MODULE observable_mod
  USE icosa
  IMPLICIT NONE
  PRIVATE

  TYPE(t_field),POINTER, SAVE :: f_buf_i(:), &
       f_buf_Fel(:), f_buf_uh(:), & ! horizontal velocity, different from prognostic velocity if NH
       f_buf_ulon(:), f_buf_ulat(:), &
       f_buf_u3d(:) ! unused, remove ?
  TYPE(t_field),POINTER, SAVE :: f_buf1_i(:), f_buf2_i(:)
  TYPE(t_field),POINTER, SAVE :: f_buf_v(:), f_buf_s(:), f_buf_p(:)
  TYPE(t_field),POINTER, SAVE :: f_pmid(:)

! temporary shared variable for caldyn
  TYPE(t_field),POINTER, SAVE :: f_theta(:)

  PUBLIC init_observable, write_output_fields_basic, f_theta

CONTAINS
  
  SUBROUTINE init_observable
    CALL allocate_field(f_buf_i,   field_t,type_real,llm,name="buffer_i")
    CALL allocate_field(f_buf1_i,   field_t,type_real,llm,name="buffer1_i")
    CALL allocate_field(f_buf2_i,   field_t,type_real,llm,name="buffer2_i")
    CALL allocate_field(f_buf_p,   field_t,type_real,llm+1) 
    CALL allocate_field(f_buf_u3d, field_t,type_real,3,llm)  ! 3D vel at cell centers
    CALL allocate_field(f_buf_ulon,field_t,type_real,llm, name="buf_ulon")
    CALL allocate_field(f_buf_ulat,field_t,type_real,llm, name="buf_ulat")
    CALL allocate_field(f_buf_uh,  field_u,type_real,llm, name="buf_uh")
    CALL allocate_field(f_buf_Fel, field_u,type_real,llm+1, name="buf_F_el")
    CALL allocate_field(f_buf_v,   field_z,type_real,llm, name="buf_v")
    CALL allocate_field(f_buf_s,   field_t,type_real, name="buf_s")

    CALL allocate_field(f_theta, field_t,type_real,llm,nqdyn,  name='theta') ! potential temperature
    CALL allocate_field(f_pmid,  field_t,type_real,llm,  name='pmid')       ! mid layer pressure
  END SUBROUTINE init_observable

  SUBROUTINE write_output_fields_basic(init, f_phis, f_ps, f_mass, f_geopot, f_theta_rhodz, f_u, f_W, f_q)
    USE xios_mod
    USE disvert_mod
    USE wind_mod
    USE output_field_mod
    USE omp_para
    USE time_mod
    USE xios_mod
    USE earth_const
    USE pression_mod
    USE vertical_interp_mod
    USE theta2theta_rhodz_mod
    USE omega_mod
    USE diagflux_mod
    LOGICAL, INTENT(IN) :: init
    INTEGER :: l
    REAL :: scalar(1)
    REAL :: mid_ap(llm)
    REAL :: mid_bp(llm)

    TYPE(t_field),POINTER :: f_phis(:), f_ps(:), f_mass(:), f_geopot(:), f_theta_rhodz(:), f_u(:), f_W(:), f_q(:)
!    IF (is_master) PRINT *,'CALL write_output_fields_basic'

    CALL transfert_request(f_ps,req_i1)
    
    IF(init) THEN
       IF(is_master) PRINT *, 'Creating output files ...'
       scalar(1)=dt
       IF (is_omp_master) CALL xios_send_field("timestep", scalar)
       scalar(1)=preff
       IF (is_omp_master) CALL xios_send_field("preff", scalar)
       IF (is_omp_master) CALL xios_send_field("ap",ap)
       IF (is_omp_master) CALL xios_send_field("bp",bp)
       DO l=1,llm
          mid_ap(l)=(ap(l)+ap(l+1))/2
          mid_bp(l)=(bp(l)+bp(l+1))/2
       ENDDO
       IF (is_omp_master) CALL xios_send_field("mid_ap",mid_ap)
       IF (is_omp_master) CALL xios_send_field("mid_bp",mid_bp)

