/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

/*
 * A stemmer for Brazilian words.
 */
namespace Lucene.Net.Analysis.BR
{

    public class BrazilianStemmer
    {

        /*
         * Changed term
         */
        private string TERM;
        private string CT;
        private string R1;
        private string R2;
        private string RV;


        public BrazilianStemmer()
        {
        }

        /*
         * Stemms the given term to an unique <tt>discriminator</tt>.
         *
         * <param name="term"> The term that should be stemmed.</param>
         * <returns>     Discriminator for <tt>term</tt></returns>
         */
        public string Stem(string term)
        {
            bool altered = false; // altered the term

            // creates CT
            createCT(term);

            if (!isIndexable(CT))
            {
                return null;
            }
            if (!isStemmable(CT))
            {
                return CT;
            }

            R1 = getR1(CT);
            R2 = getR1(R1);
            RV = getRV(CT);
            TERM = term + ";" + CT;

            altered = step1();
            if (!altered)
            {
                altered = step2();
            }

            if (altered)
            {
                step3();
            }
            else
            {
                step4();
            }

            step5();

            return CT;
        }

        /*
         * Checks a term if it can be processed correctly.
         *
         * <returns> true if, and only if, the given term consists in letters.</returns>
         */
        private bool isStemmable(string term)
        {
            for (int c = 0; c < term.Length; c++)
            {
                // Discard terms that contain non-letter characters.
                if (!char.IsLetter(term[c]))
                {
                    return false;
                }
            }
            return true;
        }

        /*
         * Checks a term if it can be processed indexed.
         *
         * <returns> true if it can be indexed</returns>
         */
        private bool isIndexable(string term)
        {
            return (term.Length < 30) && (term.Length > 2);
        }

        /*
         * See if string is 'a','e','i','o','u'
       *
       * <returns>true if is vowel</returns>
         */
        private bool isVowel(char value)
        {
            return (value == 'a') ||
                   (value == 'e') ||
                   (value == 'i') ||
                   (value == 'o') ||
                   (value == 'u');
        }

        /*
         * Gets R1
       *
       * R1 - is the region after the first non-vowel follwing a vowel,
       *      or is the null region at the end of the word if there is
       *      no such non-vowel.
       *
       * <returns>null or a string representing R1</returns>
         */
        private string getR1(string value)
        {
            int i;
            int j;

            // be-safe !!!
            if (value == null)
            {
                return null;
            }

            // find 1st vowel
            i = value.Length - 1;
            for (j = 0; j < i; j++)
            {
                if (isVowel(value[j]))
                {
                    break;
                }
            }

            if (!(j < i))
            {
                return null;
            }

            // find 1st non-vowel
            for (; j < i; j++)
            {
                if (!(isVowel(value[j])))
                {
                    break;
                }
            }

            if (!(j < i))
            {
                return null;
            }

            return value.Substring(j + 1);
        }

        /*
         * Gets RV
       *
       * RV - IF the second letter is a consoant, RV is the region after
       *      the next following vowel,
       *
       *      OR if the first two letters are vowels, RV is the region
       *      after the next consoant,
       *
       *      AND otherwise (consoant-vowel case) RV is the region after
       *      the third letter.
       *
       *      BUT RV is the end of the word if this positions cannot be
       *      found.
       *
       * <returns>null or a string representing RV</returns>
         */
        private string getRV(string value)
        {
            int i;
            int j;

            // be-safe !!!
            if (value == null)
            {
                return null;
            }

            i = value.Length - 1;

            // RV - IF the second letter is a consoant, RV is the region after
            //      the next following vowel,
            if ((i > 0) && !isVowel(value[1]))
            {
                // find 1st vowel
                for (j = 2; j < i; j++)
                {
                    if (isVowel(value[j]))
                    {
                        break;
                    }
                }

                if (j < i)
                {
                    return value.Substring(j + 1);
                }
            }


