/*
    * Copyright (C) 2008, Shawn O. Pearce <spearce@spearce.org> 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.util.regex.Pattern;
  
  import org.eclipse.jgit.internal.JGitText;
  import org.eclipse.jgit.revwalk.RevCommit;
  import org.eclipse.jgit.util.RawCharSequence;
  import org.eclipse.jgit.util.RawParseUtils;
  
  /**
   * Matches only commits whose committer name matches the pattern.
   */
  public class CommitterRevFilter {
  	/**
  	 * Create a new committer filter.
  	 * <p>
  	 * An optimized substring search may be automatically selected if the
  	 * pattern does not contain any regular expression meta-characters.
  	 * <p>
  	 * The search is performed using a case-insensitive comparison. The
  	 * character encoding of the commit message itself is not respected. The
  	 * filter matches on raw UTF-8 byte sequences.
  	 *
  	 * @param pattern
  	 *            regular expression pattern to match.
  	 * @return a new filter that matches the given expression against the author
  	 *         name and address of a commit.
  	 */
  	public static RevFilter create(String pattern) {
  		if (pattern.length() == 0)
  			throw new IllegalArgumentException(JGitText.get().cannotMatchOnEmptyString);
  		if (SubStringRevFilter.safe(pattern))
  			return new SubStringSearch(pattern);
  		return new PatternSearch(pattern);
  	}
  
  	private CommitterRevFilter() {
  		// Don't permit us to be created.
  	}
  
  	static RawCharSequence textFor(RevCommit cmit) {
  		final byte[] raw = cmit.getRawBuffer();
  		final int b = RawParseUtils.committer(raw, 0);
  		if (b < 0)
  			return RawCharSequence.EMPTY;
  		final int e = RawParseUtils.nextLF(raw, b, '>');
  		return new RawCharSequence(raw, b, e);
  	}
  
  	private static class PatternSearch extends PatternMatchRevFilter {
  		PatternSearch(String patternText) {
  			super(patternText, true, true, Pattern.CASE_INSENSITIVE);
  		}
  
  		@Override
  		protected CharSequence text(RevCommit cmit) {
  			return textFor(cmit);
  		}
  
  		@Override
  		public RevFilter clone() {
  			return new PatternSearch(pattern());
  		}
  	}
  
  	private static class SubStringSearch extends SubStringRevFilter {
  		SubStringSearch(String patternText) {
  			super(patternText);
  		}
  
  		@Override
  		protected RawCharSequence text(RevCommit cmit) {
  			return textFor(cmit);
  		}
  	}
  }