/*
* EncodingCmd.java --
*
* Copyright (c) 2001 Bruce A. Johnson
*
* See the file "license.terms" for information on usage and
* redistribution of this file, and for a DISCLAIMER OF ALL
* WARRANTIES.
* 
* Included in SQLite3 port to C# for use in testharness only;  2008 Noah B Hart
*
* RCS @(#) $Id: EncodingCmd.java,v 1.2 2002/04/12 15:32:44 mdejong Exp $
*
*/
using System;
using System.Text;
using System.Collections;
using System.IO;

namespace tcl.lang
{

  /// <summary> This class implements the built-in "encoding" command in Tcl.</summary>

  class EncodingCmd : Command
  {
    // FIXME: Make sure this is a global property and not a per-interp
    // property!
    internal static string systemTclEncoding = "utf-8";
    internal static Encoding systemJavaEncoding = UTF8Encoding.UTF8;

    internal static string[] tclNames = new string[] { "utf-8", "unicode", "ascii", "utf-7" };

    internal static readonly Encoding[] encodings = new Encoding[] { UTF8Encoding.UTF8, UnicodeEncoding.Unicode, ASCIIEncoding.Unicode, UTF7Encoding.UTF7 };

    internal static int[] bytesPerChar = new int[] { 1, 2, 1, 1 };

    private static readonly string[] validCmds = new string[] { "convertfrom", "convertto", "names", "system" };

    internal const int OPT_CONVERTFROM = 0;
    internal const int OPT_CONVERTTO = 1;
    internal const int OPT_NAMES = 2;
    internal const int OPT_SYSTEM = 3;

    /// <summary> This procedure is invoked to process the "encoding" Tcl command.
    /// See the user documentation for details on what it does.
    /// 
    /// </summary>
    /// <param name="interp">the current interpreter.
    /// </param>
    /// <param name="argv">command arguments.
    /// </param>

    public TCL.CompletionCode cmdProc( Interp interp, TclObject[] argv )
    {
      if ( argv.Length < 2 )
      {
        throw new TclNumArgsException( interp, 1, argv, "option ?arg ...?" );
      }

      int index = TclIndex.get( interp, argv[1], validCmds, "option", 0 );

      switch ( index )
      {

        case OPT_CONVERTTO:
        case OPT_CONVERTFROM:
          {
            string tclEncoding;
            Encoding javaEncoding;
            TclObject data;

            if ( argv.Length == 3 )
            {
              tclEncoding = systemTclEncoding;
              data = argv[2];
            }
            else if ( argv.Length == 4 )
            {

              tclEncoding = argv[2].ToString();
              data = argv[3];
            }
            else
            {
              throw new TclNumArgsException( interp, 2, argv, "?encoding? data" );
            }

            javaEncoding = getJavaName( tclEncoding );

            if ( (System.Object)javaEncoding == null )
            {
              throw new TclException( interp, "unknown encoding \"" + tclEncoding + "\"" );
            }

            try
            {
              if ( index == OPT_CONVERTFROM )
              {
                // Treat the string as binary data
                byte[] bytes = TclByteArray.getBytes( interp, data );

                // ATK
                interp.setResult( System.Text.Encoding.UTF8.GetString( bytes, 0, bytes.Length) );
              }
              else
              {
                // Store the result as binary data


                // ATK byte[] bytes = data.ToString().getBytes(javaEncoding);
                byte[] bytes = System.Text.Encoding.UTF8.GetBytes( data.ToString() );
                interp.setResult( TclByteArray.newInstance( bytes ) );
              }
            }
            catch ( IOException ex )
            {
              throw new TclRuntimeError( "Encoding.cmdProc() error: " + "unsupported java encoding \"" + javaEncoding + "\"" );
            }

            break;
          }

        case OPT_NAMES:
          {
            if ( argv.Length > 2 )
            {
              throw new TclNumArgsException( interp, 2, argv, null );
            }

            TclObject list = TclList.newInstance();
            for ( int i = 0; i < tclNames.Length; i++ )
            {
              TclList.append( interp, list, TclString.newInstance( tclNames[i] ) );
            }
            interp.setResult( list );
            break;
          }

        case OPT_SYSTEM:
          {
            if ( argv.Length > 3 )
              throw new TclNumArgsException( interp, 2, argv, "?encoding?" );

            if ( argv.Length == 2 )
            {
              interp.setResult( systemTclEncoding );
            }
            else
            {

              string tclEncoding = argv[2].ToString();
              Encoding javaEncoding = getJavaName( tclEncoding );

              if ( javaEncoding == null )
              {
                throw new TclException( interp, "unknown encoding \"" + tclEncoding + "\"" );
              }

              systemTclEncoding = tclEncoding;
              systemJavaEncoding = javaEncoding;
            }

            break;
          }

        default:
          {
            throw new TclRuntimeError( "Encoding.cmdProc() error: " + "incorrect index returned from TclIndex.get()" );
          }

      }
      return TCL.CompletionCode.RETURN;
    }

    internal static int getBytesPerChar( Encoding encoding )
    {
      return encoding.GetMaxByteCount( 1 );
    }

    internal static System.Text.Encoding getJavaName( string name )
    {
      for ( int x = 0; x < EncodingCmd.tclNames.Length; x++ )
      {
        if ( EncodingCmd.tclNames[x] == name )
          return EncodingCmd.encodings[x];
      }
      return null;
    }

    internal static string getTclName( Encoding encoding )
    {
      for ( int x = 0; x < EncodingCmd.encodings.Length; x++ )
      {
        if ( EncodingCmd.encodings[x].EncodingName == encoding.EncodingName )
          return EncodingCmd.tclNames[x];
      }
      return null;
    }
  }
}