/*
    * Copyright (C) 2009, Google Inc.
    * Copyright (C) 2008, Shawn O. Pearce <spearce@spearce.org> 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.pgm.opt;
  
  import java.io.IOException;
  
  import org.eclipse.jgit.errors.IncorrectObjectTypeException;
  import org.eclipse.jgit.errors.MissingObjectException;
  import org.eclipse.jgit.lib.ObjectId;
  import org.eclipse.jgit.pgm.internal.CLIText;
  import org.eclipse.jgit.revwalk.RevCommit;
  import org.eclipse.jgit.revwalk.RevFlag;
  import org.kohsuke.args4j.CmdLineException;
  import org.kohsuke.args4j.CmdLineParser;
  import org.kohsuke.args4j.OptionDef;
  import org.kohsuke.args4j.spi.OptionHandler;
  import org.kohsuke.args4j.spi.Parameters;
  import org.kohsuke.args4j.spi.Setter;
  
  /**
   * Custom argument handler {@link org.eclipse.jgit.revwalk.RevCommit} from
   * string values.
   * <p>
   * Assumes the parser has been initialized with a Repository.
   */
  public class RevCommitHandler extends OptionHandler<RevCommit> {
  	private final org.eclipse.jgit.pgm.opt.CmdLineParser clp;
  
  	/**
  	 * Create a new handler for the command name.
  	 * <p>
  	 * This constructor is used only by args4j.
  	 *
  	 * @param parser
  	 *            a {@link org.kohsuke.args4j.CmdLineParser} object.
  	 * @param option
  	 *            a {@link org.kohsuke.args4j.OptionDef} object.
  	 * @param setter
  	 *            a {@link org.kohsuke.args4j.spi.Setter} object.
  	 */
  	public RevCommitHandler(final CmdLineParser parser, final OptionDef option,
  			final Setter<? super RevCommit> setter) {
  		super(parser, option, setter);
  		clp = (org.eclipse.jgit.pgm.opt.CmdLineParser) parser;
  	}
  
  	/** {@inheritDoc} */
  	@Override
  	public int parseArguments(Parameters params) throws CmdLineException {
  		String name = params.getParameter(0);
  
  		boolean interesting = true;
  		if (name.startsWith("^")) { //$NON-NLS-1$
  			name = name.substring(1);
  			interesting = false;
  		}
  
  		final int dot2 = name.indexOf(".."); //$NON-NLS-1$
  		if (dot2 != -1) {
  			if (!option.isMultiValued())
  				throw new CmdLineException(clp,
  						CLIText.format(CLIText.get().onlyOneMetaVarExpectedIn),
  						option.metaVar(), name);
  
  			final String left = name.substring(0, dot2);
  			final String right = name.substring(dot2 + 2);
  			addOne(left, false);
  			addOne(right, true);
  			return 1;
  		}
  
  		addOne(name, interesting);
  		return 1;
  	}
  
  	private void addOne(String name, boolean interesting)
  			throws CmdLineException {
  		final ObjectId id;
  		try {
  			id = clp.getRepository().resolve(name);
  		} catch (IOException e) {
  			throw new CmdLineException(clp, CLIText.format(e.getMessage()));
  		}
  		if (id == null)
  			throw new CmdLineException(clp,
  					CLIText.format(CLIText.get().notACommit), name);
  
  		final RevCommit c;
  		try {
  			c = clp.getRevWalk().parseCommit(id);
 		} catch (MissingObjectException | IncorrectObjectTypeException e) {
 			CmdLineException cle = new CmdLineException(clp,
 					CLIText.format(CLIText.get().notACommit), name);
 			cle.initCause(e);
 			throw cle;
 		} catch (IOException e) {
 			throw new CmdLineException(clp,
 					CLIText.format(CLIText.get().cannotReadBecause), name,
 					e.getMessage());
 		}
 
 		if (interesting)
 			c.remove(RevFlag.UNINTERESTING);
 		else
 			c.add(RevFlag.UNINTERESTING);
 
 		setter.addValue(c);
 	}
 
 	/** {@inheritDoc} */
 	@Override
 	public String getDefaultMetaVariable() {
 		return CLIText.get().metaVar_commitish;
 	}
 }