       CALL output_field("phis",f_phis)
       CALL output_field("Ai",geom%Ai) 
       IF(is_master) PRINT *, '... done creating output files. Writing initial condition ...'
    END IF

    IF(nqdyn>1) THEN
       CALL divide_by_mass(2, f_mass, f_theta_rhodz, f_buf_i)
       IF(init) THEN
          CALL output_field("dyn_q_init",f_buf_i)
       ELSE
          CALL output_field("dyn_q",f_buf_i)
       END IF
    END IF

    CALL divide_by_mass(1, f_mass, f_theta_rhodz, f_buf_i)
    IF(init) THEN
       CALL output_field("theta_init",f_buf_i)
    ELSE
       CALL output_field("theta",f_buf_i)
    END IF

    CALL pression_mid(f_ps, f_pmid)
    CALL diagnose_temperature(f_pmid, f_q, f_buf_i) ! f_buf_i : IN = theta, out = T

    IF(init) THEN
       CALL output_field("temp_init",f_buf_i)
    ELSE
       CALL output_field("temp",f_buf_i)
       CALL vertical_interp(f_pmid,f_buf_i,f_buf_s,85000.)
       CALL output_field("t850",f_buf_s)
       CALL vertical_interp(f_pmid,f_buf_i,f_buf_s,50000.)
       CALL output_field("t500",f_buf_s)
       CALL vertical_interp(f_pmid,f_buf_i,f_buf_s,preff)
       CALL output_field("SST",f_buf_s)       
    END IF
    
    CALL progonostic_vel_to_horiz(f_geopot, f_ps, f_mass, f_u, f_W, f_buf_uh, f_buf_i)
    CALL transfert_request(f_buf_uh,req_e1_vect) 
    CALL un2ulonlat(f_buf_uh, f_buf_ulon, f_buf_ulat)
    IF(init) THEN
       CALL output_field("uz_init",f_buf_i)
       CALL output_field("ulon_init",f_buf_ulon)
       CALL output_field("ulat_init",f_buf_ulat)
       CALL output_field("p_init",f_pmid)
       CALL output_field("ps_init",f_ps)
       CALL output_field("mass_init",f_mass)
       CALL output_field("geopot_init",f_geopot)
       CALL output_field("q_init",f_q)
       IF(is_master) PRINT *, 'Done writing initial condition ...'
    ELSE
       CALL output_field("uz",f_buf_i)
       CALL output_field("ulon",f_buf_ulon)
       CALL output_field("ulat",f_buf_ulat)
       CALL output_field("p",f_pmid)
       CALL output_field("ps",f_ps)
       CALL output_field("mass",f_mass)
       CALL output_field("geopot",f_geopot)
       CALL output_field("q",f_q)

       !       CALL output_field("exner",f_pk)
       !       CALL output_field("pv",f_qv)
       
       CALL vertical_interp(f_pmid,f_buf_ulon,f_buf_s,85000.)
       CALL output_field("u850",f_buf_s)
       CALL vertical_interp(f_pmid,f_buf_ulon,f_buf_s,50000.)
       CALL output_field("u500",f_buf_s)
       
       CALL vertical_interp(f_pmid,f_buf_ulat,f_buf_s,85000.)
       CALL output_field("v850",f_buf_s)
       CALL vertical_interp(f_pmid,f_buf_ulat,f_buf_s,50000.)
       CALL output_field("v500",f_buf_s)

       CALL vertical_interp(f_pmid,f_buf_i,f_buf_s,85000.)
       CALL output_field("w850",f_buf_s)
       CALL vertical_interp(f_pmid,f_buf_i,f_buf_s,50000.)
       CALL output_field("w500",f_buf_s)    

