/*
 * Copyright (C) 2009, Christian Halstrick <christian.halstrick@sap.com>
 * Copyright (C) 2010, Google Inc.
 * and other copyright owners as documented in the project'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
 * available at http://www.eclipse.org/org/documents/edl-v10.php
 *
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or
 * without modification, are permitted provided that the following
 * conditions are met:
 *
 * - 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.
 *
 * - Neither the name of the Eclipse Foundation, Inc. nor the
 *   names of its contributors may be used to endorse or promote
 *   products derived from this software without specific prior
 *   written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
 * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

package org.eclipse.jgit.merge;

/**
 * One chunk from a merge result. Each chunk contains a range from a
 * single sequence. In case of conflicts multiple chunks are reported for one
 * conflict. The conflictState tells when conflicts start and end.
 */
public class MergeChunk {
	/**
	 * A state telling whether a MergeChunk belongs to a conflict or not. The
	 * first chunk of a conflict is reported with a special state to be able to
	 * distinguish the border between two consecutive conflicts
	 */
	public enum ConflictState {
		/**
		 * This chunk does not belong to a conflict
		 */
		NO_CONFLICT,

		/**
		 * This chunk does belong to a conflict and is the first one of the
		 * conflicting chunks
		 */
		FIRST_CONFLICTING_RANGE,

		/**
		 * This chunk does belong to a conflict but is not the first one of the
		 * conflicting chunks. It's a subsequent one.
		 */
		NEXT_CONFLICTING_RANGE
	}

	private final int sequenceIndex;

	private final int begin;

	private final int end;

	private final ConflictState conflictState;

	/**
	 * Creates a new empty MergeChunk
	 *
	 * @param sequenceIndex
	 *            determines to which sequence this chunks belongs to. Same as
	 *            in {@link org.eclipse.jgit.merge.MergeResult#add}
	 * @param begin
	 *            the first element from the specified sequence which should be
	 *            included in the merge result. Indexes start with 0.
	 * @param end
	 *            specifies the end of the range to be added. The element this
	 *            index points to is the first element which not added to the
	 *            merge result. All elements between begin (including begin) and
	 *            this element are added.
	 * @param conflictState
	 *            the state of this chunk. See
	 *            {@link org.eclipse.jgit.merge.MergeChunk.ConflictState}
	 */
	protected MergeChunk(int sequenceIndex, int begin, int end,
			ConflictState conflictState) {
		this.sequenceIndex = sequenceIndex;
		this.begin = begin;
		this.end = end;
		this.conflictState = conflictState;
	}

	/**
	 * Get the index of the sequence to which this sequence chunks belongs to.
	 *
	 * @return the index of the sequence to which this sequence chunks belongs
	 *         to. Same as in {@link org.eclipse.jgit.merge.MergeResult#add}
	 */
	public int getSequenceIndex() {
		return sequenceIndex;
	}

	/**
	 * Get the first element from the specified sequence which should be
	 * included in the merge result.
	 *
	 * @return the first element from the specified sequence which should be
	 *         included in the merge result. Indexes start with 0.
	 */
	public int getBegin() {
		return begin;
	}

	/**
	 * Get the end of the range of this chunk.
	 *
	 * @return the end of the range of this chunk. The element this index points
	 *         to is the first element which not added to the merge result. All
	 *         elements between begin (including begin) and this element are
	 *         added.
	 */
	public int getEnd() {
		return end;
	}

	/**
	 * Get the state of this chunk.
	 *
	 * @return the state of this chunk. See
	 *         {@link org.eclipse.jgit.merge.MergeChunk.ConflictState}
	 */
	public ConflictState getConflictState() {
		return conflictState;
	}
}