/*
    * 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 java.io.Writer;
  import java.lang.reflect.Field;
  import java.util.ArrayList;
  import java.util.Iterator;
  import java.util.List;
  import java.util.ResourceBundle;
  
  import org.eclipse.jgit.lib.ObjectId;
  import org.eclipse.jgit.lib.Repository;
  import org.eclipse.jgit.pgm.Die;
  import org.eclipse.jgit.pgm.TextBuiltin;
  import org.eclipse.jgit.pgm.internal.CLIText;
  import org.eclipse.jgit.revwalk.RevCommit;
  import org.eclipse.jgit.revwalk.RevTree;
  import org.eclipse.jgit.revwalk.RevWalk;
  import org.eclipse.jgit.transport.RefSpec;
  import org.eclipse.jgit.treewalk.AbstractTreeIterator;
  import org.kohsuke.args4j.CmdLineException;
  import org.kohsuke.args4j.IllegalAnnotationError;
  import org.kohsuke.args4j.NamedOptionDef;
  import org.kohsuke.args4j.OptionDef;
  import org.kohsuke.args4j.OptionHandlerRegistry;
  import org.kohsuke.args4j.spi.OptionHandler;
  import org.kohsuke.args4j.spi.RestOfArgumentsHandler;
  import org.kohsuke.args4j.spi.Setter;
  
  /**
   * Extended command line parser which handles --foo=value arguments.
   * <p>
   * The args4j package does not natively handle --foo=value and instead prefers
   * to see --foo value on the command line. Many users are used to the GNU style
   * --foo=value long option, so we convert from the GNU style format to the
   * args4j style format prior to invoking args4j for parsing.
   */
  public class CmdLineParser extends org.kohsuke.args4j.CmdLineParser {
  	static {
  		OptionHandlerRegistry registry = OptionHandlerRegistry.getRegistry();
  		registry.registerHandler(AbstractTreeIterator.class,
  				AbstractTreeIteratorHandler.class);
  		registry.registerHandler(ObjectId.class, ObjectIdHandler.class);
  		registry.registerHandler(RefSpec.class, RefSpecHandler.class);
  		registry.registerHandler(RevCommit.class, RevCommitHandler.class);
  		registry.registerHandler(RevTree.class, RevTreeHandler.class);
  		registry.registerHandler(List.class, OptionWithValuesListHandler.class);
  	}
  
  	private final Repository db;
  
  	private RevWalk walk;
  
  	private boolean seenHelp;
  
  	private TextBuiltin cmd;
  
  	/**
  	 * Creates a new command line owner that parses arguments/options and set
  	 * them into the given object.
  	 *
  	 * @param bean
  	 *            instance of a class annotated by
  	 *            {@link org.kohsuke.args4j.Option} and
  	 *            {@link org.kohsuke.args4j.Argument}. this object will receive
  	 *            values.
  	 * @throws IllegalAnnotationError
  	 *             if the option bean class is using args4j annotations
  	 *             incorrectly.
  	 */
  	public CmdLineParser(Object bean) {
  		this(bean, null);
  	}
  
  	/**
  	 * Creates a new command line owner that parses arguments/options and set
  	 * them into the given object.
  	 *
  	 * @param bean
  	 *            instance of a class annotated by
  	 *            {@link org.kohsuke.args4j.Option} and
  	 *            {@link org.kohsuke.args4j.Argument}. this object will receive
  	 *            values.
  	 * @param repo
  	 *            repository this parser can translate options through.
  	 * @throws IllegalAnnotationError
  	 *             if the option bean class is using args4j annotations
  	 *             incorrectly.
  	 */
 	public CmdLineParser(Object bean, Repository repo) {
 		super(bean);
 		if (bean instanceof TextBuiltin) {
 			cmd = (TextBuiltin) bean;
 		}
 		if (repo == null && cmd != null) {
 			repo = cmd.getRepository();
 		}
 		this.db = repo;
 	}
 
 	/** {@inheritDoc} */
 	@Override
 	public void parseArgument(String... args) throws CmdLineException {
 		final ArrayList<String> tmp = new ArrayList<>(args.length);
 		for (int argi = 0; argi < args.length; argi++) {
 			final String str = args[argi];
 			if (str.equals("--")) { //$NON-NLS-1$
 				while (argi < args.length)
 					tmp.add(args[argi++]);
 				break;
 			}
 
 			if (str.startsWith("--")) { //$NON-NLS-1$
 				final int eq = str.indexOf('=');
 				if (eq > 0) {
 					tmp.add(str.substring(0, eq));
 					tmp.add(str.substring(eq + 1));
 					continue;
 				}
 			}
 
 			tmp.add(str);
 
 			if (containsHelp(args)) {
 				// suppress exceptions on required parameters if help is present
 				seenHelp = true;
 				// stop argument parsing here
 				break;
 			}
 		}
 		List<OptionHandler> backup = null;
 		if (seenHelp) {
 			backup = unsetRequiredOptions();
 		}
 