            // RV - OR if the first two letters are vowels, RV is the region
            //      after the next consoant,
            if ((i > 1) &&
                isVowel(value[0]) &&
                isVowel(value[1]))
            {
                // find 1st consoant
                for (j = 2; j < i; j++)
                {
                    if (!isVowel(value[j]))
                    {
                        break;
                    }
                }

                if (j < i)
                {
                    return value.Substring(j + 1);
                }
            }

            // RV - AND otherwise (consoant-vowel case) RV is the region after
            //      the third letter.
            if (i > 2)
            {
                return value.Substring(3);
            }

            return null;
        }

        /*
       * 1) Turn to lowercase
       * 2) Remove accents
       * 3) ã -> a ; õ -> o
       * 4) ç -> c
       *
       * <returns>null or a string transformed</returns>
         */
        private string changeTerm(string value)
        {
            int j;
            string r = "";

            // be-safe !!!
            if (value == null)
            {
                return null;
            }

            value = value.ToLower();
            for (j = 0; j < value.Length; j++)
            {
                if ((value[j] == 'á') ||
                    (value[j] == 'â') ||
                    (value[j] == 'ã'))
                {
                    r = r + "a"; continue;
                }
                if ((value[j] == 'é') ||
                    (value[j] == 'ê'))
                {
                    r = r + "e"; continue;
                }
                if (value[j] == 'í')
                {
                    r = r + "i"; continue;
                }
                if ((value[j] == 'ó') ||
                    (value[j] == 'ô') ||
                    (value[j] == 'õ'))
                {
                    r = r + "o"; continue;
                }
                if ((value[j] == 'ú') ||
                    (value[j] == 'ü'))
                {
                    r = r + "u"; continue;
                }
                if (value[j] == 'ç')
                {
                    r = r + "c"; continue;
                }
                if (value[j] == 'ñ')
                {
                    r = r + "n"; continue;
                }

                r = r + value[j];
            }

            return r;
        }

        /*
       * Check if a string ends with a suffix
       *
       * <returns>true if the string ends with the specified suffix</returns>
         */
        private bool suffix(string value, string suffix)
        {

            // be-safe !!!
            if ((value == null) || (suffix == null))
            {
                return false;
            }

            if (suffix.Length > value.Length)
            {
                return false;
            }

            return value.Substring(value.Length - suffix.Length).Equals(suffix);
        }

        /*
       * Replace a string suffix by another
       *
       * <returns>the replaced string</returns>
         */
        private string replaceSuffix(string value, string toReplace, string changeTo)
        {
            string vvalue;

            // be-safe !!!
            if ((value == null) ||
                (toReplace == null) ||
                (changeTo == null))
            {
                return value;
            }

            vvalue = removeSuffix(value, toReplace);

            if (value.Equals(vvalue))
            {
                return value;
            }
            else
            {
                return vvalue + changeTo;
            }
        }

        /*
       * Remove a string suffix
       *
       * <returns>the string without the suffix</returns>
         */
        private string removeSuffix(string value, string toRemove)
        {
            // be-safe !!!
            if ((value == null) ||
                (toRemove == null) ||
                !suffix(value, toRemove))
            {
                return value;
            }

            return value.Substring(0, value.Length - toRemove.Length);
        }

        /*
       * See if a suffix is preceded by a string
       *
       * <returns>true if the suffix is preceded</returns>
         */
        private bool suffixPreceded(string value, string _suffix, string preceded)
        {
            // be-safe !!!
            if ((value == null) ||
                (_suffix == null) ||
                (preceded == null) ||
                !suffix(value, _suffix))
            {
                return false;
            }

            return suffix(removeSuffix(value, _suffix), preceded);
        }




        /*
         * Creates CT (changed term) , substituting * 'ã' and 'õ' for 'a~' and 'o~'.
         */
        private void createCT(string term)
        {
            CT = changeTerm(term);

            if (CT.Length < 2) return;

            // if the first character is ... , remove it
            if ((CT[0] == '"') ||
                (CT[0] == '\'') ||
                (CT[0] == '-') ||
                (CT[0] == ',') ||
                (CT[0] == ';') ||
                (CT[0] == '.') ||
                (CT[0] == '?') ||
                (CT[0] == '!')
                )
            {
                CT = CT.Substring(1);
            }

            if (CT.Length < 2) return;

