/*******************************************************************************
 * Copyright (c) 2000, 2016 IBM Corporation and others.
 * 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:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.dltk.internal.testing.ui;

import java.lang.reflect.InvocationTargetException;
import java.util.HashSet;
import java.util.Set;

import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IProgressMonitor;
import org.eclipse.dltk.core.DLTKLanguageManager;
import org.eclipse.dltk.core.IModelElement;
import org.eclipse.dltk.core.IType;
import org.eclipse.dltk.core.search.IDLTKSearchConstants;
import org.eclipse.dltk.core.search.IDLTKSearchScope;
import org.eclipse.dltk.core.search.SearchEngine;
import org.eclipse.dltk.core.search.SearchMatch;
import org.eclipse.dltk.core.search.SearchParticipant;
import org.eclipse.dltk.core.search.SearchPattern;
import org.eclipse.dltk.core.search.SearchRequestor;
import org.eclipse.dltk.internal.testing.Messages;
import org.eclipse.dltk.testing.DLTKTestingMessages;
import org.eclipse.dltk.ui.ModelElementLabelProvider;
import org.eclipse.jface.dialogs.MessageDialog;
import org.eclipse.jface.operation.IRunnableWithProgress;
import org.eclipse.swt.widgets.Shell;
import org.eclipse.ui.PlatformUI;
import org.eclipse.ui.dialogs.ElementListSelectionDialog;

/**
 * A dialog to select a test method.
 */
public class TestMethodSelectionDialog extends ElementListSelectionDialog {

	private IModelElement fElement;

	public static class TestReferenceCollector extends SearchRequestor {
		Set fResult = new HashSet(200);

		@Override
		public void acceptSearchMatch(SearchMatch match) throws CoreException {
			IModelElement enclosingElement = (IModelElement) match.getElement();
			if (enclosingElement.getElementName().startsWith("test")) //$NON-NLS-1$
				fResult.add(enclosingElement);
		}

		public Object[] getResult() {
			return fResult.toArray();
		}
	}

	public TestMethodSelectionDialog(Shell shell, IModelElement element) {
		super(shell, new ModelElementLabelProvider(
				ModelElementLabelProvider.SHOW_PARAMETERS
						| ModelElementLabelProvider.SHOW_POST_QUALIFIED));
		fElement = element;
	}

	@Override
	protected void configureShell(Shell newShell) {
		super.configureShell(newShell);
		PlatformUI.getWorkbench().getHelpSystem().setHelp(newShell,
				IDLTKTestingHelpContextIds.TEST_SELECTION_DIALOG);
	}

	@Override
	public int open() {
		Object[] elements;
		IType testType = null;

		if (testType == null)
			return CANCEL;

		try {
			elements = searchTestMethods(fElement, testType);
		} catch (InterruptedException e) {
			return CANCEL;
		} catch (InvocationTargetException e) {
			MessageDialog.openError(getParentShell(),
					DLTKTestingMessages.TestMethodSelectionDialog_error_title,
					e.getTargetException().getMessage());
			return CANCEL;
		}

		if (elements.length == 0) {
			String msg = Messages
					.format(
							DLTKTestingMessages.TestMethodSelectionDialog_notfound_message,
							fElement.getElementName());
			MessageDialog
					.openInformation(
							getParentShell(),
							DLTKTestingMessages.TestMethodSelectionDialog_no_tests_title,
							msg);
			return CANCEL;
		}
		setElements(elements);
		return super.open();
	}

	public Object[] searchTestMethods(final IModelElement element,
			final IType testType) throws InvocationTargetException,
			InterruptedException {
		final TestReferenceCollector[] col = new TestReferenceCollector[1];

		IRunnableWithProgress runnable = new IRunnableWithProgress() {
			@Override
			public void run(IProgressMonitor pm)
					throws InvocationTargetException {
				try {
					col[0] = doSearchTestMethods(element, testType, pm);
				} catch (CoreException e) {
					throw new InvocationTargetException(e);
				}
			}
		};
		PlatformUI.getWorkbench().getProgressService()
				.busyCursorWhile(runnable);
		return col[0].getResult();
	}

	private TestReferenceCollector doSearchTestMethods(IModelElement element,
			IType testType, IProgressMonitor pm) throws CoreException {
		int matchRule = SearchPattern.R_EXACT_MATCH
				| SearchPattern.R_CASE_SENSITIVE
				| SearchPattern.R_ERASURE_MATCH;
		SearchPattern pattern = SearchPattern.createPattern(element,
				IDLTKSearchConstants.REFERENCES, matchRule, DLTKLanguageManager
						.getLanguageToolkit(testType));
		SearchParticipant[] participants = new SearchParticipant[] { SearchEngine
				.getDefaultSearchParticipant() };
		IDLTKSearchScope scope = SearchEngine.createHierarchyScope(testType);
		TestReferenceCollector requestor = new TestReferenceCollector();
		new SearchEngine().search(pattern, participants, scope, requestor, pm);
		return requestor;
	}
}