Copyright (c) 2006, 2018 IBM Corporation and others.
This program and the accompanying materials
are made available under the terms of the Eclipse Public License 2.0
which accompanies this distribution, and is available at
https://www.eclipse.org/legal/epl-2.0/
SPDX-License-Identifier: EPL-2.0
Contributors:
    IBM Corporation - initial API and implementation
/*******************************************************************************
 * Copyright (c) 2006, 2018 IBM Corporation and others.
 *
 * This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License 2.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.debug.internal.core;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Set;

import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IConfigurationElement;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.core.runtime.Status;
import org.eclipse.debug.core.DebugPlugin;
import org.eclipse.debug.core.ILaunchDelegate;
import org.eclipse.debug.core.model.ILaunchConfigurationDelegate;

import com.ibm.icu.text.MessageFormat;

Proxy to a launch delegate extension.

Clients can contribute launch delegates through the
launchDelegates extension point


Example contribution of the local java launch delegate

<extension point="org.eclipse.debug.core.launchDelegates">
   <launchDelegate
         delegate="org.eclipse.jdt.launching.JavaLaunchDelegate"
         id="org.eclipse.jdt.launching.localJavaApplicationDelegate"
         modes="run, debug"
         name="%localJavaApplication"
         type="org.eclipse.jdt.launching.localJavaApplication">
       <modeCombination
         modes="run, profile">
         perspective="com.example.Perspective">
       </modeCombination>
   </launchDelegate>

Clients are NOT intended to subclass this class
See Also:
IConfigurationElementConstants
Since:
3.3/**
 * Proxy to a launch delegate extension.
 * <p>
 * Clients can contribute launch delegates through the
 * <code>launchDelegates</code> extension point
 * </p>
 * <p>
 * Example contribution of the local java launch delegate
 * </p>
 *
 * <pre>
 * &lt;extension point="org.eclipse.debug.core.launchDelegates"&gt;
 *    &lt;launchDelegate
 *          delegate="org.eclipse.jdt.launching.JavaLaunchDelegate"
 *          id="org.eclipse.jdt.launching.localJavaApplicationDelegate"
 *          modes="run, debug"
 *          name="%localJavaApplication"
 *          type="org.eclipse.jdt.launching.localJavaApplication"&gt;
 *        &lt;modeCombination
 *          modes="run, profile"&gt;
 *          perspective="com.example.Perspective"&gt;
 *        &lt;/modeCombination&gt;
 *    &lt;/launchDelegate&gt;
 * </pre>
 *
 * Clients are NOT intended to subclass this class
 *
 * @see IConfigurationElementConstants
 *
 * @since 3.3
 */
public final class LaunchDelegate implements ILaunchDelegate {

	
The configuration element for this delegate
/**
	 * The configuration element for this delegate
	 */
	private IConfigurationElement fElement = null;

	
The cached delegate. Remains null until asked for, then persisted
/**
	 * The cached delegate. Remains null until asked for, then persisted
	 */
	private ILaunchConfigurationDelegate fDelegate = null;

	//a listing of sets of
	private List<Set<String>> fLaunchModes = null;
	private String fType = null;
	private HashMap<Set<String>, String> fPerspectiveIds = null;

	
Constructor
Params:
element – the configuration element to associate with this launch delegate/**
	 * Constructor
	 * @param element the configuration element to associate with this launch delegate
	 */
	public LaunchDelegate(IConfigurationElement element) {
		fElement = element;
	}

	@Override
	public ILaunchConfigurationDelegate getDelegate() throws CoreException {
		if(fDelegate == null) {
			Object obj = fElement.createExecutableExtension(IConfigurationElementConstants.DELEGATE);
			if(obj instanceof ILaunchConfigurationDelegate) {
				fDelegate = (ILaunchConfigurationDelegate)obj;
			} else {
				throw new CoreException(new Status(IStatus.ERROR, DebugPlugin.getUniqueIdentifier(), DebugPlugin.ERROR, MessageFormat.format(DebugCoreMessages.LaunchDelegate_3, new Object[] { getId() }), null));
			}
		}
		return fDelegate;
	}

	@Override
	public String getId() {
		return fElement.getAttribute(IConfigurationElementConstants.ID);
	}

	
Returns the id of the associated ILaunchConfigurationType or null if none provided
Returns:
the id of the ILaunchConfigurationType associated with this delegate/**
	 * Returns the id of the associated <code>ILaunchConfigurationType</code> or <code>null</code> if none provided
	 * @return the id of the <code>ILaunchConfigurationType</code> associated with this delegate
	 */
	public String getLaunchConfigurationTypeId() {
		if(fType == null) {
			//fall back to single association if no appliesTo
			fType = fElement.getAttribute(IConfigurationElementConstants.TYPE);
			if(fType == null) {
				//the case when we have passed a launch configuration type to the launch delegate
				fType = fElement.getAttribute(IConfigurationElementConstants.ID);
			}
		}
		return fType;
	}

