package eu.dnetlib.data.mdstore.modular.mongodb.utils;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import com.ximpleware.AutoPilot;
import com.ximpleware.VTDGen;
import com.ximpleware.VTDNav;
import eu.dnetlib.data.mdstore.modular.MDFormatDescription;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

/**
 * Created by sandro on 11/29/16.
 */
public class IndexFieldRecordParser {

    private static final Log log = LogFactory.getLog(IndexFieldRecordParser.class);

    private static List<String> getTextValue(final AutoPilot ap, final VTDNav vn, final String xpath) throws Exception {
        List<String> results = new ArrayList<>();
        ap.selectXPath(xpath);
        while (ap.evalXPath() != -1) {
            int t = vn.getText();
            if (t > -1) results.add(vn.toNormalizedString(t));
        }
        return results;
    }

    public Map<String, List<String>> parseRecord(final String record, final List<MDFormatDescription> mdformats) throws IndexFieldRecordParserException {
        if (mdformats == null || mdformats.size() == 0)
            return null;
        final Map<String, List<String>> result = new HashMap<>();

        try {
            final VTDGen vg = new VTDGen();
            vg.setDoc(record.getBytes());
            vg.parse(true);
            final VTDNav vn = vg.getNav();
            final AutoPilot ap = new AutoPilot(vn);

            for (MDFormatDescription description : mdformats) {
                List<String> xpathResult = getTextValue(ap, vn, description.getXpath());
                result.put(description.getName(), xpathResult);
            }
            return result;
        } catch (Throwable e) {
            throw new IndexFieldRecordParserException("Cannot index record", e);
        }
    }


}