#include "cppdefs.h"
      MODULE nf_fread2d_bry_mod
!
!svn $Id$
!================================================== Hernan G. Arango ===
!  Copyright (c) 2002-2020 The ROMS/TOMS Group                         !
!    Licensed under a MIT/X style license                              !
!    See License_ROMS.txt                                              !
!=======================================================================
!                                                                      !
!  This function writes out a generic floating point 2D boundary array !
!  into an output NetCDF file.                                         !
!                                                                      !
!  On Input:                                                           !
!                                                                      !
!     ng           Nested grid number (integer)                        !
!     model        Calling model identifier (integer)                  !
!     ncname       NetCDF output file name (string)                    !
!     ncvname      NetCDF variable name (string)                       !
!     ncid         NetCDF file ID (integer)                            !
!     ncvarid      NetCDF variable ID (integer)                        !
!     tindex       NetCDF time record index to write (integer)         !
!     gtype        Grid type (integer)                                 !
!     LBij         IJ-dimension Lower bound (integer)                  !
!     UBij         IJ-dimension Upper bound (integer)                  !
!     Nrec         Number of boundary records (integer)                !
!     Ascl         Factor to scale field before writing (real)         !
!                                                                      !
!  On Output:                                                          !
!                                                                      !
!     Amin         Field minimum value (real)                          !
!     Amax         Field maximum value (real)                          !
!     A            2D boundary field to read in (real array)           !
!     status       Error flag (integer)                                !
!                                                                      !
!=======================================================================
!
      implicit none

      CONTAINS

!
!***********************************************************************
      FUNCTION nf_fread2d_bry (ng, model, ncname, ncid,                 &
     &                         ncvname, ncvarid,                        &
     &                         tindex, gtype,                           &
     &                         LBij, UBij, Nrec,                        &
     &                         Ascl, Amin, Amax,                        &
     &                         A)  RESULT(status)
!***********************************************************************
!
      USE mod_param
      USE mod_parallel
      USE mod_iounits
      USE mod_ncparam
      USE mod_netcdf
      USE mod_scalars

#if !defined PARALLEL_IN && defined DISTRIBUTE
      USE distribute_mod, ONLY : mp_bcastf
#endif
      USE strings_mod,    ONLY : FoundError
!
!  Imported variable declarations.
!
      integer, intent(in) :: ng, model, ncid, ncvarid, tindex, gtype
      integer, intent(in) :: LBij, UBij, Nrec

      real(dp), intent(in)  :: Ascl
      real(r8), intent(out) :: Amin
      real(r8), intent(out) :: Amax

      character (len=*), intent(in) :: ncname
      character (len=*), intent(in) :: ncvname

#ifdef ASSUMED_SHAPE
      real(r8), intent(out) :: A(LBij:,:,:)
#else
      real(r8), intent(out) :: A(LBij:UBij,4,Nrec)
#endif
!
!  Local variable declarations.
!
      logical, dimension(3) :: foundit
      logical, dimension(4) :: bounded

      integer :: bc, ghost, i, ib, ic, ir, j, rc, tile
      integer :: Cgrid, IorJ, Imin, Imax, Jmin, Jmax, Npts
      integer :: Istr, Iend, Jstr, Jend
      integer, dimension(4) :: start, total

      integer :: status

      real(r8) :: Afactor, Aoffset, Aspval

      real(r8), dimension(3) :: AttValue

#if !defined PARALLEL_IN && defined DISTRIBUTE
      real(r8), dimension(3) :: buffer
#endif
      real(r8), dimension((UBij-LBij+1)*4*Nrec) :: wrk

      character (len=12), dimension(3) :: AttName
!
!-----------------------------------------------------------------------
!  Set starting and ending indices to process.
!-----------------------------------------------------------------------
!
!  Set first and last grid point according to staggered C-grid
!  classification.
!
!  Notice that (Imin,Jmin) and (Imax,Jmax) are the corner of the
!  computational tile. If ghost=0, ghost points are not processed.
!  They will be processed elsewhere by the appropriate call to any
!  of the routines in "mp_exchange.F".  If ghost=1, the ghost points
!  are read.
!
      IF (model.eq.iADM) THEN
        ghost=0                      ! non-overlapping, no ghost points
      ELSE
        ghost=1                      ! overlapping, read ghost points
      END IF

      SELECT CASE (gtype)
        CASE (p2dvar, p3dvar)
          Cgrid=1
        CASE (r2dvar, r3dvar)
          Cgrid=2
        CASE (u2dvar, u3dvar)
          Cgrid=3
        CASE (v2dvar, v3dvar)
          Cgrid=4
        CASE DEFAULT
          Cgrid=2
      END SELECT

