MODULE stopping_crit
!-----------------------------------------------------------------------
! NAME
!     stopping_crit
!
! DESCRIPTION
!     Stopping criteria for PEM.
!
! AUTHORS & DATE
!     JB Clement, 2025
!
! NOTES
!
!-----------------------------------------------------------------------

! DEPENDENCIES
! ------------
use numerics, only: dp, qp, di, k4, minieps_qp

! DECLARATION
! -----------
implicit none

! PARAMETERS
! ----------
real(dp), protected :: h2oice_crit ! Change of the surface of H2O ice sublimating before stopping the PEM
real(dp), protected :: co2ice_crit ! Change of the surface of CO2 ice sublimating before stopping the PEM
real(dp), protected :: ps_crit     ! Change of averaged surface pressure before stopping the PEM

! VARIABLES
! ---------
type :: stopFlags
    logical(k4) :: surface_h2oice_change  = .false.
    logical(k4) :: zero_dh2oice           = .false.
    logical(k4) :: surface_co2ice_change  = .false.
    logical(k4) :: pressure_change        = .false.
    logical(k4) :: nmax_yr_run_reached    = .false.
    logical(k4) :: nmax_yr_runorb_reached = .false.
    logical(k4) :: nmax_yr_sim_reached    = .false.
    logical(k4) :: time_limit_reached     = .false.
contains
    procedure :: is_any_set
    procedure :: stop_code
    procedure :: stop_message
end type

contains
!+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

!=======================================================================
SUBROUTINE set_stopping_crit_config(h2oice_crit_in,co2ice_crit_in,ps_crit_in)
!-----------------------------------------------------------------------
! NAME
!     set_stopping_crit_config
!
! DESCRIPTION
!     Setter for 'stopping_crit' configuration parameters.
!
! AUTHORS & DATE
!     JB Clement, 02/2026
!
! NOTES
!
!-----------------------------------------------------------------------

! DEPENDENCIES
! ------------
use utility, only: real2str
use display, only: print_msg

! DECLARATION
! -----------
implicit none

! ARGUMENTS
! ---------
real(dp), intent(in) :: h2oice_crit_in, co2ice_crit_in, ps_crit_in

! CODE
! ----
h2oice_crit = h2oice_crit_in
co2ice_crit = co2ice_crit_in
ps_crit = ps_crit_in
call print_msg('h2oice_crit = '//real2str(h2oice_crit))
call print_msg('co2ice_crit = '//real2str(co2ice_crit))
call print_msg('ps_crit     = '//real2str(ps_crit))

END SUBROUTINE set_stopping_crit_config
!=======================================================================

!=======================================================================
FUNCTION is_any_set(this) RESULT(stopPEM)
!-----------------------------------------------------------------------
! NAME
!     is_any_set
!
! DESCRIPTION
!     Detect if any stopping flag is set to true.
!
! AUTHORS & DATE
!     JB Clement, 2025
!
! NOTES
!
!-----------------------------------------------------------------------

! DECLARATION
! -----------
implicit none

! ARGUMENTS
! ---------
class(stopFlags), intent(in) :: this    ! Stopping flags object
logical(k4)                  :: stopPEM ! True if any flag is set

! CODE
! ----
stopPEM = this%surface_h2oice_change  .or. &
          this%zero_dh2oice           .or. &
          this%surface_co2ice_change  .or. &
          this%pressure_change        .or. &
          this%nmax_yr_run_reached    .or. &
          this%nmax_yr_runorb_reached .or. &
          this%nmax_yr_sim_reached    .or. &
          this%time_limit_reached

END FUNCTION is_any_set
!=======================================================================

!=======================================================================
FUNCTION stop_code(this) result(code)
!-----------------------------------------------------------------------
! NAME
!     stop_code
!
! DESCRIPTION
!     Return digit code corresponding to the active stopping flag.
!
! AUTHORS & DATE
!     JB Clement, 2025
!
! NOTES
!
!-----------------------------------------------------------------------

! DECLARATION
! -----------
implicit none

! ARGUMENTS
! ---------
class(StopFlags), intent(in) :: this ! Stopping flags object
integer(di)                  :: code ! Code corresponding to active flag (0 if none)

