sigil/org.cauldron.sigil.core/src/org/cauldron/sigil/internal/install/OSGiInstallManager.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 * 
 *   http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

package org.cauldron.sigil.internal.install;

import java.util.Collections;
import java.util.Comparator;
import java.util.HashMap;
import java.util.LinkedList;
import java.util.Map;

import org.cauldron.sigil.SigilCore;
import org.cauldron.sigil.install.IOSGiInstall;
import org.cauldron.sigil.install.IOSGiInstallBuilder;
import org.cauldron.sigil.install.IOSGiInstallManager;
import org.cauldron.sigil.install.IOSGiInstallType;
import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IConfigurationElement;
import org.eclipse.core.runtime.IExtension;
import org.eclipse.core.runtime.IExtensionPoint;
import org.eclipse.core.runtime.IExtensionRegistry;
import org.eclipse.core.runtime.IPath;
import org.eclipse.core.runtime.Path;
import org.eclipse.core.runtime.Platform;
import org.eclipse.jface.dialogs.IDialogConstants;
import org.eclipse.jface.dialogs.MessageDialogWithToggle;
import org.eclipse.jface.preference.IPreferenceStore;
import org.eclipse.jface.preference.PreferenceDialog;
import org.eclipse.jface.util.IPropertyChangeListener;
import org.eclipse.jface.util.PropertyChangeEvent;
import org.eclipse.swt.widgets.Display;
import org.eclipse.ui.PlatformUI;
import org.eclipse.ui.dialogs.PreferencesUtil;

public class OSGiInstallManager implements IOSGiInstallManager, IPropertyChangeListener {
	private static final int NORMAL_PRIORITY = 0;
	
	private LinkedList<IOSGiInstallBuilder> builders = new LinkedList<IOSGiInstallBuilder>();

	private HashMap<IPath, IOSGiInstall> pathToinstall = new HashMap<IPath, IOSGiInstall>();
	private HashMap<String, IOSGiInstall> idToInstall = new HashMap<String, IOSGiInstall>();
	
	private String defaultId;
	
	private boolean initialised;
		
	public IOSGiInstall findInstall(String id) {
		init();
		return idToInstall.get(id);
	}

	public String[] getInstallIDs() {
		init();
		return idToInstall.keySet().toArray( new String[idToInstall.size()] );
	}

	public IOSGiInstall[] getInstalls() {
		init();
		return idToInstall.values().toArray( new IOSGiInstall[idToInstall.size()] );
	}

	public IOSGiInstall getDefaultInstall() {
		init();
		return findInstall(defaultId);
	}

	public IOSGiInstallType findInstallType(String location) {
		IOSGiInstallType type = null;
		
		try {
			IOSGiInstall install = buildInstall("tmp", new Path( location ) );
			type = install == null ? null : install.getType();
		} catch (CoreException e) {
			SigilCore.error( "Failed to build install", e);
		}
		
		return type;
	}
	
	public void propertyChange(PropertyChangeEvent event) {
		synchronized( this ) {
			if ( event.getProperty().equals(SigilCore.OSGI_INSTALLS) ) {
				clearInstalls();
				String val = (String) event.getNewValue();
				addInstalls(val);
			}
			else if ( event.getProperty().equals( SigilCore.OSGI_DEFAULT_INSTALL_ID ) ) {
				defaultId = (String) event.getNewValue();
			}
		}
	}

	private void init() {
		boolean show = false;
		
		IPreferenceStore prefs = getPreferenceStore(); 
		
		synchronized( this ) {
			if ( !initialised ) {
				initialised = true;
				
				prefs.addPropertyChangeListener(this);
				
