/*
    * Copyright (C) 2006, Robin Rosenberg <robin.rosenberg@dewire.com>
    * 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;
  
  import static java.nio.charset.StandardCharsets.UTF_8;
  
  import java.io.File;
  import java.io.IOException;
  import java.io.OutputStreamWriter;
  import java.io.PrintWriter;
  import java.lang.reflect.InvocationTargetException;
  import java.net.MalformedURLException;
  import java.net.URL;
  import java.text.MessageFormat;
  import java.util.ArrayList;
  import java.util.List;
  import java.util.Locale;
  import java.util.concurrent.ExecutorService;
  import java.util.concurrent.Executors;
  import java.util.concurrent.ThreadFactory;
  import java.util.concurrent.TimeUnit;
  
  import org.eclipse.jgit.awtui.AwtAuthenticator;
  import org.eclipse.jgit.awtui.AwtCredentialsProvider;
  import org.eclipse.jgit.errors.TransportException;
  import org.eclipse.jgit.lfs.BuiltinLFS;
  import org.eclipse.jgit.lib.Repository;
  import org.eclipse.jgit.lib.RepositoryBuilder;
  import org.eclipse.jgit.pgm.internal.CLIText;
  import org.eclipse.jgit.pgm.opt.CmdLineParser;
  import org.eclipse.jgit.pgm.opt.SubcommandHandler;
  import org.eclipse.jgit.transport.HttpTransport;
  import org.eclipse.jgit.transport.http.apache.HttpClientConnectionFactory;
  import org.eclipse.jgit.util.CachedAuthenticator;
  import org.kohsuke.args4j.Argument;
  import org.kohsuke.args4j.CmdLineException;
  import org.kohsuke.args4j.Option;
  import org.kohsuke.args4j.OptionHandlerFilter;
  
  /**
   * Command line entry point.
   */
  public class Main {
  	@Option(name = "--help", usage = "usage_displayThisHelpText", aliases = { "-h" })
  	private boolean help;
  
  	@Option(name = "--version", usage = "usage_displayVersion")
  	private boolean version;
  
  	@Option(name = "--show-stack-trace", usage = "usage_displayThejavaStackTraceOnExceptions")
  	private boolean showStackTrace;
  
  	@Option(name = "--git-dir", metaVar = "metaVar_gitDir", usage = "usage_setTheGitRepositoryToOperateOn")
  	private String gitdir;
  
  	@Argument(index = 0, metaVar = "metaVar_command", required = true, handler = SubcommandHandler.class)
  	private TextBuiltin subcommand;
  
  	@Argument(index = 1, metaVar = "metaVar_arg")
  	private List<String> arguments = new ArrayList<>();
  
  	PrintWriter writer;
  
  	private ExecutorService gcExecutor;
  
  	/**
  	 * <p>Constructor for Main.</p>
  	 */
  	public Main() {
  		HttpTransport.setConnectionFactory(new HttpClientConnectionFactory());
  		BuiltinLFS.register();
  		gcExecutor = Executors.newSingleThreadExecutor(new ThreadFactory() {
  			private final ThreadFactory baseFactory = Executors
  					.defaultThreadFactory();
  
  			@Override
  			public Thread newThread(Runnable taskBody) {
  				Thread thr = baseFactory.newThread(taskBody);
  				thr.setName("JGit-autoGc"); //$NON-NLS-1$
  				return thr;
  			}
  		});
  	}
  
  	/**
  	 * Execute the command line.
  	 *
  	 * @param argv
  	 *            arguments.
  	 * @throws java.lang.Exception
 	 */
 	public static void main(String[] argv) throws Exception {
 		// make sure built-in filters are registered
 		BuiltinLFS.register();
 
 		new Main().run(argv);
 	}
 
 	/**
 	 * Parse the command line and execute the requested action.
 	 *
 	 * Subclasses should allocate themselves and then invoke this method:
 	 *
 	 * <pre>
 	 * class ExtMain {
 	 * 	public static void main(String[] argv) {
 	 * 		new ExtMain().run(argv);
 	 * 	}
 	 * }
 	 * </pre>
 	 *
 	 * @param argv
 	 *            arguments.
 	 * @throws java.lang.Exception
 	 */
 	protected void run(String[] argv) throws Exception {
 		writer = createErrorWriter();
 		try {
 			if (!installConsole()) {
 				AwtAuthenticator.install();
 				AwtCredentialsProvider.install();
 			}
 			configureHttpProxy();
 			execute(argv);
 		} catch (Die err) {
 			if (err.isAborted()) {
 				exit(1, err);
 			}
 			writer.println(CLIText.fatalError(err.getMessage()));
 			if (showStackTrace) {
 				err.printStackTrace(writer);
 			}
 			exit(128, err);
 		} catch (Exception err) {
 			// Try to detect errno == EPIPE and exit normally if that happens
 			// There may be issues with operating system versions and locale,
 			// but we can probably assume that these messages will not be thrown
 			// under other circumstances.
 			if (err.getClass() == IOException.class) {
 				// Linux, OS X
 				if (err.getMessage().equals("Broken pipe")) { //$NON-NLS-1$
 					exit(0, err);
 				}
 				// Windows
 				if (err.getMessage().equals("The pipe is being closed")) { //$NON-NLS-1$
 					exit(0, err);
 				}
 			}
 			if (!showStackTrace && err.getCause() != null
 					&& err instanceof TransportException) {
 				writer.println(CLIText.fatalError(err.getCause().getMessage()));
 			}
 
