/*******************************************************************************
 * Copyright (c) 2014, 2018 Willink Transformations 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
 * http://www.eclipse.org/legal/epl-v20.html
 *
 * Contributors:
 *	E.D.Willink - initial API and implementation
 *******************************************************************************/
package org.eclipse.ocl.examples.validity.locator;

import java.io.IOException;
import java.util.HashMap;
import java.util.Map;

import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IProgressMonitor;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.core.runtime.Status;
import org.eclipse.debug.core.DebugPlugin;
import org.eclipse.debug.core.ILaunch;
import org.eclipse.debug.core.ILaunchConfigurationType;
import org.eclipse.debug.core.ILaunchConfigurationWorkingCopy;
import org.eclipse.debug.core.ILaunchManager;
import org.eclipse.emf.common.util.URI;
import org.eclipse.emf.ecore.EObject;
import org.eclipse.emf.ecore.resource.Resource;
import org.eclipse.emf.ecore.resource.ResourceSet;
import org.eclipse.jdt.annotation.NonNull;
import org.eclipse.jdt.annotation.Nullable;
import org.eclipse.jface.dialogs.ErrorDialog;
import org.eclipse.jface.dialogs.MessageDialog;
import org.eclipse.jface.operation.IRunnableWithProgress;
import org.eclipse.ocl.examples.debug.launching.OCLLaunchConstants;
import org.eclipse.ocl.examples.debug.vm.ui.utils.DebugUtil;
import org.eclipse.ocl.examples.emf.validation.validity.ResultConstrainingNode;
import org.eclipse.ocl.examples.emf.validation.validity.ValidatableNode;
import org.eclipse.ocl.examples.emf.validation.validity.locator.ConstraintLocator;
import org.eclipse.ocl.examples.emf.validation.validity.ui.locator.ConstraintUILocator;
import org.eclipse.ocl.examples.emf.validation.validity.ui.view.ValidityView;
import org.eclipse.ocl.examples.xtext.console.XtextConsolePlugin;
import org.eclipse.ocl.examples.xtext.console.messages.ConsoleMessages;
import org.eclipse.ocl.pivot.Constraint;
import org.eclipse.ocl.pivot.ExpressionInOCL;
import org.eclipse.ocl.pivot.LanguageExpression;
import org.eclipse.ocl.pivot.internal.manager.PivotMetamodelManager;
import org.eclipse.ocl.pivot.internal.prettyprint.PrettyPrinter;
import org.eclipse.ocl.pivot.internal.utilities.EnvironmentFactoryInternal;
import org.eclipse.ocl.pivot.internal.utilities.PivotUtilInternal;
import org.eclipse.ocl.pivot.utilities.ClassUtil;
import org.eclipse.ocl.pivot.utilities.ParserException;
import org.eclipse.ocl.pivot.utilities.PivotUtil;
import org.eclipse.ocl.xtext.base.utilities.BaseCSResource;
import org.eclipse.ocl.xtext.base.utilities.ElementUtil;
import org.eclipse.osgi.util.NLS;
import org.eclipse.swt.widgets.Shell;

public class DelegateUIConstraintLocator extends DelegateConstraintLocator implements ConstraintUILocator
{
	/**
	 * The DebugStarter sequences the start up of the debugger off the thread.
	 */
	protected static class DebugStarter implements IRunnableWithProgress
	{
		protected final @NonNull Shell shell;
		protected final @NonNull EnvironmentFactoryInternal environmentFactory;
		protected final @Nullable EObject contextObject;
		protected final @NonNull String expression;
		private @Nullable ILaunch launch = null;

		public DebugStarter(@NonNull Shell shell, @NonNull EnvironmentFactoryInternal environmentFactory, @Nullable EObject contextObject, @NonNull String expression) {
			this.shell = shell;
			this.environmentFactory = environmentFactory;
			this.contextObject = contextObject;
			this.expression = expression;
		}

		/**
		 * Create a test Complete OCL document that wraps the required OCL text up as the body of a test operation.
		 * Returns its URI.
		 */
		protected @NonNull URI createDocument(IProgressMonitor monitor) throws IOException, CoreException {
			return DebugUtil.createDebugDocument(environmentFactory, contextObject, expression, monitor);
		}

		public ILaunch getLaunch() {
			return launch;
		}

		/**
		 * Create and launch an internal launch configuration to debug expressionInOCL applied to contextObject.
		 */
		protected ILaunch launchDebugger(IProgressMonitor monitor, @Nullable EObject contextObject, @NonNull ExpressionInOCL expressionInOCL) throws CoreException {
			ILaunchManager launchManager = DebugPlugin.getDefault().getLaunchManager();
			ILaunchConfigurationType launchConfigurationType = launchManager.getLaunchConfigurationType(OCLLaunchConstants.LAUNCH_CONFIGURATION_TYPE_ID);
			ILaunchConfigurationWorkingCopy launchConfiguration = launchConfigurationType.newInstance(null, "test" /*constraint.getName()*/);
			Map<String,Object> attributes = new HashMap<String,Object>();
			attributes.put(OCLLaunchConstants.EXPRESSION_OBJECT, expressionInOCL);
			attributes.put(OCLLaunchConstants.CONTEXT_OBJECT, contextObject);
			launchConfiguration.setAttributes(attributes);
			return launchConfiguration.launch(ILaunchManager.DEBUG_MODE, monitor);
		}