 		try {
 			super.parseArgument(tmp.toArray(new String[0]));
 		} catch (Die e) {
 			if (!seenHelp) {
 				throw e;
 			}
 			printToErrorWriter(CLIText.fatalError(e.getMessage()));
 		} finally {
 			// reset "required" options to defaults for correct command printout
 			if (backup != null && !backup.isEmpty()) {
 				restoreRequiredOptions(backup);
 			}
 			seenHelp = false;
 		}
 	}
 
 	private void printToErrorWriter(String error) {
 		if (cmd == null) {
 			System.err.println(error);
 		} else {
 			try {
 				cmd.getErrorWriter().println(error);
 			} catch (IOException e1) {
 				System.err.println(error);
 			}
 		}
 	}
 
 	private List<OptionHandler> unsetRequiredOptions() {
 		List<OptionHandler> options = getOptions();
 		List<OptionHandler> backup = new ArrayList<>(options);
 		for (Iterator<OptionHandler> iterator = options.iterator(); iterator
 				.hasNext();) {
 			OptionHandler handler = iterator.next();
 			if (handler.option instanceof NamedOptionDef
 					&& handler.option.required()) {
 				iterator.remove();
 			}
 		}
 		return backup;
 	}
 
 	private void restoreRequiredOptions(List<OptionHandler> backup) {
 		List<OptionHandler> options = getOptions();
 		options.clear();
 		options.addAll(backup);
 	}
 
 	/**
 	 * Check if array contains help option
 	 *
 	 * @param args
 	 *            non null
 	 * @return true if the given array contains help option
 	 * @since 4.2
 	 */
 	protected boolean containsHelp(String... args) {
 		return TextBuiltin.containsHelp(args);
 	}
 
 	/**
 	 * Get the repository this parser translates values through.
 	 *
 	 * @return the repository, if specified during construction.
 	 */
 	public Repository getRepository() {
 		if (db == null)
 			throw new IllegalStateException(CLIText.get().noGitRepositoryConfigured);
 		return db;
 	}
 
 	/**
 	 * Get the revision walker used to support option parsing.
 	 *
 	 * @return the revision walk used by this option parser.
 	 */
 	public RevWalk getRevWalk() {
 		if (walk == null)
 			walk = new RevWalk(getRepository());
 		return walk;
 	}
 
 	/**
 	 * Get the revision walker used to support option parsing.
 	 * <p>
 	 * This method does not initialize the RevWalk and may return null.
 	 *
 	 * @return the revision walk used by this option parser, or null.
 	 */
 	public RevWalk getRevWalkGently() {
 		return walk;
 	}
 
 	class MyOptionDef extends OptionDef {
 
 		public MyOptionDef(OptionDef o) {
 			super(o.usage(), o.metaVar(), o.required(), o.help(), o.hidden(),
 					o.handler(), o.isMultiValued());
 		}
 
 		@Override
 		public String toString() {
 			if (metaVar() == null)
 				return "ARG"; //$NON-NLS-1$
 			try {
 				Field field = CLIText.class.getField(metaVar());
 				String ret = field.get(CLIText.get()).toString();
 				return ret;
 			} catch (Exception e) {
 				e.printStackTrace(System.err);
 				return metaVar();
 			}
 		}
 
 		@Override
 		public boolean required() {
 			return seenHelp ? false : super.required();
 		}
 	}
 
 	/** {@inheritDoc} */
 	@Override
 	protected OptionHandler createOptionHandler(OptionDef o, Setter setter) {
 		if (o instanceof NamedOptionDef) {
 			return super.createOptionHandler(o, setter);
 		}
 		return super.createOptionHandler(new MyOptionDef(o), setter);
 
 	}
 
 	/** {@inheritDoc} */
 	@Override
 	public void printSingleLineUsage(Writer w, ResourceBundle rb) {
 		List<OptionHandler> options = getOptions();
 		if (options.isEmpty()) {
 			super.printSingleLineUsage(w, rb);
 			return;
 		}
 		List<OptionHandler> backup = new ArrayList<>(options);
 		boolean changed = sortRestOfArgumentsHandlerToTheEnd(options);
 		try {
 			super.printSingleLineUsage(w, rb);
 		} finally {
 			if (changed) {
 				options.clear();
 				options.addAll(backup);
 			}
 		}
 	}
 
 	private boolean sortRestOfArgumentsHandlerToTheEnd(
 			List<OptionHandler> options) {
 		for (int i = 0; i < options.size(); i++) {
 			OptionHandler handler = options.get(i);
 			if (handler instanceof RestOfArgumentsHandler
 					|| handler instanceof PathTreeFilterHandler) {
 				options.remove(i);
 				options.add(handler);
 				return true;
 			}
 		}
 		return false;
 	}
 }