using System.Text;
/*
* RegsubCmd.java
*
* 	This contains the Jacl implementation of the built-in Tcl
*	"regsub" command.
*
* Copyright (c) 1997-1999 Sun Microsystems, Inc.
*
* 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: RegsubCmd.java,v 1.4 2000/02/23 22:07:23 mo Exp $
*/
using Regexp = sunlabs.brazil.util.regexp.Regexp;
using Regsub = sunlabs.brazil.util.regexp.Regsub;
namespace tcl.lang
{

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

  class RegsubCmd : Command
  {

    private static readonly string[] validOpts = new string[] { "-all", "-nocase", "--" };
    private const int OPT_ALL = 0;
    private const int OPT_NOCASE = 1;
    private const int OPT_LAST = 2;
    public TCL.CompletionCode cmdProc( Interp interp, TclObject[] argv )
    {
      bool all = false;
      bool nocase = false;

      try
      {
        int i = 1;

        while ( argv[i].ToString().StartsWith( "-" ) )
        {
          int index = TclIndex.get( interp, argv[i], validOpts, "switch", 0 );
          i++;
          switch ( index )
          {

            case OPT_ALL:
              {
                all = true;
                break;
              }

            case OPT_NOCASE:
              {
                nocase = true;
                break;
              }

            case OPT_LAST:
              {
                goto opts_brk;
              }
          }
        }

opts_brk:
        ;


        TclObject exp = argv[i++];

        string inString = argv[i++].ToString();

        string subSpec = argv[i++].ToString();

        string varName = null;
        if (i != argv.Length) varName = argv[i++].ToString();
        if ( i != argv.Length )
        {
          throw new System.IndexOutOfRangeException();
        }

        Regexp r = TclRegexp.compile( interp, exp, nocase );

        int count = 0;
        string result;

        if ( all == false )
        {
          result = r.sub( inString, subSpec );
          if ( (System.Object)result == null )
          {
            result = inString;
          }
          else
          {
            count++;
          }
        }
        else
        {
          StringBuilder sb = new StringBuilder();
          Regsub s = new Regsub( r, inString );
          while ( s.nextMatch() )
          {
            count++;
            sb.Append( s.skipped() );
            Regexp.applySubspec( s, subSpec, sb );
          }
          sb.Append( s.rest() );
          result = sb.ToString();
        }

        TclObject obj = TclString.newInstance( result );
        if ( varName == null )
          interp.setResult( result );
        else {
          try
          {
            interp.setVar( varName, obj, 0 );
          }
          catch ( TclException e )
          {
            throw new TclException( interp, "couldn't set variable \"" + varName + "\"" );
          }
          interp.setResult( count );
        }
      }
      catch ( System.IndexOutOfRangeException e )
      {
        throw new TclNumArgsException( interp, 1, argv, "?switches? exp string subSpec ?varName?" );
      }
      return TCL.CompletionCode.RETURN;
    }
  } // end RegsubCmd
}