/*
 * Copyright (C) 2007 Esmertec AG.
 * Copyright (C) 2007 The Android Open Source Project
 *
 * Licensed 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.
 */

package com.google.android.mms.pdu;

import android.compat.annotation.UnsupportedAppUsage;

import java.io.UnsupportedEncodingException;
import java.util.HashMap;

public class CharacterSets {
    /**
     * IANA assigned MIB enum numbers.
     *
     * From wap-230-wsp-20010705-a.pdf
     * Any-charset = <Octet 128>
     * Equivalent to the special RFC2616 charset value "*"
     */
    public static final int ANY_CHARSET = 0x00;
    public static final int US_ASCII    = 0x03;
    public static final int ISO_8859_1  = 0x04;
    public static final int ISO_8859_2  = 0x05;
    public static final int ISO_8859_3  = 0x06;
    public static final int ISO_8859_4  = 0x07;
    public static final int ISO_8859_5  = 0x08;
    public static final int ISO_8859_6  = 0x09;
    public static final int ISO_8859_7  = 0x0A;
    public static final int ISO_8859_8  = 0x0B;
    public static final int ISO_8859_9  = 0x0C;
    public static final int SHIFT_JIS   = 0x11;
    public static final int UTF_8       = 0x6A;
    public static final int BIG5        = 0x07EA;
    public static final int UCS2        = 0x03E8;
    public static final int UTF_16      = 0x03F7;

    /**
     * Extend charsets.
     *
     * From http://www.iana.org/assignments/character-sets/
     */
    public static final int BIG5_HKSCS = 0x0835; //2101
    public static final int BOCU_1 = 0x03FC; //1020
    public static final int CESU_8 = 0x03F8; //1016
    public static final int CP864 = 0x0803; //2051
    public static final int EUC_JP = 0x12; //18
    public static final int EUC_KR = 0x26; //38
    public static final int GB18030 = 0x72; //114
    public static final int GBK = 0x71; //113
    public static final int HZ_GB_2312 = 0x0825; //2085
    public static final int GB_2312 = 0x07E9; //2025
    public static final int ISO_2022_CN = 0x68; //104
    public static final int ISO_2022_CN_EXT = 0x69; //105
    public static final int ISO_2022_JP = 0x27; //39
    public static final int ISO_2022_KR = 0x25; //37
    public static final int ISO_8859_10 = 0x0D; //13
    public static final int ISO_8859_13 = 0x6D; //109
    public static final int ISO_8859_14 = 0x6E; //110
    public static final int ISO_8859_15 = 0x6F; //111
    public static final int ISO_8859_16 = 0x70; //112
    public static final int KOI8_R = 0x0824; //2084
    public static final int KOI8_U = 0x0828; //2088
    public static final int MACINTOSH = 0x07EB; //2027
    public static final int SCSU = 0x03F3; //1011
    public static final int TIS_620 = 0x08D3; //2259
    public static final int UTF_16BE = 0x03F5; //1013
    public static final int UTF_16LE = 0x03F6; //1014
    public static final int UTF_32 = 0x03F9; //1017
    public static final int UTF_32BE = 0x03FA; //1018
    public static final int UTF_32LE = 0x03FB; //1019
    public static final int UTF_7 = 0x03F4; //1012
    public static final int WINDOWS_1250 = 0x08CA; //2250
    public static final int WINDOWS_1251 = 0x08CB; //2251
    public static final int WINDOWS_1252 = 0x08CC; //2252
    public static final int WINDOWS_1253 = 0x08CD; //2253
    public static final int WINDOWS_1254 = 0x08CE; //2254
    public static final int WINDOWS_1255 = 0x08CF; //2255
    public static final int WINDOWS_1256 = 0x08D0; //2256
    public static final int WINDOWS_1257 = 0x08D1; //2257
    public static final int WINDOWS_1258 = 0x08D2; //2258

    /**
     * If the encoding of given data is unsupported, use UTF_8 to decode it.
     */
    public static final int DEFAULT_CHARSET = UTF_8;

    /**
     * Array of MIB enum numbers.
     */
    private static final int[] MIBENUM_NUMBERS = {
        ANY_CHARSET,
        US_ASCII,
        ISO_8859_1,
        ISO_8859_2,
        ISO_8859_3,
        ISO_8859_4,
        ISO_8859_5,
        ISO_8859_6,
        ISO_8859_7,
        ISO_8859_8,
        ISO_8859_9,
        SHIFT_JIS,
        UTF_8,
        BIG5,
        UCS2,
        UTF_16,
        BIG5_HKSCS,
        BOCU_1,
        CESU_8,
        CP864,
        EUC_JP,
        EUC_KR,
        GB18030,
        GBK,
        HZ_GB_2312,
        GB_2312,
        ISO_2022_CN,
        ISO_2022_CN_EXT,
        ISO_2022_JP,
        ISO_2022_KR,
        ISO_8859_10,
        ISO_8859_13,
        ISO_8859_14,
        ISO_8859_15,
        ISO_8859_16,
        KOI8_R,
        KOI8_U,
        MACINTOSH,
        SCSU,
        TIS_620,
        UTF_16BE,
        UTF_16LE,
        UTF_32,
        UTF_32BE,
        UTF_32LE,
        UTF_7,
        WINDOWS_1250,
        WINDOWS_1251,
        WINDOWS_1252,
        WINDOWS_1253,
        WINDOWS_1254,
        WINDOWS_1255,
        WINDOWS_1256,
        WINDOWS_1257,
        WINDOWS_1258,
    };