 			if (err.getClass().getName().startsWith("org.eclipse.jgit.errors.")) { //$NON-NLS-1$
 				writer.println(CLIText.fatalError(err.getMessage()));
 				if (showStackTrace) {
 					err.printStackTrace();
 				}
 				exit(128, err);
 			}
 			err.printStackTrace();
 			exit(1, err);
 		}
 		if (System.out.checkError()) {
 			writer.println(CLIText.get().unknownIoErrorStdout);
 			exit(1, null);
 		}
 		if (writer.checkError()) {
 			// No idea how to present an error here, most likely disk full or
 			// broken pipe
 			exit(1, null);
 		}
 		gcExecutor.shutdown();
 		gcExecutor.awaitTermination(10, TimeUnit.MINUTES);
 	}
 
 	PrintWriter createErrorWriter() {
 		return new PrintWriter(new OutputStreamWriter(System.err, UTF_8));
 	}
 
 	private void execute(String[] argv) throws Exception {
 		final CmdLineParser clp = new SubcommandLineParser(this);
 
 		try {
 			clp.parseArgument(argv);
 		} catch (CmdLineException err) {
 			if (argv.length > 0 && !help && !version) {
 				writer.println(CLIText.fatalError(err.getMessage()));
 				writer.flush();
 				exit(1, err);
 			}
 		}
 
 		if (argv.length == 0 || help) {
 			final String ex = clp.printExample(OptionHandlerFilter.ALL,
 					CLIText.get().resourceBundle());
 			writer.println("jgit" + ex + " command [ARG ...]"); //$NON-NLS-1$ //$NON-NLS-2$
 			if (help) {
 				writer.println();
 				clp.printUsage(writer, CLIText.get().resourceBundle());
 				writer.println();
 			} else if (subcommand == null) {
 				writer.println();
 				writer.println(CLIText.get().mostCommonlyUsedCommandsAre);
 				final CommandRef[] common = CommandCatalog.common();
 				int width = 0;
 				for (CommandRef c : common) {
 					width = Math.max(width, c.getName().length());
 				}
 				width += 2;
 
 				for (CommandRef c : common) {
 					writer.print(' ');
 					writer.print(c.getName());
 					for (int i = c.getName().length(); i < width; i++) {
 						writer.print(' ');
 					}
 					writer.print(CLIText.get().resourceBundle().getString(c.getUsage()));
 					writer.println();
 				}
 				writer.println();
 			}
 			writer.flush();
 			exit(1, null);
 		}
 
 		if (version) {
 			String cmdId = Version.class.getSimpleName()
 					.toLowerCase(Locale.ROOT);
 			subcommand = CommandCatalog.get(cmdId).create();
 		}
 
 		final TextBuiltin cmd = subcommand;
 		init(cmd);
 		try {
 			cmd.execute(arguments.toArray(new String[0]));
 		} finally {
 			if (cmd.outw != null) {
 				cmd.outw.flush();
 			}
 			if (cmd.errw != null) {
 				cmd.errw.flush();
 			}
 		}
 	}
 
 	void init(TextBuiltin cmd) throws IOException {
 		if (cmd.requiresRepository()) {
 			cmd.init(openGitDir(gitdir), null);
 		} else {
 			cmd.init(null, gitdir);
 		}
 	}
 
 	/**
 	 * @param status
 	 * @param t
 	 *            can be {@code null}
 	 * @throws Exception
 	 */
 	void exit(int status, Exception t) throws Exception {
 		writer.flush();
 		System.exit(status);
 	}
 
