! (C) Copyright 2005- ECMWF.
!
! This software is licensed under the terms of the Apache Licence Version 2.0
! which can be obtained at http://www.apache.org/licenses/LICENSE-2.0.
!
! In applying this licence, ECMWF does not waive the privileges and immunities granted to it by
! virtue of its status as an intergovernmental organisation nor does it submit to any jurisdiction.
!
!
!  Description: How to decode GRIB messages containing multiple
!               fields. Try to turn on and off multi support to
!               see the difference. Default is OFF.
!               For all the tools (e.g., grib_ls etc) multi support is ON.
!
!
program multi
   use eccodes
   implicit none

   integer              :: iret
   integer(kind=4)    ::  parameterCategory, parameterNumber, discipline
   integer              :: ifile, igrib

   call codes_open_file(ifile, '../../data/multi.grib2', 'r')

   ! Turn on support for multi-field messages */
   call codes_grib_multi_support_on()

   ! Turn off support for multi-field messages */
   !call codes_grib_multi_support_off()

   call codes_grib_new_from_file(ifile, igrib)
   ! Loop on all the messages in a file.

   do while (igrib .ne. -1)

      ! get as a integer*4
      call codes_get(igrib, 'discipline', discipline)
      write (*, *) 'discipline=', discipline

      ! get as a integer*4
      call codes_get(igrib, 'parameterCategory', &
                     parameterCategory)
      write (*, *) 'parameterCategory=', parameterCategory

      ! get as a integer*4
      call codes_get(igrib, 'parameterNumber', &
                     parameterNumber)
      write (*, *) 'parameterNumber=', parameterNumber

      if (discipline .eq. 0 .and. parameterCategory .eq. 2) then
         if (parameterNumber .eq. 2) then
            write (*, *) "-------- u -------"
         end if
         if (parameterNumber .eq. 3) then
            write (*, *) "-------- v -------"
         end if
      end if

      call codes_release(igrib)
      call codes_grib_new_from_file(ifile, igrib, iret)

   end do
   call codes_close_file(ifile)

end program multi
