MODULE stopping_crit_mod

implicit none

!=======================================================================
contains
!=======================================================================

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!
!!! Purpose: Criterions to check if the PEM needs to call the PCM
!!! Author: RV & LL, 02/2023
!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

SUBROUTINE stopping_crit_h2o_ice(cell_area,h2oice_ini_surf,is_h2oice_sublim_ini,h2o_ice,stopPEM,ngrid)

use time_evol_mod, only: h2o_ice_crit
use comslope_mod,  only: subslope_dist, nslope

implicit none

!=======================================================================
!
! Routine to check if the h2o ice criterion to stop the PEM is reached
!
!=======================================================================
! Inputs
!-------
integer,                          intent(in) :: ngrid                ! # of physical grid points
real,    dimension(ngrid),        intent(in) :: cell_area            ! Area of the cells
real,    dimension(ngrid,nslope), intent(in) :: h2o_ice              ! Actual density of h2o ice
real,                             intent(in) :: h2oice_ini_surf      ! Initial surface of sublimating h2o ice
logical, dimension(ngrid,nslope), intent(in) :: is_h2oice_sublim_ini ! Grid points where h2o ice was initially sublimating
! Outputs
!--------
integer, intent(inout) :: stopPEM ! Stopping criterion code
! Locals
! ------
integer :: i, islope       ! Loop
real    :: h2oice_now_surf ! Current surface of h2o ice

!=======================================================================
if (stopPEM > 0) return

! Computation of the present surface of h2o ice still sublimating
h2oice_now_surf = 0.
do i = 1,ngrid
    do islope = 1,nslope
        if (is_h2oice_sublim_ini(i,islope) .and. h2o_ice(i,islope) > 0.) h2oice_now_surf = h2oice_now_surf + cell_area(i)*subslope_dist(i,islope)
    enddo
enddo

! Check of the criterion
if (h2oice_now_surf < h2oice_ini_surf*(1. - h2o_ice_crit)) then
    stopPEM = 1
    write(*,*) "Reason of stopping: the surface of h2o ice sublimating reaches the threshold"
    write(*,*) "h2oice_now_surf < h2oice_ini_surf*(1. - h2o_ice_crit)", h2oice_now_surf < h2oice_ini_surf*(1. - h2o_ice_crit)
    write(*,*) "Initial surface of h2o ice sublimating =", h2oice_ini_surf
    write(*,*) "Current surface of h2o ice sublimating =", h2oice_now_surf
    write(*,*) "Percentage of change accepted =", h2o_ice_crit*100
else if (h2oice_now_surf > h2oice_ini_surf*(1. + h2o_ice_crit)) then
    stopPEM = 1
    write(*,*) "Reason of stopping: the surface of h2o ice sublimating reaches the threshold"
    write(*,*) "h2oice_now_surf > h2oice_ini_surf*(1. + h2o_ice_crit)", h2oice_now_surf > h2oice_ini_surf*(1. + h2o_ice_crit)
    write(*,*) "Initial surface of h2o ice sublimating =", h2oice_ini_surf
    write(*,*) "Current surface of h2o ice sublimating =", h2oice_now_surf
    write(*,*) "Percentage of change accepted =", h2o_ice_crit*100
endif

END SUBROUTINE stopping_crit_h2o_ice

!=======================================================================

SUBROUTINE stopping_crit_co2(cell_area,co2ice_sublim_surf_ini,is_co2ice_sublim_ini,co2_ice,stopPEM,ngrid,ps_avg_global_ini,ps_avg_global,nslope)

use time_evol_mod, only: co2_ice_crit, ps_criterion
use comslope_mod,  only: subslope_dist

implicit none

!=======================================================================
!
! Routine to check if the co2 and pressure criteria to stop the PEM are reached
!
!=======================================================================
! Inputs
!-------
integer,                          intent(in) :: ngrid, nslope          ! # of grid physical grid points
real,    dimension(ngrid),        intent(in) :: cell_area              ! Area of the cells
real,    dimension(ngrid,nslope), intent(in) :: co2_ice                ! Actual density of co2 ice
real,                             intent(in) :: co2ice_sublim_surf_ini ! Initial surface of sublimatingco2 ice
logical, dimension(ngrid,nslope), intent(in) :: is_co2ice_sublim_ini   ! Grid points where co2 ice was initially sublimating
real,                             intent(in) :: ps_avg_global_ini      ! Planet average pressure from the PCM start files
real,                             intent(in) :: ps_avg_global          ! Planet average pressure from the PEM computations
! Outputs
!--------
integer, intent(inout) :: stopPEM ! Stopping criterion code

