/*=============================================================================#
 # Copyright (c) 2012, 2017 Stephan Wahlbrink and others.
 # 
 # This program and the accompanying materials are made available under the
 # terms of the Eclipse Public License 2.0 which is available at
 # https://www.eclipse.org/legal/epl-2.0, or the Apache License, Version 2.0
 # which is available at https://www.apache.org/licenses/LICENSE-2.0.
 # 
 # SPDX-License-Identifier: EPL-2.0 OR Apache-2.0
 # 
 # Contributors:
 #     Stephan Wahlbrink <sw@wahlbrink.eu> - initial API and implementation
 #=============================================================================*/

package org.eclipse.statet.r.ui.rhelp;

import org.eclipse.core.commands.AbstractHandler;
import org.eclipse.core.commands.ExecutionEvent;
import org.eclipse.core.commands.ExecutionException;
import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.core.runtime.Status;
import org.eclipse.ui.statushandlers.StatusManager;

import org.eclipse.statet.ecommons.ui.util.UIAccess;
import org.eclipse.statet.ecommons.ui.util.UIAccess.CheckedRunnable;

import org.eclipse.statet.internal.r.ui.rhelp.RHelpUIServlet;
import org.eclipse.statet.internal.r.ui.rhelp.RHelpView;
import org.eclipse.statet.nico.ui.NicoUITools;
import org.eclipse.statet.r.console.core.RProcess;
import org.eclipse.statet.r.core.RCore;
import org.eclipse.statet.r.core.renv.IREnv;
import org.eclipse.statet.r.core.rhelp.IRHelpManager;
import org.eclipse.statet.r.ui.RUI;


public class OpenRHelpHandler extends AbstractHandler {
	
	
	private final IREnv rEnv;
	private final RProcess tool;
	
	private final boolean reuse;
	
	
	public OpenRHelpHandler(final IREnv rEnv, final RProcess tool, final boolean reuse) {
		if (rEnv == null) {
			throw new NullPointerException("rEnv"); //$NON-NLS-1$
		}
		this.rEnv= rEnv;
		this.tool= tool;
		this.reuse= reuse;
	}
	
	
	@Override
	public Object execute(final ExecutionEvent event) throws ExecutionException {
		return execute(event.getParameter("url")); //$NON-NLS-1$
	}
	
	public IStatus execute(String url) {
		final RProcess tool= this.tool;
		final IRHelpManager rHelpManager= RCore.getRHelpManager();
		if (url == null || url.isEmpty() || url.equals("about:blank")) { //$NON-NLS-1$
			url= rHelpManager.getREnvHttpUrl(this.rEnv, RHelpUIServlet.BROWSE_TARGET);
		}
		else {
			url= rHelpManager.toHttpUrl(url, this.rEnv, RHelpUIServlet.BROWSE_TARGET);
		}
		if (url == null) {
			return null;
		}
		try {
			final String urlToOpen= url;
			UIAccess.checkedSyncExec(new CheckedRunnable() {
				@Override
				public void run() throws CoreException {
					final RHelpView view= (RHelpView) NicoUITools.getView(RUI.R_HELP_VIEW_ID, tool, true);
					view.openUrl(urlToOpen, (OpenRHelpHandler.this.reuse) ? view.findBrowserSession(urlToOpen) : null);
				}
			});
			return Status.OK_STATUS;
		}
		catch (final CoreException e) {
			final IStatus status= new Status(IStatus.ERROR, RUI.BUNDLE_ID, -1,
					"An error occured when opening R help page in R help view.", e );
			StatusManager.getManager().handle(status);
			return status;
		}
	}
	
}