            // if the last character is ... , remove it
            if ((CT[CT.Length - 1] == '-') ||
                (CT[CT.Length - 1] == ',') ||
                (CT[CT.Length - 1] == ';') ||
                (CT[CT.Length - 1] == '.') ||
                (CT[CT.Length - 1] == '?') ||
                (CT[CT.Length - 1] == '!') ||
                (CT[CT.Length - 1] == '\'') ||
                (CT[CT.Length - 1] == '"')
                )
            {
                CT = CT.Substring(0, CT.Length - 1);
            }
        }


        /*
         * Standart suffix removal.
       * Search for the longest among the following suffixes, and perform
       * the following actions:
       *
       * <returns>false if no ending was removed</returns>
         */
        private bool step1()
        {
            if (CT == null) return false;

            // suffix lenght = 7
            if (suffix(CT, "uciones") && suffix(R2, "uciones"))
            {
                CT = replaceSuffix(CT, "uciones", "u"); return true;
            }

            // suffix lenght = 6
            if (CT.Length >= 6)
            {
                if (suffix(CT, "imentos") && suffix(R2, "imentos"))
                {
                    CT = removeSuffix(CT, "imentos"); return true;
                }
                if (suffix(CT, "amentos") && suffix(R2, "amentos"))
                {
                    CT = removeSuffix(CT, "amentos"); return true;
                }
                if (suffix(CT, "adores") && suffix(R2, "adores"))
                {
                    CT = removeSuffix(CT, "adores"); return true;
                }
                if (suffix(CT, "adoras") && suffix(R2, "adoras"))
                {
                    CT = removeSuffix(CT, "adoras"); return true;
                }
                if (suffix(CT, "logias") && suffix(R2, "logias"))
                {
                    replaceSuffix(CT, "logias", "log"); return true;
                }
                if (suffix(CT, "encias") && suffix(R2, "encias"))
                {
                    CT = replaceSuffix(CT, "encias", "ente"); return true;
                }
                if (suffix(CT, "amente") && suffix(R1, "amente"))
                {
                    CT = removeSuffix(CT, "amente"); return true;
                }
                if (suffix(CT, "idades") && suffix(R2, "idades"))
                {
                    CT = removeSuffix(CT, "idades"); return true;
                }
            }

            // suffix lenght = 5
            if (CT.Length >= 5)
            {
                if (suffix(CT, "acoes") && suffix(R2, "acoes"))
                {
                    CT = removeSuffix(CT, "acoes"); return true;
                }
                if (suffix(CT, "imento") && suffix(R2, "imento"))
                {
                    CT = removeSuffix(CT, "imento"); return true;
                }
                if (suffix(CT, "amento") && suffix(R2, "amento"))
                {
                    CT = removeSuffix(CT, "amento"); return true;
                }
                if (suffix(CT, "adora") && suffix(R2, "adora"))
                {
                    CT = removeSuffix(CT, "adora"); return true;
                }
                if (suffix(CT, "ismos") && suffix(R2, "ismos"))
                {
                    CT = removeSuffix(CT, "ismos"); return true;
                }
                if (suffix(CT, "istas") && suffix(R2, "istas"))
                {
                    CT = removeSuffix(CT, "istas"); return true;
                }
                if (suffix(CT, "logia") && suffix(R2, "logia"))
                {
                    CT = replaceSuffix(CT, "logia", "log"); return true;
                }
                if (suffix(CT, "ucion") && suffix(R2, "ucion"))
                {
                    CT = replaceSuffix(CT, "ucion", "u"); return true;
                }
                if (suffix(CT, "encia") && suffix(R2, "encia"))
                {
                    CT = replaceSuffix(CT, "encia", "ente"); return true;
                }
                if (suffix(CT, "mente") && suffix(R2, "mente"))
                {
                    CT = removeSuffix(CT, "mente"); return true;
                }
                if (suffix(CT, "idade") && suffix(R2, "idade"))
                {
                    CT = removeSuffix(CT, "idade"); return true;
                }
            }