! Locals
! ------
integer :: i, islope       ! Loop
real    :: co2ice_now_surf ! Current surface of co2 ice

!=======================================================================
if (stopPEM > 0) return

! Computation of the present surface of co2 ice still sublimating
co2ice_now_surf = 0.
do i = 1,ngrid
    do islope = 1,nslope
        if (is_co2ice_sublim_ini(i,islope) .and. co2_ice(i,islope) > 0.) co2ice_now_surf = co2ice_now_surf + cell_area(i)*subslope_dist(i,islope)
    enddo
enddo

! Check of the criterion
if (co2ice_now_surf < co2ice_sublim_surf_ini*(1. - co2_ice_crit)) then
    stopPEM = 3
    write(*,*) "Reason of stopping: the surface of co2 ice sublimating reaches the threshold"
    write(*,*) "co2ice_now_surf < co2ice_sublim_surf_ini*(1. - co2_ice_crit)", co2ice_now_surf < co2ice_sublim_surf_ini*(1. - co2_ice_crit)
    write(*,*) "Initial surface of co2 ice sublimating =", co2ice_sublim_surf_ini
    write(*,*) "Current surface of co2 ice sublimating =", co2ice_now_surf
    write(*,*) "Percentage of change accepted =", co2_ice_crit*100.
else if (co2ice_now_surf > co2ice_sublim_surf_ini*(1. + co2_ice_crit)) then
    stopPEM = 3
    write(*,*) "Reason of stopping: the surface of co2 ice sublimating reaches the threshold"
    write(*,*) "co2ice_now_surf > co2ice_sublim_surf_ini*(1. + co2_ice_crit)", co2ice_now_surf > co2ice_sublim_surf_ini*(1. + co2_ice_crit)
    write(*,*) "Current surface of co2 ice sublimating =", co2ice_now_surf
    write(*,*) "Initial surface of co2 ice sublimating =", co2ice_sublim_surf_ini
    write(*,*) "Percentage of change accepted =", co2_ice_crit*100.
endif

if (ps_avg_global < ps_avg_global_ini*(1. - ps_criterion)) then
    stopPEM = 4
    write(*,*) "Reason of stopping: the global pressure reaches the threshold"
    write(*,*) "ps_avg_global < ps_avg_global_ini*(1. - ps_criterion)", ps_avg_global < ps_avg_global_ini*(1. - ps_criterion)
    write(*,*) "Initial global pressure =", ps_avg_global_ini
    write(*,*) "Current global pressure =", ps_avg_global
    write(*,*) "Percentage of change accepted =", ps_criterion*100.
else if (ps_avg_global > ps_avg_global_ini*(1. + ps_criterion)) then
    stopPEM = 4
    write(*,*) "Reason of stopping: the global pressure reaches the threshold"
    write(*,*) "ps_avg_global > ps_avg_global_ini*(1. + ps_criterion)", ps_avg_global > ps_avg_global_ini*(1. + ps_criterion)
    write(*,*) "Initial global pressure =", ps_avg_global_ini
    write(*,*) "Current global pressure =", ps_avg_global
    write(*,*) "Percentage of change accepted =", ps_criterion*100.
endif