	
Simple method to parse mode strings (separated by commas)
Params:
element – the config element to read the mode string from
Returns:
a set of the parsed strings or an empty collection
Since:
3.3/**
	 * Simple method to parse mode strings (separated by commas)
	 * @param element the config element to read the mode string from
	 * @return a set of the parsed strings or an empty collection
	 * @since 3.3
	 */
	private Set<String> parseModes(IConfigurationElement element) {
		HashSet<String> set = new HashSet<>();
		String modes = element.getAttribute(IConfigurationElementConstants.MODES);
		if (modes != null) {
			String[] strings = modes.split(","); //$NON-NLS-1$
			for (String string : strings) {
				set.add(string.trim());
			}
		}
		return set;
	}

	@Override
	public List<Set<String>> getModes() {
		if(fLaunchModes == null) {
			fLaunchModes = new ArrayList<>();
			fPerspectiveIds = new HashMap<>();
			IConfigurationElement[] children = fElement.getChildren(IConfigurationElementConstants.MODE_COMBINATION);
			Set<String> modeset = null;
			for (IConfigurationElement child : children) {
				modeset = parseModes(child);
				fLaunchModes.add(modeset);
				fPerspectiveIds.put(modeset, child.getAttribute(IConfigurationElementConstants.PERSPECTIVE));
			}
			//try to get the modes from the old definition and make each one
			//a separate set of one element
			modeset = null;
			String modes = fElement.getAttribute(IConfigurationElementConstants.MODES);
			if (modes != null) {
				String[] strings = modes.split(","); //$NON-NLS-1$
				for (String string : strings) {
					modeset = new HashSet<>();
					modeset.add(string.trim());
					fLaunchModes.add(modeset);
				}
			}
		}
		return fLaunchModes;
	}

	
Returns the human readable name for this launch delegate
Returns:
the human readable name for this launch delegate, or null if none/**
	 * Returns the human readable name for this launch delegate
	 * @return the human readable name for this launch delegate, or <code>null</code> if none
	 */
	@Override
	public String getName() {
		//try a delegateName attribute first, in the event this delegate was made from an ILaunchConfigurationType
		String name = fElement.getAttribute(IConfigurationElementConstants.DELEGATE_NAME);
		if(name == null) {
			name = fElement.getAttribute(IConfigurationElementConstants.NAME);
			if (name == null) {
				name = getContributorName();
			}
			name = name.trim();
			if (Character.isUpperCase(name.charAt(0))) {
				name = MessageFormat.format(DebugCoreMessages.LaunchDelegate_1, new Object[] { name });
			} else {
				name = MessageFormat.format(DebugCoreMessages.LaunchDelegate_2, new Object[] { name });
			}
		}
		return name;
	}

	
Returns the contributor name of this delegate (plug-in name).
Returns:
contributor name/**
	 * Returns the contributor name of this delegate (plug-in name).
	 *
	 * @return contributor name
	 */
	@Override
	public String getContributorName() {
		return fElement.getContributor().getName();
	}

	
Returns the associated source locator id or null
Returns:
the associated source locator id or null if not provided/**
	 * Returns the associated source locator id or <code>null</code>
	 * @return the associated source locator id or <code>null</code> if not provided
	 */
	public String getSourceLocatorId() {
		return fElement.getAttribute(IConfigurationElementConstants.SOURCE_LOCATOR);
	}

	
Returns the associated source path computer id or null
Returns:
the associated source path computer id or null if not provided/**
	 * Returns the associated source path computer id or <code>null</code>
	 * @return the associated source path computer id or <code>null</code> if not provided
	 */
	public String getSourcePathComputerId() {
		return fElement.getAttribute(IConfigurationElementConstants.SOURCE_PATH_COMPUTER);
	}

	@Override
	public String getDescription() {
		String desc = fElement.getAttribute(IConfigurationElementConstants.DELEGATE_DESCRIPTION);
		if(desc == null) {
			return DebugCoreMessages.LaunchDelegate_0;
		}
		return desc;
	}

	@Override
	public String getPluginIdentifier() {
		return fElement.getContributor().getName();
	}

	@Override
	public boolean equals(Object obj) {
		if(obj == null) {
			return false;
		}
		return obj instanceof ILaunchDelegate && getId() != null && getId().equals(((ILaunchDelegate)obj).getId());
	}

	@Override
	public int hashCode() {
		String id = getId();
		return id == null ? 0 : id.hashCode();
	}

	@Override
	public String getPerspectiveId(Set<String> modes) {
		if(fPerspectiveIds == null) {
			getModes();
		}
		return fPerspectiveIds.get(modes);
	}
}