/*  Copyright (C) 2017 Andreas Shimokawa, ivanovlev, lazarosfs, Yaron
    Shahrabani

    This file is part of Gadgetbridge.

    Gadgetbridge is free software: you can redistribute it and/or modify
    it under the terms of the GNU Affero General Public License as published
    by the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    Gadgetbridge 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 <http://www.gnu.org/licenses/>. */
package nodomain.freeyourgadget.gadgetbridge.util;

import org.apache.commons.lang3.text.WordUtils;

import java.util.HashMap;
import java.util.Map;
import java.text.Normalizer;
import nodomain.freeyourgadget.gadgetbridge.GBApplication;

public class LanguageUtils {
    //transliteration map with english equivalent for unsupported chars
    private static Map<Character, String> transliterateMap = new HashMap<Character, String>(){
        {
            //extended ASCII characters
            put('æ', "ae"); put('œ', "oe"); put('ª', "a"); put('º', "o"); put('«',"\""); put('»',"\"");

            //german characters
            put('ä',"ae"); put('ö',"oe"); put('ü',"ue");
            put('Ä',"Ae"); put('Ö',"Oe"); put('Ü',"Üe");
            put('ß',"ss"); put('ẞ',"SS");

            //russian chars
            put('а', "a"); put('б', "b"); put('в', "v");  put('г', "g"); put('д', "d"); put('е', "e"); put('ё', "jo"); put('ж', "zh");
            put('з', "z"); put('и', "i"); put('й', "jj"); put('к', "k"); put('л', "l"); put('м', "m"); put('н', "n");  put('о', "o");
            put('п', "p"); put('р', "r"); put('с', "s");  put('т', "t"); put('у', "u"); put('ф', "f"); put('х', "kh"); put('ц', "c");
            put('ч', "ch");put('ш', "sh");put('щ', "shh");put('ъ', "\"");put('ы', "y"); put('ь', "'"); put('э', "eh"); put('ю', "ju");
            put('я', "ja");
            
            //hebrew chars
            put('א', "a"); put('ב', "b"); put('ג', "g");  put('ד', "d"); put('ה', "h"); put('ו', "u"); put('ז', "z"); put('ח', "kh");
            put('ט', "t"); put('י', "y"); put('כ', "c"); put('ל', "l"); put('מ', "m"); put('נ', "n"); put('ס', "s");  put('ע', "'");
            put('פ', "p"); put('צ', "ts"); put('ק', "k");  put('ר', "r"); put('ש', "sh"); put('ת', "th"); put('ף', "f"); put('ץ', "ts");
            put('ך', "ch");put('ם', "m");put('ן', "n");

            // greek chars
            put('α',"a");put('ά',"a");put('β',"v");put('γ',"g");put('δ',"d");put('ε',"e");put('έ',"e");put('ζ',"z");put('η',"i");
            put('ή',"i");put('θ',"th");put('ι',"i");put('ί',"i");put('ϊ',"i");put('ΐ',"i");put('κ',"k");put('λ',"l");put('μ',"m");
            put('ν',"n");put('ξ',"ks");put('ο',"o");put('ό',"o");put('π',"p");put('ρ',"r");put('σ',"s");put('ς',"s");put('τ',"t");
            put('υ',"y");put('ύ',"y");put('ϋ',"y");put('ΰ',"y");put('φ',"f");put('χ',"ch");put('ψ',"ps");put('ω',"o");put('ώ',"o");
            put('Α',"A");put('Ά',"A");put('Β',"B");put('Γ',"G");put('Δ',"D");put('Ε',"E");put('Έ',"E");put('Ζ',"Z");put('Η',"I");
            put('Ή',"I");put('Θ',"TH");put('Ι',"I");put('Ί',"I");put('Ϊ',"I");put('Κ',"K");put('Λ',"L");put('Μ',"M");put('Ν',"N");
            put('Ξ',"KS");put('Ο',"O");put('Ό',"O");put('Π',"P");put('Ρ',"R");put('Σ',"S");put('Τ',"T");put('Υ',"Y");put('Ύ',"Y");
            put('Ϋ',"Y");put('Φ',"F");put('Χ',"CH");put('Ψ',"PS");put('Ω',"O");put('Ώ',"O");

            //TODO: these must be configurabe. If someone wants to transliterate cyrillic it does not mean his device has no German umlauts
            //all or nothing is really bad here
        }
    };

    /**
     * Checks the status of transliteration option
     * @return true if transliterate option is On, and false, if Off or not exist
     */
    public static boolean transliterate()
    {
        return GBApplication.getPrefs().getBoolean("transliteration", false);
    }

    /**
     * Replaces unsupported symbols to english
     * @param txt input text
     * @return transliterated text
     */
    public static String transliterate(String txt){
        if (txt == null || txt.isEmpty()) {
            return txt;
        }

        StringBuilder message = new StringBuilder();

        char[] chars = txt.toCharArray();

        for (char c : chars)
        {
            message.append(transliterate(c));
        }

        return flattenToAscii(message.toString());
    }

    /**
     * Replaces unsupported symbol to english by {@code transliterateMap}
     * @param c input char
     * @return replacement text
     */
    private static String transliterate(char c){
        char lowerChar = Character.toLowerCase(c);

        if (transliterateMap.containsKey(lowerChar)) {
            String replace = transliterateMap.get(lowerChar);

            if (lowerChar != c)
            {
                return WordUtils.capitalize(replace);
            }

            return replace;
        }

        return String.valueOf(c);
    }

    /**
     * Converts the diacritics
     * @param string input text
     * @return converted text
     */
    private static String flattenToAscii(String string) {
        string = Normalizer.normalize(string, Normalizer.Form.NFD);
        return string.replaceAll("\\p{M}", "");
    }
}