Copyright (c) 2000, 2013 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, 2013 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.dom.rewrite;

import java.util.Arrays;
import java.util.List;

import org.eclipse.jdt.core.dom.LineComment;
import org.eclipse.jdt.core.formatter.IndentManipulation;
import org.eclipse.jdt.internal.compiler.util.Util;

@SuppressWarnings("rawtypes")
public class LineCommentEndOffsets {

	private int[] offsets;
	private final List commentList;

	public LineCommentEndOffsets(List commentList) {
		this.commentList= commentList;
		this.offsets= null; // create on demand
	}

	private int[] getOffsets() {
		if (this.offsets == null) {
			if (this.commentList != null) {
				int nComments= this.commentList.size();
				// count the number of line comments
				int count= 0;
				for (int i= 0; i < nComments; i++) {
					Object curr= this.commentList.get(i);
					if (curr instanceof LineComment) {
						count++;
					}
				}
				// fill the offset table
				this.offsets= new int[count];
				for (int i= 0, k= 0; i < nComments; i++) {
					Object curr= this.commentList.get(i);
					if (curr instanceof LineComment) {
						LineComment comment= (LineComment) curr;
						this.offsets[k++]= comment.getStartPosition() + comment.getLength();
					}
				}
			} else {
				this.offsets= Util.EMPTY_INT_ARRAY;
			}
		}
		return this.offsets;
	}

	public boolean isEndOfLineComment(int offset) {
		return offset >= 0 && Arrays.binarySearch(getOffsets(), offset) >= 0;
	}

	public boolean isEndOfLineComment(int offset, char[] content) {
		if (offset < 0 || (offset < content.length && !IndentManipulation.isLineDelimiterChar(content[offset]))) {
			return false;
		}
		return Arrays.binarySearch(getOffsets(), offset) >= 0;
	}

	public boolean remove(int offset) {
		int[] offsetArray= getOffsets(); // returns the shared array
		int index= Arrays.binarySearch(offsetArray, offset);
		if (index >= 0) {
			if (index > 0) {
				// shift from the beginning and insert -1 (smallest number) at the beginning
				// 1, 2, 3, x, 4, 5 -> -1, 1, 2, 3, 4, 5
				System.arraycopy(offsetArray, 0, offsetArray, 1, index);
			}
			offsetArray[0]= -1;
			return true;
		}
		return false;
	}

}