/*
 Copyright (C) 2002-2004 MySQL AB

 This program is free software; you can redistribute it and/or modify
 it under the terms of version 2 of the GNU General Public License as
 published by the Free Software Foundation.
 

 There are special exceptions to the terms and conditions of the GPL 
 as it is applied to this software. View the full text of the 
 exception exception in file EXCEPTIONS-CONNECTOR-J in the directory of this 
 software distribution.

 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 com.mysql.jdbc;

import java.util.Collections;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;


/**
 * Mapping between MySQL charset names
 * and Java charset names.
 *
 * I've investigated placing these in a .properties file,
 * but unfortunately under most appservers this complicates
 * configuration because the security policy needs to be changed
 * by the user to allow the driver to read them :(
 *
 * @author Mark Matthews
 */
public class CharsetMapping {
    //~ Static fields/initializers ---------------------------------------------

    /**
     * Mapping of Java charset names to MySQL charset names
     */
    public static final Map JAVA_TO_MYSQL_CHARSET_MAP;
    
    /**
     * Mapping of upper-case Java charset names to MySQL charset names
     */
    public static final Map JAVA_UC_TO_MYSQL_CHARSET_MAP;
    
   
    /**
     * Mapping of MySQL charset names to Java charset names
     */
    public static final Map MYSQL_TO_JAVA_CHARSET_MAP;

    /**
     * Map/List of multibyte character sets (using MySQL names)
     */
    public static final Map MULTIBYTE_CHARSETS;

    /**
     * Map of MySQL-4.1 charset indexes to Java encoding names
     */
    public static final String[] INDEX_TO_CHARSET;

    static {
        HashMap tempMap = new HashMap();

        // MySQL Name     | Java Name
        tempMap.put("usa7", "US-ASCII");
        tempMap.put("ascii", "US-ASCII");
        tempMap.put("big5", "Big5");
        tempMap.put("gbk", "GBK");
        tempMap.put("sjis", "SJIS");
        tempMap.put("gb2312", "EUC_CN");
        tempMap.put("ujis", "EUC_JP");
        tempMap.put("eucjpms", "EUC_JP_Solaris");
        tempMap.put("euc_kr", "EUC_KR");
        tempMap.put("euckr", "EUC_KR");
        tempMap.put("latin1", "ISO8859_1");
        tempMap.put("latin1_de", "ISO8859_1");
        tempMap.put("german1", "ISO8859_1");
        tempMap.put("danish", "ISO8859_1");
        tempMap.put("latin2", "ISO8859_2");
        tempMap.put("czech", "ISO8859_2");
        tempMap.put("hungarian", "ISO8859_2");
        tempMap.put("croat", "ISO8859_2");
        tempMap.put("greek", "ISO8859_7");
        tempMap.put("latin7", "ISO8859_7");
        tempMap.put("hebrew", "ISO8859_8");
        tempMap.put("latin5", "ISO8859_9");
        tempMap.put("latvian", "ISO8859_13");
        tempMap.put("latvian1", "ISO8859_13");
        tempMap.put("estonia", "ISO8859_13");
        tempMap.put("dos", "Cp437");
        tempMap.put("Cp850", "Cp850");
        tempMap.put("Cp852", "Cp852");
        tempMap.put("cp866", "Cp866");
        tempMap.put("koi8_ru", "KOI8_R");
        tempMap.put("koi8r", "KOI8_R");
        tempMap.put("tis620", "TIS620");
        tempMap.put("cp1250", "Cp1250");
        tempMap.put("win1250", "Cp1250");
        tempMap.put("win1251", "Cp1251");
        tempMap.put("cp1251", "Cp1251");
        tempMap.put("cp1251cias", "Cp1251");
        tempMap.put("cp1251csas", "Cp1251");
        tempMap.put("cp1256", "Cp1256");
        tempMap.put("win1251ukr", "Cp1251");
        tempMap.put("cp1257", "Cp1257");
        tempMap.put("macroman", "MacRoman");
        tempMap.put("macce", "MacCentralEurope");
        tempMap.put("utf8", "UTF-8");
        tempMap.put("ucs2", "UnicodeBig");
        tempMap.put("binary", "US-ASCII"); // closest match

