Copyright (c) 2000, 2010 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
/*******************************************************************************
 * Copyright (c) 2000, 2010 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.core.search.matching;

import org.eclipse.jdt.core.compiler.CharOperation;
import org.eclipse.jdt.core.search.SearchPattern;

public class PackageReferencePattern extends IntersectingPattern {

protected char[] pkgName;

protected char[][] segments;
protected int currentSegment;

protected static char[][] CATEGORIES = { REF };

public PackageReferencePattern(char[] pkgName, int matchRule) {
	this(matchRule);

	if (pkgName == null || pkgName.length == 0) {
		this.pkgName = null;
		this.segments = new char[][] {CharOperation.NO_CHAR};
		this.mustResolve = false;
	} else {
		this.pkgName = (this.isCaseSensitive || this.isCamelCase) ? pkgName : CharOperation.toLowerCase(pkgName);
		this.segments = CharOperation.splitOn('.', this.pkgName);
		this.mustResolve = true;
	}
}
PackageReferencePattern(int matchRule) {
	super(PKG_REF_PATTERN, matchRule);
}
@Override
public void decodeIndexKey(char[] key) {
	// Package reference keys are encoded as 'name' (where 'name' is the last segment of the package name)
	this.pkgName = key;
}
@Override
public SearchPattern getBlankPattern() {
	return new PackageReferencePattern(R_EXACT_MATCH | R_CASE_SENSITIVE);
}
@Override
public char[] getIndexKey() {
	// Package reference keys are encoded as 'name' (where 'name' is the last segment of the package name)
	if (this.currentSegment >= 0)
		return this.segments[this.currentSegment];
	return null;
}
@Override
public char[][] getIndexCategories() {
	return CATEGORIES;
}
@Override
protected boolean hasNextQuery() {
	// if package has at least 4 segments, don't look at the first 2 since they are mostly
	// redundant (e.g. in 'org.eclipse.jdt.core.*' 'org.eclipse' is used all the time)
	return --this.currentSegment >= (this.segments.length >= 4 ? 2 : 0);
}
@Override
public boolean matchesDecodedKey(SearchPattern decodedPattern) {
	return true; // index key is not encoded so query results all match
}
@Override
protected void resetQuery() {
	/* walk the segments from end to start as it will find less potential references using 'lang' than 'java' */
	this.currentSegment = this.segments.length - 1;
}
@Override
protected StringBuffer print(StringBuffer output) {
	output.append("PackageReferencePattern: <"); //$NON-NLS-1$
	if (this.pkgName != null)
		output.append(this.pkgName);
	else
		output.append("*"); //$NON-NLS-1$
	output.append(">"); //$NON-NLS-1$
	return super.print(output);
}
}