END SUBROUTINE stopping_crit_co2

!=======================================================================

SUBROUTINE stopping_crit_h2o(ngrid,nslope,cell_area,delta_h2o_adsorbed,delta_h2o_icetablesublim,h2o_ice,d_h2oice,S_atm_2_h2o,S_h2o_2_atm,S_atm_2_h2oice,S_h2oice_2_atm,stopPEM)

use time_evol_mod, only: dt
use comslope_mod,  only: subslope_dist, def_slope_mean
#ifndef CPP_STD
    use comcstfi_h,   only: pi
#else
    use comcstfi_mod, only: pi
#endif

implicit none

!=======================================================================
!
! Routine to check if the h2o is only exchanged between grid points
!
!=======================================================================
! Inputs
!-------
integer,                       intent(in) :: ngrid, nslope            ! # of grid points, # of subslopes
real, dimension(ngrid),        intent(in) :: cell_area                ! Area of each mesh grid (m^2)
real, dimension(ngrid),        intent(in) :: delta_h2o_adsorbed       ! Mass of H2O adsorbed/desorbded in the soil (kg/m^2)
real, dimension(ngrid),        intent(in) :: delta_h2o_icetablesublim ! Mass of H2O that condensed/sublimated at the ice table
real, dimension(ngrid,nslope), intent(in) :: h2o_ice                  ! H2O ice (kg/m^2)
real, dimension(ngrid,nslope), intent(in) :: d_h2oice                 ! Tendency of H2O ice (kg/m^2/year)
! Outputs
!--------
integer, intent(inout) :: stopPEM ! Stopping criterion code
real,    intent(out) :: S_atm_2_h2o, S_h2o_2_atm, S_atm_2_h2oice, S_h2oice_2_atm ! Variables to conserve H2O

! Locals
! ------
integer :: i, islope ! Loop

!=======================================================================
if (stopPEM > 0) return

! We compute the amount of water going out from the atmosphere (S_atm_2_h2o) and going into the atmophere (S_h2o_2_atm)
S_atm_2_h2o = 0.
S_h2o_2_atm = 0.
S_atm_2_h2oice = 0.
S_h2oice_2_atm = 0.
do i = 1,ngrid
    if (delta_h2o_adsorbed(i) > 0.) then
        S_atm_2_h2o = S_atm_2_h2o + delta_h2o_adsorbed(i)*cell_area(i)
    else
        S_h2o_2_atm = S_h2o_2_atm + delta_h2o_adsorbed(i)*cell_area(i)
    endif
    if (delta_h2o_icetablesublim(i) > 0.) then
        S_atm_2_h2o = S_atm_2_h2o + delta_h2o_icetablesublim(i)*cell_area(i)
    else
        S_h2o_2_atm = S_h2o_2_atm + delta_h2o_icetablesublim(i)*cell_area(i)
    endif
    do islope = 1,nslope
        if (d_h2oice(i,islope) > 0.) then
            S_atm_2_h2o = S_atm_2_h2o + d_h2oice(i,islope)*dt*cell_area(i)*subslope_dist(i,islope)/cos(def_slope_mean(islope)*pi/180.)
            S_atm_2_h2oice = S_atm_2_h2oice + d_h2oice(i,islope)*dt*cell_area(i)*subslope_dist(i,islope)/cos(def_slope_mean(islope)*pi/180.)
        else if (d_h2oice(i,islope) < 0. .and. h2o_ice(i,islope) > 0.) then
            S_h2o_2_atm = S_h2o_2_atm - d_h2oice(i,islope)*dt*cell_area(i)*subslope_dist(i,islope)/cos(def_slope_mean(islope)*pi/180.)
            S_h2oice_2_atm = S_h2oice_2_atm - d_h2oice(i,islope)*dt*cell_area(i)*subslope_dist(i,islope)/cos(def_slope_mean(islope)*pi/180.)
        endif
    enddo
enddo

! Since relative atmospheric water is kept constant, we need to equate condensing reservoirs to the sublimating ones.
! It is not possible if one of them is missing.
if (abs(S_atm_2_h2oice) < 1.e-10 .or. abs(S_h2oice_2_atm) < 1.e-10) then
    write(*,*) "Reason of stopping: there is no sublimating or condensing h2o ice!"
    write(*,*) "This can be due to the absence of h2o ice in the PCM run."
    write(*,*) "Amount of condensing ice  =", S_atm_2_h2oice
    write(*,*) "Amount of sublimating ice =", S_h2oice_2_atm
    stopPEM = 2
endif

END SUBROUTINE stopping_crit_h2o

END MODULE