            // suffix lenght = 4
            if (CT.Length >= 4)
            {
                if (suffix(CT, "acao") && suffix(R2, "acao"))
                {
                    CT = removeSuffix(CT, "acao"); return true;
                }
                if (suffix(CT, "ezas") && suffix(R2, "ezas"))
                {
                    CT = removeSuffix(CT, "ezas"); return true;
                }
                if (suffix(CT, "icos") && suffix(R2, "icos"))
                {
                    CT = removeSuffix(CT, "icos"); return true;
                }
                if (suffix(CT, "icas") && suffix(R2, "icas"))
                {
                    CT = removeSuffix(CT, "icas"); return true;
                }
                if (suffix(CT, "ismo") && suffix(R2, "ismo"))
                {
                    CT = removeSuffix(CT, "ismo"); return true;
                }
                if (suffix(CT, "avel") && suffix(R2, "avel"))
                {
                    CT = removeSuffix(CT, "avel"); return true;
                }
                if (suffix(CT, "ivel") && suffix(R2, "ivel"))
                {
                    CT = removeSuffix(CT, "ivel"); return true;
                }
                if (suffix(CT, "ista") && suffix(R2, "ista"))
                {
                    CT = removeSuffix(CT, "ista"); return true;
                }
                if (suffix(CT, "osos") && suffix(R2, "osos"))
                {
                    CT = removeSuffix(CT, "osos"); return true;
                }
                if (suffix(CT, "osas") && suffix(R2, "osas"))
                {
                    CT = removeSuffix(CT, "osas"); return true;
                }
                if (suffix(CT, "ador") && suffix(R2, "ador"))
                {
                    CT = removeSuffix(CT, "ador"); return true;
                }
                if (suffix(CT, "ivas") && suffix(R2, "ivas"))
                {
                    CT = removeSuffix(CT, "ivas"); return true;
                }
                if (suffix(CT, "ivos") && suffix(R2, "ivos"))
                {
                    CT = removeSuffix(CT, "ivos"); return true;
                }
                if (suffix(CT, "iras") &&
                    suffix(RV, "iras") &&
                    suffixPreceded(CT, "iras", "e"))
                {
                    CT = replaceSuffix(CT, "iras", "ir"); return true;
                }
            }

            // suffix lenght = 3
            if (CT.Length >= 3)
            {
                if (suffix(CT, "eza") && suffix(R2, "eza"))
                {
                    CT = removeSuffix(CT, "eza"); return true;
                }
                if (suffix(CT, "ico") && suffix(R2, "ico"))
                {
                    CT = removeSuffix(CT, "ico"); return true;
                }
                if (suffix(CT, "ica") && suffix(R2, "ica"))
                {
                    CT = removeSuffix(CT, "ica"); return true;
                }
                if (suffix(CT, "oso") && suffix(R2, "oso"))
                {
                    CT = removeSuffix(CT, "oso"); return true;
                }
                if (suffix(CT, "osa") && suffix(R2, "osa"))
                {
                    CT = removeSuffix(CT, "osa"); return true;
                }
                if (suffix(CT, "iva") && suffix(R2, "iva"))
                {
                    CT = removeSuffix(CT, "iva"); return true;
                }
                if (suffix(CT, "ivo") && suffix(R2, "ivo"))
                {
                    CT = removeSuffix(CT, "ivo"); return true;
                }
                if (suffix(CT, "ira") &&
                    suffix(RV, "ira") &&
                    suffixPreceded(CT, "ira", "e"))
                {
                    CT = replaceSuffix(CT, "ira", "ir"); return true;
                }
            }

            // no ending was removed by step1
            return false;
        }


        /*
         * Verb suffixes.
       *
       * Search for the longest among the following suffixes in RV,
       * and if found, delete.
       *
       * <returns>false if no ending was removed</returns>
        */
        private bool step2()
        {
            if (RV == null) return false;