       CALL w_omega(f_ps, f_u, f_buf_i)
       CALL output_field("omega",f_buf_i)
       CALL vertical_interp(f_pmid,f_buf_i,f_buf_s,85000.)
       CALL output_field("omega850",f_buf_s)
       CALL vertical_interp(f_pmid,f_buf_i,f_buf_s,50000.)
       CALL output_field("omega500",f_buf_s)
    END IF

    IF(.NOT. init) THEN
       IF(diagflux_on) THEN
          CALL flux_centered_lonlat(1./(itau_out*dt) , f_massfluxt, f_buf_ulon, f_buf_ulat)
          CALL output_field("mass_t", f_masst)
          CALL output_field("massflux_lon",f_buf_ulon)
          CALL output_field("massflux_lat",f_buf_ulat)
          CALL flux_centered_lonlat(1./(itau_out*dt) , f_epotfluxt, f_buf_ulon, f_buf_ulat)
          CALL output_field("epot_t", f_epot)
          CALL output_field("epotflux_lon",f_buf_ulon)
          CALL output_field("epotflux_lat",f_buf_ulat)
          CALL flux_centered_lonlat(1./(itau_out*dt) , f_ekinfluxt, f_buf_ulon, f_buf_ulat)
          CALL output_field("ekin_t", f_ekin)
          CALL output_field("ekinflux_lon",f_buf_ulon)
          CALL output_field("ekinflux_lat",f_buf_ulat)
          CALL flux_centered_lonlat(1./(itau_out*dt) , f_enthalpyfluxt, f_buf_ulon, f_buf_ulat)
          CALL output_field("enthalpy_t", f_enthalpy)
          CALL output_field("enthalpyflux_lon",f_buf_ulon)
          CALL output_field("enthalpyflux_lat",f_buf_ulat)
          CALL qflux_centered_lonlat(1./(itau_out*dt) , f_qfluxt, f_qfluxt_lon, f_qfluxt_lat)
          CALL output_field("qmass_t", f_qmasst)
          CALL output_field("qflux_lon",f_qfluxt_lon)
          CALL output_field("qflux_lat",f_qfluxt_lat)
          CALL zero_qfluxt  ! restart accumulating fluxes
       END IF
    END IF
  END SUBROUTINE write_output_fields_basic
  
 !------------------- Conversion from prognostic to observable variables ------------------

  SUBROUTINE progonostic_vel_to_horiz(f_geopot, f_ps, f_rhodz, f_u, f_W, f_uh, f_uz)
    USE disvert_mod
    TYPE(t_field), POINTER :: f_geopot(:), f_ps(:), f_rhodz(:), &
         f_u(:), f_W(:), f_uz(:), &  ! IN
         f_uh(:)                         ! OUT
    REAL(rstd),POINTER :: geopot(:,:), ps(:), rhodz(:,:), u(:,:), W(:,:), uh(:,:), uz(:,:), F_el(:,:)
    INTEGER :: ind
    
    DO ind=1,ndomain
       IF (.NOT. assigned_domain(ind)) CYCLE
       CALL swap_dimensions(ind)
       CALL swap_geometry(ind)
       geopot = f_geopot(ind)
       rhodz = f_rhodz(ind)
       u = f_u(ind)
       W = f_W(ind)
       uh  = f_uh(ind)
       F_el  = f_buf_Fel(ind)
       IF(caldyn_eta==eta_mass) THEN
          ps=f_ps(ind)
          CALL compute_rhodz(.TRUE., ps, rhodz)
       END IF
       uz = f_uz(ind)
       !$OMP BARRIER
       CALL compute_prognostic_vel_to_horiz(geopot,rhodz,u,W, F_el, uh,uz)
       !$OMP BARRIER
    END DO
  END SUBROUTINE progonostic_vel_to_horiz
  
