/*
    * Copyright (C) 2008, 2020 Google Inc. 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.transport;
  
  import static org.eclipse.jgit.util.StringUtils.equalsIgnoreCase;
  import static org.eclipse.jgit.util.StringUtils.toLowerCase;
  
  import java.io.File;
  import java.util.EnumSet;
  import java.util.HashMap;
  import java.util.Map;
  
  import org.eclipse.jgit.annotations.Nullable;
  import org.eclipse.jgit.internal.storage.file.LazyObjectIdSetFile;
  import org.eclipse.jgit.lib.Config;
  import org.eclipse.jgit.lib.ConfigConstants;
  import org.eclipse.jgit.lib.Config.SectionParser;
  import org.eclipse.jgit.lib.ObjectChecker;
  import org.eclipse.jgit.lib.ObjectIdSet;
  import org.eclipse.jgit.lib.Ref;
  import org.eclipse.jgit.lib.Repository;
  import org.eclipse.jgit.util.SystemReader;
  
  /**
   * The standard "transfer", "fetch", "protocol", "receive", and "uploadpack"
   * configuration parameters.
   */
  public class TransferConfig {
  	private static final String FSCK = "fsck"; //$NON-NLS-1$
  
  	/** Key for {@link Config#get(SectionParser)}. */
  	public static final Config.SectionParser<TransferConfig> KEY =
  			TransferConfig::new;
  
  	/**
  	 * A git configuration value for how to handle a fsck failure of a particular kind.
  	 * Used in e.g. fsck.missingEmail.
  	 * @since 4.9
  	 */
  	public enum FsckMode {
  		/**
  		 * Treat it as an error (the default).
  		 */
  		ERROR,
  		/**
  		 * Issue a warning (in fact, jgit treats this like IGNORE, but git itself does warn).
  		 */
  		WARN,
  		/**
  		 * Ignore the error.
  		 */
  		IGNORE;
  	}
  
  	/**
  	 * A git configuration variable for which versions of the Git protocol to
  	 * prefer. Used in protocol.version.
  	 *
  	 * @since 5.9
  	 */
  	public enum ProtocolVersion {
  		/**
  		 * Git wire protocol version 0 (the default).
  		 */
  		V0("0"), //$NON-NLS-1$
  		/**
  		 * Git wire protocol version 2.
  		 */
  		V2("2"); //$NON-NLS-1$
  
  		final String name;
  
  		ProtocolVersion(String name) {
  			this.name = name;
  		}
  
  		/**
  		 * Returns version number
  		 *
  		 * @return string version
  		 */
  		public String version() {
  			return name;
  		}
  
  		@Nullable
  		static ProtocolVersion parse(@Nullable String name) {
  			if (name == null) {
  				return null;
  			}
  			for (ProtocolVersion v : ProtocolVersion.values()) {
 				if (v.name.equals(name)) {
 					return v;
 				}
 			}
 			if ("1".equals(name)) { //$NON-NLS-1$
 				return V0;
 			}
 			return null;
 		}
 	}
 
 	private final boolean fetchFsck;
 	private final boolean receiveFsck;
 	private final String fsckSkipList;
 	private final EnumSet<ObjectChecker.ErrorType> ignore;
 	private final boolean allowInvalidPersonIdent;
 	private final boolean safeForWindows;
 	private final boolean safeForMacOS;
 	private final boolean allowRefInWant;
 	private final boolean allowTipSha1InWant;
 	private final boolean allowReachableSha1InWant;
 	private final boolean allowFilter;
 	private final boolean allowSidebandAll;
 	private final boolean advertiseSidebandAll;
 	final @Nullable ProtocolVersion protocolVersion;
 	final String[] hideRefs;
 
 	/**
 	 * Create a configuration honoring the repository's settings.
 	 *
 	 * @param db
 	 *            the repository to read settings from. The repository is not
 	 *            retained by the new configuration, instead its settings are
 	 *            copied during the constructor.
 	 * @since 5.1.4
 	 */
 	public TransferConfig(Repository db) {
 		this(db.getConfig());
 	}
 
