/*******************************************************************************
 * Copyright (c) 2014 OPCoach.
 *
 * 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:
 *     Olivier Prouvost <olivier.prouvost@opcoach.com> - initial API and implementation
 *     Olivier Prouvost <olivier.prouvost@opcoach.com> - Bug 428903 - Having a common 'debug' window for all spies
 *     Olivier Prouvost <olivier.prouvost@opcoach.com> - Bug 482250 - Add a menu 'E4 Spies' to access to the spies
 *     Olivier Prouvost <olivier.prouvost@opcoach.com> - Bug 528877 - NPE when using the windows Spies menu with version 0.18
 *     Marco Descher <marco@descher.at> - Bug 519136
 *******************************************************************************/
package org.eclipse.pde.spy.core;

import java.util.List;

import javax.inject.Inject;

import org.eclipse.core.runtime.IConfigurationElement;
import org.eclipse.core.runtime.IExtensionRegistry;
import org.eclipse.core.runtime.InvalidRegistryObjectException;
import org.eclipse.core.runtime.Platform;
import org.eclipse.e4.core.di.annotations.Execute;
import org.eclipse.e4.ui.di.AboutToShow;
import org.eclipse.e4.ui.model.application.MApplication;
import org.eclipse.e4.ui.model.application.commands.MBindingContext;
import org.eclipse.e4.ui.model.application.commands.MBindingTable;
import org.eclipse.e4.ui.model.application.commands.MCommand;
import org.eclipse.e4.ui.model.application.commands.MKeyBinding;
import org.eclipse.e4.ui.model.application.commands.MParameter;
import org.eclipse.e4.ui.model.application.descriptor.basic.MPartDescriptor;
import org.eclipse.e4.ui.model.application.ui.menu.MHandledMenuItem;
import org.eclipse.e4.ui.model.application.ui.menu.MMenuElement;
import org.eclipse.e4.ui.workbench.IWorkbench;
import org.eclipse.e4.ui.workbench.modeling.EModelService;
import org.osgi.framework.Bundle;
import org.osgi.framework.FrameworkUtil;

/** A base class for all spies processors */
public class SpyProcessor {
	static final String SPY_TAG = "Spy";

	public static final String SPY_COMMAND = "org.eclipse.pde.spy.core.command";
	public static final String SPY_COMMAND_PARAM = "org.eclipse.pde.spy.core.command.partID";

	private static final String E4_SPIES_BINDING_TABLE = "org.eclipse.pde.spy.core.bindings";

	MApplication application;
	EModelService modelService;

	@Inject
	public SpyProcessor(MApplication application, EModelService modelService) {
		this.application = application;
		this.modelService = modelService;
	}

	@Execute
	public void process(IExtensionRegistry extRegistry) {
		// This processor will read all spy extensions and automatically fill
		// the dynamics contents where spies are used

		MCommand command = getSpyCommand();
		MBindingTable bindingTable = getBindingTable();

		for (IConfigurationElement e : extRegistry.getConfigurationElementsFor("org.eclipse.pde.spy.core.spyPart")) {
			String partName = e.getAttribute("name");
			String shortCut = e.getAttribute("shortcut");
			String iconPath = e.getAttribute("icon");
			String desc = e.getAttribute("description");

			Bundle b = Platform.getBundle(e.getNamespaceIdentifier());
			String partID = e.getAttribute("part");
			try {
				Class<?> partClass = b.loadClass(partID);
				// Bind the command with the binding, and add the view ID as
				// parameter.
				// The part class name will be the ID of the part descriptor
				bindSpyKeyBinding(bindingTable, shortCut, command, partID);

				// Add the descriptor in application
				addSpyPartDescriptor(partID, partName, iconPath, partClass, desc);

			} catch (InvalidRegistryObjectException e1) {
				e1.printStackTrace();
			} catch (ClassNotFoundException e1) {
				Platform.getLog(this.getClass()).error("The class '" + partID + "' can not be instantiated. Check name or launch config");
				e1.printStackTrace();
			}

		}

	}

	public MCommand getSpyCommand() {

		// Warning : DO NOT USE findElement on ModelService (it searches only in
		// MUIElements)
		for (MCommand cmd : application.getCommands()) {
			if (SPY_COMMAND.equals(cmd.getElementId())) {
				// Do nothing if command exists
				return cmd;
			}
		}
		Platform.getLog(this.getClass()).error("The Spy command (with ID : " + SPY_COMMAND
				+ " cannot be found (It should be provided by org.eclipse.pde.spy.core/fragmenE4.xmi");

		return null;
	}


	/**
	 * Helper method to get or create the binding table for all spies (where
	 * spies will add their key binding). Bind this table with the
	 * org.eclipse.ui.contexts.dialogAndWindow binding context which should be
	 * present (create it if not)
	 *
	 * This method will probably move to the common spy plugin providing common
	 * spy stuff (see bug #428903)
	 *
	 * @param keySequence
	 * @param cmd
	 * @param paramViewId
	 */
	public void bindSpyKeyBinding(MBindingTable spyBindingTable, String keySequence, MCommand cmd, String paramViewId) {
		// This method must :
		// search for a binding table having the binding context 'dialog and
		// window'
		// If none found, create it and also the binding context
		// Then can add the KeyBinding if not already added


		// Search for the key binding if already present
		for (MKeyBinding kb : spyBindingTable.getBindings())
			if (keySequence.equals(kb.getKeySequence())) {
				// A binding with this key sequence is already present. Check if
				// command is the same
				if (kb.getCommand().getElementId().equals(cmd.getElementId()))
					return;
				else {
					// Must log an error : key binding already exists in this
					// table but with another command
					System.out.println("WARNING : Cannot bind the command '" + cmd.getElementId()
							+ "' to the keySequence : " + keySequence + " because the command "
							+ kb.getCommand().getElementId() + " is already bound !");
					return;
				}
			}