! CODE
! ----
code = 0
if     (this%surface_h2oice_change)  then; code = 1
elseif (this%zero_dh2oice)           then; code = 2
elseif (this%surface_co2ice_change)  then; code = 3
elseif (this%pressure_change)        then; code = 4
elseif (this%nmax_yr_run_reached)    then; code = 5
elseif (this%nmax_yr_runorb_reached) then; code = 6
elseif (this%nmax_yr_sim_reached)    then; code = 7
elseif (this%time_limit_reached)     then; code = 8
end if

END FUNCTION stop_code
!=======================================================================

!=======================================================================
FUNCTION stop_message(this) result(msg)
!-----------------------------------------------------------------------
! NAME
!     stop_message
!
! DESCRIPTION
!     Return descriptive message corresponding to the active stopping flag.
!
! AUTHORS & DATE
!     JB Clement, 2025
!
! NOTES
!
!-----------------------------------------------------------------------

! DECLARATION
! -----------
implicit none

! ARGUMENTS
! ---------
class(StopFlags), intent(in) :: this ! Stopping flags object
character(:), allocatable    :: msg  ! Descriptive message for active flag

! CODE
! ----
if     (this%surface_h2oice_change)  then; msg = "**** STOPPING because surface of H2O ice has changed too much (see message above)."
elseif (this%zero_dh2oice)           then; msg = "**** STOPPING because tendencies on H2O ice = 0 (see message above)."
elseif (this%surface_co2ice_change)  then; msg = "**** STOPPING because surface of CO2 ice has changed too much (see message above)."
elseif (this%pressure_change)        then; msg = "**** STOPPING because surface global pressure has changed too much (see message above)."
elseif (this%nmax_yr_run_reached)    then; msg = "**** STOPPING because maximum number of years is reached."
elseif (this%nmax_yr_runorb_reached) then; msg = "**** STOPPING because maximum number of years due to orbital parameters is reached."
elseif (this%nmax_yr_sim_reached)    then; msg = "**** STOPPING because the number of years to be simulated is reached."
elseif (this%time_limit_reached)     then; msg = "**** STOPPING because the job time limit is going to be reached."
end if

END FUNCTION stop_message
!=======================================================================

!=======================================================================
SUBROUTINE stopping_crit_h2oice(h2oice_sublim_coverage_ini,h2o_ice,d_h2oice,stopcrit)

!-----------------------------------------------------------------------
! NAME
!     stopping_crit_h2oice
!
! DESCRIPTION
!     Check if H2O ice surface has changed too much.
!
! AUTHORS & DATE
!     R. Vandemeulebrouck
!     L. Lange, 2023
!     JB Clement, 2023-2025
!
! NOTES
!
!-----------------------------------------------------------------------

! DEPENDENCIES
! ------------
use slopes,   only: subslope_dist, def_slope_mean
use geometry, only: ngrid, nslope, cell_area
use maths,    only: pi
use display,  only: print_msg
use utility,  only: real2str

! DECLARATION
! -----------
implicit none

! ARGUMENTS
! ---------
real(dp), dimension(:,:), intent(in)    :: h2o_ice, d_h2oice
real(dp),                 intent(in)    :: h2oice_sublim_coverage_ini
type(stopFlags),          intent(inout) :: stopcrit

! LOCAL VARIABLES
! ---------------
integer(di) :: i, islope
real(dp)    :: h2oice_now_surf

! CODE
! ----
! Check to escape the subroutine (if the PEM should stop already)
if (stopcrit%stop_code() > 0) return

! Computation of the present surface of sublimating H2O ice
h2oice_now_surf = 0._dp
do i = 1,ngrid
    do islope = 1,nslope
        if (h2o_ice(i,islope) > 0._dp .and. d_h2oice(i,islope) < 0._dp) h2oice_now_surf = h2oice_now_surf + cell_area(i)*subslope_dist(i,islope)/cos(pi*def_slope_mean(islope)/180._dp)
    end do
end do

