/**
 * Copyright (c) 2011, 2015 - Lunifera GmbH (Gross Enzersdorf, Austria), Loetz GmbH&Co.KG (69115 Heidelberg, Germany)
 * 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:
 *         Florian Pirchner - Initial implementation
 */
package org.eclipse.osbp.vaaclipse.ui.preferences.addon;

import java.util.HashMap;
import java.util.Map;

import javax.annotation.PostConstruct;
import javax.inject.Inject;

import org.eclipse.core.internal.preferences.PreferencesService;
import org.eclipse.core.runtime.preferences.IEclipsePreferences;
import org.eclipse.core.runtime.preferences.IPreferencesService;
import org.eclipse.e4.core.contexts.IEclipseContext;
import org.eclipse.e4.core.services.contributions.IContributionFactory;
import org.eclipse.e4.ui.model.application.MApplication;
import org.eclipse.e4.ui.model.application.MContribution;
import org.eclipse.osbp.vaaclipse.ui.preferences.addon.internal.util.PrefHelper;
import org.eclipse.osbp.vaaclipse.ui.preferences.model.BooleanFieldEditor;
import org.eclipse.osbp.vaaclipse.ui.preferences.model.FieldEditor;
import org.eclipse.osbp.vaaclipse.ui.preferences.model.IntegerFieldEditor;
import org.eclipse.osbp.vaaclipse.ui.preferences.model.PreferencesCategory;
import org.eclipse.osbp.vaaclipse.ui.preferences.model.PreferencesPage;
import org.eclipse.osbp.vaaclipse.ui.preferences.model.ScaleFieldEditor;
import org.eclipse.osbp.vaaclipse.ui.preferences.model.metadata.PreferencesFactory;
import org.eclipse.osbp.vaaclipse.ui.preferences.model.util.PreferencesSwitch;
import org.osgi.framework.Bundle;
import org.osgi.framework.BundleContext;
import org.osgi.framework.FrameworkUtil;
import org.osgi.framework.ServiceReference;
import org.osgi.service.prefs.Preferences;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import e4modelextension.VaaclipseApplication;

/**
 * @author rushan
 *
 */
public class PreferencesAddon {

	@Inject
	MApplication app;

	@Inject
	IEclipseContext context;

	Map<String, Bundle> bundlesByName = new HashMap<>();
	Logger logger = LoggerFactory.getLogger(PreferencesAddon.class);

	@SuppressWarnings("restriction")
	IPreferencesService equinoxPrefService = PreferencesService.getDefault();
	IEclipsePreferences root = equinoxPrefService.getRootNode();

	private PreferencesAuthorization authService;

	private VaaclipseApplication vaaApp;

	@PostConstruct
	void init() {
		vaaApp = (VaaclipseApplication) app;
		context.set(VaaclipseApplication.class, vaaApp);

		BundleContext bundleContext = FrameworkUtil.getBundle(
				PreferencesAddon.class).getBundleContext();

		obtainPreferencesAuthService(bundleContext);

		for (Bundle b : bundleContext.getBundles()) {
			bundlesByName.put(b.getSymbolicName(), b);
		}

		for (PreferencesCategory c : vaaApp.getPreferencesCategories()) {
			setupPreferences(c, "");
		}

		for (PreferencesPage page : vaaApp.getPreferencesPages()) {
			setTypedDefaultValues(page);
			initContributions(page);
		}

		logger.info("Preferences adon activated");
	}

	private void setupPreferences(PreferencesCategory category,
			String currentPath) {

		String catPath = currentPath + "/" + category.getId();

		if (category.getPage() != null) {
			for (FieldEditor<?> editor : category.getPage().getChildren()) {

				Bundle bundle = bundlesByName.get(editor.getBundle());
				if (bundle != null) {
					String absolutePreferencePath = PrefHelper
							.toEquinoxPreferencePath(bundle, catPath);

					Preferences pref = root.node(absolutePreferencePath);
					editor.setPreferences(pref);
					editor.setEquinoxPath(absolutePreferencePath);
				} else {
					logger.warn("Could not find bundle {} for editor {}",
							editor.getBundle(), editor);
				}
			}

		}

		for (PreferencesCategory childCat : category.getChildCategories()) {
			setupPreferences(childCat, catPath);
		}
	}

	private void obtainPreferencesAuthService(BundleContext bundleContext) {

		ServiceReference<PreferencesAuthorization> ref = bundleContext
				.getServiceReference(PreferencesAuthorization.class);
		if (ref != null) {
			authService = bundleContext.getService(ref);
			context.set(PreferencesAuthorization.class, authService);
		}

		ServiceReference<PreferencesFactory> prefFactoryRef = bundleContext
				.getServiceReference(PreferencesFactory.class);
		if (prefFactoryRef != null) {
			PreferencesFactory service = bundleContext
					.getService(prefFactoryRef);
			context.set(PreferencesFactory.class, service);
		}
	}

	private void setTypedDefaultValues(PreferencesPage page) {
		for (FieldEditor<?> ed : page.getChildren()) {
			FieldEditor<Object> editor = (FieldEditor<Object>) ed;

			PreferencesSwitch<?> sw = new PreferencesSwitch() {
				@Override
				public Object caseBooleanFieldEditor(BooleanFieldEditor object) {
					if (object.getDefaultValue() == null)
						return false;
					return Boolean.valueOf(object.getDefaultValue());
				}

				@Override
				public Object caseScaleFieldEditor(ScaleFieldEditor object) {
					if (object.getDefaultValue() == null)
						return 0;
					return Integer.valueOf(object.getDefaultValue());
				}

				@Override
				public Object caseIntegerFieldEditor(IntegerFieldEditor object) {
					if (object.getDefaultValue() == null)
						return 0;
					return Integer.valueOf(object.getDefaultValue());
				}
			};
			Object converted = sw.doSwitch(editor);
			if (converted == null) {
				converted = editor.getDefaultValue();
				if (converted == null)
					converted = "";
			}
			editor.setDefaultValueTyped(converted);
			editor.setDefaultValue(converted.toString());
		}
	}

	@SuppressWarnings("restriction")
	private void initContributions(PreferencesPage page) {
		for (FieldEditor<?> ed : page.getChildren()) {
			if (ed instanceof MContribution) {
				MContribution editorWithContribution = (MContribution) ed;
				String contributorURI = editorWithContribution
						.getContributionURI();
				if (contributorURI != null) {
					IEclipseContext childContext = context.createChild();
					PrefHelper.populateInterfaces(
							(FieldEditor<?>) editorWithContribution,
							childContext, editorWithContribution.getClass()
									.getInterfaces());
					IContributionFactory contributionFactory = (IContributionFactory) childContext
							.get(IContributionFactory.class.getName());
					Object editorContribution = contributionFactory.create(
							contributorURI, childContext);
					editorWithContribution.setObject(editorContribution);
				}
			}
		}
	}
}