				String val = prefs.getString(SigilCore.OSGI_INSTALLS);
				
				boolean noAsk = prefs.getBoolean(SigilCore.PREFERENCES_NOASK_OSGI_INSTALL);
				if(val == null || val.trim().length() == 0) {
					show = !noAsk;
				}
				else {
					addInstalls(val);
					defaultId = prefs.getString(SigilCore.OSGI_DEFAULT_INSTALL_ID);
				}
			}
		}
		
		if ( show ) {
			showInstallPrefs(prefs);
		}		
	}
	
	private void addInstalls(String prop) {
		if ( prop != null && prop.trim().length() > 0 ) {
			IPreferenceStore prefs = getPreferenceStore();
			
			for (String id : prop.split(",")) {
				String path = prefs.getString( SigilCore.OSGI_INSTALL_PREFIX + id );
				addInstall(id, new Path( path ) );
			}
		}				
	}

	private IPreferenceStore getPreferenceStore() {
		return SigilCore.getDefault().getPreferenceStore();
	}

	private void showInstallPrefs(final IPreferenceStore prefs) {
		Runnable r = new Runnable() {
			public void run() {
				MessageDialogWithToggle questionDialog = MessageDialogWithToggle.openYesNoQuestion(PlatformUI.getWorkbench().getActiveWorkbenchWindow().getShell(), "Sigil Configuration", "Missing OSGi installation. Open preferences to configure it now?", "Do not show this message again", false, null, null);
				prefs.setValue(SigilCore.PREFERENCES_NOASK_OSGI_INSTALL, questionDialog.getToggleState());
				if(questionDialog.getReturnCode() == IDialogConstants.YES_ID) {
					PreferenceDialog dialog = PreferencesUtil.createPreferenceDialogOn(null, SigilCore.OSGI_INSTALLS_PREFERENCES_ID, null, null);
					dialog.open();
				}
			}
		};
		Display d = Display.getCurrent();
		if ( d == null ) {
			d = Display.getDefault();
			d.asyncExec(r);
		}
		else {
			d.syncExec(r);
		}
	}

	private IOSGiInstall addInstall(String id, IPath path) {
		IOSGiInstall install = pathToinstall.get(path);
		
		if ( install == null ) {
			try {
				install = buildInstall(id, path);
				if ( install != null ) {
					pathToinstall.put( path, install );
					idToInstall.put( install.getId(), install );
				}
			}
			catch (CoreException e) {
				SigilCore.error( "Failed to build install for " + path, e);
			}
		}
		
		return install;
	}
	
	private IOSGiInstall buildInstall(String id, IPath path) throws CoreException {
		initBuilders();
		IOSGiInstall install = null;
		
		for ( IOSGiInstallBuilder b : builders ) {
			install = b.build(id, path);

			if ( install != null ) {
				break;
			}
		}
		
		return install;
	}

	private void clearInstalls() {
		idToInstall.clear();
		pathToinstall.clear();
	}

	private void initBuilders() {
		synchronized( builders ) {
			if ( builders.isEmpty() ) {
				final HashMap<IOSGiInstallBuilder, Integer> tmp = new HashMap<IOSGiInstallBuilder, Integer>();
				
				IExtensionRegistry registry = Platform.getExtensionRegistry();
				IExtensionPoint p = registry.getExtensionPoint(SigilCore.INSTALL_BUILDER_EXTENSION_POINT_ID);
				for ( IExtension e : p.getExtensions() ) {
					for ( IConfigurationElement c : e.getConfigurationElements() ) {
						createBuilderFromElement(c, tmp);
					}
				}
				
				builders = new LinkedList<IOSGiInstallBuilder>(tmp.keySet());
				Collections.sort(builders, new Comparator<IOSGiInstallBuilder>() {
					public int compare(IOSGiInstallBuilder o1, IOSGiInstallBuilder o2) {
						int p1 = tmp.get(o1);
						int p2 = tmp.get(o2);
						
						if ( p1 == p2 ) {
							return 0;
						}
						else if ( p1 > p2 ) {
							return -1;
						}
						else {
							return 1;
						}
					}
				});
			}
		}
	}

	private void createBuilderFromElement(IConfigurationElement c, Map<IOSGiInstallBuilder, Integer> builder) {
		try {
			IOSGiInstallBuilder b = (IOSGiInstallBuilder) c.createExecutableExtension("class");
			int priority = parsePriority( c );
			builder.put(b, priority);
		} catch (CoreException e) {
			SigilCore.error("Failed to create builder", e);
		}
	}
	
	private int parsePriority(IConfigurationElement c) {
		String str = c.getAttribute("priority");
		
		if ( str == null ) {
			return NORMAL_PRIORITY;
		}
		else {
			return Integer.parseInt(str);
		}
	}
}