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/*
    This file is part of the iText (R) project.
    Copyright (c) 1998-2023 iText Group NV
    Authors: Bruno Lowagie, Paulo Soares, et al.

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU Affero General Public License version 3
    as published by the Free Software Foundation with the addition of the
    following permission added to Section 15 as permitted in Section 7(a):
    FOR ANY PART OF THE COVERED WORK IN WHICH THE COPYRIGHT IS OWNED BY
    ITEXT GROUP. ITEXT GROUP DISCLAIMS THE WARRANTY OF NON INFRINGEMENT
    OF THIRD PARTY RIGHTS

    This program is distributed in the hope that it will be useful, but
    WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
    or FITNESS FOR A PARTICULAR PURPOSE.
    See the GNU Affero General Public License for more details.
    You should have received a copy of the GNU Affero General Public License
    along with this program; if not, see http://www.gnu.org/licenses or write to
    the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
    Boston, MA, 02110-1301 USA, or download the license from the following URL:
    http://itextpdf.com/terms-of-use/

    The interactive user interfaces in modified source and object code versions
    of this program must display Appropriate Legal Notices, as required under
    Section 5 of the GNU Affero General Public License.

    In accordance with Section 7(b) of the GNU Affero General Public License,
    a covered work must retain the producer line in every PDF that is created
    or manipulated using iText.

    You can be released from the requirements of the license by purchasing
    a commercial license. Buying such a license is mandatory as soon as you
    develop commercial activities involving the iText software without
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 */
package com.itextpdf.styledxmlparser.css.parse;

import com.itextpdf.commons.utils.MessageFormatUtil;
import com.itextpdf.styledxmlparser.logs.StyledXmlParserLogMessageConstant;
import com.itextpdf.styledxmlparser.css.CssDeclaration;
import com.itextpdf.styledxmlparser.css.CssRuleSet;
import com.itextpdf.styledxmlparser.css.selector.CssSelector;
import com.itextpdf.styledxmlparser.css.util.CssUtils;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.util.ArrayList;
import java.util.List;

/**
 * Utilities class to parse CSS rule sets.
 */
public final class CssRuleSetParser {

    /**
     * The logger.
     */
    private static final Logger logger = LoggerFactory.getLogger(CssRuleSetParser.class);

    /**
     * Creates a new {@link CssRuleSetParser} instance.
     */
    private CssRuleSetParser() {
    }

    /**
     * Parses property declarations.
     *
     * @param propertiesStr the property declarations in the form of a {@link String}
     * @return the list of {@link CssDeclaration} instances
     */
    public static List parsePropertyDeclarations(String propertiesStr) {
        List declarations = new ArrayList<>();
        int openedCommentPos = propertiesStr.indexOf("/*", 0);
        if (openedCommentPos != -1) {
            declarations.addAll(parsePropertyDeclarations(propertiesStr.substring(0, openedCommentPos)));
            int closedCommentPos = propertiesStr.indexOf("*/", openedCommentPos);
            if (closedCommentPos != -1) {
                declarations.addAll(parsePropertyDeclarations(propertiesStr.substring(closedCommentPos + 2, propertiesStr.length())));
            }
        } else {
            int pos = getSemicolonPosition(propertiesStr, 0);
            while (pos != -1) {
                String[] propertySplit = splitCssProperty(propertiesStr.substring(0, pos));
                if (propertySplit != null) {
                    declarations.add(new CssDeclaration(propertySplit[0], propertySplit[1]));
                }
                propertiesStr = propertiesStr.substring(pos + 1);
                pos = getSemicolonPosition(propertiesStr, 0);
            }
            if (!propertiesStr.replaceAll("[\\n\\r\\t ]", "").isEmpty()) {
                String[] propertySplit = splitCssProperty(propertiesStr);
                if (propertySplit != null) {
                    declarations.add(new CssDeclaration(propertySplit[0], propertySplit[1]));
                }
                return declarations;
            }
        }
        return declarations;
    }


    /**
     * Parses a rule set into a list of {@link CssRuleSet} instances.
     * This method returns a {@link List} because a selector can
     * be compound, like "p, div, #navbar".
     *
     * @param selectorStr   the selector
     * @param propertiesStr the properties
     * @return the resulting list of {@link CssRuleSet} instances
     */
    public static List parseRuleSet(String selectorStr, String propertiesStr) {
        List declarations = parsePropertyDeclarations(propertiesStr);
        List ruleSets = new ArrayList<>();

        //check for rules like p, {…}
        String[] selectors = selectorStr.split(",");
        for (int i = 0; i < selectors.length; i++) {
            selectors[i] = CssUtils.removeDoubleSpacesAndTrim(selectors[i]);
            if (selectors[i].length() == 0)
                return ruleSets;
        }
        for (String currentSelectorStr : selectors) {
            try {
                ruleSets.add(new CssRuleSet( new CssSelector(currentSelectorStr), declarations));
            } catch (Exception exc) {
                logger.error(MessageFormatUtil.format(StyledXmlParserLogMessageConstant.ERROR_PARSING_CSS_SELECTOR,
                        currentSelectorStr), exc);
                //if any separated selector has errors, all others become invalid.
                //in this case we just clear map, it is the easies way to support this.
                declarations.clear();
                return ruleSets;
            }
        }

        return ruleSets;
    }

    /**
     * Splits CSS properties into an array of {@link String} values.
     *
     * @param property the properties
     * @return the array of property values
     */
    private static String[] splitCssProperty(String property) {
        if (property.trim().isEmpty()) {
            return null;
        }
        String[] result = new String[2];
        int position = property.indexOf(":");
        if (position < 0) {
            logger.error(MessageFormatUtil.format(StyledXmlParserLogMessageConstant.INVALID_CSS_PROPERTY_DECLARATION,
                    property.trim()));
            return null;
        }
        result[0] = property.substring(0, position);
        result[1] = property.substring(position + 1);

        return result;
    }

    /**
     * Gets the semicolon position.
     *
     * @param propertiesStr the properties
     * @param fromIndex     the from index
     * @return the semicolon position
     */
    private static int getSemicolonPosition(String propertiesStr, int fromIndex) {
        int semiColonPos = propertiesStr.indexOf(";", fromIndex);
        int closedBracketPos = propertiesStr.indexOf(")", semiColonPos + 1);
        int openedBracketPos = propertiesStr.indexOf("(", fromIndex);
        if (semiColonPos != -1 && openedBracketPos < semiColonPos && closedBracketPos > 0) {
            int nextOpenedBracketPos = openedBracketPos;
            do {
                openedBracketPos = nextOpenedBracketPos;
                nextOpenedBracketPos = propertiesStr.indexOf("(", openedBracketPos + 1);
            } while (nextOpenedBracketPos < closedBracketPos && nextOpenedBracketPos > 0);
        }
        if (semiColonPos != -1 && semiColonPos > openedBracketPos && semiColonPos < closedBracketPos) {
            return getSemicolonPosition(propertiesStr, closedBracketPos + 1);
        }
        return semiColonPos;
    }
}




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