    /**
     * The Well-known-charset Mime name.
     */
    public static final String MIMENAME_ANY_CHARSET = "*";
    public static final String MIMENAME_US_ASCII    = "us-ascii";
    public static final String MIMENAME_ISO_8859_1  = "iso-8859-1";
    public static final String MIMENAME_ISO_8859_2  = "iso-8859-2";
    public static final String MIMENAME_ISO_8859_3  = "iso-8859-3";
    public static final String MIMENAME_ISO_8859_4  = "iso-8859-4";
    public static final String MIMENAME_ISO_8859_5  = "iso-8859-5";
    public static final String MIMENAME_ISO_8859_6  = "iso-8859-6";
    public static final String MIMENAME_ISO_8859_7  = "iso-8859-7";
    public static final String MIMENAME_ISO_8859_8  = "iso-8859-8";
    public static final String MIMENAME_ISO_8859_9  = "iso-8859-9";
    public static final String MIMENAME_SHIFT_JIS   = "shift_JIS";
    public static final String MIMENAME_UTF_8       = "utf-8";
    public static final String MIMENAME_BIG5        = "big5";
    public static final String MIMENAME_UCS2        = "iso-10646-ucs-2";
    public static final String MIMENAME_UTF_16      = "utf-16";

    /**
     * Extend charsets.
     *
     * From http://www.iana.org/assignments/character-sets/
     */
    public static final String MIMENAME_BIG5_HKSCS = "Big5-HKSCS";
    public static final String MIMENAME_BOCU_1 = "BOCU-1";
    public static final String MIMENAME_CESU_8 = "CESU-8";
    public static final String MIMENAME_CP864 = "cp864";
    public static final String MIMENAME_EUC_JP = "EUC-JP";
    public static final String MIMENAME_EUC_KR = "EUC-KR";
    public static final String MIMENAME_GB18030 = "GB18030";
    public static final String MIMENAME_GBK = "GBK";
    public static final String MIMENAME_HZ_GB_2312 = "HZ-GB-2312";
    public static final String MIMENAME_GB_2312 = "GB2312";
    public static final String MIMENAME_ISO_2022_CN = "ISO-2022-CN";
    public static final String MIMENAME_ISO_2022_CN_EXT = "ISO-2022-CN-EXT";
    public static final String MIMENAME_ISO_2022_JP = "ISO-2022-JP";
    public static final String MIMENAME_ISO_2022_KR = "ISO-2022-KR";
    public static final String MIMENAME_ISO_8859_10 = "ISO-8859-10";
    public static final String MIMENAME_ISO_8859_13 = "ISO-8859-13";
    public static final String MIMENAME_ISO_8859_14 = "ISO-8859-14";
    public static final String MIMENAME_ISO_8859_15 = "ISO-8859-15";
    public static final String MIMENAME_ISO_8859_16 = "ISO-8859-16";
    public static final String MIMENAME_KOI8_R = "KOI8-R";
    public static final String MIMENAME_KOI8_U = "KOI8-U";
    public static final String MIMENAME_MACINTOSH = "macintosh";
    public static final String MIMENAME_SCSU = "SCSU";
    public static final String MIMENAME_TIS_620 = "TIS-620";
    public static final String MIMENAME_UTF_16BE = "UTF-16BE";
    public static final String MIMENAME_UTF_16LE = "UTF-16LE";
    public static final String MIMENAME_UTF_32 = "UTF-32";
    public static final String MIMENAME_UTF_32BE = "UTF-32BE";
    public static final String MIMENAME_UTF_32LE = "UTF-32LE";
    public static final String MIMENAME_UTF_7 = "UTF-7";
    public static final String MIMENAME_WINDOWS_1250 = "windows-1250";
    public static final String MIMENAME_WINDOWS_1251 = "windows-1251";
    public static final String MIMENAME_WINDOWS_1252 = "windows-1252";
    public static final String MIMENAME_WINDOWS_1253 = "windows-1253";
    public static final String MIMENAME_WINDOWS_1254 = "windows-1254";
    public static final String MIMENAME_WINDOWS_1255 = "windows-1255";
    public static final String MIMENAME_WINDOWS_1256 = "windows-1256";
    public static final String MIMENAME_WINDOWS_1257 = "windows-1257";
    public static final String MIMENAME_WINDOWS_1258 = "windows-1258";

    public static final String DEFAULT_CHARSET_NAME = MIMENAME_UTF_8;