            // suffix lenght = 7
            if (RV.Length >= 7)
            {
                if (suffix(RV, "issemos"))
                {
                    CT = removeSuffix(CT, "issemos"); return true;
                }
                if (suffix(RV, "essemos"))
                {
                    CT = removeSuffix(CT, "essemos"); return true;
                }
                if (suffix(RV, "assemos"))
                {
                    CT = removeSuffix(CT, "assemos"); return true;
                }
                if (suffix(RV, "ariamos"))
                {
                    CT = removeSuffix(CT, "ariamos"); return true;
                }
                if (suffix(RV, "eriamos"))
                {
                    CT = removeSuffix(CT, "eriamos"); return true;
                }
                if (suffix(RV, "iriamos"))
                {
                    CT = removeSuffix(CT, "iriamos"); return true;
                }
            }

            // suffix lenght = 6
            if (RV.Length >= 6)
            {
                if (suffix(RV, "iremos"))
                {
                    CT = removeSuffix(CT, "iremos"); return true;
                }
                if (suffix(RV, "eremos"))
                {
                    CT = removeSuffix(CT, "eremos"); return true;
                }
                if (suffix(RV, "aremos"))
                {
                    CT = removeSuffix(CT, "aremos"); return true;
                }
                if (suffix(RV, "avamos"))
                {
                    CT = removeSuffix(CT, "avamos"); return true;
                }
                if (suffix(RV, "iramos"))
                {
                    CT = removeSuffix(CT, "iramos"); return true;
                }
                if (suffix(RV, "eramos"))
                {
                    CT = removeSuffix(CT, "eramos"); return true;
                }
                if (suffix(RV, "aramos"))
                {
                    CT = removeSuffix(CT, "aramos"); return true;
                }
                if (suffix(RV, "asseis"))
                {
                    CT = removeSuffix(CT, "asseis"); return true;
                }
                if (suffix(RV, "esseis"))
                {
                    CT = removeSuffix(CT, "esseis"); return true;
                }
                if (suffix(RV, "isseis"))
                {
                    CT = removeSuffix(CT, "isseis"); return true;
                }
                if (suffix(RV, "arieis"))
                {
                    CT = removeSuffix(CT, "arieis"); return true;
                }
                if (suffix(RV, "erieis"))
                {
                    CT = removeSuffix(CT, "erieis"); return true;
                }
                if (suffix(RV, "irieis"))
                {
                    CT = removeSuffix(CT, "irieis"); return true;
                }
            }


