!> @file data_output_flight.f90
!--------------------------------------------------------------------------------------------------!
! 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 1997-2021 Leibniz Universitaet Hannover
!--------------------------------------------------------------------------------------------------!
!
! Description:
! ------------
!> Writing data from flight measurements on file.
!--------------------------------------------------------------------------------------------------!
 SUBROUTINE data_output_flight

#if defined( __netcdf )
    USE control_parameters,                                                                        &
        ONLY:  num_leg, num_var_fl, time_since_reference_point, virtual_flight

    USE cpulog,                                                                                    &
        ONLY:  cpu_log, log_point

    USE flight_mod,                                                                                &
        ONLY:  sensor, x_pos, y_pos, z_pos

    USE kinds

    USE NETCDF

    USE netcdf_interface,                                                                          &
        ONLY:  dofl_time_count, id_set_fl, id_var_dofl, id_var_time_fl, id_var_x_fl, id_var_y_fl,  &
               id_var_z_fl, nc_stat, netcdf_handle_error

    USE pegrid

    IMPLICIT NONE

    INTEGER(iwp) ::  i !< loop variable for output quantities
    INTEGER(iwp) ::  l !< loop variable for flight legs
    INTEGER(iwp) ::  k !< internal count for variable labels and units

    CALL cpu_log( log_point(64), 'data_output_flight', 'start' )

!
!-- Check if virtual flights are carried out
    IF ( .NOT. virtual_flight )  RETURN

!
!-- Output is only performed on PE0
    IF ( myid == 0 )  THEN

!
!--    Open file for flight output in NetCDF format
       CALL check_open( 199 )

!
!--    Increment the counter for number of output times
       dofl_time_count = dofl_time_count + 1

!
!--    Update the flight-output time and spatial coordinates
       nc_stat = NF90_PUT_VAR( id_set_fl, id_var_time_fl,                                          &
                               (/ time_since_reference_point /),                                   &
                               start = (/ dofl_time_count /),                                      &
                               count = (/ 1 /) )
       CALL netcdf_handle_error( 'data_output_flight', 554 )

       DO  l = 1, num_leg
          nc_stat = NF90_PUT_VAR( id_set_fl, id_var_x_fl(l),                                       &
                                  (/ x_pos(l) /),                                                  &
                                  start = (/ dofl_time_count /),                                   &
                                  count = (/ 1 /) )
          nc_stat = NF90_PUT_VAR( id_set_fl, id_var_y_fl(l),                                       &
                                  (/ y_pos(l) /),                                                  &
                                  start = (/ dofl_time_count /),                                   &
                                  count = (/ 1 /) )
          nc_stat = NF90_PUT_VAR( id_set_fl, id_var_z_fl(l),                                       &
                                  (/ z_pos(l) /),                                                  &
                                  start = (/ dofl_time_count /),                                   &
                                  count = (/ 1 /) )
          CALL netcdf_handle_error( 'data_output_flight', 555 )
       ENDDO
!
!--    Output measured quantities
       k = 1
       DO  l = 1, num_leg
          DO i = 1, num_var_fl
             nc_stat = NF90_PUT_VAR( id_set_fl, id_var_dofl(k),                                    &
                                     (/ sensor(i,l) /),                                            &
                                     start = (/ dofl_time_count /),                                &
                                     count = (/ 1 /) )

             CALL netcdf_handle_error( 'data_output_flight', 556 )

             k = k + 1
          ENDDO
       ENDDO
    ENDIF

    CALL cpu_log( log_point(64), 'data_output_flight', 'stop' )

#endif
 END SUBROUTINE data_output_flight