        MYSQL_TO_JAVA_CHARSET_MAP = Collections.unmodifiableMap(tempMap);
        
        HashMap javaToMysqlMap = new HashMap();
        
        Set keySet = MYSQL_TO_JAVA_CHARSET_MAP.keySet();

        Iterator keys = keySet.iterator();

        while (keys.hasNext()) {
            Object mysqlEncodingName = keys.next();
            Object javaEncodingName = MYSQL_TO_JAVA_CHARSET_MAP.get(mysqlEncodingName);

            //
            // Use 'closest' encodings here...as Java encoding names
            // overlap with some MySQL character sets.
            //
            if ("ISO8859_1".equals(javaEncodingName)) {
            	if ("latin1".equals(mysqlEncodingName)) {
					javaToMysqlMap.put(javaEncodingName, mysqlEncodingName);
					
            	}
            } else if ("ISO8859_2".equals(javaEncodingName)) {
				if ("latin2".equals(mysqlEncodingName)) {
					javaToMysqlMap.put(javaEncodingName, mysqlEncodingName);
				}
			} 
			else if ("ISO8859_13".equals(javaEncodingName)) {
				if ("latin7".equals(mysqlEncodingName)) {
					javaToMysqlMap.put(javaEncodingName, mysqlEncodingName);
				}
			} else {
            	javaToMysqlMap.put(javaEncodingName, mysqlEncodingName);
            }
        }

        JAVA_TO_MYSQL_CHARSET_MAP = Collections.unmodifiableMap(javaToMysqlMap);
    
        HashMap ucMap = new HashMap(JAVA_TO_MYSQL_CHARSET_MAP.size());
        
        Iterator javaNamesKeys = JAVA_TO_MYSQL_CHARSET_MAP.keySet().iterator();
        
        while (javaNamesKeys.hasNext()) {
        	String key = (String)javaNamesKeys.next();
        	
        	ucMap.put(key.toUpperCase(), JAVA_TO_MYSQL_CHARSET_MAP.get(key));
        }
        
        ucMap.put("ASCII", "ascii"); // special case
        ucMap.put("LATIN5", "latin5");
        ucMap.put("LATIN7", "latin7");
        ucMap.put("HEBREW", "hebrew");
        ucMap.put("GREEK", "greek");
        ucMap.put("EUCKR", "euckr");
        ucMap.put("GB2312", "gb2312");
        ucMap.put("LATIN2", "latin2");
        
        // These are _functionally_ equivalent
        ucMap.put("WINDOWS-31J", "sjis");
        ucMap.put("MS932", "sjis");
        ucMap.put("SHIFT_JIS", "sjis");
        ucMap.put("CP943", "sjis");
        ucMap.put("EUC_JP", "ujis");
        
        JAVA_UC_TO_MYSQL_CHARSET_MAP = Collections.unmodifiableMap(ucMap);


        //
        // Character sets that we can't convert
        // ourselves.
        //
        HashMap tempMapMulti = new HashMap();

        tempMapMulti.put("big5", "big5");
        tempMapMulti.put("euc_kr", "euc_kr");
        tempMapMulti.put("euckr", "euckr");
        tempMapMulti.put("gb2312", "gb2312");
        tempMapMulti.put("gbk", "gbk");
        tempMapMulti.put("sjis", "sjis");
        tempMapMulti.put("ujis", "ujis");
        tempMapMulti.put("utf8", "utf8");
        tempMapMulti.put("ucs2", "UnicodeBig");
        tempMapMulti.put("windows-31j", "sjis");
        tempMapMulti.put("ms932", "sjis");
        tempMapMulti.put("shift_jis", "sjis");
        tempMapMulti.put("cp943", "sjis");
        tempMapMulti.put("eucjpms", "ujis");
        tempMapMulti.put("EUC_JP_Solaris", "eucjpms");

        
        MULTIBYTE_CHARSETS = Collections.unmodifiableMap(tempMapMulti);

        INDEX_TO_CHARSET = new String[99];

