/* ***** BEGIN LICENSE BLOCK *****
    * Version: MPL 1.1/GPL 2.0/LGPL 2.1
    *
    * The contents of this file are subject to the Mozilla Public License Version
    * 1.1 (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.mozilla.org/MPL/
    *
    * Software distributed under the License is distributed on an "AS IS" basis,
   * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
   * for the specific language governing rights and limitations under the
   * License.
   *
   * The Original Code is "SMS Library for the Java platform".
   *
   * The Initial Developer of the Original Code is Markus Eriksson.
   * Portions created by the Initial Developer are Copyright (C) 2002
   * the Initial Developer. All Rights Reserved.
   *
   * Contributor(s):
   *
   * Alternatively, the contents of this file may be used under the terms of
   * either the GNU General Public License Version 2 or later (the "GPL"), or
   * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
   * in which case the provisions of the GPL or the LGPL are applicable instead
   * of those above. If you wish to allow use of your version of this file only
   * under the terms of either the GPL or the LGPL, and not to allow others to
   * use your version of this file under the terms of the MPL, indicate your
   * decision by deleting the provisions above and replace them with the notice
   * and other provisions required by the GPL or the LGPL. If you do not delete
   * the provisions above, a recipient may use your version of this file under
   * the terms of any one of the MPL, the GPL or the LGPL.
   *
   * ***** END LICENSE BLOCK ***** */
  package org.marre.sms;
  
  /***
   * Represents a SMS DCS (Data Coding Scheme).
   *
   * @version $Id: SmsDcs.java,v 1.3 2005/05/06 13:55:11 c95men Exp $
   * @author Markus Eriksson
   */
  public class SmsDcs
  {
      /***
       * Alphabet as defined in GSM 03.38. It contains all characters needed for most
       * Western European languages. It also contains upper case Greek characters.
       */
      public static final int ALPHABET_GSM = 0;
      /*** ISO 8859-1 (ISO Latin-1). */
      public static final int ALPHABET_8BIT = 1;
      /*** Unicode UCS-2. */
      public static final int ALPHABET_UCS2 = 2;
      /*** Reserved. */
      public static final int ALPHABET_RESERVED = 3;
      /*** Unknown. */
      public static final int ALPHABET_UNKNOWN = 4;
  
      /*** Class 0 SMS. Sometimes called FLASH message. */
      public static final byte MSG_CLASS_0 = 0;
      /*** Class 1 SMS. Default meaning: ME-specific. */
      public static final byte MSG_CLASS_1 = 1;
      /*** Class 2 SMS, SIM specific message. */
      public static final byte MSG_CLASS_2 = 2;
      /*** Class 3 SMS. Default meaning: TE specific (See GSM TS 07.05). */
      public static final byte MSG_CLASS_3 = 3;
      /*** Message with no specific message class (Often handled as an class 1 SMS). */
      public static final byte MSG_CLASS_UNKNOWN = 4;
  
      /*** DCS general data coding indication group. 00xxxxxx. */
      public static final int GROUP_GENERAL_DATA_CODING = 0;
      /*** DCS message waiting indication group: discard message. 1100xxxx. */
      public static final int GROUP_MESSAGE_WAITING_DISCARD = 1;
      /*** DCS message waiting indication group: store message (gsm). 1101xxxx. */
      public static final int GROUP_MESSAGE_WAITING_STORE_GSM = 2;
      /*** DCS message waiting indication group: store message (ucs2). 1110xxxx. */
      public static final int GROUP_MESSAGE_WAITING_STORE_UCS2 = 3;
      /*** DCS data coding/message class: 1111xxxx. */
      public static final int GROUP_DATA_CODING_MESSAGE = 4;
      /*** DCS group unknown. */
      public static final int GROUP_UNKNOWN = 5;
      
      /*** Message waiting indication type - voicemail. */
      public static final byte DCS_MSG_WAITING_VOICEMAIL = 0;
      /*** Message waiting indication type - fax. */
      public static final byte DCS_MSG_WAITING_FAX = 1;
      /*** Message waiting indication type - email. */
      public static final byte DCS_MSG_WAITING_EMAIL = 2;
      /*** Message waiting indication type - other. Should not be used. */
      public static final byte DCS_MSG_WAITING_OTHER = 3;
            
      /*** The encoded dcs. */
      protected byte dcs_;
      
      /***
       * Creates a specific DCS.
       * 
       * @param dcs The dcs.
       */
     public SmsDcs(byte dcs)
     {
         dcs_ = dcs;
     }
     
     /***
      * Returns the encoded dcs.
      * 
      * @return The dcs.
      */
     public byte getValue()
     {
         return dcs_;
     }
     
     /***
      * Builds a general-data-coding dcs.
      * 
      * @param alphabet The alphabet. Possible values are ALPHABET_GSM, ALPHABET_8BIT, ALPHABET_UCS2 and ALPHABET_RESERVED. 
      * @param messageClass The message class. Possible values are MSG_CLASS_0, MSG_CLASS_1, MSG_CLASS_2 and MSG_CLASS_3.
      * 
      * @return A valid general data coding DCS.
      */
     public static SmsDcs getGeneralDataCodingDcs(int alphabet, byte messageClass)
     {
         byte dcs = 0x00;
         
