signed int __thiscall sub_100016CD(int this, int a2)
{
  char v2; // dl@1
  signed int result; // eax@3
  int v4; // esi@3

  v2 = a2 != 0;
  if ( *(_BYTE *)(this + 130) )
    v2 = v2 == 0;
  v4 = *(_WORD *)(this + 128);
  result = *(_WORD *)(this + 128);
  if ( *(_WORD *)(this + 128) )
  {
    if ( result > 0 )
    {
      if ( result <= 8 )
      {
        *(_BYTE *)(this + 121) &= v2;
        *(_WORD *)(this + 128) = v4 - 1;
      }
      else
      {
        if ( (unsigned int)(result - 21) <= 7 )
        {
          *(_BYTE *)(this + 121) |= v2;
          if ( v4 == 21 )
            result = 0;
          else
            --result;
          *(_WORD *)(this + 128) = result;
        }
      }
    }
  }
  else
  {
    *(_BYTE *)(this + 121) = v2;
  }
  return result;
}