using System;
using System.Collections;
using System.Data.SqlTypes;
using Microsoft.SqlServer.Server;

public class CLR_fix
{

    private class fixstep : IEnumerator
    {
        string  _str;
        int     itemlen;
        int     _start_ix;
        int     _end_ix;
        int     _listpos;


        public string str {
           get {
              return this._str;
           }
        }

        public int start_ix {
           get {
              return this._start_ix;
           }
        }

        public int end_ix {
           get {
              return this._end_ix;
           }
        }

        public int listpos {
           get {
              return this._listpos;
           }
        }


        public fixstep(SqlString  str,
                       SqlByte    itemlen) {
           this._str    = str.IsNull ? "" : str.Value;
           this.itemlen = itemlen.IsNull ? this._str.Length
                                         : itemlen.Value;
           Reset();
        }

        public bool MoveNext() {
           this._start_ix = this._end_ix;
           if (this._start_ix == this._str.Length) {
              return false;
           }
           this._end_ix = this._start_ix + this.itemlen;
           this._listpos++;
           if (this._end_ix > this._str.Length) {
              this._end_ix = this._str.Length;
           }
           return true;
        }

        public Object Current {
          get {
            return this;
          }
        }

        public void Reset() {
           this._start_ix = -1;
           this._end_ix   = 0;
           this._listpos  = 0;
        }
    }

    [SqlFunction(FillRowMethodName="CharlistFillRow")]
    public static IEnumerator CLR_charlist_fix(SqlString str,
                                               SqlByte    itemlen)
    {
        return new fixstep(str, itemlen);
    }

    public static void CharlistFillRow(object     obj,
                                       out int    listpos,
                                       out string str)
    {
        fixstep iter = (fixstep) obj;
        listpos = iter.listpos;
        str = iter.str.Substring(iter.start_ix, iter.end_ix - iter.start_ix);
        str = str.Trim();
    }


    [SqlFunction(FillRowMethodName="IntlistFillRow")]
    public static IEnumerator CLR_intlist_fix(SqlString str,
                                              SqlByte    itemlen)
    {
        return new fixstep(str, itemlen);
    }

    public static void IntlistFillRow(object     obj,
                                      out int    listpos,
                                      out int    number)
    {
        fixstep iter = (fixstep) obj;
        listpos = iter.listpos;
        string str = iter.str.Substring(iter.start_ix, iter.end_ix - iter.start_ix);
        number = System.Convert.ToInt32(str);
    }
}