!> @file src/get_netcdf_variable.inc
!------------------------------------------------------------------------------!
! This file is part of the PALM model system.
!
! PALM is free software: you can redistribute it and/or modify it under the
! terms of the GNU General Public License as published by the Free Software
! Foundation, either version 3 of the License, or (at your option) any later
! version.
!
! PALM is distributed in the hope that it will be useful, but WITHOUT ANY
! WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
! A PARTICULAR PURPOSE.  See the GNU General Public License for more details.
!
! You should have received a copy of the GNU General Public License along with
! PALM. If not, see <http://www.gnu.org/licenses/>.
!
! Copyright 2017-2018 Leibniz Universitaet Hannover
! Copyright 2017-2018 Deutscher Wetterdienst Offenbach
!------------------------------------------------------------------------------!
!
! Current revisions:
! -----------------
! Initial revision
! 
! 
! Former revisions:
! -----------------
! $Id$
!
! 
!
! Authors:
! --------
! @author Eckhard Kadasch
!
! Description:
! ------------
!> This file provides the implementation of the io.f90 subroutines
!> get_netcdf_variable_int() and get_netcdf_variable_real(). Both routines
!> differ only in the type of the netCDF variable to be read and otherwise share
!> their functionality. In order to avoid duplicating code, both routines source
!> the implementation below using Fortran's INCLUDE statement.
!> 
!------------------------------------------------------------------------------!
 INTEGER ::  i, ncid, start(3)

 ! Read in_var NetCDF attributes
 IF ( nf90_open( TRIM(in_file), NF90_NOWRITE, ncid ) .EQ. NF90_NOERR .AND. &
      nf90_inq_varid( ncid, in_var % name, in_var % varid ) .EQ. NF90_NOERR )  THEN

    CALL check(nf90_get_att(ncid, in_var % varid, "long_name", in_var % long_name))
    CALL check(nf90_get_att(ncid, in_var % varid, "units", in_var % units))

    ! Read in_var NetCDF dimensions
    CALL check(nf90_inquire_variable( ncid, in_var % varid,              &
                                      ndims  = in_var % ndim,            &
                                      dimids = in_var % dimids ))
                                  
    DO i = 1, in_var % ndim
       CALL check(nf90_inquire_dimension( ncid, in_var % dimids(i),      &
                                          name = in_var % dimname(i),    &
                                          len  = in_var % dimlen(i) ))
    END DO

    start = (/ 1, 1, 1 /)
    IF ( TRIM(in_var % name) .EQ. 'T_SO' )  THEN
       ! Skip depth = 0.0 for T_SO and reduce number of depths from 9 to 8
       in_var % dimlen(3) = in_var % dimlen(3) - 1

       ! Start reading from second level, e.g. depth = 0.005 instead of 0.0
       start(3) = 2
    END IF

    SELECT CASE(in_var % ndim)

    CASE (2)

       ALLOCATE( buffer( in_var % dimlen(1),                             &
                         in_var % dimlen(2),                             &
                         1 ) )

    CASE (3, 4)

       ALLOCATE( buffer( in_var % dimlen(1),                             &
                         in_var % dimlen(2),                             &
                         in_var % dimlen(3) ) )

    CASE DEFAULT

       message = "Failed reading NetCDF variable " //                    &
          TRIM(in_var % name) // " with " // TRIM(str(in_var%ndim)) //   &
          " dimensions because only two- and and three-dimensional" //   &
          " variables are supported."
       CALL abort('get_netcdf_variable', message) 

    END SELECT
 CALL run_control('time', 'alloc')
          
    ! TODO: Check for matching dimensions of buffer and var
    CALL check(nf90_get_var( ncid, in_var % varid, buffer,               &
                             start = start,                              &
                             count = in_var % dimlen(1:3) ) )

 CALL run_control('time', 'read')
 ELSE

    message = "Failed to read '" // TRIM(in_var % name) // &
       "' from file '" // TRIM(in_file) // "'."
    CALL report('get_netcdf_variable', message)

 END IF

 CALL check(nf90_close(ncid))

 CALL run_control('time', 'read')