            // suffix lenght = 5
            if (RV.Length >= 5)
            {
                if (suffix(RV, "irmos"))
                {
                    CT = removeSuffix(CT, "irmos"); return true;
                }
                if (suffix(RV, "iamos"))
                {
                    CT = removeSuffix(CT, "iamos"); return true;
                }
                if (suffix(RV, "armos"))
                {
                    CT = removeSuffix(CT, "armos"); return true;
                }
                if (suffix(RV, "ermos"))
                {
                    CT = removeSuffix(CT, "ermos"); return true;
                }
                if (suffix(RV, "areis"))
                {
                    CT = removeSuffix(CT, "areis"); return true;
                }
                if (suffix(RV, "ereis"))
                {
                    CT = removeSuffix(CT, "ereis"); return true;
                }
                if (suffix(RV, "ireis"))
                {
                    CT = removeSuffix(CT, "ireis"); return true;
                }
                if (suffix(RV, "asses"))
                {
                    CT = removeSuffix(CT, "asses"); return true;
                }
                if (suffix(RV, "esses"))
                {
                    CT = removeSuffix(CT, "esses"); return true;
                }
                if (suffix(RV, "isses"))
                {
                    CT = removeSuffix(CT, "isses"); return true;
                }
                if (suffix(RV, "astes"))
                {
                    CT = removeSuffix(CT, "astes"); return true;
                }
                if (suffix(RV, "assem"))
                {
                    CT = removeSuffix(CT, "assem"); return true;
                }
                if (suffix(RV, "essem"))
                {
                    CT = removeSuffix(CT, "essem"); return true;
                }
                if (suffix(RV, "issem"))
                {
                    CT = removeSuffix(CT, "issem"); return true;
                }
                if (suffix(RV, "ardes"))
                {
                    CT = removeSuffix(CT, "ardes"); return true;
                }
                if (suffix(RV, "erdes"))
                {
                    CT = removeSuffix(CT, "erdes"); return true;
                }
                if (suffix(RV, "irdes"))
                {
                    CT = removeSuffix(CT, "irdes"); return true;
                }
                if (suffix(RV, "ariam"))
                {
                    CT = removeSuffix(CT, "ariam"); return true;
                }
                if (suffix(RV, "eriam"))
                {
                    CT = removeSuffix(CT, "eriam"); return true;
                }
                if (suffix(RV, "iriam"))
                {
                    CT = removeSuffix(CT, "iriam"); return true;
                }
                if (suffix(RV, "arias"))
                {
                    CT = removeSuffix(CT, "arias"); return true;
                }
                if (suffix(RV, "erias"))
                {
                    CT = removeSuffix(CT, "erias"); return true;
                }
                if (suffix(RV, "irias"))
                {
                    CT = removeSuffix(CT, "irias"); return true;
                }
                if (suffix(RV, "estes"))
                {
                    CT = removeSuffix(CT, "estes"); return true;
                }
                if (suffix(RV, "istes"))
                {
                    CT = removeSuffix(CT, "istes"); return true;
                }
                if (suffix(RV, "areis"))
                {
                    CT = removeSuffix(CT, "areis"); return true;
                }
                if (suffix(RV, "aveis"))
                {
                    CT = removeSuffix(CT, "aveis"); return true;
                }
            }

