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/***************************************************************************
 *   Copyright (C) 2010-2015 by                                            *
 *      Itamar Syn-Hershko                      *
 *                                                                         *
 *   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.              *
 *                                                                         *
 *   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                          *
 *   .                                       *
 **************************************************************************/
package org.apache.lucene.analysis.hebrew;

import com.code972.hebmorph.*;
import com.code972.hebmorph.datastructures.DictHebMorph;
import com.code972.hebmorph.datastructures.DictRadix;
import com.code972.hebmorph.lemmafilters.BasicLemmaFilter;
import org.apache.lucene.analysis.Analyzer;
import org.apache.lucene.analysis.util.CharArraySet;
import org.apache.lucene.analysis.util.WordlistLoader;
import org.apache.lucene.util.IOUtils;

import java.io.IOException;
import java.io.InputStream;
import java.nio.charset.StandardCharsets;
import java.util.HashMap;
import java.util.List;

public abstract class HebrewAnalyzer extends Analyzer {
    private static final Byte dummyData = (byte) 0;

    protected DictHebMorph dict;
    protected final char originalTermSuffix = '$';
    protected DictRadix SPECIAL_TOKENIZATION_CASES = null;

    protected CharArraySet commonWords = null;

    public DictRadix setCustomTokenizationCases(InputStream input) throws IOException {
        if (input != null) {
            final CharArraySet wordsList = WordlistLoader.getSnowballWordSet(IOUtils.getDecodingReader(
                    input, StandardCharsets.UTF_8));

            final DictRadix radix = new DictRadix<>(false);
            for (Object aWordsList : wordsList) {
                radix.addNode((char[]) aWordsList, dummyData);
            }
            SPECIAL_TOKENIZATION_CASES = radix;
        }
        return SPECIAL_TOKENIZATION_CASES;
    }

    protected HebrewAnalyzer(DictHebMorph dict) throws IOException {
        this.dict = dict;
    }

    public HebrewAnalyzer() throws IOException {
        this(DictionaryLoader.lookForDefaultDictionary());
    }

    public static boolean isHebrewWord(final CharSequence word) {
        for (int i = 0; i < word.length(); i++) {
            if (HebrewUtils.isHebrewLetter(word.charAt(i)))
                return true;
        }
        return false;
    }

    public WordType isRecognizedWord(final String word, final boolean tolerate) {
        return isRecognizedWord(word, tolerate, this.dict);
    }

    public static WordType isRecognizedWord(final String word, final boolean tolerate, final DictHebMorph dict) {
        byte prefLen = 0;
        Integer prefixMask;
        MorphData md;
        HashMap prefixesTree = dict.getPref();
        DictRadix dictRadix = dict.getRadix();

        if (!isHebrewWord(word))
            return WordType.NON_HEBREW;

        try {
            if (dict.lookup(word) != null) return WordType.HEBREW;
        } catch (IllegalArgumentException ignored_ex) {
        }

        if (word.endsWith("'")) { // Try ommitting closing Geresh
            try {
                if (dict.lookup(word.substring(0, word.length() - 1)) != null) return WordType.HEBREW;
            } catch (IllegalArgumentException ignored_ex) {
            }
        }

        prefLen = 0;
        while (true) {
            // Make sure there are at least 2 letters left after the prefix (the words של, שלא for example)
            if (word.length() - prefLen < 2)
                break;

            if ((prefixMask = prefixesTree.get(word.substring(0, ++prefLen))) == null)
                break;

            try {
                md = dict.lookup(word.substring(prefLen));
            } catch (IllegalArgumentException e) {
                md = null;
            }
            if ((md != null) && ((md.getPrefixes() & prefixMask) > 0)) {
                for (int result = 0; result < md.getLemmas().length; result++) {
                    if ((md.getLemmas()[result].getPrefix().getValue() & prefixMask) > 0) {
                        return WordType.HEBREW_WITH_PREFIX;
                    }
                }
            }
        }

        if (tolerate) {
            // Don't try tolerating long words. Longest Hebrew word is 19 chars long
            // http://en.wikipedia.org/wiki/Longest_words#Hebrew
            if (word.length() > 20) {
                return WordType.UNRECOGNIZED;
            }

            List.LookupResult> tolerated = dictRadix.lookupTolerant(word, LookupTolerators.TolerateEmKryiaAll);
            if (tolerated != null && tolerated.size() > 0) {
                return WordType.HEBREW_TOLERATED;
            }

            prefLen = 0;
            while (true) {
                // Make sure there are at least 2 letters left after the prefix (the words של, שלא for example)
                if (word.length() - prefLen < 2)
                    break;

                if ((prefixMask = prefixesTree.get(word.substring(0, ++prefLen))) == null)
                    break;

                tolerated = dictRadix.lookupTolerant(word.substring(prefLen), LookupTolerators.TolerateEmKryiaAll);
                if (tolerated != null) {
                    for (DictRadix.LookupResult lr : tolerated) {
                        for (int result = 0; result < lr.getData().getLemmas().length; result++) {
                            if ((lr.getData().getLemmas()[result].getPrefix().getValue() & prefixMask) > 0) {
                                return WordType.HEBREW_TOLERATED_WITH_PREFIX;
                            }
                        }
                    }
                }
            }
        }
        return WordType.UNRECOGNIZED;
    }
}