!> @file salsa_util_mod.f90
!--------------------------------------------------------------------------------!
! This file is part of PALM-4U.
!
! PALM-4U is free software: you can redistribute it and/or modify it under the 
! terms of the GNU General Public License as published by the Free Software 
! Foundation, either version 3 of the License, or (at your option) any later 
! version.
!
! PALM-4U is distributed in the hope that it will be useful, but WITHOUT ANY
! WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
! A PARTICULAR PURPOSE.  See the GNU General Public License for more details.
!
! You should have received a copy of the GNU General Public License along with
! PALM. If not, see <http://www.gnu.org/licenses/>.
!
! Copyright 1997-2018 Leibniz Universitaet Hannover
!--------------------------------------------------------------------------------!
!
! Current revisions:
! -----------------
! 
! 
! Former revisions:
! -----------------
! $Id: salsa_util_mod.f90 3494 2018-11-06 14:51:27Z raasch $
! Initial revision
! 
! 
!
! Authors:
! --------
! @author monakurppa
!
!
! Description:
! ------------
!> Utility functions used in salsa_mod.
!------------------------------------------------------------------------------!
 MODULE salsa_util_mod
 
    USE kinds
    
    USE pegrid
    
    IMPLICIT NONE
    
    REAL(wp), DIMENSION(:,:), ALLOCATABLE ::  sums_salsa_ws_l !< subdomain sum 
                                        !< of vertical passive salsa flux w's' 
                                        !< (5th-order advection scheme only)

!-- Component index
    TYPE component_index
       INTEGER(iwp) ::  ncomp !< Number of components
       INTEGER(iwp), ALLOCATABLE ::  ind(:) !< Component index
       CHARACTER(len=3), ALLOCATABLE ::  comp(:) !< Component name
    END TYPE component_index 
    
    SAVE
    
    INTERFACE component_index_constructor
       MODULE PROCEDURE component_index_constructor
    END INTERFACE component_index_constructor
    
    INTERFACE get_index
       MODULE PROCEDURE get_index
    END INTERFACE get_index
    
    INTERFACE get_n_comp
       MODULE PROCEDURE get_n_comp
    END INTERFACE get_n_comp
    
    INTERFACE is_used
       MODULE PROCEDURE is_used
    END INTERFACE is_used
    
    PRIVATE
    PUBLIC component_index, component_index_constructor, get_index, get_n_comp,&
           is_used, sums_salsa_ws_l
    
 CONTAINS
    
!------------------------------------------------------------------------------!    
! Description:
! ------------
!> Creates index tables for different (aerosol) components 
!------------------------------------------------------------------------------!
    SUBROUTINE component_index_constructor( SELF, ncomp, nlist, listcomp )

       IMPLICIT NONE
       
       TYPE(component_index), INTENT(inout) ::  SELF !< Object containing the indices 
                                                     !< of different aerosol components
       INTEGER(iwp), INTENT(inout) ::  ncomp !< Number of components
       INTEGER(iwp), INTENT(in) ::     nlist !< Maximum number of components
       CHARACTER(len=3), INTENT(in) ::  listcomp(nlist) !< List cof component
                                                        !< names
       INTEGER(iwp) ::  i, jj
       
       ncomp = 0
       
       DO  WHILE ( listcomp(ncomp+1) /= '  ' .AND. ncomp < nlist )
          ncomp = ncomp + 1
       ENDDO
       
       SELF%ncomp = ncomp 
       ALLOCATE( SELF%ind(ncomp), SELF%comp(ncomp) )
       
       DO i = 1, ncomp
          SELF%ind(i) = i
       ENDDO
       
       jj = 1
       DO i = 1, nlist
          IF ( listcomp(i) == '') CYCLE
          SELF%comp(jj) = listcomp(i)
          jj = jj+1
       ENDDO
       
    END SUBROUTINE component_index_constructor

!------------------------------------------------------------------------------!
! Description:
! ------------
!> Gives the index of a component in the component list
!------------------------------------------------------------------------------!
    INTEGER FUNCTION get_index( SELF, incomp )

       IMPLICIT NONE
       
       TYPE(component_index), INTENT(in) ::  SELF !< Object containing the 
                                                  !< indices of different 
                                                  !< aerosol components
       CHARACTER(len=*), INTENT(in) ::  incomp !< Component name
       INTEGER(iwp) ::  i
       
       IF ( ANY(SELF%comp == incomp) ) THEN
          i = 1
          DO WHILE ( (SELF%comp(i) /= incomp) )
             i = i+1
          ENDDO
          get_index = i
       ELSEIF ( incomp == 'H2O' ) THEN
          get_index = SELF%ncomp + 1
       ELSE
          STOP 'get_index: FAILED, no such component -'
       ENDIF
       
       RETURN
       
    END FUNCTION get_index

!------------------------------------------------------------------------------!
! Description:
! ------------
!> Get the number of (aerosol) components used
!------------------------------------------------------------------------------!
    INTEGER FUNCTION get_n_comp( SELF )

       IMPLICIT NONE

       TYPE(component_index), INTENT(in) ::  SELF !< Object containing the 
                                                  !< indices of different 
                                                  !< aerosol components
       get_n_comp = SELF%ncomp
       RETURN
       
    END FUNCTION

!------------------------------------------------------------------------------!
! Description:
! ------------
!> Tells if the (aerosol) component is being used in the simulation
!------------------------------------------------------------------------------!
    LOGICAL FUNCTION is_used( SELF, icomp )

       IMPLICIT NONE
       
       TYPE(component_index), INTENT(in) ::  SELF !< Object containing the 
                                                  !< indices of different 
                                                  !< aerosol components
       CHARACTER(len=*), INTENT(in) ::  icomp !< Component name
       
       IF ( ANY(SELF%comp == icomp) ) THEN
          is_used = .TRUE.
       ELSE
          is_used = .FALSE.
       ENDIF
       
       RETURN
       
    END FUNCTION

 END MODULE salsa_util_mod