            // suffix lenght = 4
            if (RV.Length >= 4)
            {
                if (suffix(RV, "aria"))
                {
                    CT = removeSuffix(CT, "aria"); return true;
                }
                if (suffix(RV, "eria"))
                {
                    CT = removeSuffix(CT, "eria"); return true;
                }
                if (suffix(RV, "iria"))
                {
                    CT = removeSuffix(CT, "iria"); return true;
                }
                if (suffix(RV, "asse"))
                {
                    CT = removeSuffix(CT, "asse"); return true;
                }
                if (suffix(RV, "esse"))
                {
                    CT = removeSuffix(CT, "esse"); return true;
                }
                if (suffix(RV, "isse"))
                {
                    CT = removeSuffix(CT, "isse"); return true;
                }
                if (suffix(RV, "aste"))
                {
                    CT = removeSuffix(CT, "aste"); return true;
                }
                if (suffix(RV, "este"))
                {
                    CT = removeSuffix(CT, "este"); return true;
                }
                if (suffix(RV, "iste"))
                {
                    CT = removeSuffix(CT, "iste"); return true;
                }
                if (suffix(RV, "arei"))
                {
                    CT = removeSuffix(CT, "arei"); return true;
                }
                if (suffix(RV, "erei"))
                {
                    CT = removeSuffix(CT, "erei"); return true;
                }
                if (suffix(RV, "irei"))
                {
                    CT = removeSuffix(CT, "irei"); return true;
                }
                if (suffix(RV, "aram"))
                {
                    CT = removeSuffix(CT, "aram"); return true;
                }
                if (suffix(RV, "eram"))
                {
                    CT = removeSuffix(CT, "eram"); return true;
                }
                if (suffix(RV, "iram"))
                {
                    CT = removeSuffix(CT, "iram"); return true;
                }
                if (suffix(RV, "avam"))
                {
                    CT = removeSuffix(CT, "avam"); return true;
                }
                if (suffix(RV, "arem"))
                {
                    CT = removeSuffix(CT, "arem"); return true;
                }
                if (suffix(RV, "erem"))
                {
                    CT = removeSuffix(CT, "erem"); return true;
                }
                if (suffix(RV, "irem"))
                {
                    CT = removeSuffix(CT, "irem"); return true;
                }
                if (suffix(RV, "ando"))
                {
                    CT = removeSuffix(CT, "ando"); return true;
                }
                if (suffix(RV, "endo"))
                {
                    CT = removeSuffix(CT, "endo"); return true;
                }
                if (suffix(RV, "indo"))
                {
                    CT = removeSuffix(CT, "indo"); return true;
                }
                if (suffix(RV, "arao"))
                {
                    CT = removeSuffix(CT, "arao"); return true;
                }
                if (suffix(RV, "erao"))
                {
                    CT = removeSuffix(CT, "erao"); return true;
                }
                if (suffix(RV, "irao"))
                {
                    CT = removeSuffix(CT, "irao"); return true;
                }
                if (suffix(RV, "adas"))
                {
                    CT = removeSuffix(CT, "adas"); return true;
                }
                if (suffix(RV, "idas"))
                {
                    CT = removeSuffix(CT, "idas"); return true;
                }
                if (suffix(RV, "aras"))
                {
                    CT = removeSuffix(CT, "aras"); return true;
                }
                if (suffix(RV, "eras"))
                {
                    CT = removeSuffix(CT, "eras"); return true;
                }
                if (suffix(RV, "iras"))
                {
                    CT = removeSuffix(CT, "iras"); return true;
                }
                if (suffix(RV, "avas"))
                {
                    CT = removeSuffix(CT, "avas"); return true;
                }
                if (suffix(RV, "ares"))
                {
                    CT = removeSuffix(CT, "ares"); return true;
                }
                if (suffix(RV, "eres"))
                {
                    CT = removeSuffix(CT, "eres"); return true;
                }
                if (suffix(RV, "ires"))
                {
                    CT = removeSuffix(CT, "ires"); return true;
                }
                if (suffix(RV, "ados"))
                {
                    CT = removeSuffix(CT, "ados"); return true;
                }
                if (suffix(RV, "idos"))
                {
                    CT = removeSuffix(CT, "idos"); return true;
                }
                if (suffix(RV, "amos"))
                {
                    CT = removeSuffix(CT, "amos"); return true;
                }
                if (suffix(RV, "emos"))
                {
                    CT = removeSuffix(CT, "emos"); return true;
                }
                if (suffix(RV, "imos"))
                {
                    CT = removeSuffix(CT, "imos"); return true;
                }
                if (suffix(RV, "iras"))
                {
                    CT = removeSuffix(CT, "iras"); return true;
                }
                if (suffix(RV, "ieis"))
                {
                    CT = removeSuffix(CT, "ieis"); return true;
                }
            }

            // suffix lenght = 3
            if (RV.Length >= 3)
            {
                if (suffix(RV, "ada"))
                {
                    CT = removeSuffix(CT, "ada"); return true;
                }
                if (suffix(RV, "ida"))
                {
                    CT = removeSuffix(CT, "ida"); return true;
                }
                if (suffix(RV, "ara"))
                {
                    CT = removeSuffix(CT, "ara"); return true;
                }
                if (suffix(RV, "era"))
                {
                    CT = removeSuffix(CT, "era"); return true;
                }
                if (suffix(RV, "ira"))
                {
                    CT = removeSuffix(CT, "ava"); return true;
                }
                if (suffix(RV, "iam"))
                {
                    CT = removeSuffix(CT, "iam"); return true;
                }
                if (suffix(RV, "ado"))
                {
                    CT = removeSuffix(CT, "ado"); return true;
                }
                if (suffix(RV, "ido"))
                {
                    CT = removeSuffix(CT, "ido"); return true;
                }
                if (suffix(RV, "ias"))
                {
                    CT = removeSuffix(CT, "ias"); return true;
                }
                if (suffix(RV, "ais"))
                {
                    CT = removeSuffix(CT, "ais"); return true;
                }
                if (suffix(RV, "eis"))
                {
                    CT = removeSuffix(CT, "eis"); return true;
                }
                if (suffix(RV, "ira"))
                {
                    CT = removeSuffix(CT, "ira"); return true;
                }
                if (suffix(RV, "ear"))
                {
                    CT = removeSuffix(CT, "ear"); return true;
                }
            }

