/*******************************************************************************
 * Copyright (c) 2012, 2013 Association for Decentralized Information Management in
 * Industry THTH ry.
 * 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:
 *     VTT Technical Research Centre of Finland - initial API and implementation
 *******************************************************************************/
package org.simantics.g3d.toolbar;

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

import org.eclipse.core.commands.Command;
import org.eclipse.core.commands.State;
import org.eclipse.ui.IWorkbenchPart;
import org.eclipse.ui.PlatformUI;
import org.eclipse.ui.commands.ICommandService;
import org.eclipse.ui.handlers.IHandlerService;
import org.eclipse.ui.handlers.RadioState;
import org.eclipse.ui.handlers.RegistryToggleState;

/**
 * Registry for storing command states separately for each IEditorPart
 * 
 * TODO : how to change toggle/radios state from editor?
 *   TODO : how to update visible buttons (ToolbarContributor)
 * 
 * @author Marko Luukkainen <marko.luukkainen@vtt.fi>
 *
 */
public class CommandStateRegistry {

	
	private static CommandStateRegistry instance;
	
	
	public static CommandStateRegistry getInstance() {
		if (instance == null)
			instance = new CommandStateRegistry();
		return instance;
	}
	
	
	
	private Map<IWorkbenchPart,Map<String,Boolean>> toggleStates = new HashMap<IWorkbenchPart, Map<String,Boolean>>();
	private Map<String,Boolean> defaultToggleStates = new HashMap<String, Boolean>();
	
	private Map<String,String> defaultRadioStates = new HashMap<String, String>();
	private Map<IWorkbenchPart,Map<String,String>> radioStates = new HashMap<IWorkbenchPart, Map<String,String>>();

	private ICommandService service;
	private IHandlerService handlerService;
	
	private CommandStateRegistry() {
		service = (ICommandService) PlatformUI.getWorkbench().getService(ICommandService.class);
		handlerService = (IHandlerService) PlatformUI.getWorkbench().getService(IHandlerService.class);
	}
	
	/**
	 * Stores default state for a command.
	 * 
	 * Note: uses current state as default. 
	 * 
	 * @param commandId
	 */
	public void storeDefaultState(String commandId) {
		Command command = service.getCommand(commandId);
		State toggleState = command.getState(RegistryToggleState.STATE_ID);
		State radioState = command.getState(RadioState.STATE_ID);
		if (toggleState != null) {
			if (!defaultToggleStates.containsKey(commandId))
				defaultToggleStates.put(commandId, getToggleState(command));
		} else if (radioState != null) {
			String value = (String) radioState.getValue();
			if (!defaultRadioStates.containsKey(commandId))
				defaultRadioStates.put(commandId, value);
		} else {
			throw new IllegalArgumentException("Command " + commandId + " does not have a state");
		}
	}
	/**
	 * Stores toggle state of a command.
	 * @param part
	 * @param commandId
	 * @param checked
	 */
	public void setEditorState(IWorkbenchPart part, String commandId, boolean checked) {
		Map<String,Boolean> editorStates = toggleStates.get(part);
		if (editorStates == null) {
			editorStates = new HashMap<String, Boolean>();
			toggleStates.put(part, editorStates);
		}
		editorStates.put(commandId, checked);
	}
	
	/**
	 * Stores radio state of a command.
	 * @param part
	 * @param commandId
	 * @param value
	 */
	public void setEditorState(IWorkbenchPart part, String commandId, String value) {
		Map<String,String> editorStates = radioStates.get(part);
		if (editorStates == null) {
			editorStates = new HashMap<String, String>();
			radioStates.put(part, editorStates);
		}
		editorStates.put(commandId, value);
	}
	
	public Map<String, Boolean> getDefaultToggleStates() {
		return defaultToggleStates;
	}
	
	public Map<String, String> getDefaultRadioStates() {
		return defaultRadioStates;
	}
	
	public Map<String, Boolean> getEditorToggleStates(IWorkbenchPart part) {
		return toggleStates.get(part);
	}
	
	public Map<String, String> getEditorRadioStates(IWorkbenchPart part) {
		return radioStates.get(part);
	}
	
	public Boolean getToggleState(IWorkbenchPart part, String commandId) {
		if (part == null)
			return defaultToggleStates.get(commandId);
		Map<String,Boolean> editorStates = toggleStates.get(part);
		if (editorStates == null) {
			return defaultToggleStates.get(commandId);
		}
		return editorStates.get(commandId);
	}
	
	public String getRadioState(IWorkbenchPart part, String commandId) {
		if (part == null)
			return defaultRadioStates.get(commandId);
		Map<String,String> editorStates = radioStates.get(part);
		if (editorStates == null) {
			return defaultRadioStates.get(commandId);
		}
		return editorStates.get(commandId);
	}
	
	public void clearStates(IWorkbenchPart part) {
		toggleStates.remove(part);
		radioStates.remove(part);
	}
	
	private boolean getToggleState(Command command) {
		State toggleState = command.getState(RegistryToggleState.STATE_ID);
		return (Boolean)toggleState.getValue();
	}
	
	
}