        INDEX_TO_CHARSET[1]  = (String) MYSQL_TO_JAVA_CHARSET_MAP.get("big5");
        INDEX_TO_CHARSET[2]  = (String) MYSQL_TO_JAVA_CHARSET_MAP.get("czech");
        INDEX_TO_CHARSET[3]  = (String) MYSQL_TO_JAVA_CHARSET_MAP.get("dec8");
        INDEX_TO_CHARSET[4]  = (String) MYSQL_TO_JAVA_CHARSET_MAP.get("dos");
        INDEX_TO_CHARSET[5]  = (String) MYSQL_TO_JAVA_CHARSET_MAP.get("german1");
        INDEX_TO_CHARSET[6]  = (String) MYSQL_TO_JAVA_CHARSET_MAP.get("hp8");
        INDEX_TO_CHARSET[7]  = (String) MYSQL_TO_JAVA_CHARSET_MAP.get("koi8_ru");
        INDEX_TO_CHARSET[8]  = (String) MYSQL_TO_JAVA_CHARSET_MAP.get("latin1");
        INDEX_TO_CHARSET[9]  = (String) MYSQL_TO_JAVA_CHARSET_MAP.get("latin2");
        INDEX_TO_CHARSET[10] = (String) MYSQL_TO_JAVA_CHARSET_MAP.get("swe7");
        INDEX_TO_CHARSET[11] = (String) MYSQL_TO_JAVA_CHARSET_MAP.get("usa7");
        INDEX_TO_CHARSET[12] = (String) MYSQL_TO_JAVA_CHARSET_MAP.get("ujis");
        INDEX_TO_CHARSET[13] = (String) MYSQL_TO_JAVA_CHARSET_MAP.get("sjis");
        INDEX_TO_CHARSET[14] = (String) MYSQL_TO_JAVA_CHARSET_MAP.get("cp1251");
        INDEX_TO_CHARSET[15] = (String) MYSQL_TO_JAVA_CHARSET_MAP.get("danish");
        INDEX_TO_CHARSET[16] = (String) MYSQL_TO_JAVA_CHARSET_MAP.get("hebrew");
        INDEX_TO_CHARSET[18] = (String) MYSQL_TO_JAVA_CHARSET_MAP.get("tis620");
        INDEX_TO_CHARSET[19] = (String) MYSQL_TO_JAVA_CHARSET_MAP.get("euc_kr");
        INDEX_TO_CHARSET[20] = (String) MYSQL_TO_JAVA_CHARSET_MAP.get("estonia");
        INDEX_TO_CHARSET[21] = (String) MYSQL_TO_JAVA_CHARSET_MAP.get("hungarian");
        INDEX_TO_CHARSET[22] = (String) MYSQL_TO_JAVA_CHARSET_MAP.get("koi8_ukr");
        INDEX_TO_CHARSET[23] = (String) MYSQL_TO_JAVA_CHARSET_MAP.get("win1251ukr");
        INDEX_TO_CHARSET[24] = (String) MYSQL_TO_JAVA_CHARSET_MAP.get("gb2312");
        INDEX_TO_CHARSET[25] = (String) MYSQL_TO_JAVA_CHARSET_MAP.get("greek");
        INDEX_TO_CHARSET[26] = (String) MYSQL_TO_JAVA_CHARSET_MAP.get("win1250");
        INDEX_TO_CHARSET[27] = (String) MYSQL_TO_JAVA_CHARSET_MAP.get("croat");
        INDEX_TO_CHARSET[28] = (String) MYSQL_TO_JAVA_CHARSET_MAP.get("gbk");
        INDEX_TO_CHARSET[29] = (String) MYSQL_TO_JAVA_CHARSET_MAP.get("cp1257");
        INDEX_TO_CHARSET[30] = (String) MYSQL_TO_JAVA_CHARSET_MAP.get("latin5");
        INDEX_TO_CHARSET[31] = (String) MYSQL_TO_JAVA_CHARSET_MAP.get("latin1_de");
        INDEX_TO_CHARSET[32] = (String) MYSQL_TO_JAVA_CHARSET_MAP.get("armscii8");
        INDEX_TO_CHARSET[33] = (String) MYSQL_TO_JAVA_CHARSET_MAP.get("utf8");
