/*
* TclIndex.java
*
*	This file implements objects of type "index".  This object type
*	is used to lookup a keyword in a table of valid values and cache
*	the index of the matching entry.
*
* 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: TclIndex.java,v 1.5 2003/01/10 01:35:58 mdejong Exp $
*/
using System.Text;
namespace tcl.lang
{

  public class TclIndex : InternalRep
  {

    /// <summary> The variable slots for this object.</summary>
    private int index;

    /// <summary> Table of valid options.</summary>

    private string[] table;

    /// <summary> Construct a TclIndex representation with the given index & table.</summary>
    private TclIndex( int i, string[] tab )
    {
      index = i;
      table = tab;
    }

    /// <summary> Returns a dupilcate of the current object.</summary>
    /// <param name="obj">the TclObject that contains this internalRep.
    /// </param>
    public InternalRep duplicate()
    {
      return new TclIndex( index, table );
    }

    /// <summary> Implement this no-op for the InternalRep interface.</summary>

    public void dispose()
    {
    }

    /// <summary> Called to query the string representation of the Tcl object. This
    /// method is called only by TclObject.toString() when
    /// TclObject.stringRep is null.
    /// 
    /// </summary>
    /// <returns> the string representation of the Tcl object.
    /// </returns>
    public override string ToString()
    {
      return table[index];
    }

    /// <summary> Tcl_GetIndexFromObj -> get
    /// 
    /// Gets the index into the table of the object.  Generate an error
    /// it it doesn't occur.  This also converts the object to an index
    /// which should catch the lookup for speed improvement.
    /// 
    /// </summary>
    /// <param name="interp">the interperter or null
    /// </param>
    /// <param name="tobj">the object to operate on.
    /// @paran table the list of commands
    /// @paran msg used as part of any error messages
    /// @paran flags may be TCL.EXACT.
    /// </param>

    public static int get( Interp interp, TclObject tobj, string[] table, string msg, int flags )
    {
      InternalRep rep = tobj.InternalRep;

      if ( rep is TclIndex )
      {
        if ( ( (TclIndex)rep ).table == table )
        {
          return ( (TclIndex)rep ).index;
        }
      }

      string str = tobj.ToString();
      int strLen = str.Length;
      int tableLen = table.Length;
      int index = -1;
      int numAbbrev = 0;

      {
        if ( strLen > 0 )
        {

          for ( int i = 0; i < tableLen; i++ )
          {
            string option = table[i];

            if ( ( ( flags & TCL.EXACT ) == TCL.EXACT ) && ( option.Length != strLen ) )
            {
              continue;
            }
            if ( option.Equals( str ) )
            {
              // Found an exact match already. Return it.

              index = i;
              goto checking_brk;
            }
            if ( option.StartsWith( str ) )
            {
              numAbbrev++;
              index = i;
            }
          }
        }
        if ( numAbbrev != 1 )
        {
          StringBuilder sbuf = new StringBuilder();
          if ( numAbbrev > 1 )
          {
            sbuf.Append( "ambiguous " );
          }
          else
          {
            sbuf.Append( "bad " );
          }
          sbuf.Append( msg );
          sbuf.Append( " \"" );
          sbuf.Append( str );
          sbuf.Append( "\"" );
          sbuf.Append( ": must be " );
          sbuf.Append( table[0] );
          for ( int i = 1; i < tableLen; i++ )
          {
            if ( i == ( tableLen - 1 ) )
            {
              sbuf.Append( ( i > 1 ) ? ", or " : " or " );
            }
            else
            {
              sbuf.Append( ", " );
            }
            sbuf.Append( table[i] );
          }
          throw new TclException( interp, sbuf.ToString() );
        }
      }
checking_brk:
      ;
      // Create a new index object.
      tobj.InternalRep = new TclIndex( index, table );
      return index;
    }
  }
}