/*
This code is derived from jgit (http://eclipse.org/jgit).
Copyright owners are documented in jgit's IP log.

This program and the accompanying materials are made available
under the terms of the Eclipse Distribution License v1.0 which
accompanies this distribution, is reproduced below, and is
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All rights reserved.

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without modification, are permitted provided that the following
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- Redistributions of source code must retain the above copyright
  notice, this list of conditions and the following disclaimer.

- Redistributions in binary form must reproduce the above
  copyright notice, this list of conditions and the following
  disclaimer in the documentation and/or other materials provided
  with the distribution.

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  names of its contributors may be used to endorse or promote
  products derived from this software without specific prior
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THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
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ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
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*/

using System;
using NGit.Internal;
using NGit.Revwalk;
using NGit.Revwalk.Filter;
using NGit.Util;
using Sharpen;

namespace NGit.Revwalk.Filter
{
	/// <summary>Matches only commits whose author name matches the pattern.</summary>
	/// <remarks>Matches only commits whose author name matches the pattern.</remarks>
	public class AuthorRevFilter
	{
		/// <summary>Create a new author filter.</summary>
		/// <remarks>
		/// Create a new author 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.
		/// </remarks>
		/// <param name="pattern">regular expression pattern to match.</param>
		/// <returns>
		/// a new filter that matches the given expression against the author
		/// name and address of a commit.
		/// </returns>
		public static RevFilter Create(string pattern)
		{
			if (pattern.Length == 0)
			{
				throw new ArgumentException(JGitText.Get().cannotMatchOnEmptyString);
			}
			if (SubStringRevFilter.Safe(pattern))
			{
				return new AuthorRevFilter.SubStringSearch(pattern);
			}
			return new AuthorRevFilter.PatternSearch(pattern);
		}

		public AuthorRevFilter()
		{
		}

		// Don't permit us to be created.
		internal static RawCharSequence TextFor(RevCommit cmit)
		{
			byte[] raw = cmit.RawBuffer;
			int b = RawParseUtils.Author(raw, 0);
			if (b < 0)
			{
				return RawCharSequence.EMPTY;
			}
			int e = RawParseUtils.NextLF(raw, b, '>');
			return new RawCharSequence(raw, b, e);
		}

		private class PatternSearch : PatternMatchRevFilter
		{
			internal PatternSearch(string patternText) : base(patternText, true, true, Sharpen.Pattern
				.CASE_INSENSITIVE)
			{
			}

			protected internal override CharSequence Text(RevCommit cmit)
			{
				return TextFor(cmit);
			}

			public override RevFilter Clone()
			{
				return new AuthorRevFilter.PatternSearch(Pattern());
			}
		}

		private class SubStringSearch : SubStringRevFilter
		{
			protected internal SubStringSearch(string patternText) : base(patternText)
			{
			}

			protected internal override RawCharSequence Text(RevCommit cmit)
			{
				return TextFor(cmit);
			}
		}
	}
}