        INDEX_TO_CHARSET[34] = (String) MYSQL_TO_JAVA_CHARSET_MAP.get("win1250ch");
        INDEX_TO_CHARSET[35] = (String) MYSQL_TO_JAVA_CHARSET_MAP.get("ucs2");
        INDEX_TO_CHARSET[36] = (String) MYSQL_TO_JAVA_CHARSET_MAP.get("cp866");
        INDEX_TO_CHARSET[37] = (String) MYSQL_TO_JAVA_CHARSET_MAP.get("keybcs2");
        INDEX_TO_CHARSET[38] = (String) MYSQL_TO_JAVA_CHARSET_MAP.get("macce");
        INDEX_TO_CHARSET[39] = (String) MYSQL_TO_JAVA_CHARSET_MAP.get("macroman");
        INDEX_TO_CHARSET[40] = (String) MYSQL_TO_JAVA_CHARSET_MAP.get("pclatin2");
        INDEX_TO_CHARSET[41] = (String) MYSQL_TO_JAVA_CHARSET_MAP.get("latvian");
        INDEX_TO_CHARSET[42] = (String) MYSQL_TO_JAVA_CHARSET_MAP.get("latvian1");
        INDEX_TO_CHARSET[43] = (String) MYSQL_TO_JAVA_CHARSET_MAP.get("maccebin");
        INDEX_TO_CHARSET[44] = (String) MYSQL_TO_JAVA_CHARSET_MAP.get("macceciai");
        INDEX_TO_CHARSET[45] = (String) MYSQL_TO_JAVA_CHARSET_MAP.get("maccecias");
        INDEX_TO_CHARSET[46] = (String) MYSQL_TO_JAVA_CHARSET_MAP.get("maccecsas");
        INDEX_TO_CHARSET[47] = (String) MYSQL_TO_JAVA_CHARSET_MAP.get("latin1bin");
        INDEX_TO_CHARSET[48] = (String) MYSQL_TO_JAVA_CHARSET_MAP.get("latin1cias");
        INDEX_TO_CHARSET[49] = (String) MYSQL_TO_JAVA_CHARSET_MAP.get("latin1csas");
        INDEX_TO_CHARSET[50] = (String) MYSQL_TO_JAVA_CHARSET_MAP.get("cp1251bin");
        INDEX_TO_CHARSET[51] = (String) MYSQL_TO_JAVA_CHARSET_MAP.get("cp1251cias");
        INDEX_TO_CHARSET[52] = (String) MYSQL_TO_JAVA_CHARSET_MAP.get("cp1251csas");
        INDEX_TO_CHARSET[53] = (String) MYSQL_TO_JAVA_CHARSET_MAP.get("macromanbin");
        INDEX_TO_CHARSET[54] = (String) MYSQL_TO_JAVA_CHARSET_MAP.get("macromancias");
        INDEX_TO_CHARSET[55] = (String) MYSQL_TO_JAVA_CHARSET_MAP.get("macromanciai");
        INDEX_TO_CHARSET[56] = (String) MYSQL_TO_JAVA_CHARSET_MAP.get("macromancsas");
        INDEX_TO_CHARSET[57] = (String) MYSQL_TO_JAVA_CHARSET_MAP.get("cp1256");
        INDEX_TO_CHARSET[63] = (String) MYSQL_TO_JAVA_CHARSET_MAP.get("binary");
        INDEX_TO_CHARSET[64] = (String) MYSQL_TO_JAVA_CHARSET_MAP.get("armscii");
        INDEX_TO_CHARSET[65] = (String) MYSQL_TO_JAVA_CHARSET_MAP.get("ascii");
        INDEX_TO_CHARSET[66] = (String) MYSQL_TO_JAVA_CHARSET_MAP.get("cp1250");
        INDEX_TO_CHARSET[67] = (String) MYSQL_TO_JAVA_CHARSET_MAP.get("cp1256");
        INDEX_TO_CHARSET[68] = (String) MYSQL_TO_JAVA_CHARSET_MAP.get("cp866");
        INDEX_TO_CHARSET[69] = (String) MYSQL_TO_JAVA_CHARSET_MAP.get("dec8");
