/*
    * Copyright (C) 2008-2009, 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.File;
  import java.io.IOException;
  import java.text.MessageFormat;
  
  import org.eclipse.jgit.dircache.DirCache;
  import org.eclipse.jgit.dircache.DirCacheIterator;
  import org.eclipse.jgit.errors.IncorrectObjectTypeException;
  import org.eclipse.jgit.errors.MissingObjectException;
  import org.eclipse.jgit.lib.ObjectId;
  import org.eclipse.jgit.lib.ObjectReader;
  import org.eclipse.jgit.pgm.internal.CLIText;
  import org.eclipse.jgit.treewalk.AbstractTreeIterator;
  import org.eclipse.jgit.treewalk.CanonicalTreeParser;
  import org.eclipse.jgit.treewalk.FileTreeIterator;
  import org.eclipse.jgit.treewalk.WorkingTreeOptions;
  import org.eclipse.jgit.util.FS;
  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.treewalk.AbstractTreeIterator} from string values.
   * <p>
   * Assumes the parser has been initialized with a Repository.
   */
  public class AbstractTreeIteratorHandler extends
  		OptionHandler<AbstractTreeIterator> {
  	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 AbstractTreeIteratorHandler(final CmdLineParser parser,
  			final OptionDef option,
  			final Setter<? super AbstractTreeIterator> setter) {
  		super(parser, option, setter);
  		clp = (org.eclipse.jgit.pgm.opt.CmdLineParser) parser;
  	}
  
  	/** {@inheritDoc} */
  	@Override
  	public int parseArguments(Parameters params) throws CmdLineException {
  		final String name = params.getParameter(0);
  
  		if (new File(name).isDirectory()) {
  			setter.addValue(new FileTreeIterator(
  				new File(name),
  				FS.DETECTED,
  				clp.getRepository().getConfig().get(WorkingTreeOptions.KEY)));
  			return 1;
  		}
  
  		if (new File(name).isFile()) {
  			final DirCache dirc;
  			try {
  				dirc = DirCache.read(new File(name), FS.DETECTED);
  			} catch (IOException e) {
  				throw new CmdLineException(clp, MessageFormat.format(CLIText.get().notAnIndexFile, name), e);
  			}
  			setter.addValue(new DirCacheIterator(dirc));
  			return 1;
  		}
  
  		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().notATree), name);
  
 		final CanonicalTreeParser p = new CanonicalTreeParser();
 		try (ObjectReader curs = clp.getRepository().newObjectReader()) {
 			p.reset(curs, clp.getRevWalk().parseTree(id));
 		} catch (MissingObjectException | IncorrectObjectTypeException e) {
 			CmdLineException cle = new CmdLineException(clp,
 					CLIText.format(CLIText.get().notATree), name);
 			cle.initCause(e);
 			throw cle;
 		} catch (IOException e) {
 			throw new CmdLineException(clp,
 					CLIText.format(CLIText.get().cannotReadBecause), name,
 					e.getMessage());
 		}
 
 		setter.addValue(p);
 		return 1;
 	}
 
 	/** {@inheritDoc} */
 	@Override
 	public String getDefaultMetaVariable() {
 		return CLIText.get().metaVar_treeish;
 	}
 }