/*******************************************************************************
 * Copyright (c) 2000, 2008 IBM Corporation and others.
 *
 * 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:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.jdt.internal.corext.util;

import org.eclipse.jdt.core.ICompilationUnit;
import org.eclipse.jdt.core.IJavaElement;
import org.eclipse.jdt.core.JavaCore;
import org.eclipse.jdt.core.search.SearchEngine;
import org.eclipse.jdt.core.search.SearchMatch;
import org.eclipse.jdt.core.search.SearchParticipant;
import org.eclipse.jdt.core.search.SearchPattern;

public class SearchUtils {

	/**
	 * @param match the search match
	 * @return the enclosing {@link IJavaElement}, or null iff none
	 */
	public static IJavaElement getEnclosingJavaElement(SearchMatch match) {
		Object element = match.getElement();
		if (element instanceof IJavaElement)
			return (IJavaElement) element;
		else
			return null;
	}

	/**
	 * @param match the search match
	 * @return the enclosing {@link ICompilationUnit} of the given match, or null iff none
	 */
	public static ICompilationUnit getCompilationUnit(SearchMatch match) {
		IJavaElement enclosingElement = getEnclosingJavaElement(match);
		if (enclosingElement != null){
			if (enclosingElement instanceof ICompilationUnit)
				return (ICompilationUnit) enclosingElement;
			ICompilationUnit cu= (ICompilationUnit) enclosingElement.getAncestor(IJavaElement.COMPILATION_UNIT);
			if (cu != null)
				return cu;
		}

		IJavaElement jElement= JavaCore.create(match.getResource());
		if (jElement != null && jElement.exists() && jElement.getElementType() == IJavaElement.COMPILATION_UNIT)
			return (ICompilationUnit) jElement;
		return null;
	}

	public static SearchParticipant[] getDefaultSearchParticipants() {
		return new SearchParticipant[] { SearchEngine.getDefaultSearchParticipant() };
	}

    /**
     * Constant for use as matchRule in {@link SearchPattern#createPattern(IJavaElement, int, int)}
     * to get search behavior as of 3.1M3 (all generic instantiations are found).
     */
    public final static int GENERICS_AGNOSTIC_MATCH_RULE= SearchPattern.R_EXACT_MATCH | SearchPattern.R_CASE_SENSITIVE | SearchPattern.R_ERASURE_MATCH;

    /**
     * Returns whether the given pattern is a camel case pattern or not.
     * <em>Note: this method does not consider the
     * {@link SearchPattern#R_CAMELCASE_SAME_PART_COUNT_MATCH} variant.<em>
     *
     * @param pattern the pattern to inspect
     * @return whether it is a camel case pattern or not
     */
	public static boolean isCamelCasePattern(String pattern) {
		return SearchPattern.validateMatchRule(pattern, SearchPattern.R_CAMELCASE_MATCH) == SearchPattern.R_CAMELCASE_MATCH;
	}
}