package vkc.analyse;


/* ====================================================================
 * The Apache Software License, Version 1.1
 *
 * Copyright (c) 2001 The Apache Software Foundation.  All rights
 * reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution,
 *    if any, must include the following acknowledgment:
 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowledgment may appear in the software itself,
 *    if and wherever such third-party acknowledgments normally appear.
 *
 * 4. The names "Apache" and "Apache Software Foundation" and
 *    "Apache Lucene" must not be used to endorse or promote products
 *    derived from this software without prior written permission. For
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 *
 * 5. Products derived from this software may not be called "Apache",
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 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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 *
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/*

   Porter stemmer in Java. The original paper is in

       Porter, 1980, An algorithm for suffix stripping, Program, Vol. 14,
       no. 3, pp 130-137,

   See also http://www.muscat.com/~martin/stem.html

   Bug 1 (reported by Gonzalo Parra 16/10/99) fixed as marked below.
   Tthe words 'aed', 'eed', 'oed' leave k at 'a' for step 3, and b[k-1]
   is then out outside the bounds of b.

   Similarly,

   Bug 2 (reported by Steve Dyrdahl 22/2/00) fixed as marked below.
   'ion' by itself leaves j = -1 in the test for 'ion' in step 5, and
   b[j] is then outside the bounds of b.

   Release 3.

   [ This version is derived from Release 3, modified by Brian Goetz to 
     optimize for fewer object creations.  ]

*/
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;

import vkc.misc.VKCLogManager;


/**
 * Stemmer, implementing the Porter Stemming Algorithm The Stemmer class
 * transforms a word into its root form.  The input word can be provided a
 * character at time (by calling add()), or at once by calling one of the
 * various stem(something) methods.
 */
public class PorterStemmer {
    private static final int INC = 50; /* unit of size whereby b is increased */
    private static final int EXTRA = 1;
    private char[] b;
    private int i;
    private int j;
    private int k;
    private int k0;
    private boolean dirty = false;

    public PorterStemmer() {
        b = new char[INC];
        i = 0;
    }

    /**
     * reset() resets the stemmer so it can stem another word.  If you invoke
     * the stemmer by calling add(char) and then stem(), you must call reset()
     * before starting another word.
     */
    public void reset() {
        i = 0;
        dirty = false;
    }

    /**
     * Add a character to the word being stemmed.  When you are finished
     * adding characters, you can call stem(void) to process the word.
     */
    public void add(char ch) {
        if (b.length <= (i + EXTRA)) {
            char[] new_b = new char[b.length + INC];

            for (int c = 0; c < b.length; c++)
                new_b[c] = b[c];

            b = new_b;
        }

        b[i++] = ch;
    }

    /**
     * After a word has been stemmed, it can be retrieved by toString(),  or a
     * reference to the internal buffer can be retrieved by getResultBuffer
     * and getResultLength (which is generally more efficient.)
     */
    public String toString() {
        return new String(b, 0, i);
    }

    /**
     * Returns the length of the word resulting from the stemming process.
     */
    public int getResultLength() {
        return i;
    }

    /**
     * Returns a reference to a character buffer containing the results of the
     * stemming process.  You also need to consult getResultLength() to
     * determine the length of the result.
     */
    public char[] getResultBuffer() {
        return b;
    }

    /* cons(i) is true <=> b[i] is a consonant. */
    private final boolean cons(int i) {
        switch (b[i]) {
        case 'a':
        case 'e':
        case 'i':
        case 'o':
        case 'u':
            return false;

        case 'y':
            return (i == k0) ? true : (!cons(i - 1));

        default:
            return true;
        }
    }

    /* m() measures the number of consonant sequences between k0 and j. if c is
   a consonant sequence and v a vowel sequence, and <..> indicates arbitrary
   presence,