 	/**
 	 * Create a configuration honoring settings in a
 	 * {@link org.eclipse.jgit.lib.Config}.
 	 *
 	 * @param rc
 	 *            the source to read settings from. The source is not retained
 	 *            by the new configuration, instead its settings are copied
 	 *            during the constructor.
 	 * @since 5.1.4
 	 */
 	@SuppressWarnings("nls")
 	public TransferConfig(Config rc) {
 		boolean fsck = rc.getBoolean("transfer", "fsckobjects", false);
 		fetchFsck = rc.getBoolean("fetch", "fsckobjects", fsck);
 		receiveFsck = rc.getBoolean("receive", "fsckobjects", fsck);
 		fsckSkipList = rc.getString(FSCK, null, "skipList");
 		allowInvalidPersonIdent = rc.getBoolean(FSCK, "allowInvalidPersonIdent",
 				false);
 		safeForWindows = rc.getBoolean(FSCK, "safeForWindows",
 						SystemReader.getInstance().isWindows());
 		safeForMacOS = rc.getBoolean(FSCK, "safeForMacOS",
 						SystemReader.getInstance().isMacOS());
 
 		ignore = EnumSet.noneOf(ObjectChecker.ErrorType.class);
 		EnumSet<ObjectChecker.ErrorType> set = EnumSet
 				.noneOf(ObjectChecker.ErrorType.class);
 		for (String key : rc.getNames(FSCK)) {
 			if (equalsIgnoreCase(key, "skipList")
 					|| equalsIgnoreCase(key, "allowLeadingZeroFileMode")
 					|| equalsIgnoreCase(key, "allowInvalidPersonIdent")
 					|| equalsIgnoreCase(key, "safeForWindows")
 					|| equalsIgnoreCase(key, "safeForMacOS")) {
 				continue;
 			}
 
 			ObjectChecker.ErrorType id = FsckKeyNameHolder.parse(key);
 			if (id != null) {
 				switch (rc.getEnum(FSCK, null, key, FsckMode.ERROR)) {
 				case ERROR:
 					ignore.remove(id);
 					break;
 				case WARN:
 				case IGNORE:
 					ignore.add(id);
 					break;
 				}
 				set.add(id);
 			}
 		}
 		if (!set.contains(ObjectChecker.ErrorType.ZERO_PADDED_FILEMODE)
 				&& rc.getBoolean(FSCK, "allowLeadingZeroFileMode", false)) {
 			ignore.add(ObjectChecker.ErrorType.ZERO_PADDED_FILEMODE);
 		}
 
 		allowRefInWant = rc.getBoolean("uploadpack", "allowrefinwant", false);
 		allowTipSha1InWant = rc.getBoolean(
 				"uploadpack", "allowtipsha1inwant", false);
 		allowReachableSha1InWant = rc.getBoolean(
 				"uploadpack", "allowreachablesha1inwant", false);
 		allowFilter = rc.getBoolean(
 				"uploadpack", "allowfilter", false);
 		protocolVersion = ProtocolVersion.parse(rc
 				.getString(ConfigConstants.CONFIG_PROTOCOL_SECTION, null,
 						ConfigConstants.CONFIG_KEY_VERSION));
 		hideRefs = rc.getStringList("uploadpack", null, "hiderefs");
 		allowSidebandAll = rc.getBoolean(
 				"uploadpack", "allowsidebandall", false);
 		advertiseSidebandAll = rc.getBoolean("uploadpack",
 				"advertisesidebandall", false);
 	}
 
 	/**
 	 * Create checker to verify fetched objects
 	 *
 	 * @return checker to verify fetched objects, or null if checking is not
 	 *         enabled in the repository configuration.
 	 * @since 3.6
 	 */
 	@Nullable
 	public ObjectChecker newObjectChecker() {
 		return newObjectChecker(fetchFsck);
 	}
 
 	/**
 	 * Create checker to verify objects pushed into this repository
 	 *
 	 * @return checker to verify objects pushed into this repository, or null if
 	 *         checking is not enabled in the repository configuration.
 	 * @since 4.2
 	 */
 	@Nullable
 	public ObjectChecker newReceiveObjectChecker() {
 		return newObjectChecker(receiveFsck);
 	}
 
 	private ObjectChecker newObjectChecker(boolean check) {
 		if (!check) {
 			return null;
 		}
 		return new ObjectChecker()
 			.setIgnore(ignore)
 			.setAllowInvalidPersonIdent(allowInvalidPersonIdent)
 			.setSafeForWindows(safeForWindows)
 			.setSafeForMacOS(safeForMacOS)
 			.setSkipList(skipList());
 	}
 
 	private ObjectIdSet skipList() {
 		if (fsckSkipList != null && !fsckSkipList.isEmpty()) {
 			return new LazyObjectIdSetFile(new File(fsckSkipList));
 		}
 		return null;
 	}
 
