable to find a free
	 *         port
	 */
	public static int findFreePort()
	{
		ServerSocket socket = null;
		try
		{
			socket = new ServerSocket(0);
			return socket.getLocalPort();
		}
		catch (IOException e)
		{
			LaunchingPlugin.log(e);
		}
		finally
		{
			if (socket != null)
			{
				try
				{
					socket.close();
				}
				catch (IOException e)
				{
					LaunchingPlugin.log(e);
				}
			}
		}
		return -1;
	}

	public boolean getOpenFileOnCompletion()
	{
		return openFileOnCompletion;
	}
	

	public boolean getFormatFileOnCompletion()
	{
		return formatFileOnCompletion;
	}

}