/*
    * Copyright (C) 2011, Google Inc. 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.internal.storage.dfs;
  
  import java.io.IOException;
  import java.io.InputStream;
  import java.text.MessageFormat;
  import java.util.Collections;
  
  import org.eclipse.jgit.attributes.AttributesNode;
  import org.eclipse.jgit.attributes.AttributesNodeProvider;
  import org.eclipse.jgit.attributes.AttributesRule;
  import org.eclipse.jgit.internal.JGitText;
  import org.eclipse.jgit.lib.Constants;
  import org.eclipse.jgit.lib.RefUpdate;
  import org.eclipse.jgit.lib.ReflogReader;
  import org.eclipse.jgit.lib.Repository;
  import org.eclipse.jgit.lib.StoredConfig;
  
  /**
   * A Git repository on a DFS.
   */
  public abstract class DfsRepository extends Repository {
  	private final DfsConfig config;
  
  	private final DfsRepositoryDescription description;
  
  	/**
  	 * Initialize a DFS repository.
  	 *
  	 * @param builder
  	 *            description of the repository.
  	 */
  	protected DfsRepository(DfsRepositoryBuilder builder) {
  		super(builder);
  		this.config = new DfsConfig();
  		this.description = builder.getRepositoryDescription();
  	}
  
  	/** {@inheritDoc} */
  	@Override
  	public abstract DfsObjDatabase getObjectDatabase();
  
  	/**
  	 * Get the description of this repository.
  	 *
  	 * @return the description of this repository.
  	 */
  	public DfsRepositoryDescription getDescription() {
  		return description;
  	}
  
  	/**
  	 * Check if the repository already exists.
  	 *
  	 * @return true if the repository exists; false if it is new.
  	 * @throws java.io.IOException
  	 *             the repository cannot be checked.
  	 */
  	public boolean exists() throws IOException {
  		if (getRefDatabase() instanceof DfsRefDatabase) {
  			return ((DfsRefDatabase) getRefDatabase()).exists();
  		}
  		return true;
  	}
  
  	/** {@inheritDoc} */
  	@Override
  	public void create(boolean bare) throws IOException {
  		if (exists())
  			throw new IOException(MessageFormat.format(
  					JGitText.get().repositoryAlreadyExists, "")); //$NON-NLS-1$
  
  		String master = Constants.R_HEADS + Constants.MASTER;
  		RefUpdate.Result result = updateRef(Constants.HEAD, true).link(master);
  		if (result != RefUpdate.Result.NEW)
  			throw new IOException(result.name());
  	}
  
  	/** {@inheritDoc} */
  	@Override
  	public StoredConfig getConfig() {
  		return config;
  	}
  
  	/** {@inheritDoc} */
  	@Override
  	public String getIdentifier() {
  		return getDescription().getRepositoryName();
  	}
  
 	/** {@inheritDoc} */
 	@Override
 	public void scanForRepoChanges() throws IOException {
 		getRefDatabase().refresh();
 		getObjectDatabase().clearCache();
 	}
 
 	/** {@inheritDoc} */
 	@Override
 	public void notifyIndexChanged(boolean internal) {
 		// Do not send notifications.
 		// There is no index, as there is no working tree.
 	}
 
 	/** {@inheritDoc} */
 	@Override
 	public ReflogReader getReflogReader(String refName) throws IOException {
 		throw new UnsupportedOperationException();
 	}
 
 	/** {@inheritDoc} */
 	@Override
 	public AttributesNodeProvider createAttributesNodeProvider() {
 		// TODO Check if the implementation used in FileRepository can be used
 		// for this kind of repository
 		return new EmptyAttributesNodeProvider();
 	}
 
 	private static class EmptyAttributesNodeProvider implements
 			AttributesNodeProvider {
 		private EmptyAttributesNode emptyAttributesNode = new EmptyAttributesNode();
 
 		@Override
 		public AttributesNode getInfoAttributesNode() throws IOException {
 			return emptyAttributesNode;
 		}
 
 		@Override
 		public AttributesNode getGlobalAttributesNode() throws IOException {
 			return emptyAttributesNode;
 		}
 
 		private static class EmptyAttributesNode extends AttributesNode {
 
 			public EmptyAttributesNode() {
 				super(Collections.<AttributesRule> emptyList());
 			}
 
 			@Override
 			public void parse(InputStream in) throws IOException {
 				// Do nothing
 			}
 		}
 	}
 }