/*
* PutsCmd.java
*
* Copyright (c) 1997 Cornell University.
* 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: IfCmd.java,v 1.2 2003/02/07 03:41:49 mdejong Exp $
*
*/
using System;
namespace tcl.lang
{

  /// <summary> This class implements the built-in "if" command in Tcl.</summary>
  class IfCmd : Command
  {

    /// <summary> See Tcl user documentation for details.</summary>
    /// <exception cref=""> TclException If incorrect number of arguments.
    /// </exception>
    public TCL.CompletionCode cmdProc( Interp interp, TclObject[] argv )
    {
      int i;
      bool value;

      i = 1;
      while ( true )
      {
        /*
        * At this point in the loop, argv and argc refer to an
        * expression to test, either for the main expression or
        * an expression following an "elseif".  The arguments
        * after the expression must be "then" (optional) and a
        * script to execute if the expression is true.
        */

        if ( i >= argv.Length )
        {

          throw new TclException( interp, "wrong # args: no expression after \"" + argv[i - 1] + "\" argument" );
        }
        try
        {

          value = interp.expr.evalBoolean( interp, argv[i].ToString() );
        }
        catch ( TclException e )
        {
          switch ( e.getCompletionCode() )
          {

            case TCL.CompletionCode.ERROR:
              interp.addErrorInfo( "\n    (\"if\" test expression)" );
              break;
          }
          throw;
        }

        i++;

        if ( ( i < argv.Length ) && ( argv[i].ToString().Equals( "then" ) ) )
        {
          i++;
        }
        if ( i >= argv.Length )
        {

          throw new TclException( interp, "wrong # args: no script following \"" + argv[i - 1] + "\" argument" );
        }
        if ( value )
        {
          try
          {
            interp.eval( argv[i], 0 );
          }
          catch ( TclException e )
          {
            switch ( e.getCompletionCode() )
            {

              case TCL.CompletionCode.ERROR:
                interp.addErrorInfo( "\n    (\"if\" then script line " + interp.errorLine + ")" );
                break;
            }
            throw;
          }
          return TCL.CompletionCode.RETURN;
        }

        /*
        * The expression evaluated to false.  Skip the command, then
        * see if there is an "else" or "elseif" clause.
        */

        i++;
        if ( i >= argv.Length )
        {
          interp.resetResult();
          return TCL.CompletionCode.RETURN;
        }

        if ( argv[i].ToString().Equals( "elseif" ) )
        {
          i++;
          continue;
        }
        break;
      }

      /*
      * Couldn't find a "then" or "elseif" clause to execute.
      * Check now for an "else" clause.  We know that there's at
      * least one more argument when we get here.
      */


      if ( argv[i].ToString().Equals( "else" ) )
      {
        i++;
        if ( i >= argv.Length )
        {
          throw new TclException( interp, "wrong # args: no script following \"else\" argument" );
        }
        else if ( i != ( argv.Length - 1 ) )
        {
          throw new TclException( interp, "wrong # args: extra words after \"else\" clause in " + "\"if\" command" );
        }
      }
      try
      {
        interp.eval( argv[i], 0 );
      }
      catch ( TclException e )
      {
        switch ( e.getCompletionCode() )
        {

          case TCL.CompletionCode.ERROR:
            interp.addErrorInfo( "\n    (\"if\" else script line " + interp.errorLine + ")" );
            break;
        }
        throw;
      }
      return TCL.CompletionCode.RETURN;
    }
  }
}