! Check of the criterion
if (h2oice_now_surf < h2oice_sublim_coverage_ini*(1._dp - h2oice_crit) .or. h2oice_now_surf > h2oice_sublim_coverage_ini*(1. + h2oice_crit)) then
    stopcrit%surface_h2oice_change = .true.
    call print_msg("Surface of H2O ice sublimating (ini|now) [m2] = "//real2str(h2oice_sublim_coverage_ini)//' | '//real2str(h2oice_now_surf))
    call print_msg("Change (accepted|current) [%] = +/- "//real2str(h2oice_crit*100._dp)//' | '//real2str(100._dp*(h2oice_now_surf - h2oice_sublim_coverage_ini)/h2oice_sublim_coverage_ini))
end if

END SUBROUTINE stopping_crit_h2oice
!=======================================================================

!=======================================================================
SUBROUTINE stopping_crit_co2ice(co2ice_sublim_coverage_ini,co2_ice,d_co2ice,stopcrit)
!-----------------------------------------------------------------------
! NAME
!     stopping_crit_co2ice
!
! DESCRIPTION
!     Check if CO2 ice surface has changed too much.
!
! AUTHORS & DATE
!     R. Vandemeulebrouck
!     L. Lange, 2023
!     JB Clement, 2023-2025
!
! NOTES
!
!-----------------------------------------------------------------------

! DEPENDENCIES
! ------------
use slopes,   only: subslope_dist, def_slope_mean
use geometry, only: ngrid, nslope, cell_area
use maths,    only: pi
use display,  only: print_msg
use utility,  only: real2str

! DECLARATION
! -----------
implicit none

! ARGUMENTS
! ---------
real(dp), dimension(:,:), intent(in)    :: co2_ice, d_co2ice
real(dp),                 intent(in)    :: co2ice_sublim_coverage_ini
type(stopFlags),          intent(inout) :: stopcrit

! LOCAL VARIABLES
! ---------------
integer(di) :: i, islope
real(dp)    :: co2ice_now_surf ! Current surface of CO2 ice

! CODE
! ----
! Check to escape the subroutine (not relevant in 1D or if the PEM should stop already)
if (ngrid == 1 .or. stopcrit%stop_code() > 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 (co2_ice(i,islope) > 0._dp .and. d_co2ice(i,islope) < 0._dp) co2ice_now_surf = co2ice_now_surf + cell_area(i)*subslope_dist(i,islope)/cos(pi*def_slope_mean(islope)/180._dp)
    end do
end do

! Check of the criterion
if (co2ice_now_surf < co2ice_sublim_coverage_ini*(1. - co2ice_crit) .or. co2ice_now_surf > co2ice_sublim_coverage_ini*(1._dp + co2ice_crit)) then
    stopcrit%surface_co2ice_change = .true.
    call print_msg("Initial surface of CO2 ice sublimating (ini|now) [m2] = "//real2str(co2ice_sublim_coverage_ini)//' | '//real2str(co2ice_now_surf))
    call print_msg("Change (accepted|current) [%] = +/- "//real2str(co2ice_crit*100._dp)//' | '//real2str(100._dp*(co2ice_now_surf - co2ice_sublim_coverage_ini)/co2ice_sublim_coverage_ini))
end if

END SUBROUTINE stopping_crit_co2ice
!=======================================================================

!=======================================================================
SUBROUTINE stopping_crit_pressure(ps_avg_glob_ini,ps_avg_global,stopcrit)
!-----------------------------------------------------------------------
! NAME
!     stopping_crit_pressure
!
! DESCRIPTION
!     Check if pressure has changed too much.
!
! AUTHORS & DATE
!     R. Vandemeulebrouck
!     L. Lange, 2023
!     JB Clement, 2023-2025
!
! NOTES
!
!-----------------------------------------------------------------------

! DEPENDENCIES
! ------------
use display,  only: print_msg
use utility,  only: real2str

! DECLARATION
! -----------
implicit none

! ARGUMENTS
! ---------
real(dp),        intent(in)    :: ps_avg_glob_ini, ps_avg_global
type(stopFlags), intent(inout) :: stopcrit

