MODULE tracers
!-----------------------------------------------------------------------
! NAME
!     tracers
!
! DESCRIPTION
!     Tracer species management for tracking.
!
! AUTHORS & DATE
!     JB Clement, 12/2025
!
! NOTES
!
!-----------------------------------------------------------------------

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

! MODULE VARIABLES
! ----------------
integer                         :: iPCM_qh2o ! Index for H2O vapor tracer from PCM
real, dimension(:), allocatable :: mmol      ! Molar masses of tracers [g/mol]

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

!=======================================================================
SUBROUTINE ini_tracers_id(nqtot,noms)
!-----------------------------------------------------------------------
! NAME
!     ini_tracers_id
!
! DESCRIPTION
!     Initialize tracer indices from PCM tracer names.
!
! AUTHORS & DATE
!     JB Clement, 12/2025
!
! NOTES
!
!-----------------------------------------------------------------------

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

! ARGUMENTS
! ---------
integer,                        intent(in) :: nqtot ! Total number of tracers
character(*), dimension(nqtot), intent(in) :: noms  ! Names of tracers

! LOCAL VARIABLES
! ---------------
integer :: i

! CODE
! ----
! Allocation
call ini_tracers(nqtot)

! Initialization
iPCM_qh2o = -1

! Getting the index
do i = 1,nqtot
    if (noms(i) == "h2o_vap") then
        iPCM_qh2o = i
        mmol(i) = 18.
    endif
enddo

! Checking if everything has been found
if (iPCM_qh2o < 0) error stop 'ini_frost_id: H2O vapour index not found!'

END SUBROUTINE ini_tracers_id
!=======================================================================

!=======================================================================
SUBROUTINE ini_tracers(nqtot)
!-----------------------------------------------------------------------
! NAME
!     ini_tracers
!
! DESCRIPTION
!     Allocate tracer molar mass array.
!
! AUTHORS & DATE
!     JB Clement, 12/2025
!
! NOTES
!
!-----------------------------------------------------------------------

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

! ARGUMENTS
! ---------
integer, intent(in) :: nqtot ! Total number of tracers

! CODE
! ----
if (.not. allocated(mmol)) allocate(mmol(nqtot))

END SUBROUTINE ini_tracers
!=======================================================================

!=======================================================================
SUBROUTINE end_tracers()
!-----------------------------------------------------------------------
! NAME
!     end_tracers
!
! DESCRIPTION
!     Deallocate tracer molar mass array.
!
! AUTHORS & DATE
!     JB Clement, 12/2025
!
! NOTES
!
!-----------------------------------------------------------------------

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

! CODE
! ----
if (allocated(mmol)) deallocate(mmol)

END SUBROUTINE end_tracers
!=======================================================================

END MODULE tracers