/*
 * Copyright (C) 2014, Andrey Loskutov <loskutov@gmx.de> 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.ignore;

import static org.eclipse.jgit.ignore.IMatcher.NO_MATCH;
import static org.eclipse.jgit.ignore.internal.Strings.isDirectoryPattern;
import static org.eclipse.jgit.ignore.internal.Strings.stripTrailing;
import static org.eclipse.jgit.ignore.internal.Strings.stripTrailingWhitespace;

import org.eclipse.jgit.errors.InvalidPatternException;
import org.eclipse.jgit.ignore.internal.PathMatcher;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

"Fast" (compared with IgnoreRule) git ignore rule implementation supporting also double star ** pattern. 

This class is immutable and thread safe.
Since:
3.6/**
 * "Fast" (compared with IgnoreRule) git ignore rule implementation supporting
 * also double star {@code **} pattern.
 * <p>
 * This class is immutable and thread safe.
 *
 * @since 3.6
 */
public class FastIgnoreRule {
	private static final Logger LOG = LoggerFactory
			.getLogger(FastIgnoreRule.class);

	
Character used as default path separator for ignore entries
/**
	 * Character used as default path separator for ignore entries
	 */
	public static final char PATH_SEPARATOR = '/';

	private final IMatcher matcher;

	private final boolean inverse;

	private final boolean dirOnly;

	
Constructor for FastIgnoreRule
Params:
pattern – 
           ignore pattern as described in git manual. If pattern is invalid or is not a pattern
           (comment), this rule doesn't match anything./**
	 * Constructor for FastIgnoreRule
	 *
	 * @param pattern
	 *            ignore pattern as described in <a href=
	 *            "https://www.kernel.org/pub/software/scm/git/docs/gitignore.html"
	 *            >git manual</a>. If pattern is invalid or is not a pattern
	 *            (comment), this rule doesn't match anything.
	 */
	public FastIgnoreRule(String pattern) {
		if (pattern == null)
			throw new IllegalArgumentException("Pattern must not be null!"); //$NON-NLS-1$
		if (pattern.length() == 0) {
			dirOnly = false;
			inverse = false;
			this.matcher = NO_MATCH;
			return;
		}
		inverse = pattern.charAt(0) == '!';
		if (inverse) {
			pattern = pattern.substring(1);
			if (pattern.length() == 0) {
				dirOnly = false;
				this.matcher = NO_MATCH;
				return;
			}
		}
		if (pattern.charAt(0) == '#') {
			this.matcher = NO_MATCH;
			dirOnly = false;
			return;
		}
		if (pattern.charAt(0) == '\\' && pattern.length() > 1) {
			char next = pattern.charAt(1);
			if (next == '!' || next == '#') {
				// remove backslash escaping first special characters
				pattern = pattern.substring(1);
			}
		}
		dirOnly = isDirectoryPattern(pattern);
		if (dirOnly) {
			pattern = stripTrailingWhitespace(pattern);
			pattern = stripTrailing(pattern, PATH_SEPARATOR);
			if (pattern.length() == 0) {
				this.matcher = NO_MATCH;
				return;
			}
		}
		IMatcher m;
		try {
			m = PathMatcher.createPathMatcher(pattern,
					Character.valueOf(PATH_SEPARATOR), dirOnly);
		} catch (InvalidPatternException e) {
			m = NO_MATCH;
			LOG.error(e.getMessage(), e);
		}
		this.matcher = m;
	}

	
Returns true if a match was made. 
 This function does NOT return the actual ignore status of the target! Please consult getResult() for the negation status. The actual ignore status may be true or false depending on whether this rule is an ignore rule or a negation rule. 
Params:
path – 
           Name pattern of the file, relative to the base directory of
           this rule
directory – 
           Whether the target file is a directory or not
Returns:
True if a match was made. This does not necessarily mean that the target is ignored. Call getResult() for the result./**
	 * Returns true if a match was made. <br>
	 * This function does NOT return the actual ignore status of the target!
	 * Please consult {@link #getResult()} for the negation status. The actual
	 * ignore status may be true or false depending on whether this rule is an
	 * ignore rule or a negation rule.
	 *
	 * @param path
	 *            Name pattern of the file, relative to the base directory of
	 *            this rule
	 * @param directory
	 *            Whether the target file is a directory or not
	 * @return True if a match was made. This does not necessarily mean that the
	 *         target is ignored. Call {@link #getResult() getResult()} for the
	 *         result.
	 */
	public boolean isMatch(String path, boolean directory) {
		return isMatch(path, directory, false);
	}