! CODE
! ----
! Check to escape the subroutine (not relevant if the PEM should stop already)
if (stopcrit%stop_code() > 0) return

if (ps_avg_global < ps_avg_glob_ini*(1._dp - ps_crit) .or. ps_avg_global > ps_avg_glob_ini*(1._dp + ps_crit)) then
    stopcrit%pressure_change = .true.
    call print_msg("Initial global pressure (ini|now) [Pa] = "//real2str(ps_avg_glob_ini)//' | '//real2str(ps_avg_global))
    call print_msg("Change (accepted|current) [%] = +/- "//real2str(ps_crit*100._dp)//' | '//real2str(100._dp*(ps_avg_global - ps_avg_glob_ini)/ps_avg_glob_ini))
end if

END SUBROUTINE stopping_crit_pressure
!=======================================================================

!=======================================================================
SUBROUTINE stopping_crit_h2o(delta_h2o_ads,delta_icetable,h2o_ice,d_h2oice,S_atm_2_h2o,S_h2o_2_atm,S_atm_2_h2oice,S_h2oice_2_atm,stopcrit)
!-----------------------------------------------------------------------
! NAME
!     stopping_crit_h2o
!
! DESCRIPTION
!     Check if PEM oscillates infinitely with H2O (no net exchange).
!
! AUTHORS & DATE
!     L. Lange, 2024
!     JB Clement, 2025
!
! NOTES
!
!-----------------------------------------------------------------------

! DEPENDENCIES
! ------------
use geometry,  only: ngrid, nslope, cell_area
use evolution, only: dt
use slopes,    only: subslope_dist, def_slope_mean
use maths,     only: pi
use display,   only: print_msg
use utility,   only: real2str

! DECLARATION
! -----------
implicit none

! ARGUMENTS
! ---------
real(dp), dimension(:),   intent(in)    :: delta_h2o_ads            ! Mass of H2O adsorbed/desorbded in the soil (kg/m^2)
real(dp), dimension(:),   intent(in)    :: delta_icetable ! Mass of H2O that condensed/sublimated at the ice table
real(dp), dimension(:,:), intent(in)    :: h2o_ice, d_h2oice
real(qp),                 intent(out)   :: S_atm_2_h2o, S_h2o_2_atm, S_atm_2_h2oice, S_h2oice_2_atm
type(stopFlags),          intent(inout) :: stopcrit

! LOCAL VARIABLES
! ---------------
integer(di) :: i, islope

! CODE
! ----
! Check to escape the subroutine (not relevant in 1D or if the PEM should stop already)
if (ngrid == 1 .or. stopcrit%stop_code() > 0) then
    S_atm_2_h2o = 1._qp
    S_h2o_2_atm = S_atm_2_h2o
    S_atm_2_h2oice = 1._qp
    S_h2oice_2_atm = S_atm_2_h2oice
    return
end if

! 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._qp
S_h2o_2_atm = 0._qp
S_atm_2_h2oice = 0._qp
S_h2oice_2_atm = 0._qp
do i = 1,ngrid
    if (delta_h2o_ads(i) > 0._dp) then
        S_atm_2_h2o = S_atm_2_h2o + delta_h2o_ads(i)*cell_area(i)
    else
        S_h2o_2_atm = S_h2o_2_atm + delta_h2o_ads(i)*cell_area(i)
    end if
    if (delta_icetable(i) > 0._dp) then
        S_atm_2_h2o = S_atm_2_h2o + delta_icetable(i)*cell_area(i)
    else
        S_h2o_2_atm = S_h2o_2_atm + delta_icetable(i)*cell_area(i)
    end if
    do islope = 1,nslope
        if (d_h2oice(i,islope) > 0._dp) 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._dp)
            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._dp)
        else if (d_h2oice(i,islope) < 0._dp .and. h2o_ice(i,islope) > 0._dp) 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._dp)
            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._dp)
        end if
    end do
end do

! 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) < minieps_qp .or. abs(S_h2oice_2_atm) < minieps_qp)) then
    call print_msg("There is no sublimating or condensing H2O ice! This can be due to the absence of H2O ice in the PCM run.")
    call print_msg("Amount of condensing ice  [kg] = "//real2str(S_atm_2_h2oice))
    call print_msg("Amount of sublimating ice [kg] = "//real2str(S_h2oice_2_atm))
    stopcrit%zero_dh2oice = .true.
end if

END SUBROUTINE stopping_crit_h2o
!=======================================================================

END MODULE stopping_crit