    /**
     * Array of the names of character sets.
     */
    private static final String[] MIME_NAMES = {
        MIMENAME_ANY_CHARSET,
        MIMENAME_US_ASCII,
        MIMENAME_ISO_8859_1,
        MIMENAME_ISO_8859_2,
        MIMENAME_ISO_8859_3,
        MIMENAME_ISO_8859_4,
        MIMENAME_ISO_8859_5,
        MIMENAME_ISO_8859_6,
        MIMENAME_ISO_8859_7,
        MIMENAME_ISO_8859_8,
        MIMENAME_ISO_8859_9,
        MIMENAME_SHIFT_JIS,
        MIMENAME_UTF_8,
        MIMENAME_BIG5,
        MIMENAME_UCS2,
        MIMENAME_UTF_16,
        MIMENAME_BIG5_HKSCS,
        MIMENAME_BOCU_1,
        MIMENAME_CESU_8,
        MIMENAME_CP864,
        MIMENAME_EUC_JP,
        MIMENAME_EUC_KR,
        MIMENAME_GB18030,
        MIMENAME_GBK,
        MIMENAME_HZ_GB_2312,
        MIMENAME_GB_2312,
        MIMENAME_ISO_2022_CN,
        MIMENAME_ISO_2022_CN_EXT,
        MIMENAME_ISO_2022_JP,
        MIMENAME_ISO_2022_KR,
        MIMENAME_ISO_8859_10,
        MIMENAME_ISO_8859_13,
        MIMENAME_ISO_8859_14,
        MIMENAME_ISO_8859_15,
        MIMENAME_ISO_8859_16,
        MIMENAME_KOI8_R,
        MIMENAME_KOI8_U,
        MIMENAME_MACINTOSH,
        MIMENAME_SCSU,
        MIMENAME_TIS_620,
        MIMENAME_UTF_16BE,
        MIMENAME_UTF_16LE,
        MIMENAME_UTF_32,
        MIMENAME_UTF_32BE,
        MIMENAME_UTF_32LE,
        MIMENAME_UTF_7,
        MIMENAME_WINDOWS_1250,
        MIMENAME_WINDOWS_1251,
        MIMENAME_WINDOWS_1252,
        MIMENAME_WINDOWS_1253,
        MIMENAME_WINDOWS_1254,
        MIMENAME_WINDOWS_1255,
        MIMENAME_WINDOWS_1256,
        MIMENAME_WINDOWS_1257,
        MIMENAME_WINDOWS_1258,
    };

    private static final HashMap<Integer, String> MIBENUM_TO_NAME_MAP;
    private static final HashMap<String, Integer> NAME_TO_MIBENUM_MAP;

    static {
        // Create the HashMaps.
        MIBENUM_TO_NAME_MAP = new HashMap<Integer, String>();
        NAME_TO_MIBENUM_MAP = new HashMap<String, Integer>();
        assert(MIBENUM_NUMBERS.length == MIME_NAMES.length);
        int count = MIBENUM_NUMBERS.length - 1;
        for(int i = 0; i <= count; i++) {
            MIBENUM_TO_NAME_MAP.put(MIBENUM_NUMBERS[i], MIME_NAMES[i]);
            NAME_TO_MIBENUM_MAP.put(MIME_NAMES[i], MIBENUM_NUMBERS[i]);
        }
    }

    private CharacterSets() {} // Non-instantiatable

    /**
     * Map an MIBEnum number to the name of the charset which this number
     * is assigned to by IANA.
     *
     * @param mibEnumValue An IANA assigned MIBEnum number.
     * @return The name string of the charset.
     * @throws UnsupportedEncodingException
     */
    @UnsupportedAppUsage
    public static String getMimeName(int mibEnumValue)
            throws UnsupportedEncodingException {
        String name = MIBENUM_TO_NAME_MAP.get(mibEnumValue);
        if (name == null) {
            throw new UnsupportedEncodingException();
        }
        return name;
    }

    /**
     * Map a well-known charset name to its assigned MIBEnum number.
     *
     * @param mimeName The charset name.
     * @return The MIBEnum number assigned by IANA for this charset.
     * @throws UnsupportedEncodingException
     */
    @UnsupportedAppUsage
    public static int getMibEnumValue(String mimeName)
            throws UnsupportedEncodingException {
        if(null == mimeName) {
            return -1;
        }

        Integer mibEnumValue = NAME_TO_MIBENUM_MAP.get(mimeName);
        if (mibEnumValue == null) {
            throw new UnsupportedEncodingException();
        }
        return mibEnumValue;
    }
}