         // Bits 3 and 2 indicate the alphabet being used, as follows :
         // Bit3 Bit2 Alphabet:
         //    0   0  Default alphabet
         //    0   1  8 bit data
         //    1   0  UCS2 (16bit) [10]
         //    1   1  Reserved
         switch (alphabet)
         {
         case ALPHABET_GSM:      dcs |= 0x00; break; 
         case ALPHABET_8BIT:     dcs |= 0x04; break;
         case ALPHABET_UCS2:     dcs |= 0x08; break;
         case ALPHABET_RESERVED: dcs |= 0x0C; break;
         
         case ALPHABET_UNKNOWN:
         default:
             throw new IllegalArgumentException("Invalid alphabet");
         }
         
         switch (messageClass)
         {
         case MSG_CLASS_0:          dcs |= 0x10; break; 
         case MSG_CLASS_1:          dcs |= 0x11; break;
         case MSG_CLASS_2:          dcs |= 0x12; break;
         case MSG_CLASS_3:          dcs |= 0x13; break;
         case MSG_CLASS_UNKNOWN:    dcs |= 0x00; break;
             
         default:
             throw new IllegalArgumentException("Invalid message class");
         }
                 
         return new SmsDcs(dcs);
     }
     
     /***
      * Decodes the given dcs and returns the alphabet.
      *
      * <pre>
      * Return value can be one of:
      * - ALPHABET_GSM
      * - ALPHABET_8BIT
      * - ALPHABET_UCS2
      * - ALPHABET_RESERVED
      * - ALPHABET_UNKNOWN
      * </pre>
      * 
      * @return Returns the alphabet.
      */
     public int getAlphabet()
     {
         switch (getGroup())
         {
         case GROUP_GENERAL_DATA_CODING:
             // General Data Coding Indication
             if (dcs_ == 0x00)
             {
                 return ALPHABET_GSM;
             }
             
             switch (dcs_ & 0x0C)
             {
             case 0x00: return ALPHABET_GSM;
             case 0x04: return ALPHABET_8BIT;
             case 0x08: return ALPHABET_UCS2;
             case 0x0C: return ALPHABET_RESERVED;
             default:   return ALPHABET_UNKNOWN;
             }
             
         case GROUP_MESSAGE_WAITING_STORE_GSM:
             return ALPHABET_GSM;
         
         case GROUP_MESSAGE_WAITING_STORE_UCS2:
             return ALPHABET_UCS2;
 
         case GROUP_DATA_CODING_MESSAGE:
             switch (dcs_ & 0x04)
             {
             case 0x00: return ALPHABET_GSM;
             case 0x04: return ALPHABET_8BIT;
             default:   return ALPHABET_UNKNOWN;
             }
         
         default:
             return ALPHABET_UNKNOWN;
         }                
     }
     
     /***
      * What group (type of message) is the given dcs.
      * 
      * @param theDcs the dcs to test
      * @return Any of the GROUP_ constants.
      */
     public int getGroup()
     {
         if ((dcs_ & 0xC0) == 0x00) 
         {
             return GROUP_GENERAL_DATA_CODING;
         }
         
         switch ((dcs_ & 0xF0))
         {
         case 0xC0: return GROUP_MESSAGE_WAITING_DISCARD;
         case 0xD0: return GROUP_MESSAGE_WAITING_STORE_GSM;
         case 0xE0: return GROUP_MESSAGE_WAITING_STORE_UCS2;
         case 0xF0: return GROUP_DATA_CODING_MESSAGE;
         default:   return GROUP_UNKNOWN;
         }
     }
     
     /***
      * Get the message class.
      *
      * <pre>
      * Return value can be one of:
      * - MSG_CLASS_UNKNOWN
      * - MSG_CLASS_0
      * - MSG_CLASS_1
      * - MSG_CLASS_2
      * - MSG_CLASS_3
      * </pre>
      *
      * @return Returns the message class.
      */
     public int getMessageClass()
     {
         switch (getGroup())
         {
         case GROUP_GENERAL_DATA_CODING:
             // General Data Coding Indication
             if (dcs_ == 0x00)
             {
                 return MSG_CLASS_UNKNOWN;
             }
             
             switch (dcs_ & 0x13)
             {
             case 0x10: return MSG_CLASS_0;
             case 0x11: return MSG_CLASS_1;
             case 0x12: return MSG_CLASS_2;
             case 0x13: return MSG_CLASS_3;
             default:   return MSG_CLASS_UNKNOWN;
             }
             
         case GROUP_DATA_CODING_MESSAGE:
             // Data coding/message class
             switch (dcs_ & 0x03)
             {
             case 0x00: return MSG_CLASS_0;
             case 0x01: return MSG_CLASS_1;
             case 0x02: return MSG_CLASS_2;
             case 0x03: return MSG_CLASS_3;
             default:   return MSG_CLASS_UNKNOWN;
             }
             
         default:
             return MSG_CLASS_UNKNOWN;
         }
     }
 }