/*
    * Copyright (C) 2016, 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.internal.storage.reftree;
  
  import static org.eclipse.jgit.lib.Constants.HEAD;
  import static org.eclipse.jgit.lib.RefUpdate.Result.REJECTED;
  import static org.eclipse.jgit.lib.RefUpdate.Result.RENAMED;
  
  import java.io.IOException;
  import java.util.ArrayList;
  import java.util.List;
  
  import org.eclipse.jgit.lib.ObjectId;
  import org.eclipse.jgit.lib.ObjectIdRef;
  import org.eclipse.jgit.lib.Ref;
  import org.eclipse.jgit.lib.RefRename;
  import org.eclipse.jgit.lib.RefUpdate;
  import org.eclipse.jgit.lib.RefUpdate.Result;
  import org.eclipse.jgit.lib.SymbolicRef;
  import org.eclipse.jgit.revwalk.RevWalk;
  
  /** Single reference rename to {@link RefTreeDatabase}. */
  class RefTreeRename extends RefRename {
  	private final RefTreeDatabase refdb;
  
  	RefTreeRename(RefTreeDatabase refdb, RefUpdate src, RefUpdate dst) {
  		super(src, dst);
  		this.refdb = refdb;
  	}
  
  	@Override
  	protected Result doRename() throws IOException {
  		try (RevWalk rw = new RevWalk(refdb.getRepository())) {
  			RefTreeBatch batch = new RefTreeBatch(refdb);
  			batch.setRefLogIdent(getRefLogIdent());
  			batch.setRefLogMessage(getRefLogMessage(), false);
  			batch.init(rw);
  
  			Ref head = batch.exactRef(rw.getObjectReader(), HEAD);
  			Ref oldRef = batch.exactRef(rw.getObjectReader(), source.getName());
  			if (oldRef == null) {
  				return REJECTED;
  			}
  
  			Ref newRef = asNew(oldRef);
  			List<Command> mv = new ArrayList<>(3);
  			mv.add(new Command(oldRef, null));
  			mv.add(new Command(null, newRef));
  			if (head != null && head.isSymbolic()
  					&& head.getTarget().getName().equals(oldRef.getName())) {
  				mv.add(new Command(
  					head,
  					new SymbolicRef(head.getName(), newRef)));
  			}
  			batch.execute(rw, mv);
  			return RefTreeUpdate.translate(mv.get(1).getResult(), RENAMED);
  		}
  	}
 
 	private Ref asNew(Ref src) {
 		String name = destination.getName();
 		if (src.isSymbolic()) {
 			return new SymbolicRef(name, src.getTarget());
 		}
 
 		ObjectId peeled = src.getPeeledObjectId();
 		if (peeled != null) {
 			return new ObjectIdRef.PeeledTag(
 					src.getStorage(),
 					name,
 					src.getObjectId(),
 					peeled);
 		}
 
 		return new ObjectIdRef.PeeledNonTag(
 				src.getStorage(),
 				name,
 				src.getObjectId());
 	}
 }