/*
* SwitchCmd.java
*
* Copyright (c) 1997 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: SwitchCmd.java,v 1.2 1999/05/09 01:32:03 dejong Exp $
*
*/
using System;
namespace tcl.lang
{

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

  class SwitchCmd : Command
  {

    private static readonly string[] validCmds = new string[] { "-exact", "-glob", "-regexp", "--" };
    private const int EXACT = 0;
    private const int GLOB = 1;
    private const int REGEXP = 2;
    private const int LAST = 3;
    public TCL.CompletionCode cmdProc( Interp interp, TclObject[] argv )
    {
      int i, mode, body;
      bool matched;
      string inString;
      TclObject[] switchArgv = null;

      mode = EXACT;
      for ( i = 1; i < argv.Length; i++ )
      {

        if ( !argv[i].ToString().StartsWith( "-" ) )
        {
          break;
        }
        int opt = TclIndex.get( interp, argv[i], validCmds, "option", 1 );
        if ( opt == LAST )
        {
          i++;
          break;
        }
        else if ( opt > LAST )
        {
          throw new TclException( interp, "SwitchCmd.cmdProc: bad option " + opt + " index to validCmds" );
        }
        else
        {
          mode = opt;
        }
      }

      if ( argv.Length - i < 2 )
      {
        throw new TclNumArgsException( interp, 1, argv, "?switches? string pattern body ... ?default body?" );
      }

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

      // If all of the pattern/command pairs are lumped into a single
      // argument, split them out again.

      if ( argv.Length - i == 1 )
      {
        switchArgv = TclList.getElements( interp, argv[i] );
        i = 0;
      }
      else
      {
        switchArgv = argv;
      }

      for ( ; i < switchArgv.Length; i += 2 )
      {
        if ( i == ( switchArgv.Length - 1 ) )
        {
          throw new TclException( interp, "extra switch pattern with no body" );
        }

        // See if the pattern matches the string.

        matched = false;

        string pattern = switchArgv[i].ToString();

        if ( ( i == switchArgv.Length - 2 ) && pattern.Equals( "default" ) )
        {
          matched = true;
        }
        else
        {
          switch ( mode )
          {

            case EXACT:
              matched = inString.Equals( pattern );
              break;

            case GLOB:
              matched = Util.stringMatch( inString, pattern );
              break;

            case REGEXP:
              matched = Util.regExpMatch( interp, inString, switchArgv[i] );
              break;
          }
        }
        if ( !matched )
        {
          continue;
        }

        // We've got a match.  Find a body to execute, skipping bodies
        // that are "-".

        for ( body = i + 1; ; body += 2 )
        {
          if ( body >= switchArgv.Length )
          {

            throw new TclException( interp, "no body specified for pattern \"" + switchArgv[i] + "\"" );
          }

          if ( !switchArgv[body].ToString().Equals( "-" ) )
          {
            break;
          }
        }

        try
        {
          interp.eval( switchArgv[body], 0 );
          return TCL.CompletionCode.RETURN;
        }
        catch ( TclException e )
        {
          if ( e.getCompletionCode() == TCL.CompletionCode.ERROR )
          {

            interp.addErrorInfo( "\n    (\"" + switchArgv[i] + "\" arm line " + interp.errorLine + ")" );
          }
          throw;
        }
      }

      // Nothing matched:  return nothing.
      return TCL.CompletionCode.RETURN;
    }
  } // end SwitchCmd
}