/*
    * Copyright (C) 2011, Tomasz Zarna <Tomasz.Zarna@pl.ibm.com> and others
    *
    * This program and the accompanying materials are made available under the
    * terms of the Eclipse Distribution License v. 1.0 which is available at
    * https://www.eclipse.org/org/documents/edl-v10.php.
    *
    * SPDX-License-Identifier: BSD-3-Clause
    */
  package org.eclipse.jgit.revwalk.filter;
  
  import java.io.IOException;
  
  import org.eclipse.jgit.errors.IncorrectObjectTypeException;
  import org.eclipse.jgit.errors.MissingObjectException;
  import org.eclipse.jgit.errors.StopWalkException;
  import org.eclipse.jgit.internal.JGitText;
  import org.eclipse.jgit.revwalk.RevCommit;
  import org.eclipse.jgit.revwalk.RevWalk;
  
  /**
   * Filter that includes commits after a configured number are skipped.
   */
  public class SkipRevFilter extends RevFilter {
  
  	private final int skip;
  
  	private int count;
  
  	/**
  	 * Create a new skip filter.
  	 *
  	 * @param skip
  	 *            the number of commits to skip
  	 * @return a new filter
  	 */
  	public static RevFilter create(int skip) {
  		if (skip < 0)
  			throw new IllegalArgumentException(
  					JGitText.get().skipMustBeNonNegative);
  		return new SkipRevFilter(skip);
  	}
  
  	private SkipRevFilter(int skip) {
  		this.skip = skip;
  	}
  
  	/** {@inheritDoc} */
  	@Override
  	public boolean include(RevWalk walker, RevCommit cmit)
  			throws StopWalkException, MissingObjectException,
  			IncorrectObjectTypeException, IOException {
  		if (skip > count++)
  			return false;
  		return true;
  	}
  
  	/** {@inheritDoc} */
  	@Override
  	public RevFilter clone() {
  		return new SkipRevFilter(skip);
  	}
  }