        <c><v>       gives 0
        <c>vc<v>     gives 1
        <c>vcvc<v>   gives 2
        <c>vcvcvc<v> gives 3
        ....
*/
    private final int m() {
        int n = 0;
        int i = k0;

        while (true) {
            if (i > j) {
                return n;
            }

            if (!cons(i)) {
                break;
            }

            i++;
        }

        i++;

        while (true) {
            while (true) {
                if (i > j) {
                    return n;
                }

                if (cons(i)) {
                    break;
                }

                i++;
            }

            i++;
            n++;

            while (true) {
                if (i > j) {
                    return n;
                }

                if (!cons(i)) {
                    break;
                }

                i++;
            }

            i++;
        }
    }

    /* vowelinstem() is true <=> k0,...j contains a vowel */
    private final boolean vowelinstem() {
        int i;

        for (i = k0; i <= j; i++)
            if (!cons(i)) {
                return true;
            }

        return false;
    }

    /* doublec(j) is true <=> j,(j-1) contain a double consonant. */
    private final boolean doublec(int j) {
        if (j < (k0 + 1)) {
            return false;
        }

        if (b[j] != b[j - 1]) {
            return false;
        }

        return cons(j);
    }

    /* cvc(i) is true <=> i-2,i-1,i has the form consonant - vowel - consonant
   and also if the second c is not w,x or y. this is used when trying to
   restore an e at the end of a short word. e.g.

        cav(e), lov(e), hop(e), crim(e), but
        snow, box, tray.

*/
    private final boolean cvc(int i) {
        if ((i < (k0 + 2)) || !cons(i) || cons(i - 1) || !cons(i - 2)) {
            return false;
        } 

        int ch = b[i];

        if ((ch == 'w') || (ch == 'x') || (ch == 'y')) {
            return false;
        }

        return true;
    }

    private final boolean ends(String s) {
        int l = s.length();
        int o = k - l + 1;

        if (o < k0) {
            return false;
        }

        for (int i = 0; i < l; i++)
            if (b[o + i] != s.charAt(i)) {
                return false;
            }

        j = k - l;

        return true;
    }

    /* setto(s) sets (j+1),...k to the characters in the string s, readjusting
   k. */
    void setto(String s) {
        int l = s.length();
        int o = j + 1;

        for (int i = 0; i < l; i++)
            b[o + i] = s.charAt(i);

        k = j + l;
        dirty = true;
    }

    /* r(s) is used further down. */
    void r(String s) {
        if (m() > 0) {
            setto(s);
        }
    }

    /* step1() gets rid of plurals and -ed or -ing. e.g.

         caresses  ->  caress
         ponies    ->  poni
         ties      ->  ti
         caress    ->  caress
         cats      ->  cat

         feed      ->  feed
         agreed    ->  agree
         disabled  ->  disable

         matting   ->  mat
         mating    ->  mate
         meeting   ->  meet
         milling   ->  mill
         messing   ->  mess

         meetings  ->  meet

*/
    private final void step1() {
        if (b[k] == 's') {
            if (ends("sses")) {
                k -= 2;
            } else if (ends("ies")) {
                setto("i");
            } else if (b[k - 1] != 's') {
                k--;
            }
        }

        if (ends("eed")) {
            if (m() > 0) {
                k--;
            }
        } else if ((ends("ed") || ends("ing")) && vowelinstem()) {
            k = j;

            if (ends("at")) {
                setto("ate");
            } else if (ends("bl")) {
                setto("ble");
            } else if (ends("iz")) {
                setto("ize");
            } else if (doublec(k)) {
                int ch = b[k--];

                if ((ch == 'l') || (ch == 's') || (ch == 'z')) {
                    k++;
                }
            } else if ((m() == 1) && cvc(k)) {
                setto("e");
            }
        }
    }

    /* step2() turns terminal y to i when there is another vowel in the stem. */
    private final void step2() {
        if (ends("y") && vowelinstem()) {
            b[k] = 'i';
            dirty = true;
        }
    }

