! (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 read attributes of keys in BUFR messages.
!
!
program bufr_attributes
   use eccodes
   implicit none
   integer            :: ifile
   integer            :: iret
   integer            :: ibufr
   integer            :: count = 0
   integer(kind=4)    :: iVal, conf
   real(kind=8)       :: t2m
   character(len=32)   :: units, confUnits

   call codes_open_file(ifile, '../../data/bufr/syno_multi.bufr', 'r')

   do while (.true.)
      ! A BUFR message is loaded from the file,
      ! ibufr is the BUFR id to be used in subsequent calls
      call codes_bufr_new_from_file(ifile, ibufr, iret)
      if (iret == CODES_END_OF_FILE) exit

      ! Get and print some keys from the BUFR header
      write (*, *) 'message: ', count

      ! We need to instruct ecCodes to expand all the descriptors
      ! i.e. unpack the data values
      call codes_set(ibufr, "unpack", 1);
      ! ----------------------------------------------------------------
      ! We will read the value and all the attributes available for
      ! the 2m temperature.
      ! ----------------------------------------------------------------

      ! Get the element's value as as real
      call codes_get(ibufr, 'airTemperatureAt2M', t2m);
      write (*, *) '  airTemperatureAt2M:', t2m

      ! Get the element's code (see BUFR code table B)
      call codes_get(ibufr, 'airTemperatureAt2M->code', iVal);
      write (*, *) '  airTemperatureAt2M->code:', iVal

      ! Get the element's units (see BUFR code table B)
      call codes_get(ibufr, 'airTemperatureAt2M->units', units)
      write (*, *) '  airTemperatureAt2M->units:', units

      ! Get the element's scale (see BUFR code table B)
      call codes_get(ibufr, 'airTemperatureAt2M->scale', iVal);
      write (*, *) '  airTemperatureAt2M->code:', iVal

      ! Get the element's reference (see BUFR code table B)
      call codes_get(ibufr, 'airTemperatureAt2M->reference', iVal);
      write (*, *) '  airTemperatureAt2M->reference:', iVal

      ! Get the element's width (see BUFR code table B)
      call codes_get(ibufr, 'airTemperatureAt2M->width', iVal);
      write (*, *) '  airTemperatureAt2M->width:', iVal

      ! -------------------------------------------------------------------
      ! The 2m temperature data element in this message has an associated
      ! field: percentConfidence. Its value and attributes can be accessed
      ! in a similar manner as was shown above for 2m temperature.
      ! -------------------------------------------------------------------

      ! Get the element's value as as real
      call codes_get(ibufr, 'airTemperatureAt2M->percentConfidence', conf);
      write (*, *) '  airTemperatureAt2M->percentConfidence:', conf

      ! Get the element's code (see BUFR code table B)
      call codes_get(ibufr, 'airTemperatureAt2M->percentConfidence->code', iVal);
      write (*, *) '  airTemperatureAt2M->percentConfidence->code:', iVal

      ! Get the element's units (see BUFR code table B)
      call codes_get(ibufr, 'airTemperatureAt2M->percentConfidence->units', confUnits)
      write (*, *) '  airTemperatureAt2M->percentConfidence->units:', confUnits

      ! Get the element's scale (see BUFR code table B)
      call codes_get(ibufr, 'airTemperatureAt2M->percentConfidence->scale', iVal);
      write (*, *) '  airTemperatureAt2M->percentConfidence->code:', iVal

      ! Get the element's reference (see BUFR code table B)
      call codes_get(ibufr, 'airTemperatureAt2M->percentConfidence->reference', iVal);
      write (*, *) '  airTemperatureAt2M->percentConfidence->reference:', iVal

      ! Get the element's width (see BUFR code table B)
      call codes_get(ibufr, 'airTemperatureAt2M->percentConfidence->width', iVal);
      write (*, *) '  airTemperatureAt2M->percentConfidence->width:', iVal

      ! Release the BUFR message
      call codes_release(ibufr)

      count = count + 1

   end do

   ! Close file
   call codes_close_file(ifile)

end program bufr_attributes