/*******************************************************************************
 * Copyright (c) 2013 Christian Pontesegger and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v2.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-2.0/
 *
 * Contributors:
 *     Christian Pontesegger - initial API and implementation
 *******************************************************************************/
package org.eclipse.ease.ui.modules.ui;

import java.util.ArrayList;
import java.util.Collection;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import org.eclipse.core.runtime.IPath;
import org.eclipse.core.runtime.Path;
import org.eclipse.core.runtime.preferences.InstanceScope;
import org.eclipse.ease.modules.ModuleDefinition;
import org.eclipse.ease.service.IScriptService;
import org.eclipse.ease.ui.Activator;
import org.eclipse.ease.ui.preferences.IPreferenceConstants;
import org.eclipse.ease.ui.tools.AbstractPopupItem;
import org.eclipse.jface.action.IContributionItem;
import org.eclipse.ui.PlatformUI;
import org.eclipse.ui.actions.CompoundContributionItem;
import org.eclipse.ui.menus.IWorkbenchContribution;
import org.eclipse.ui.services.IServiceLocator;
import org.osgi.service.prefs.Preferences;

public final class ModuleContributionFactory extends CompoundContributionItem implements IWorkbenchContribution {

	private IServiceLocator fServiceLocator;

	@Override
	public void initialize(final IServiceLocator serviceLocator) {
		fServiceLocator = serviceLocator;
	}

	@Override
	protected IContributionItem[] getContributionItems() {

		final List<IContributionItem> contributions = new ArrayList<>();

		final IScriptService scriptService = PlatformUI.getWorkbench().getService(IScriptService.class);
		final Collection<ModuleDefinition> modules = scriptService.getAvailableModules();

		// read preferences for tree/list layout
		final Preferences prefs = InstanceScope.INSTANCE.getNode(Activator.PLUGIN_ID).node(IPreferenceConstants.NODE_SHELL);
		final boolean flatMode = prefs.getBoolean(IPreferenceConstants.SHELL_MODULES_AS_LIST, IPreferenceConstants.DEFAULT_SHELL_MODULES_AS_LIST);

		// create root menu (only used as a container while populating)
		final HashMap<IPath, ModulePopupMenu> moduleTree = new HashMap<>();
		ModulePopupMenu menu = new ModulePopupMenu("");
		moduleTree.put(new Path("/"), menu);

		for (final ModuleDefinition definition : modules) {
			if (definition.isVisible()) {
				if (!flatMode) {
					// find correct menu for tree layout
					final IPath path = definition.getPath();
					if (!moduleTree.containsKey(path.removeLastSegments(1)))
						createPath(moduleTree, path.removeLastSegments(1));

					menu = moduleTree.get(path.removeLastSegments(1));
				}

				menu.addEntry(new ModulePopupItem(definition));
			}
		}

		// sort all menus
		for (final ModulePopupMenu popupMenu : moduleTree.values())
			popupMenu.sortEntries();

		// populate root contributions
		final ModulePopupMenu root = moduleTree.get(new Path("/"));
		for (final AbstractPopupItem item : root.getEntries())
			contributions.add(item.getContribution(fServiceLocator));

		return contributions.toArray(new IContributionItem[contributions.size()]);
	}

	@Override
	public boolean isDirty() {
		return true;
	}

	private static ModulePopupMenu createPath(final Map<IPath, ModulePopupMenu> moduleTree, final IPath path) {
		if (!moduleTree.containsKey(path)) {
			final ModulePopupMenu parentMenu = createPath(moduleTree, path.removeLastSegments(1));
			final ModulePopupMenu menu = new ModulePopupMenu(path.lastSegment());

			parentMenu.addEntry(menu);
			moduleTree.put(path, menu);
			return menu;
		}

		return moduleTree.get(path);
	}
}