    /* step3() maps double suffices to single ones. so -ization ( = -ize plus
   -ation) maps to -ize etc. note that the string before the suffix must give
   m() > 0. */
    private final void step3() {
        if (k == k0) {
            return; /* For Bug 1 */
        }

        switch (b[k - 1]) {
        case 'a':

            if (ends("ational")) {
                r("ate");

                break;
            }

            if (ends("tional")) {
                r("tion");

                break;
            }

            break;

        case 'c':

            if (ends("enci")) {
                r("ence");

                break;
            }

            if (ends("anci")) {
                r("ance");

                break;
            }

            break;

        case 'e':

            if (ends("izer")) {
                r("ize");

                break;
            }

            break;

        case 'l':

            if (ends("bli")) {
                r("ble");

                break;
            }

            if (ends("alli")) {
                r("al");

                break;
            }

            if (ends("entli")) {
                r("ent");

                break;
            }

            if (ends("eli")) {
                r("e");

                break;
            }

            if (ends("ousli")) {
                r("ous");

                break;
            }

            break;

        case 'o':

            if (ends("ization")) {
                r("ize");

                break;
            }

            if (ends("ation")) {
                r("ate");

                break;
            }

            if (ends("ator")) {
                r("ate");

                break;
            }

            break;

        case 's':

            if (ends("alism")) {
                r("al");

                break;
            }

            if (ends("iveness")) {
                r("ive");

                break;
            }

            if (ends("fulness")) {
                r("ful");

                break;
            }

            if (ends("ousness")) {
                r("ous");

                break;
            }

            break;

        case 't':

            if (ends("aliti")) {
                r("al");

                break;
            }

            if (ends("iviti")) {
                r("ive");

                break;
            }

            if (ends("biliti")) {
                r("ble");

                break;
            }

            break;

        case 'g':

            if (ends("logi")) {
                r("log");

                break;
            }
        }
    }

    /* step4() deals with -ic-, -full, -ness etc. similar strategy to step3. */
    private final void step4() {
        switch (b[k]) {
        case 'e':

            if (ends("icate")) {
                r("ic");

                break;
            }

            if (ends("ative")) {
                r("");

                break;
            }

            if (ends("alize")) {
                r("al");

                break;
            }

            break;

        case 'i':

            if (ends("iciti")) {
                r("ic");

                break;
            }

            break;

        case 'l':

            if (ends("ical")) {
                r("ic");

                break;
            }

            if (ends("ful")) {
                r("");

                break;
            }

            break;

        case 's':

            if (ends("ness")) {
                r("");

                break;
            }

            break;
        }
    }

    /* step5() takes off -ant, -ence etc., in context <c>vcvc<v>. */
    private final void step5() {
        if (k == k0) {
            return; /* for Bug 1 */
        }

        switch (b[k - 1]) {
        case 'a':

            if (ends("al")) {
                break;
            }

            return;

        case 'c':

            if (ends("ance")) {
                break;
            }

            if (ends("ence")) {
                break;
            }

            return;

        case 'e':

            if (ends("er")) {
                break;
            }

            return;

        case 'i':

            if (ends("ic")) {
                break;
            }

            return;

        case 'l':

            if (ends("able")) {
                break;
            }

            if (ends("ible")) {
                break;
            }

            return;

        case 'n':

            if (ends("ant")) {
                break;
            }

            if (ends("ement")) {
                break;
            }

            if (ends("ment")) {
                break;
            }

            /* element etc. not stripped before the m */
            if (ends("ent")) {
                break;
            }

            return;

        case 'o':

            if (ends("ion") && (j >= 0) && ((b[j] == 's') || (b[j] == 't'))) {
                break;
            }

            /* j >= 0 fixes Bug 2 */
            if (ends("ou")) {
                break;
            }

            return;

