/*
    * Copyright (C) 2010, Mathias Kinzler <mathias.kinzler@sap.com>
    * Copyright (C) 2010, Chris Aniszczyk <caniszczyk@gmail.com> 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.api;
  
  import java.io.IOException;
  import java.text.MessageFormat;
  import java.util.ArrayList;
  import java.util.Arrays;
  import java.util.HashSet;
  import java.util.List;
  import java.util.Set;
  
  import org.eclipse.jgit.api.errors.CannotDeleteCurrentBranchException;
  import org.eclipse.jgit.api.errors.GitAPIException;
  import org.eclipse.jgit.api.errors.JGitInternalException;
  import org.eclipse.jgit.api.errors.NotMergedException;
  import org.eclipse.jgit.internal.JGitText;
  import org.eclipse.jgit.lib.ConfigConstants;
  import org.eclipse.jgit.lib.Constants;
  import org.eclipse.jgit.lib.Ref;
  import org.eclipse.jgit.lib.RefUpdate;
  import org.eclipse.jgit.lib.RefUpdate.Result;
  import org.eclipse.jgit.lib.Repository;
  import org.eclipse.jgit.lib.StoredConfig;
  import org.eclipse.jgit.revwalk.RevCommit;
  import org.eclipse.jgit.revwalk.RevWalk;
  
  /**
   * Used to delete one or several branches.
   *
   * The result of {@link #call()} is a list with the (full) names of the deleted
   * branches.
   *
   * Note that we don't have a setter corresponding to the -r option; remote
   * tracking branches are simply deleted just like local branches.
   *
   * @see <a
   *      href="http://www.kernel.org/pub/software/scm/git/docs/git-branch.html"
   *      >Git documentation about Branch</a>
   */
  public class DeleteBranchCommand extends GitCommand<List<String>> {
  	private final Set<String> branchNames = new HashSet<>();
  
  	private boolean force;
  
  	/**
  	 * Constructor for DeleteBranchCommand
  	 *
  	 * @param repo
  	 *            the {@link org.eclipse.jgit.lib.Repository}
  	 */
  	protected DeleteBranchCommand(Repository repo) {
  		super(repo);
  	}
  
  	/** {@inheritDoc} */
  	@Override
  	public List<String> call() throws GitAPIException,
  			NotMergedException, CannotDeleteCurrentBranchException {
  		checkCallable();
  		List<String> result = new ArrayList<>();
  		if (branchNames.isEmpty())
  			return result;
  		try {
  			String currentBranch = repo.getFullBranch();
  			if (!force) {
  				// check if the branches to be deleted
  				// are all merged into the current branch
  				try (RevWalk walk = new RevWalk(repo)) {
  					RevCommit tip = walk
  							.parseCommit(repo.resolve(Constants.HEAD));
  					for (String branchName : branchNames) {
  						if (branchName == null)
  							continue;
  						Ref currentRef = repo.findRef(branchName);
  						if (currentRef == null)
  							continue;
  
  						RevCommit base = walk
  								.parseCommit(repo.resolve(branchName));
  						if (!walk.isMergedInto(base, tip)) {
  							throw new NotMergedException();
  						}
  					}
  				}
  			}
  			setCallable(false);
  			for (String branchName : branchNames) {
  				if (branchName == null)
  					continue;
  				Ref currentRef = repo.findRef(branchName);
 				if (currentRef == null)
 					continue;
 				String fullName = currentRef.getName();
 				if (fullName.equals(currentBranch))
 					throw new CannotDeleteCurrentBranchException(
 							MessageFormat
 									.format(
 											JGitText.get().cannotDeleteCheckedOutBranch,
 											branchName));
 				RefUpdate update = repo.updateRef(fullName);
 				update.setRefLogMessage("branch deleted", false); //$NON-NLS-1$
 				update.setForceUpdate(true);
 				Result deleteResult = update.delete();
 
 				boolean ok = true;
 				switch (deleteResult) {
 				case IO_FAILURE:
 				case LOCK_FAILURE:
 				case REJECTED:
 					ok = false;
 					break;
 				default:
 					break;
 				}
 
 				if (ok) {
 					result.add(fullName);
 					if (fullName.startsWith(Constants.R_HEADS)) {
 						String shortenedName = fullName
 								.substring(Constants.R_HEADS.length());
 						// remove upstream configuration if any
 						final StoredConfig cfg = repo.getConfig();
 						cfg.unsetSection(
 								ConfigConstants.CONFIG_BRANCH_SECTION,
 								shortenedName);
 						cfg.save();
 					}
 				} else
 					throw new JGitInternalException(MessageFormat.format(
 							JGitText.get().deleteBranchUnexpectedResult,
 							deleteResult.name()));
 			}
 			return result;
 		} catch (IOException ioe) {
 			throw new JGitInternalException(ioe.getMessage(), ioe);
 		}
 	}
 
 	/**
 	 * Set the names of the branches to delete
 	 *
 	 * @param branchnames
 	 *            the names of the branches to delete; if not set, this will do
 	 *            nothing; invalid branch names will simply be ignored
 	 * @return this instance
 	 */
 	public DeleteBranchCommand setBranchNames(String... branchnames) {
 		checkCallable();
 		this.branchNames.clear();
 		this.branchNames.addAll(Arrays.asList(branchnames));
 		return this;
 	}
 
 	/**
 	 * Set whether to forcefully delete branches
 	 *
 	 * @param force
 	 *            <code>true</code> corresponds to the -D option,
 	 *            <code>false</code> to the -d option (default) <br>
 	 *            if <code>false</code> a check will be performed whether the
 	 *            branch to be deleted is already merged into the current branch
 	 *            and deletion will be refused in this case
 	 * @return this instance
 	 */
 	public DeleteBranchCommand setForce(boolean force) {
 		checkCallable();
 		this.force = force;
 		return this;
 	}
 }