  SUBROUTINE compute_prognostic_vel_to_horiz(Phi, rhodz, u, W, F_el, uh, uz)
    USE omp_para
    REAL(rstd), INTENT(IN) :: Phi(iim*jjm,llm+1)
    REAL(rstd), INTENT(IN) :: rhodz(iim*jjm,llm)
    REAL(rstd), INTENT(IN) :: u(3*iim*jjm,llm)
    REAL(rstd), INTENT(IN) :: W(iim*jjm,llm+1)
    REAL(rstd), INTENT(OUT) :: uh(3*iim*jjm,llm)
    REAL(rstd), INTENT(OUT) :: uz(iim*jjm,llm)
    INTEGER :: ij,l
    REAL(rstd) :: F_el(3*iim*jjm,llm+1)
    REAL(rstd) :: uu_right, uu_lup, uu_ldown, W_el, DePhil
    ! NB : u and uh are not in DEC form, they are normal components    
    ! => we must divide by de
    IF(hydrostatic) THEN
       uh(:,:)=u(:,:)
       uz(:,:)=0.
    ELSE
       DO l=ll_begin, ll_endp1 ! compute on l levels (interfaces)
          DO ij=ij_begin_ext, ij_end_ext
             ! Compute on edge 'right'
             W_el   = .5*( W(ij,l)+W(ij+t_right,l) )
             DePhil = ne_right*(Phi(ij+t_right,l)-Phi(ij,l))
             F_el(ij+u_right,l)   = DePhil*W_el/de(ij+u_right)
             ! Compute on edge 'lup'
             W_el   = .5*( W(ij,l)+W(ij+t_lup,l) )
             DePhil = ne_lup*(Phi(ij+t_lup,l)-Phi(ij,l))
             F_el(ij+u_lup,l)   = DePhil*W_el/de(ij+u_lup)
             ! Compute on edge 'ldown'
             W_el   = .5*( W(ij,l)+W(ij+t_ldown,l) )
             DePhil = ne_ldown*(Phi(ij+t_ldown,l)-Phi(ij,l))
             F_el(ij+u_ldown,l) = DePhil*W_el/de(ij+u_ldown)
          END DO
       END DO

       ! We need a barrier here because we compute F_el above and do a vertical average below
       !$OMP BARRIER

       DO l=ll_begin, ll_end ! compute on k levels (full levels)
          DO ij=ij_begin_ext, ij_end_ext
             ! w = vertical momentum = g^-2*dPhi/dt = uz/g
             uz(ij,l) = (.5*g)*(W(ij,l)+W(ij,l+1))/rhodz(ij,l)
             ! uh = u-w.grad(Phi) = u - uz.grad(z)
             uh(ij+u_right,l) = u(ij+u_right,l) - (F_el(ij+u_right,l)+F_el(ij+u_right,l+1)) / (rhodz(ij,l)+rhodz(ij+t_right,l))
             uh(ij+u_lup,l)   = u(ij+u_lup,l)   - (F_el(ij+u_lup,l)+F_el(ij+u_lup,l+1))     / (rhodz(ij,l)+rhodz(ij+t_lup,l))
             uh(ij+u_ldown,l) = u(ij+u_ldown,l) - (F_el(ij+u_ldown,l)+F_el(ij+u_ldown,l+1)) / (rhodz(ij,l)+rhodz(ij+t_ldown,l))
          END DO
       END DO

    END IF
  END SUBROUTINE compute_prognostic_vel_to_horiz

  SUBROUTINE diagnose_temperature(f_pmid,f_q,f_temp)
    USE icosa
    USE pression_mod
    IMPLICIT NONE
    TYPE(t_field), POINTER :: f_pmid(:)           ! IN
    TYPE(t_field), POINTER :: f_q(:)            ! IN
    TYPE(t_field), POINTER :: f_temp(:)         ! INOUT
    
    REAL(rstd), POINTER :: pmid(:,:)
    REAL(rstd), POINTER :: q(:,:,:)
    REAL(rstd), POINTER :: temp(:,:)
    INTEGER :: ind
    