		// Key binding is not yet in table... can add it now.
		MKeyBinding binding = modelService.createModelElement(MKeyBinding.class);
		binding.setElementId(paramViewId + ".binding");
		binding.setContributorURI(cmd.getContributorURI());
		binding.setKeySequence(keySequence);
		binding.getPersistedState().put(IWorkbench.PERSIST_STATE, "false");

		MParameter p = modelService.createModelElement(MParameter.class);
		p.setName(SPY_COMMAND_PARAM);
		p.setValue(paramViewId);
		binding.getParameters().add(p);

		spyBindingTable.getBindings().add(binding);
		binding.setCommand(cmd);

	}

	/**
	 * Helper method to get or create the binding table for all spies (where
	 * spies will add their key binding). Bind this table with the
	 * org.eclipse.ui.contexts.dialogAndWindow binding context which should be
	 * present (create it if not)
	 *
	 *
	 * @param keySequence
	 * @param cmd
	 * @param paramViewId
	 */
	private MBindingTable getBindingTable() {
		// This method must :
		// search for a binding table having the binding context 'dialog and
		// window'
		// If none found, create it and also the binding context
		// Then can add the KeyBinding if not already added

		MBindingTable spyBindingTable = null;
		for (MBindingTable bt : application.getBindingTables())
			if (E4_SPIES_BINDING_TABLE.equals(bt.getElementId())) {
				spyBindingTable = bt;
			}

		// Binding table has not been yet added... Create it and bind it to
		// org.eclipse.ui.contexts.dialogAndWindow binding context
		// If this context does not yet exist, create it also.
		if (spyBindingTable == null) {

			MBindingContext bc = null;
			final List<MBindingContext> bindingContexts = application.getBindingContexts();
			if (bindingContexts.size() == 0) {
				bc = modelService.createModelElement(MBindingContext.class);
				bc.setElementId("org.eclipse.ui.contexts.window");
			} else {
				// Prefer org.eclipse.ui.contexts.dialogAndWindow but randomly
				// select another one
				// if org.eclipse.ui.contexts.dialogAndWindow cannot be found
				for (MBindingContext aBindingContext : bindingContexts) {
					bc = aBindingContext;
					if ("org.eclipse.ui.contexts.dialogAndWindow".equals(aBindingContext.getElementId())) {
						break;
					}
				}
			}

			// Can now create the binding table and bind it to this
			// context...
			spyBindingTable = modelService.createModelElement(MBindingTable.class);
			spyBindingTable.setElementId(E4_SPIES_BINDING_TABLE);
			spyBindingTable.setBindingContext(bc);
			spyBindingTable.getPersistedState().put(IWorkbench.PERSIST_STATE, "false");

			application.getBindingTables().add(spyBindingTable);

		}

		return spyBindingTable;

	}

	public void addSpyPartDescriptor(String partId, String partLabel, String iconPath, Class<?> spyPartClass,
			String desc) {
		for (MPartDescriptor mp : application.getDescriptors()) {
			if (partId.equals(mp.getElementId())) {
				// Already added, update category, description, label, ContributionURI, and IconURI
				mp.setDescription(desc);
				mp.setLabel(partLabel);
				mp.getPersistedState().remove(IWorkbench.PERSIST_STATE); // see Bug 577275
				String bundleId = FrameworkUtil.getBundle(spyPartClass).getSymbolicName();
				mp.setContributionURI("bundleclass://" + bundleId + "/" + spyPartClass.getCanonicalName());
				String contributorURI = "platform:/plugin/" + bundleId;
				mp.setContributorURI(contributorURI);
				mp.setIconURI(contributorURI + "/" + iconPath);
				return;
			}
		}

		// If descriptor not yet in descriptor list, add it now
		MPartDescriptor descriptor = modelService.createModelElement(MPartDescriptor.class);
		descriptor.setElementId(partId);
		descriptor.setDescription(desc);
		descriptor.getTags().add(SPY_TAG);
		descriptor.setLabel(partLabel);
		descriptor.setCloseable(true);
		String bundleId = FrameworkUtil.getBundle(spyPartClass).getSymbolicName();
		descriptor.setContributionURI("bundleclass://" + bundleId + "/" + spyPartClass.getCanonicalName());
		String contributorURI = "platform:/plugin/" + bundleId;
		descriptor.setContributorURI(contributorURI);
		descriptor.setIconURI(contributorURI + "/" + iconPath);
		application.getDescriptors().add(descriptor);
	}

	@AboutToShow
	public void fillE4SpyMenu(List<MMenuElement> items) {

		MCommand command = getSpyCommand();
		for (MPartDescriptor mp : application.getDescriptors()) {
			if (mp.getTags().contains(SPY_TAG)) {
				MHandledMenuItem hi = modelService.createModelElement(MHandledMenuItem.class);
				hi.setCommand(command);
				hi.setLabel(mp.getLabel());
				hi.setContributorURI(mp.getContributorURI());
				hi.setIconURI(mp.getIconURI());
				hi.setTooltip(mp.getDescription());
				hi.getPersistedState().put(IWorkbench.PERSIST_STATE, "false");

				MParameter p = modelService.createModelElement(MParameter.class);
				p.setName(SPY_COMMAND_PARAM);
				p.setValue(mp.getElementId());
				hi.getParameters().add(p);
				items.add(hi);
			}
		}

	}
}