/*******************************************************************************
 * Copyright (c) 2000, 2009 IBM Corporation and others.
 * 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:
 *     IBM Corporation - initial API and implementation
 *     Keith Seitz (keiths@redhat.com) - Bug 27243 (environment variables contribution)
 *     dakshinamurthy.karra@gmail.com - bug 165371
 *******************************************************************************/
package org.eclipse.core.externaltools.internal.launchConfigurations;


import java.io.File;

import org.eclipse.core.externaltools.internal.ExternalToolsCore;
import org.eclipse.core.externaltools.internal.IExternalToolConstants;
import org.eclipse.core.resources.IProject;
import org.eclipse.core.resources.IResource;
import org.eclipse.core.resources.IWorkspaceRoot;
import org.eclipse.core.resources.ResourcesPlugin;
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.IStringVariableManager;
import org.eclipse.core.variables.VariablesPlugin;
import org.eclipse.debug.core.DebugPlugin;
import org.eclipse.debug.core.ILaunchConfiguration;
import org.eclipse.debug.core.RefreshUtil;
import org.eclipse.osgi.util.NLS;

/**
 * Utilities for external tool launch configurations.
 * <p>
 * This class it not intended to be instantiated.
 * </p>
 */
public class ExternalToolsCoreUtil {

	/**
	 * Throws a core exception with an error status object built from
	 * the given message, lower level exception, and error code.
	 * @param message the status message
	 * @param exception lower level exception associated with the
	 *  error, or <code>null</code> if none
	 * @param code error code
	 */
	protected static void abort(String message, Throwable exception, int code) throws CoreException {
		throw new CoreException(new Status(IStatus.ERROR, IExternalToolConstants.PLUGIN_ID, code, message, exception));
	}
	
	/**
	 * Expands and returns the location attribute of the given launch
	 * configuration. The location is
	 * verified to point to an existing file, in the local file system.
	 * 
	 * @param configuration launch configuration
	 * @return an absolute path to a file in the local file system  
	 * @throws CoreException if unable to retrieve the associated launch
	 * configuration attribute, if unable to resolve any variables, or if the
	 * resolved location does not point to an existing file in the local file
	 * system
	 */
	public static IPath getLocation(ILaunchConfiguration configuration) throws CoreException {
		String location = configuration.getAttribute(IExternalToolConstants.ATTR_LOCATION, (String) null);
		if (location == null) {
			abort(NLS.bind(ExternalToolsProgramMessages.ExternalToolsUtil_Location_not_specified_by__0__1, new String[] { configuration.getName()}), null, 0);
		} else {
			String expandedLocation = getStringVariableManager().performStringSubstitution(location);
			if (expandedLocation == null || expandedLocation.length() == 0) {
				String msg = NLS.bind(ExternalToolsProgramMessages.ExternalToolsUtil_invalidLocation__0_, new Object[] { configuration.getName()});
				abort(msg, null, 0);
			} else {
				File file = new File(expandedLocation);
				if (file.isFile()) {
					return new Path(expandedLocation);
				} 
				
				String msg = NLS.bind(ExternalToolsProgramMessages.ExternalToolsUtil_invalidLocation__0_, new Object[] { configuration.getName()});
				abort(msg, null, 0);
			}
		}
		// execution will not reach here
		return null;
	}
	
	/**
	 * Returns a boolean specifying whether or not output should be captured for
	 * the given configuration
	 * 
	 * @param configuration the configuration from which the value will be
	 * extracted
	 * @return boolean specifying whether or not output should be captured
	 * @throws CoreException if unable to access the associated attribute
	 */
	public static boolean getCaptureOutput(ILaunchConfiguration configuration) throws CoreException {
	    return configuration.getAttribute(DebugPlugin.ATTR_CAPTURE_OUTPUT, true);
	}

	/**
	 * Expands and returns the working directory attribute of the given launch
	 * configuration. Returns <code>null</code> if a working directory is not
	 * specified. If specified, the working is verified to point to an existing
	 * directory in the local file system.
	 * 
	 * @param configuration launch configuration
	 * @return an absolute path to a directory in the local file system, or
	 * <code>null</code> if unspecified
	 * @throws CoreException if unable to retrieve the associated launch
	 * configuration attribute, if unable to resolve any variables, or if the
	 * resolved location does not point to an existing directory in the local
	 * file system
	 */
	public static IPath getWorkingDirectory(ILaunchConfiguration configuration) throws CoreException {
		String location = configuration.getAttribute(IExternalToolConstants.ATTR_WORKING_DIRECTORY, (String) null);
		if (location != null) {
			String expandedLocation = getStringVariableManager().performStringSubstitution(location);
			if (expandedLocation.length() > 0) {
				File path = new File(expandedLocation);
				if (path.isDirectory()) {
					return new Path(expandedLocation);
				} 
				String msg = NLS.bind(ExternalToolsProgramMessages.ExternalToolsUtil_invalidDirectory__0_, new Object[] { expandedLocation, configuration.getName()});
				abort(msg, null, 0);
			}
		}
		return null;
	}