 	/**
 	 * Evaluate the {@code --git-dir} option and open the repository.
 	 *
 	 * @param aGitdir
 	 *            the {@code --git-dir} option given on the command line. May be
 	 *            null if it was not supplied.
 	 * @return the repository to operate on.
 	 * @throws java.io.IOException
 	 *             the repository cannot be opened.
 	 */
 	protected Repository openGitDir(String aGitdir) throws IOException {
 		RepositoryBuilder rb = new RepositoryBuilder() //
 				.setGitDir(aGitdir != null ? new File(aGitdir) : null) //
 				.readEnvironment() //
 				.findGitDir();
 		if (rb.getGitDir() == null)
 			throw new Die(CLIText.get().cantFindGitDirectory);
 		return rb.build();
 	}
 
 	private static boolean installConsole() {
 		try {
 			install("org.eclipse.jgit.console.ConsoleAuthenticator"); //$NON-NLS-1$
 			install("org.eclipse.jgit.console.ConsoleCredentialsProvider"); //$NON-NLS-1$
 			return true;
 		} catch (ClassNotFoundException | NoClassDefFoundError
 				| UnsupportedClassVersionError e) {
 			return false;
 		} catch (IllegalArgumentException | SecurityException
 				| IllegalAccessException | InvocationTargetException
 				| NoSuchMethodException e) {
 			throw new RuntimeException(CLIText.get().cannotSetupConsole, e);
 		}
 	}
 
 	private static void install(String name)
 			throws IllegalAccessException, InvocationTargetException,
 			NoSuchMethodException, ClassNotFoundException {
 		try {
 			Class.forName(name).getMethod("install").invoke(null); //$NON-NLS-1$
 		} catch (InvocationTargetException e) {
 			if (e.getCause() instanceof RuntimeException)
 				throw (RuntimeException) e.getCause();
 			if (e.getCause() instanceof Error)
 				throw (Error) e.getCause();
 			throw e;
 		}
 	}
 
 	/**
 	 * Configure the JRE's standard HTTP based on <code>http_proxy</code>.
 	 * <p>
 	 * The popular libcurl library honors the <code>http_proxy</code>,
 	 * <code>https_proxy</code> environment variables as a means of specifying
 	 * an HTTP/S proxy for requests made behind a firewall. This is not natively
 	 * recognized by the JRE, so this method can be used by command line
 	 * utilities to configure the JRE before the first request is sent. The
 	 * information found in the environment variables is copied to the
 	 * associated system properties. This is not done when the system properties
 	 * are already set. The default way of telling java programs about proxies
 	 * (the system properties) takes precedence over environment variables.
 	 *
 	 * @throws MalformedURLException
 	 *             the value in <code>http_proxy</code> or
 	 *             <code>https_proxy</code> is unsupportable.
 	 */
 	static void configureHttpProxy() throws MalformedURLException {
 		for (String protocol : new String[] { "http", "https" }) { //$NON-NLS-1$ //$NON-NLS-2$
 			if (System.getProperty(protocol + ".proxyHost") != null) { //$NON-NLS-1$
 				continue;
 			}
 			String s = System.getenv(protocol + "_proxy"); //$NON-NLS-1$
 			if (s == null && protocol.equals("https")) { //$NON-NLS-1$
 				s = System.getenv("HTTPS_PROXY"); //$NON-NLS-1$
 			}
 			if (s == null || s.isEmpty()) {
 				continue;
 			}
 
 			final URL u = new URL(
 					(!s.contains("://")) ? protocol + "://" + s : s); //$NON-NLS-1$ //$NON-NLS-2$
 			if (!u.getProtocol().startsWith("http")) //$NON-NLS-1$
 				throw new MalformedURLException(MessageFormat.format(
 						CLIText.get().invalidHttpProxyOnlyHttpSupported, s));
 
 			final String proxyHost = u.getHost();
 			final int proxyPort = u.getPort();
 
 			System.setProperty(protocol + ".proxyHost", proxyHost); //$NON-NLS-1$
 			if (proxyPort > 0)
 				System.setProperty(protocol + ".proxyPort", //$NON-NLS-1$
 						String.valueOf(proxyPort));
 
 			final String userpass = u.getUserInfo();
 			if (userpass != null && userpass.contains(":")) { //$NON-NLS-1$
 				final int c = userpass.indexOf(':');
 				final String user = userpass.substring(0, c);
 				final String pass = userpass.substring(c + 1);
 				CachedAuthenticator.add(
 						new CachedAuthenticator.CachedAuthentication(proxyHost,
 								proxyPort, user, pass));
 			}
 		}
 	}
 
 	/**
 	 * Parser for subcommands which doesn't stop parsing on help options and so
 	 * proceeds all specified options
 	 */
 	static class SubcommandLineParser extends CmdLineParser {
 		public SubcommandLineParser(Object bean) {
 			super(bean);
 		}
 
 		@Override
 		protected boolean containsHelp(String... args) {
 			return false;
 		}
 	}
 }