package org.vufind.index;
/**
 * Indexing routines for dealing with SolrMarc field specs.
 *
 * Copyright (C) Villanova University 2017.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2,
 * as published by the Free Software Foundation.
 *
 * 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 */

import org.marc4j.marc.Record;
import org.marc4j.marc.DataField;
import org.marc4j.marc.Subfield;
import org.marc4j.marc.VariableField;

import org.solrmarc.index.extractor.formatter.FieldFormatter;
import org.solrmarc.index.extractor.formatter.FieldFormatterBase;
import org.solrmarc.index.extractor.formatter.FieldFormatter.eCleanVal;
import org.solrmarc.index.SolrIndexer;

import java.lang.StringBuilder;
import java.util.HashMap;
import java.util.LinkedHashSet;
import java.util.List;
import java.util.Set;

/**
 * Indexing routines for dealing with SolrMarc field specs.
 */
public class FieldSpecTools
{
    /**
     * Parse a SolrMarc fieldspec into a map of tag name to set of subfield strings
     * (note that we need to map to a set rather than a single string, because the
     * same tag may repeat with different subfields to extract different sections
     * of the same field into distinct values).
     *
     * @param tagList The field specification to parse
     * @return HashMap
     */
    public static HashMap<String, Set<String>> getParsedTagList(String tagList)
    {
        String[] tags = tagList.split(":");//convert string input to array
        HashMap<String, Set<String>> tagMap = new HashMap<String, Set<String>>();
        //cut tags array up into key/value pairs in hash map
        Set<String> currentSet;
        for(int i = 0; i < tags.length; i++){
            String tag = tags[i].substring(0, 3);
            if (!tagMap.containsKey(tag)) {
                currentSet = new LinkedHashSet<String>();
                tagMap.put(tag, currentSet);
            } else {
                currentSet = tagMap.get(tag);
            }
            currentSet.add(tags[i].substring(3));
        }
        return tagMap;
    }

    /**
     * Get field data specified by a SolrMarc tag list
     *
     * @param record  Record
     * @param tagList The field specification
     *
     * @return Set
     */
    public static final Set<String> getFieldsByTagList(final Record record, final String tagList)
    {
        return getFieldsByTagList(record, tagList, false);
    }

    /**
     * Get field data specified by a SolrMarc tag list
     *
     * @param record          Record
     * @param tagList         The field specification
     * @param removeNonFiling Whether to remove non-filing characters
     *
     * @return Set
     */
    public static final Set<String> getFieldsByTagList(final Record record, final String tagList, Boolean removeNonFiling)
    {
        Set<String> result = new LinkedHashSet<String>();
        final HashMap<String, Set<String>> parsedTagList = getParsedTagList(tagList);
        final FieldFormatter formatter = removeNonFiling
            ? new FieldFormatterBase(false).addCleanVal(eCleanVal.STRIP_INDICATOR) : null;
        for (VariableField variableField : SolrIndexer.instance().getFieldSetMatchingTagList(record, tagList)) {
            DataField field = (DataField) variableField;
            for (String subfields : parsedTagList.get(field.getTag())) {
                String current = getFieldData(field, subfields, formatter);
                if (null != current) {
                    result.add(current);
                }
            }
        }
        return result;
    }

    /**
     * Get subfields from a data field
     *
     * @param dataFiel     Data field
     * @param subfieldCode Subfield codes to get
     * @param formatter    Formatter to use (or null)
     *
     * @return Set
     */
    protected static final String getFieldData(DataField dataField, String subfieldCodes, FieldFormatter formatter)
    {
        StringBuilder result = new StringBuilder(64);
        final List<Subfield> subfields = dataField.getSubfields();
        for (Subfield subfield : subfields) {
            final char subfieldCode = subfield.getCode();
            if (subfieldCodes.indexOf(subfieldCode) != -1) {
                if (result.length() > 0) {
                    result.append(' ');
                }
                final String subfieldData = subfield.getData().trim();
                if (null != formatter) {
                    result.append(formatter.cleanData(dataField, 'a' == subfieldCode, subfieldData));
                } else {
                    result.append(subfieldData);
                }
            }
        }

        return result.length() > 0 ? result.toString() : null;
    }
}