		/**
		 * Load and parse the test document.
		 * @throws IOException
		 */
		protected @Nullable BaseCSResource loadDocument(IProgressMonitor monitor, @NonNull URI documentURI) throws Exception {
			ResourceSet resourceSet = environmentFactory.getResourceSet();
			Resource resource = resourceSet.getResource(documentURI, true);
			if (resource instanceof BaseCSResource) {
				return (BaseCSResource)resource;
			}
			return null;
		}

		protected void openError(final String message) {
			shell.getDisplay().asyncExec(new Runnable()
			{
				@Override
				public void run() {
					MessageDialog.openError(shell, ConsoleMessages.Debug_Starter, message);
				}
			});
		}

		protected void openError(final String message, final @NonNull Exception e) {
			shell.getDisplay().asyncExec(new Runnable()
			{
				@Override
				public void run() {
					IStatus status = new Status(IStatus.ERROR, XtextConsolePlugin.PLUGIN_ID, e.getLocalizedMessage(), e);
					ErrorDialog.openError(shell, ConsoleMessages.Debug_Starter, message, status);
				}
			});
		}

		@Override
		public void run(IProgressMonitor monitor) {
			monitor.beginTask(NLS.bind(ConsoleMessages.Debug_Starter, expression), 3);
			try {
				monitor.subTask(ConsoleMessages.Debug_ProgressCreate);
				URI documentURI;
				try {
					documentURI = createDocument(monitor);
				} catch (Exception e) {
					openError(ConsoleMessages.Debug_FailCreate, e);
					return;
				}
				monitor.worked(1);
				monitor.subTask(ConsoleMessages.Debug_ProgressLoad);
				BaseCSResource csResource;
				@SuppressWarnings("null")@NonNull String debug_FailLoad = ConsoleMessages.Debug_FailLoad;
				try {
					csResource = loadDocument(monitor, documentURI);
				} catch (Exception e) {
					openError(debug_FailLoad, e);
					return;
				}
				if (csResource == null) {
					openError(debug_FailLoad);
					return;
				}
				String message = PivotUtil.formatResourceDiagnostics(ClassUtil.nonNullEMF(csResource.getErrors()), debug_FailLoad, "\n\t");
				if (message != null) {
					openError(message);
					return;
				}
				ExpressionInOCL query;
				try {
					query = ElementUtil.getFirstQuery(environmentFactory.getMetamodelManager(), csResource);
				} catch (ParserException e) {
					openError(debug_FailLoad, e);
					return;
				}
				if (query == null) {
					openError(debug_FailLoad);
					return;
				}
				monitor.worked(1);
				monitor.subTask(ConsoleMessages.Debug_ProgressLoad);
				try {
					launch = launchDebugger(monitor, contextObject, query);
				} catch (CoreException e) {
					openError(ConsoleMessages.Debug_FailLaunch, e);
				}
				monitor.worked(1);
			}
			finally {
				monitor.done();
			}
		}
	}

	public static @NonNull DelegateUIConstraintLocator INSTANCE = new DelegateUIConstraintLocator();

	@Override
	public boolean debug(@NonNull ResultConstrainingNode resultConstrainingNode, final @NonNull ValidityView validityView, @NonNull IProgressMonitor monitor) throws CoreException {
		EObject constrainedObject = getConstrainedObject(resultConstrainingNode);
		Resource eResource = constrainedObject.eResource();
		if (eResource == null) {
			return false;
		}
		EnvironmentFactoryInternal environmentFactory = PivotUtilInternal.getEnvironmentFactory(eResource);
		PivotMetamodelManager metamodelManager = environmentFactory.getMetamodelManager();
		Constraint asConstraint = null;
		try {
			asConstraint = getConstraint(metamodelManager, resultConstrainingNode);
		} catch (ParserException e1) {
			// TODO Auto-generated catch block
			e1.printStackTrace();
		}
		if (asConstraint == null) {
			throw new IllegalStateException("no Pivot Constraint");
			//			return false;
		}
		LanguageExpression specification = asConstraint.getOwnedSpecification();
		String expression = specification != null ? PrettyPrinter.print(specification) : "";

		ValidatableNode parent = resultConstrainingNode.getResultValidatableNode().getParent();
		if (parent == null) {
			return false;
		}
		EObject eObject = parent.getConstrainedObject();

		Shell shell = validityView.getSite().getShell();
		if (shell == null) {
			return false;
		}
		DebugStarter runnable = new DebugStarter(shell, environmentFactory, eObject, expression);
		runnable.run(monitor);
		return runnable.getLaunch() != null;
	}

	@Override
	public @NonNull ConstraintLocator getInstance() {
		return INSTANCE;
	}
}