        INDEX_TO_CHARSET[70] = (String) MYSQL_TO_JAVA_CHARSET_MAP.get("greek");
        INDEX_TO_CHARSET[71] = (String) MYSQL_TO_JAVA_CHARSET_MAP.get("hebrew");
        INDEX_TO_CHARSET[72] = (String) MYSQL_TO_JAVA_CHARSET_MAP.get("hp8");
        INDEX_TO_CHARSET[73] = (String) MYSQL_TO_JAVA_CHARSET_MAP.get("keybcs2");
        INDEX_TO_CHARSET[74] = (String) MYSQL_TO_JAVA_CHARSET_MAP.get("koi8r");
        INDEX_TO_CHARSET[75] = (String) MYSQL_TO_JAVA_CHARSET_MAP.get("koi8ukr");
        INDEX_TO_CHARSET[77] = (String) MYSQL_TO_JAVA_CHARSET_MAP.get("latin2");
        INDEX_TO_CHARSET[78] = (String) MYSQL_TO_JAVA_CHARSET_MAP.get("latin5");
        INDEX_TO_CHARSET[79] = (String) MYSQL_TO_JAVA_CHARSET_MAP.get("latin7");
        INDEX_TO_CHARSET[80] = (String) MYSQL_TO_JAVA_CHARSET_MAP.get("cp850");
        INDEX_TO_CHARSET[81] = (String) MYSQL_TO_JAVA_CHARSET_MAP.get("cp852");
        INDEX_TO_CHARSET[82] = (String) MYSQL_TO_JAVA_CHARSET_MAP.get("swe7");
        INDEX_TO_CHARSET[83] = (String) MYSQL_TO_JAVA_CHARSET_MAP.get("utf8");
        INDEX_TO_CHARSET[84] = (String) MYSQL_TO_JAVA_CHARSET_MAP.get("big5");
        INDEX_TO_CHARSET[85] = (String) MYSQL_TO_JAVA_CHARSET_MAP.get("euckr");
        INDEX_TO_CHARSET[86] = (String) MYSQL_TO_JAVA_CHARSET_MAP.get("gb2312");
        INDEX_TO_CHARSET[87] = (String) MYSQL_TO_JAVA_CHARSET_MAP.get("gbk");
        INDEX_TO_CHARSET[88] = (String) MYSQL_TO_JAVA_CHARSET_MAP.get("sjis");
        INDEX_TO_CHARSET[89] = (String) MYSQL_TO_JAVA_CHARSET_MAP.get("tis620");
        INDEX_TO_CHARSET[90] = (String) MYSQL_TO_JAVA_CHARSET_MAP.get("ucs2");
        INDEX_TO_CHARSET[91] = (String) MYSQL_TO_JAVA_CHARSET_MAP.get("ujis");
        INDEX_TO_CHARSET[92] = (String) MYSQL_TO_JAVA_CHARSET_MAP.get("geostd8");
        INDEX_TO_CHARSET[93] = (String) MYSQL_TO_JAVA_CHARSET_MAP.get("geostd8");
        INDEX_TO_CHARSET[94] = (String) MYSQL_TO_JAVA_CHARSET_MAP.get("latin1");
        INDEX_TO_CHARSET[95] = (String) MYSQL_TO_JAVA_CHARSET_MAP.get("cp932");
		INDEX_TO_CHARSET[96] = (String) MYSQL_TO_JAVA_CHARSET_MAP.get("cp932");
		INDEX_TO_CHARSET[97] = (String) MYSQL_TO_JAVA_CHARSET_MAP.get("eucjpms");
		INDEX_TO_CHARSET[98] = (String) MYSQL_TO_JAVA_CHARSET_MAP.get("eucjpms");
    }
    
    final static boolean isAliasForSjis(String encoding) {
    	return ("SJIS".equalsIgnoreCase(encoding)
    			|| "WINDOWS-31J".equalsIgnoreCase(encoding)
    			|| "MS932".equalsIgnoreCase(encoding)
    			|| "SHIFT_JIS".equalsIgnoreCase(encoding)
    			|| "CP943".equalsIgnoreCase(encoding));
               
    }
}
