#define SPONGE_TOP

MODULE agrif_top_sponge
#if defined key_agrif && defined key_top
   USE par_oce
   USE par_trc
   USE oce
   USE dom_oce
   USE in_out_manager
   USE agrif_oce
   USE agrif_opa_sponge
   USE trc
   USE lib_mpp
   USE wrk_nemo  

   IMPLICIT NONE
   PRIVATE

   PUBLIC Agrif_Sponge_trc, interptrn_sponge

   !! * Substitutions
#  include "domzgr_substitute.h90"
   !!----------------------------------------------------------------------
   !! NEMO/NST 3.6 , NEMO Consortium (2010)
   !! $Id$
   !! Software governed by the CeCILL licence (NEMOGCM/NEMO_CeCILL.txt)
   !!----------------------------------------------------------------------

CONTAINS

   SUBROUTINE Agrif_Sponge_trc
      !!---------------------------------------------
      !!   *** ROUTINE Agrif_Sponge_Trc ***
      !!---------------------------------------------
      !! 
      REAL(wp) :: timecoeff

#if defined SPONGE_TOP
      timecoeff = REAL(Agrif_NbStepint(),wp)/Agrif_rhot()
      CALL Agrif_sponge
      Agrif_SpecialValue=0.
      Agrif_UseSpecialValue = .TRUE.
      tabspongedone_trn = .FALSE.
      CALL Agrif_Bc_Variable(trn_sponge_id,calledweight=timecoeff,procname=interptrn_sponge)
      Agrif_UseSpecialValue = .FALSE.

#endif

   END SUBROUTINE Agrif_Sponge_Trc

   SUBROUTINE interptrn_sponge(tabres,i1,i2,j1,j2,k1,k2,n1,n2,before)
      !!---------------------------------------------
      !!   *** ROUTINE interptrn_sponge ***
      !!---------------------------------------------
      INTEGER, INTENT(in) :: i1,i2,j1,j2,k1,k2,n1,n2
      REAL(wp), DIMENSION(i1:i2,j1:j2,k1:k2,n1:n2), INTENT(inout) :: tabres
      LOGICAL, INTENT(in) :: before


      INTEGER  ::   ji, jj, jk, jn   ! dummy loop indices

      REAL(wp) :: ztra, zabe1, zabe2, zbtr
      REAL(wp), DIMENSION(i1:i2,j1:j2) :: ztu, ztv
      REAL(wp), DIMENSION(i1:i2,j1:j2,k1:k2,n1:n2) ::trbdiff
      !
      IF (before) THEN
         tabres(i1:i2,j1:j2,k1:k2,n1:n2) = trn(i1:i2,j1:j2,k1:k2,n1:n2)
      ELSE      

         trbdiff(:,:,:,:) = trb(i1:i2,j1:j2,:,:) - tabres(:,:,:,:)      
         DO jn = 1, jptra
            DO jk = 1, jpkm1

               DO jj = j1,j2-1
                  DO ji = i1,i2-1
                     zabe1 = fsaht_spu(ji,jj) * umask(ji,jj,jk) * re2u_e1u(ji,jj) * fse3u_n(ji,jj,jk)
                     zabe2 = fsaht_spv(ji,jj) * vmask(ji,jj,jk) * re1v_e2v(ji,jj) * fse3v_n(ji,jj,jk)
                     ztu(ji,jj) = zabe1 * ( trbdiff(ji+1,jj  ,jk,jn) - trbdiff(ji,jj,jk,jn) )
                     ztv(ji,jj) = zabe2 * ( trbdiff(ji  ,jj+1,jk,jn) - trbdiff(ji,jj,jk,jn) )
                  ENDDO
               ENDDO

               DO jj = j1+1,j2-1
                  DO ji = i1+1,i2-1

                     IF (.NOT. tabspongedone_trn(ji,jj)) THEN 
                        zbtr = r1_e12t(ji,jj) / fse3t(ji,jj,jk)
                        ! horizontal diffusive trends
                        ztra = zbtr * (  ztu(ji,jj) - ztu(ji-1,jj  ) + ztv(ji,jj) - ztv(ji  ,jj-1)  )
                        ! add it to the general tracer trends
                        tra(ji,jj,jk,jn) = tra(ji,jj,jk,jn) + ztra
                     ENDIF

                  ENDDO
               ENDDO

            ENDDO
         ENDDO

         tabspongedone_trn(i1+1:i2-1,j1+1:j2-1) = .TRUE.
      ENDIF
      !                 
   END SUBROUTINE interptrn_sponge

#else
CONTAINS

   SUBROUTINE agrif_top_sponge_empty
      !!---------------------------------------------
      !!   *** ROUTINE agrif_top_sponge_empty ***
      !!---------------------------------------------
      WRITE(*,*)  'agrif_top_sponge : You should not have seen this print! error?'
   END SUBROUTINE agrif_top_sponge_empty
#endif

END MODULE agrif_top_sponge