            // suffix lenght = 2
            if (RV.Length >= 2)
            {
                if (suffix(RV, "ia"))
                {
                    CT = removeSuffix(CT, "ia"); return true;
                }
                if (suffix(RV, "ei"))
                {
                    CT = removeSuffix(CT, "ei"); return true;
                }
                if (suffix(RV, "am"))
                {
                    CT = removeSuffix(CT, "am"); return true;
                }
                if (suffix(RV, "em"))
                {
                    CT = removeSuffix(CT, "em"); return true;
                }
                if (suffix(RV, "ar"))
                {
                    CT = removeSuffix(CT, "ar"); return true;
                }
                if (suffix(RV, "er"))
                {
                    CT = removeSuffix(CT, "er"); return true;
                }
                if (suffix(RV, "ir"))
                {
                    CT = removeSuffix(CT, "ir"); return true;
                }
                if (suffix(RV, "as"))
                {
                    CT = removeSuffix(CT, "as"); return true;
                }
                if (suffix(RV, "es"))
                {
                    CT = removeSuffix(CT, "es"); return true;
                }
                if (suffix(RV, "is"))
                {
                    CT = removeSuffix(CT, "is"); return true;
                }
                if (suffix(RV, "eu"))
                {
                    CT = removeSuffix(CT, "eu"); return true;
                }
                if (suffix(RV, "iu"))
                {
                    CT = removeSuffix(CT, "iu"); return true;
                }
                if (suffix(RV, "iu"))
                {
                    CT = removeSuffix(CT, "iu"); return true;
                }
                if (suffix(RV, "ou"))
                {
                    CT = removeSuffix(CT, "ou"); return true;
                }
            }

            // no ending was removed by step2
            return false;
        }

        /*
         * Delete suffix 'i' if in RV and preceded by 'c'
       *
        */
        private void step3()
        {
            if (RV == null) return;

            if (suffix(RV, "i") && suffixPreceded(RV, "i", "c"))
            {
                CT = removeSuffix(CT, "i");
            }

        }

        /*
         * Residual suffix
       *
       * If the word ends with one of the suffixes (os a i o á í ó)
       * in RV, delete it
       *
        */
        private void step4()
        {
            if (RV == null) return;

            if (suffix(RV, "os"))
            {
                CT = removeSuffix(CT, "os"); return;
            }
            if (suffix(RV, "a"))
            {
                CT = removeSuffix(CT, "a"); return;
            }
            if (suffix(RV, "i"))
            {
                CT = removeSuffix(CT, "i"); return;
            }
            if (suffix(RV, "o"))
            {
                CT = removeSuffix(CT, "o"); return;
            }

        }

        /*
         * If the word ends with one of ( e é ê) in RV,delete it,
       * and if preceded by 'gu' (or 'ci') with the 'u' (or 'i') in RV,
       * delete the 'u' (or 'i')
       *
       * Or if the word ends ç remove the cedilha
       *
        */
        private void step5()
        {
            if (RV == null) return;

            if (suffix(RV, "e"))
            {
                if (suffixPreceded(RV, "e", "gu"))
                {
                    CT = removeSuffix(CT, "e");
                    CT = removeSuffix(CT, "u");
                    return;
                }

                if (suffixPreceded(RV, "e", "ci"))
                {
                    CT = removeSuffix(CT, "e");
                    CT = removeSuffix(CT, "i");
                    return;
                }

                CT = removeSuffix(CT, "e"); return;
            }
        }

        /*
         * For log and debug purpose
         *
         * <returns> TERM, CT, RV, R1 and R2</returns>
         */
        public string Log()
        {
            return " (TERM = " + TERM + ")" +
                   " (CT = " + CT + ")" +
                   " (RV = " + RV + ")" +
                   " (R1 = " + R1 + ")" +
                   " (R2 = " + R2 + ")";
        }

    }

}