#ifdef DISTRIBUTE
      tile=MyRank
      Imin=BOUNDS(ng)%Imin(Cgrid,ghost,tile)
      Imax=BOUNDS(ng)%Imax(Cgrid,ghost,tile)
      Jmin=BOUNDS(ng)%Jmin(Cgrid,ghost,tile)
      Jmax=BOUNDS(ng)%Jmax(Cgrid,ghost,tile)
#else
      tile=-1
      Imin=LBij
      Imax=UBij
      Jmin=LBij
      Jmax=UBij
#endif
      IorJ=IOBOUNDS(ng)%IorJ
      Npts=IorJ*4*Nrec
!
!  Get tile bounds.
!
      Istr=BOUNDS(ng)%Istr (tile)
      Iend=BOUNDS(ng)%Iend (tile)
      Jstr=BOUNDS(ng)%Jstr (tile)
      Jend=BOUNDS(ng)%Jend (tile)
!
!  Set switch to process boundary data by their associated tiles.
!
      bounded(iwest )=DOMAIN(ng)%Western_Edge(tile)
      bounded(ieast )=DOMAIN(ng)%Eastern_Edge(tile)
      bounded(isouth)=DOMAIN(ng)%Southern_Edge(tile)
      bounded(inorth)=DOMAIN(ng)%Northern_Edge(tile)
!
!  Set NetCDF dimension counters for processing requested field.
!
      start(1)=1
      total(1)=IorJ
      start(2)=1
      total(2)=4
      start(3)=1
      total(3)=Nrec
      start(4)=tindex
      total(4)=1
!
!  Check if the following attributes: "scale_factor", "add_offset", and
!  "_FillValue" are present in the input NetCDF variable:
!
!  If the "scale_value" attribute is present, the data is multiplied by
!  this factor after reading.
!  If the "add_offset" attribute is present, this value is added to the
!  data after reading.
!  If both "scale_factor" and "add_offset" attributes are present, the
!  data are first scaled before the offset is added.
!  If the "_FillValue" attribute is present, the data having this value
!  is treated as missing and it is replaced with zero. This feature it
!  is usually related with the land/sea masking.
!
      AttName(1)='scale_factor'
      AttName(2)='add_offset  '
      AttName(3)='_FillValue  '

      CALL netcdf_get_fatt (ng, model, ncname, ncvarid, AttName,        &
     &                      AttValue, foundit,                          &
     &                      ncid = ncid)
      IF (FoundError(exit_flag, NoError, __LINE__,                      &
     &               __FILE__)) THEN
        status=ioerror
        RETURN
      END IF

      IF (.not.foundit(1)) THEN
        Afactor=1.0_r8
      ELSE
        Afactor=AttValue(1)
      END IF

      IF (.not.foundit(2)) THEN
        Aoffset=0.0_r8
      ELSE
        Aoffset=AttValue(2)
      END IF

      IF (.not.foundit(3)) THEN
        Aspval=spval_check
      ELSE
        Aspval=AttValue(3)
      END IF
!
!-----------------------------------------------------------------------
!  Read in requested data and scale it.
!-----------------------------------------------------------------------
!
      status=nf90_noerr
      IF (InpThread) THEN
        status=nf90_get_var(ncid, ncvarid, wrk, start, total)
        IF (status.eq.nf90_noerr) THEN
          Amin=spval
          Amax=-spval
          DO i=1,Npts
            IF (ABS(wrk(i)).ge.ABS(Aspval)) THEN
              wrk(i)=0.0_r8
            ELSE
              wrk(i)=Ascl*(Afactor*wrk(i)+Aoffset)
              Amin=MIN(Amin,wrk(i))
              Amax=MAX(Amax,wrk(i))
            END IF
          END DO
        END IF
      END IF

#if !defined PARALLEL_IN && defined DISTRIBUTE
      buffer(1)=REAL(status,r8)
      buffer(2)=Amin
      buffer(3)=Amax
      CALL mp_bcastf (ng, model, buffer)
      status=INT(buffer(1))
      Amin=buffer(2)
      Amax=buffer(3)
#endif

      IF (FoundError(status, nf90_noerr, __LINE__,                      &
     &               __FILE__)) THEN
        exit_flag=2
        ioerror=status
        RETURN
      END IF

#if !defined PARALLEL_IN && defined DISTRIBUTE
!
!  Broadcast data to all spawned nodes.
!
      CALL mp_bcastf (ng, model, wrk)
#endif
!
!-----------------------------------------------------------------------
!  Unpack read data.
!-----------------------------------------------------------------------
!
      A=0.0_r8

      DO ir=1,Nrec
        rc=(ir-1)*IorJ*4
        DO ib=1,4
          IF (bounded(ib)) THEN
            bc=(ib-1)*IorJ+rc
            IF ((ib.eq.iwest).or.(ib.eq.ieast)) THEN
              DO j=Jmin,Jmax
                ic=1+(j-LBij)+bc
                A(j,ib,ir)=wrk(ic)
              END DO
            ELSE IF ((ib.eq.isouth).or.(ib.eq.inorth)) THEN
              DO i=Imin,Imax
                ic=1+(i-LBij)+bc
                A(i,ib,ir)=wrk(ic)
              END DO
            END IF
          END IF
        END DO
      END DO

      RETURN
      END FUNCTION nf_fread2d_bry

      END MODULE nf_fread2d_bry_mod