	
Returns true if a match was made. 
 This function does NOT return the actual ignore status of the target! Please consult getResult() for the negation status. The actual ignore status may be true or false depending on whether this rule is an ignore rule or a negation rule. 
Params:
path – 
           Name pattern of the file, relative to the base directory of
           this rule
directory – 
           Whether the target file is a directory or not
pathMatch –  true if the match is for the full path: see IMatcher.matches(String, int, int)
Returns:
True if a match was made. This does not necessarily mean that the target is ignored. Call getResult() for the result.
Since:
4.11/**
	 * Returns true if a match was made. <br>
	 * This function does NOT return the actual ignore status of the target!
	 * Please consult {@link #getResult()} for the negation status. The actual
	 * ignore status may be true or false depending on whether this rule is an
	 * ignore rule or a negation rule.
	 *
	 * @param path
	 *            Name pattern of the file, relative to the base directory of
	 *            this rule
	 * @param directory
	 *            Whether the target file is a directory or not
	 * @param pathMatch
	 *            {@code true} if the match is for the full path: see
	 *            {@link IMatcher#matches(String, int, int)}
	 * @return True if a match was made. This does not necessarily mean that the
	 *         target is ignored. Call {@link #getResult() getResult()} for the
	 *         result.
	 * @since 4.11
	 */
	public boolean isMatch(String path, boolean directory, boolean pathMatch) {
		if (path == null)
			return false;
		if (path.length() == 0)
			return false;
		boolean match = matcher.matches(path, directory, pathMatch);
		return match;
	}

	
Whether the pattern is just a file name and not a path
Returns:
true if the pattern is just a file name and not a path/**
	 * Whether the pattern is just a file name and not a path
	 *
	 * @return {@code true} if the pattern is just a file name and not a path
	 */
	public boolean getNameOnly() {
		return !(matcher instanceof PathMatcher);
	}

	
Whether the pattern should match directories only
Returns:
true if the pattern should match directories only/**
	 * Whether the pattern should match directories only
	 *
	 * @return {@code true} if the pattern should match directories only
	 */
	public boolean dirOnly() {
		return dirOnly;
	}

	
Indicates whether the rule is non-negation or negation.
Returns:
True if the pattern had a "!" in front of it/**
	 * Indicates whether the rule is non-negation or negation.
	 *
	 * @return True if the pattern had a "!" in front of it
	 */
	public boolean getNegation() {
		return inverse;
	}

	
Indicates whether the rule is non-negation or negation.
Returns:
True if the target is to be ignored, false otherwise./**
	 * Indicates whether the rule is non-negation or negation.
	 *
	 * @return True if the target is to be ignored, false otherwise.
	 */
	public boolean getResult() {
		return !inverse;
	}

	
Whether the rule never matches
Returns:
true if the rule never matches (comment line or broken pattern)
Since:
4.1/**
	 * Whether the rule never matches
	 *
	 * @return {@code true} if the rule never matches (comment line or broken
	 *         pattern)
	 * @since 4.1
	 */
	public boolean isEmpty() {
		return matcher == NO_MATCH;
	}

	
{@inheritDoc} /** {@inheritDoc} */
	@Override
	public String toString() {
		StringBuilder sb = new StringBuilder();
		if (inverse)
			sb.append('!');
		sb.append(matcher);
		if (dirOnly)
			sb.append(PATH_SEPARATOR);
		return sb.toString();

	}

	
{@inheritDoc} /** {@inheritDoc} */
	@Override
	public int hashCode() {
		final int prime = 31;
		int result = 1;
		result = prime * result + (inverse ? 1231 : 1237);
		result = prime * result + (dirOnly ? 1231 : 1237);
		result = prime * result + ((matcher == null) ? 0 : matcher.hashCode());
		return result;
	}

	
{@inheritDoc} /** {@inheritDoc} */
	@Override
	public boolean equals(Object obj) {
		if (this == obj)
			return true;
		if (!(obj instanceof FastIgnoreRule))
			return false;

		FastIgnoreRule other = (FastIgnoreRule) obj;
		if (inverse != other.inverse)
			return false;
		if (dirOnly != other.dirOnly)
			return false;
		return matcher.equals(other.matcher);
	}
}