// indexWord.java
// (C) 2008 by Michael Peter Christen; mc@yacy.net, Frankfurt a. M., Germany
// first published 26.03.2008 on http://yacy.net
//
// This is a part of YaCy, a peer-to-peer based web search engine
//
// $LastChangedDate: 2006-04-02 22:40:07 +0200 (So, 02 Apr 2006) $
// $LastChangedRevision: 1986 $
// $LastChangedBy: orbiter $
//
// LICENSE
// 
// This program 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 2 of the License, or
// (at your option) any later version.
//
// 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

package de.anomic.index;

import java.util.HashSet;
import java.util.Iterator;
import java.util.Set;
import java.util.TreeSet;

import de.anomic.kelondro.kelondroBase64Order;
import de.anomic.kelondro.kelondroBitfield;
import de.anomic.server.serverCodings;
import de.anomic.yacy.yacySeedDB;

public class indexWord {

    // object carries statistics for words and sentences
    
    public  int              count;       // number of occurrences
    public  int              posInText;   // unique handle, is initialized with word position (excluding double occurring words)
    public  int              posInPhrase; // position of word in phrase
    public  int              numOfPhrase; // number of phrase. 'normal' phrases begin with number 100
    HashSet<Integer>         phrases;        // a set of handles to all phrases where this word appears
    public  kelondroBitfield flags;       // the flag bits for each word

    public indexWord(int handle, int pip, int nop) {
        this.count = 1;
        this.posInText = handle;
        this.posInPhrase = pip;
        this.numOfPhrase = nop;
        this.phrases = new HashSet<Integer>();
        this.flags = null;
    }

    public void inc() {
        count++;
    }
    
    public int occurrences() {
        return count;
    }

    public void check(int i) {
        phrases.add(new Integer(i));
    }

    public Iterator<Integer> phrases() {
        // returns an iterator to handles of all phrases where the word appears
        return phrases.iterator();
    }
    
    // static methods

    // create a word hash
    public static final String word2hash(String word) {
        return kelondroBase64Order.enhancedCoder.encode(serverCodings.encodeMD5Raw(word.toLowerCase())).substring(0, yacySeedDB.commonHashLength);
    }
    
    public static final Set<String> words2hashSet(String[] words) {
        TreeSet<String> hashes = new TreeSet<String>(kelondroBase64Order.enhancedComparator);
        for (int i = 0; i < words.length; i++) hashes.add(word2hash(words[i]));
        return hashes;
    }

    public static final String words2hashString(String[] words) {
        StringBuffer sb = new StringBuffer();
        for (int i = 0; i < words.length; i++) sb.append(word2hash(words[i]));
        return new String(sb);
    }

    public static final TreeSet<String> words2hashes(Set<String> words) {
        Iterator<String> i = words.iterator();
        TreeSet<String> hashes = new TreeSet<String>(kelondroBase64Order.enhancedComparator);
        while (i.hasNext()) hashes.add(word2hash(i.next()));
        return hashes;
    }
}