        /* takes care of -ous */
        case 's':

            if (ends("ism")) {
                break;
            }

            return;

        case 't':

            if (ends("ate")) {
                break;
            }

            if (ends("iti")) {
                break;
            }

            return;

        case 'u':

            if (ends("ous")) {
                break;
            }

            return;

        case 'v':

            if (ends("ive")) {
                break;
            }

            return;

        case 'z':

            if (ends("ize")) {
                break;
            }

            return;

        default:
            return;
        }

        if (m() > 1) {
            k = j;
        }
    }

    /* step6() removes a final -e if m() > 1. */
    private final void step6() {
        j = k;

        if (b[k] == 'e') {
            int a = m();

            if ((a > 1) || ((a == 1) && !cvc(k - 1))) {
                k--;
            }
        }

        if ((b[k] == 'l') && doublec(k) && (m() > 1)) {
            k--;
        }
    }

    /**
     * Stem a word provided as a String.  Returns the result as a String.
     */
    public String stem(String s) {
        if (stem(s.toCharArray(), s.length())) {
            return toString();
        } 

        return s;
    }

    /**
     * Stem a word contained in a char[].  Returns true if the stemming process
     * resulted in a word different from the input.  You can retrieve the
     * result with getResultLength()/getResultBuffer() or toString().
     */
    public boolean stem(char[] word) {
        return stem(word, word.length);
    }

    /**
     * Stem a word contained in a portion of a char[] array.  Returns true if
     * the stemming process resulted in a word different from the input.  You
     * can retrieve the result with getResultLength()/getResultBuffer() or
     * toString().
     */
    public boolean stem(char[] wordBuffer, int offset, int wordLen) {
        reset();

        if (b.length < wordLen) {
            char[] new_b = new char[wordLen + EXTRA];
            b = new_b;
        }

        for (int j = 0; j < wordLen; j++)
            b[j] = wordBuffer[offset + j];

        i = wordLen;

        return stem(0);
    }

    /**
     * Stem a word contained in a leading portion of a char[] array. Returns
     * true if the stemming process resulted in a word different from the
     * input.  You can retrieve the result with
     * getResultLength()/getResultBuffer() or toString().
     */
    public boolean stem(char[] word, int wordLen) {
        return stem(word, 0, wordLen);
    }

    /**
     * Stem the word placed into the Stemmer buffer through calls to add().
     * Returns true if the stemming process resulted in a word different from
     * the input.  You can retrieve the result with
     * getResultLength()/getResultBuffer() or toString().
     */
    public boolean stem() {
        return stem(0);
    }

    public boolean stem(int i0) {
        k = i - 1;
        k0 = i0;

        if (k > (k0 + 1)) {
            step1();
            step2();
            step3();
            step4();
            step5();
            step6();
        }

        // Also, a word is considered dirty if we lopped off letters
        // Thanks to Ifigenia Vairelles for pointing this out.
        if (i != (k + 1)) {
            dirty = true;
        }

        i = k + 1;

        return dirty;
    }

    /**
     * Test program for demonstrating the Stemmer.  It reads a file and stems
     * each word, writing the result to standard out.   Usage: Stemmer
     * file-name
     */
    public static void main(String[] args) {
        VKCLogManager.init( "c:/temp/test_", ".log" );
        VKCLogManager.setEnableLogging(true);
        VKCLogManager.setLogToConsole(true);
        
        PorterStemmer s = new PorterStemmer();

        for (int i = 0; i < args.length; i++) {
            try {
                InputStream in = new FileInputStream(args[i]);
                byte[] buffer = new byte[1024];
                int bufferLen;
                int offset;
                int ch;

                bufferLen = in.read(buffer);
                offset = 0;
                s.reset();

                while (true) {
                    if (offset < bufferLen) {
                        ch = buffer[offset++];
                    } else {
                        bufferLen = in.read(buffer);
                        offset = 0;

                        if (bufferLen < 0) {
                            ch = -1;
                        } else {
                            ch = buffer[offset++];
                        }
                    }

                    if (Character.isLetter((char) ch)) {
                        s.add(Character.toLowerCase((char) ch));
                    } else {
                        s.stem();
                        System.out.print(s.toString());
                        s.reset();

                        if (ch < 0) {
                            break;
                        } 

                        System.out.print((char) ch);
                    }
                }

                in.close();
            } catch (IOException e) {
                System.out.println("error reading " + args[i]);
            }
        }
    }
}
