/*
 * This file is part of ***  M y C o R e  ***
 * See http://www.mycore.de/ for details.
 *
 * MyCoRe is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * MyCoRe 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with MyCoRe.  If not, see <http://www.gnu.org/licenses/>.
 */

package org.mycore.mods.bibtex;

import java.util.Locale;
import java.util.Objects;

import org.jdom2.Element;
import org.jdom2.filter.Filters;
import org.jdom2.xpath.XPathExpression;
import org.jdom2.xpath.XPathFactory;
import org.mycore.common.MCRConstants;

import bibtex.dom.BibtexEntry;

/**
 * Transforms the BibTeX entry type to mods:genre element(s).
 *
 * @author Frank Lützenkirchen
 */
class MCRGenreTransformer {

    static void setGenre(BibtexEntry entry, Element mods) {
        String type = entry.getEntryType().toLowerCase(Locale.ROOT);
        MCRFieldTransformer.buildElement("mods:genre", type, mods);
    }

    static void fixHostGenre(BibtexEntry entry, Element mods) {
        String type = entry.getEntryType().toLowerCase(Locale.ROOT);
        if (Objects.equals(type, "incollection") || Objects.equals(type, "inproceedings")
            || Objects.equals(type, "inbook")) {
            type = type.substring(2);

            Element genre = getHostGenre(mods);
            if (genre != null) {
                genre.setText(type);
            } else {
                MCRFieldTransformer.buildElement("mods:relatedItem[@type='host']/mods:genre", type, mods);
            }
        }
    }

    private static Element getHostGenre(Element mods) {
        XPathExpression<Element> expr = XPathFactory.instance().compile("mods:relatedItem[@type='host']/mods:genre",
            Filters.element(), null, MCRConstants.getStandardNamespaces());
        return expr.evaluateFirst(mods);
    }
}
