package io.gitlab.jfronny.inceptum.launcher.util.gitignore;

import java.util.List;
import java.util.function.Predicate;
import java.util.regex.Pattern;

public class IgnoreRule {
    private static final List<Replacer> REPLACERS = List.of(
            Replacers.TRAILING_SPACES,
            Replacers.ESCAPED_SPACES,
            Replacers.LITERAL_DOT,
            Replacers.LITERAL_PLUS,

            // probably not needed
            // Replacers.METACHARACTERS,
            Replacers.QUESTION_MARK,
            Replacers.NON_LEADING_SINGLE_STAR,
            Replacers.LEADING_SINGLE_STAR,
            Replacers.LEADING_DOUBLE_STAR,

            // probably not needed
            // Replacers.METACHARACTER_SLASH_AFTER_LEADING_SLASH,
            Replacers.MIDDLE_DOUBLE_STAR,
            Replacers.LEADING_SLASH,
            Replacers.TRAILING_DOUBLE_STAR,
            Replacers.OTHER_DOUBLE_STAR,
            Replacers.MIDDLE_SLASH,
            Replacers.TRAILING_SLASH,
            Replacers.NO_SLASH,
            Replacers.NO_TRAILING_SLASH,
            Replacers.ENDING
    );

    private final Predicate<String> parsedRegex;
    public final boolean negate;

    /**
     * Initializes a new instance of the IgnoreRule class.
     * Parses the given pattern as per .gitignore spec.
     *
     * @param pattern Pattern to parse
     */
    public IgnoreRule(String pattern) {
        if (pattern == null || pattern.isBlank() || pattern.startsWith("#")) { // Ignore comments and empty lines
            parsedRegex = s -> false;
            negate = false;
            return;
        }
        boolean isNegate = false;
        if (pattern.startsWith("\\!") || pattern.startsWith("\\#")) {
            pattern = pattern.substring(1);
        } else if (pattern.startsWith("!")) {
            isNegate = true;
            pattern = pattern.substring(1);
        }
        negate = isNegate;
        for (Replacer replacer : REPLACERS) {
            try {
                pattern = replacer.invoke(pattern);
            } catch (Throwable t) {
                throw new RuntimeException("Could not execute replacer " + replacer.getName() + " (" + replacer.getRegex() + ") on " + pattern, t);
            }
        }

        parsedRegex = Pattern.compile(pattern, Pattern.CASE_INSENSITIVE).asMatchPredicate();
    }

    public boolean isMatch(String input) {
        return parsedRegex.test(input);
    }
}