	/**
	 * Expands and returns the arguments attribute of the given launch
	 * configuration. Returns <code>null</code> if arguments are not specified.
	 * 
	 * @param configuration launch configuration
	 * @return an array of resolved arguments, or <code>null</code> if
	 * unspecified
	 * @throws CoreException if unable to retrieve the associated launch
	 * configuration attribute, or if unable to resolve any variables
	 */
	public static String[] getArguments(ILaunchConfiguration configuration) throws CoreException {
		String args = configuration.getAttribute(IExternalToolConstants.ATTR_TOOL_ARGUMENTS, (String) null);
		if (args != null) {
			String expanded = getStringVariableManager().performStringSubstitution(args);
			return parseStringIntoList(expanded);
		}
		return null;
	}

	private static IStringVariableManager getStringVariableManager() {
		return VariablesPlugin.getDefault().getStringVariableManager();
	}
	
	/**
	 * Returns whether the given launch configuration is enabled. This property
	 * is intended only to apply to external tool builder configurations and
	 * determines whether the project builder will launch the configuration
	 * when it builds.
	 *  
	 * @param configuration the configuration for which the enabled state should
	 * 		be determined.
	 * @return whether the given configuration is enabled to be run when a build occurs.
	 * @throws CoreException if unable to access the associated attribute
	 */
	public static boolean isBuilderEnabled(ILaunchConfiguration configuration) throws CoreException {
		return configuration.getAttribute(IExternalToolConstants.ATTR_BUILDER_ENABLED, true);
	}
	
	/**
	 * Returns the collection of resources for the build scope as specified by the given launch configuration.
	 * 
	 * @param configuration launch configuration
	 * @throws CoreException if an exception occurs while retrieving the resources
	 */
	public static IResource[] getResourcesForBuildScope(ILaunchConfiguration configuration) throws CoreException {
		String scope = configuration.getAttribute(IExternalToolConstants.ATTR_BUILDER_SCOPE, (String) null);
		if (scope == null) {
			return null;
		}
	
		return RefreshUtil.toResources(scope);
	}
	
	/**
	 * Parses the argument text into an array of individual
	 * strings using the space character as the delimiter.
	 * An individual argument containing spaces must have a
	 * double quote (") at the start and end. Two double 
	 * quotes together is taken to mean an embedded double
	 * quote in the argument text.
	 * 
	 * @param arguments the arguments as one string
	 * @return the array of arguments
	 */
	public static String[] parseStringIntoList(String arguments) {
		if (arguments == null || arguments.length() == 0) {
			return new String[0];
		}
		String[] res= DebugPlugin.parseArguments(arguments);
		return res;		
	}	
	/**
	 * Returns a collection of projects referenced by a build scope attribute.
	 * 
	 * @return collection of projects referred to by configuration
	 */
	public static IProject[] getBuildProjects(ILaunchConfiguration configuration, String buildScopeId) {
		
		String scope = null;
		String id = buildScopeId ;
		if (id == null) {
			id = IExternalToolConstants.ATTR_BUILD_SCOPE ;
		}
		try {
			scope = configuration.getAttribute(id, (String)null);
		} catch (CoreException e) {
			return null;
		}
		if (scope == null) {
			return null;
		}
		if (scope.startsWith("${projects:")) { //$NON-NLS-1$
			String pathString = scope.substring(11, scope.length() - 1);
			if (pathString.length() > 1) {
				String[] names = pathString.split(","); //$NON-NLS-1$
				IProject[] projects = new IProject[names.length];
				IWorkspaceRoot root = ResourcesPlugin.getWorkspace().getRoot();
				for (int i = 0; i < names.length; i++) {
					projects[i] = root.getProject(names[i]);
				}
				return projects;
			}
		} else if (scope.equals("${project}")) { //$NON-NLS-1$
			IStringVariableManager manager = VariablesPlugin.getDefault().getStringVariableManager();
			try {
				String pathString = manager.performStringSubstitution("${selected_resource_path}"); //$NON-NLS-1$
				IResource res = ResourcesPlugin.getWorkspace().getRoot().findMember(new Path(pathString));
				if (res != null && res.getProject() != null) {
					return new IProject[]{res.getProject()};
				}
			} catch (CoreException e) {
				// unable to resolve a selection
			}
		}
		return new IProject[0];
	}
	
	/**
	 * Whether referenced projects should be considered when building. Only valid
	 * when a set of projects is to be built.
	 * 
	 * @param configuration
	 * @return whether referenced projects should be considerd when building
	 * @throws CoreException if unable to access the associated attribute
	 */
	public static boolean isIncludeReferencedProjects(ILaunchConfiguration configuration, String includeReferencedProjectsId) throws CoreException {
		String id = includeReferencedProjectsId;
		if (id == null) {
			id = IExternalToolConstants.ATTR_INCLUDE_REFERENCED_PROJECTS ;
		}
		return configuration.getAttribute(id, true);
	}
	
	/**
	 * Returns whether the given external builder configuration should build asynchronously.
	 * 
	 * @param configuration the configuration
	 * @return whether the configuration is configured to build asynchronously
	 */
	public static boolean isAsynchronousBuild(ILaunchConfiguration configuration) {
		boolean launchInBackground= false;
		try {
			launchInBackground= configuration.getAttribute(IExternalToolConstants.ATTR_LAUNCH_IN_BACKGROUND, false);
		} catch (CoreException ce) {
			ExternalToolsCore.log(ce);
		}
		return launchInBackground;
	}
}