    DO ind=1,ndomain
       IF (.NOT. assigned_domain(ind)) CYCLE
       CALL swap_dimensions(ind)
       CALL swap_geometry(ind)
       pmid=f_pmid(ind)
       q=f_q(ind)
       temp=f_temp(ind)
       CALL compute_diagnose_temp(pmid,q,temp)
    END DO
  END SUBROUTINE diagnose_temperature
  
  SUBROUTINE compute_diagnose_temp(pmid,q,temp)
    USE omp_para
    USE pression_mod
    REAL(rstd),INTENT(IN)    :: pmid(iim*jjm,llm)
    REAL(rstd),INTENT(IN)    :: q(iim*jjm,llm,nqtot)
    REAL(rstd),INTENT(INOUT) :: temp(iim*jjm,llm)

    REAL(rstd) :: Rd, p_ik, theta_ik, temp_ik, qv, chi, Rmix
    INTEGER :: ij,l

    Rd = kappa*cpp
    DO l=ll_begin,ll_end
       DO ij=ij_begin,ij_end
          p_ik = pmid(ij,l)
          theta_ik = temp(ij,l)
          qv = q(ij,l,1) ! water vaper mixing ratio = mv/md
          SELECT CASE(caldyn_thermo)
          CASE(thermo_theta)
             temp_ik = theta_ik*((p_ik/preff)**kappa)
          CASE(thermo_entropy)
             temp_ik = Treff*exp((theta_ik + Rd*log(p_ik/preff))/cpp)
          CASE(thermo_moist)
             Rmix = Rd+qv*Rv
             chi = ( theta_ik + Rmix*log(p_ik/preff) ) / (cpp + qv*cppv) ! log(T/Treff)
             temp_ik = Treff*exp(chi)
          END SELECT
          IF(physics_thermo==thermo_fake_moist) temp_ik=temp_ik/(1+0.608*qv)
          temp(ij,l)=temp_ik
       END DO
    END DO
  END SUBROUTINE compute_diagnose_temp

  SUBROUTINE Tv2T(f_Tv, f_q, f_T)
    TYPE(t_field), POINTER :: f_TV(:)
    TYPE(t_field), POINTER :: f_q(:)
    TYPE(t_field), POINTER :: f_T(:)
    
    REAL(rstd),POINTER :: Tv(:,:), q(:,:,:), T(:,:)
    INTEGER :: ind
    
    DO ind=1,ndomain
       IF (.NOT. assigned_domain(ind)) CYCLE
       CALL swap_dimensions(ind)
       CALL swap_geometry(ind)
       Tv=f_Tv(ind)
       T=f_T(ind)
       SELECT CASE(physics_thermo)
       CASE(thermo_dry)
          T=Tv
       CASE(thermo_fake_moist)
          q=f_q(ind)
          T=Tv/(1+0.608*q(:,:,1))
       END SELECT
    END DO
  END SUBROUTINE Tv2T

  SUBROUTINE divide_by_mass(iq, f_mass, f_theta_rhodz, f_theta)
    INTEGER, INTENT(IN) :: iq
    TYPE(t_field), POINTER :: f_mass(:), f_theta_rhodz(:), f_theta(:)
    REAL(rstd), POINTER :: mass(:,:), theta_rhodz(:,:,:), theta(:,:)
    INTEGER :: ind
    DO ind=1,ndomain
       IF (.NOT. assigned_domain(ind)) CYCLE
       CALL swap_dimensions(ind)
       CALL swap_geometry(ind)
       mass=f_mass(ind)
       theta_rhodz=f_theta_rhodz(ind)
       theta=f_theta(ind)
       theta(:,:) = theta_rhodz(:,:,iq) / mass(:,:)
    END DO
  END SUBROUTINE divide_by_mass
    
END MODULE observable_mod