 	/**
 	 * Whether to allow clients to request non-advertised tip SHA-1s
 	 *
 	 * @return allow clients to request non-advertised tip SHA-1s?
 	 * @since 3.1
 	 */
 	public boolean isAllowTipSha1InWant() {
 		return allowTipSha1InWant;
 	}
 
 	/**
 	 * Whether to allow clients to request non-tip SHA-1s
 	 *
 	 * @return allow clients to request non-tip SHA-1s?
 	 * @since 4.1
 	 */
 	public boolean isAllowReachableSha1InWant() {
 		return allowReachableSha1InWant;
 	}
 
 	/**
 	 * @return true if clients are allowed to specify a "filter" line
 	 * @since 5.0
 	 */
 	public boolean isAllowFilter() {
 		return allowFilter;
 	}
 
 	/**
 	 * @return true if clients are allowed to specify a "want-ref" line
 	 * @since 5.1
 	 */
 	public boolean isAllowRefInWant() {
 		return allowRefInWant;
 	}
 
 	/**
 	 * @return true if the server accepts sideband-all requests (see
 	 *         {{@link #isAdvertiseSidebandAll()} for the advertisement)
 	 * @since 5.5
 	 */
 	public boolean isAllowSidebandAll() {
 		return allowSidebandAll;
 	}
 
 	/**
 	 * @return true to advertise sideband all to the clients
 	 * @since 5.6
 	 */
 	public boolean isAdvertiseSidebandAll() {
 		return advertiseSidebandAll && allowSidebandAll;
 	}
 
 	/**
 	 * Get {@link org.eclipse.jgit.transport.RefFilter} respecting configured
 	 * hidden refs.
 	 *
 	 * @return {@link org.eclipse.jgit.transport.RefFilter} respecting
 	 *         configured hidden refs.
 	 * @since 3.1
 	 */
 	public RefFilter getRefFilter() {
 		if (hideRefs.length == 0)
 			return RefFilter.DEFAULT;
 
 		return new RefFilter() {
 			@Override
 			public Map<String, Ref> filter(Map<String, Ref> refs) {
 				Map<String, Ref> result = new HashMap<>();
 				for (Map.Entry<String, Ref> e : refs.entrySet()) {
 					boolean add = true;
 					for (String hide : hideRefs) {
 						if (e.getKey().equals(hide) || prefixMatch(hide, e.getKey())) {
 							add = false;
 							break;
 						}
 					}
 					if (add)
 						result.put(e.getKey(), e.getValue());
 				}
 				return result;
 			}
 
 			private boolean prefixMatch(String p, String s) {
 				return p.charAt(p.length() - 1) == '/' && s.startsWith(p);
 			}
 		};
 	}
 
 	/**
 	 * Like {@code getRefFilter() == RefFilter.DEFAULT}, but faster.
 	 *
 	 * @return {@code true} if no ref filtering is needed because there
 	 *         are no configured hidden refs.
 	 */
 	boolean hasDefaultRefFilter() {
 		return hideRefs.length == 0;
 	}
 
 	static class FsckKeyNameHolder {
 		private static final Map<String, ObjectChecker.ErrorType> errors;
 
 		static {
 			errors = new HashMap<>();
 			for (ObjectChecker.ErrorType m : ObjectChecker.ErrorType.values()) {
 				errors.put(keyNameFor(m.name()), m);
 			}
 		}
 
 		@Nullable
 		static ObjectChecker.ErrorType parse(String key) {
 			return errors.get(toLowerCase(key));
 		}
 
 		private static String keyNameFor(String name) {
 			StringBuilder r = new StringBuilder(name.length());
 			for (int i = 0; i < name.length(); i++) {
 				char c = name.charAt(i);
 				if (c != '_') {
 					r.append(c);
 				}
 			}
 			return toLowerCase(r.toString());
 		}
 
 		private FsckKeyNameHolder() {
 		}
 	}
 }