/*
* ForeachCmd.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: ForeachCmd.java,v 1.4 1999/08/07 06:44:04 mo Exp $
*
*/
using System;
namespace tcl.lang
{

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

  class ForeachCmd : Command
  {
    /// <summary> Tcl_ForeachObjCmd -> ForeachCmd.cmdProc
    /// 
    /// This procedure is invoked to process the "foreach" Tcl command.
    /// See the user documentation for details on what it does.
    /// 
    /// </summary>
    /// <param name="interp">the current interpreter.
    /// </param>
    /// <param name="objv">command arguments.
    /// </param>
    /// <exception cref=""> TclException if script causes error.
    /// </exception>

    public TCL.CompletionCode cmdProc( Interp interp, TclObject[] objv )
    {
      if ( objv.Length < 4 || ( objv.Length % 2 ) != 0 )
      {
        throw new TclNumArgsException( interp, 1, objv, "varList list ?varList list ...? command" );
      }

      // foreach {n1 n2} {1 2 3 4} {n3} {1 2} {puts $n1-$n2-$n3}
      //	name[0] = {n1 n2}	value[0] = {1 2 3 4}
      //	name[1] = {n3}		value[0] = {1 2}

      TclObject[] name = new TclObject[( objv.Length - 2 ) / 2];
      TclObject[] value = new TclObject[( objv.Length - 2 ) / 2];

      int c, i, j, base_;
      int maxIter = 0;
      TclObject command = objv[objv.Length - 1];
      bool done = false;

      for ( i = 0; i < objv.Length - 2; i += 2 )
      {
        int x = i / 2;
        name[x] = objv[i + 1];
        value[x] = objv[i + 2];

        int nSize = TclList.getLength( interp, name[x] );
        int vSize = TclList.getLength( interp, value[x] );

        if ( nSize == 0 )
        {
          throw new TclException( interp, "foreach varlist is empty" );
        }

        int iter = ( vSize + nSize - 1 ) / nSize;
        if ( maxIter < iter )
        {
          maxIter = iter;
        }
      }

      for ( c = 0; !done && c < maxIter; c++ )
      {
        // Set up the variables

        for ( i = 0; i < objv.Length - 2; i += 2 )
        {
          int x = i / 2;
          int nSize = TclList.getLength( interp, name[x] );
          base_ = nSize * c;
          for ( j = 0; j < nSize; j++ )
          {
            // Test and see if the name variable is an array.


            Var[] result = Var.lookupVar( interp, name[x].ToString(), null, 0, null, false, false );
            Var var = null;

            if ( result != null )
            {
              if ( result[1] != null )
              {
                var = result[1];
              }
              else
              {
                var = result[0];
              }
            }

            try
            {
              if ( base_ + j >= TclList.getLength( interp, value[x] ) )
              {
                interp.setVar( TclList.index( interp, name[x], j ), TclString.newInstance( "" ), 0 );
              }
              else
              {
                interp.setVar( TclList.index( interp, name[x], j ), TclList.index( interp, value[x], base_ + j ), 0 );
              }
            }
            catch ( TclException e )
            {

              throw new TclException( interp, "couldn't set loop variable: \"" + TclList.index( interp, name[x], j ) + "\"" );
            }
          }
        }

        // Execute the script

        try
        {
          interp.eval( command, 0 );
        }
        catch ( TclException e )
        {
          switch ( e.getCompletionCode() )
          {

            case TCL.CompletionCode.BREAK:
              done = true;
              break;


            case TCL.CompletionCode.CONTINUE:
              continue;


            case TCL.CompletionCode.ERROR:
              interp.addErrorInfo( "\n    (\"foreach\" body line " + interp.errorLine + ")" );
              throw;


            default:
              throw;

          }
        }
      }

      interp.resetResult();
      return TCL.CompletionCode.RETURN;
    }
  }
}