! $Id$

!--This routine is to be tested with MPI / OMP parallelism 
!--OB 26/03/2018

SUBROUTINE readchlorophyll(debut)

  USE netcdf95, ONLY: nf95_close, nf95_gw_var, nf95_inq_dimid, nf95_inq_varid, nf95_open
  USE netcdf, ONLY: nf90_get_var, nf90_noerr, nf90_nowrite
  USE phys_cal_mod, ONLY: mth_cur
  USE lmdz_grid_phy, ONLY: nbp_lon, nbp_lat, klon_glo, grid2dto1d_glo
  USE lmdz_phys_mpi_data, ONLY: is_mpi_root
  USE lmdz_phys_omp_data, ONLY: is_omp_root
  USE lmdz_phys_para, ONLY: scatter
  USE phys_state_var_mod, ONLY: chl_con
  USE lmdz_print_control, ONLY: prt_level, lunout
  USE lmdz_abort_physic, ONLY: abort_physic
  USE lmdz_yomcst

  IMPLICIT NONE

  ! Variable input
  LOGICAL debut

  ! Variables locales
  INTEGER n_lat   ! number of latitudes in the input data
  INTEGER n_lon   ! number of longitudes in the input data
  INTEGER n_lev   ! number of levels in the input data
  INTEGER n_month ! number of months in the input data
  REAL, ALLOCATABLE :: latitude(:)
  REAL, ALLOCATABLE :: longitude(:)
  REAL, ALLOCATABLE :: time(:)
  INTEGER i, k
  INTEGER, SAVE :: mth_pre
  !$OMP THREADPRIVATE(mth_pre)

  ! Champs reconstitues
  REAL, ALLOCATABLE :: chlorocon(:, :, :)
  REAL, ALLOCATABLE :: chlorocon_mois(:, :)
  REAL, ALLOCATABLE :: chlorocon_mois_glo(:)

  ! For NetCDF:
  INTEGER ncid_in  ! IDs for input files
  INTEGER varid, ncerr

  !--------------------------------------------------------
  CHARACTER (len = 20) :: modname = 'readchlorophyll'
  CHARACTER (len = 80) :: abort_message

  !--only read file if beginning of run or start of new month
  IF (debut.OR.mth_cur/=mth_pre) THEN

    IF (is_mpi_root.AND.is_omp_root) THEN

      CALL nf95_open("chlorophyll.nc", nf90_nowrite, ncid_in)

      CALL nf95_inq_varid(ncid_in, "lon", varid)
      CALL nf95_gw_var(ncid_in, varid, longitude)
      n_lon = size(longitude)
      IF (n_lon/=nbp_lon) THEN
        abort_message = 'Le nombre de lon n est pas egal a nbp_lon'
        CALL abort_physic(modname, abort_message, 1)
      ENDIF

      CALL nf95_inq_varid(ncid_in, "lat", varid)
      CALL nf95_gw_var(ncid_in, varid, latitude)
      n_lat = size(latitude)
      IF (n_lat/=nbp_lat) THEN
        abort_message = 'Le nombre de lat n est pas egal a jnbp_lat'
        CALL abort_physic(modname, abort_message, 1)
      ENDIF

      CALL nf95_inq_varid(ncid_in, "time", varid)
      CALL nf95_gw_var(ncid_in, varid, time)
      n_month = size(time)
      IF (n_month/=12) THEN
        abort_message = 'Le nombre de month n est pas egal a 12'
        CALL abort_physic(modname, abort_message, 1)
      ENDIF

      IF (.NOT.ALLOCATED(chlorocon))          ALLOCATE(chlorocon(n_lon, n_lat, n_month))
      IF (.NOT.ALLOCATED(chlorocon_mois))     ALLOCATE(chlorocon_mois(n_lon, n_lat))
      IF (.NOT.ALLOCATED(chlorocon_mois_glo)) ALLOCATE(chlorocon_mois_glo(klon_glo))

      !--reading stratospheric AOD at 550 nm
      CALL nf95_inq_varid(ncid_in, "CHL", varid)
      ncerr = nf90_get_var(ncid_in, varid, chlorocon)
      WRITE(lunout, *)'code erreur readchlorophyll=', ncerr, varid

      CALL nf95_close(ncid_in)

      !---select the correct month
      IF (mth_cur<1.OR.mth_cur>12) THEN
        WRITE(lunout, *)'probleme avec le mois dans readchlorophyll =', mth_cur
      ENDIF
      chlorocon_mois(:, :) = chlorocon(:, :, mth_cur)

      !---reduce to a klon_glo grid
      CALL grid2dTo1d_glo(chlorocon_mois, chlorocon_mois_glo)

      WRITE(lunout, *)"chrolophyll current month", mth_cur
      DO i = 1, klon_glo
        !      IF(isnan(chlorocon_mois_glo(i)))then ! isnan() is not in the Fortran standard...
        !      Another way to check for NaN:
        IF (chlorocon_mois_glo(i)/=chlorocon_mois_glo(i)) chlorocon_mois_glo(i) = 0.
      ENDDO

      !    DEALLOCATE(chlorocon)
      !    DEALLOCATE(chlorocon_mois)
      !    DEALLOCATE(chlorocon_mois_glo)

    ENDIF !--is_mpi_root and is_omp_root

    !--scatter on all proc
    CALL scatter(chlorocon_mois_glo, chl_con)

    !--keep memory of previous month
    mth_pre = mth_cur

  ENDIF !--debut ou nouveau mois

END SUBROUTINE readchlorophyll