! This modules contains the definitions of the unit numbers used for
! all the GRAY output ifles and a mechanism to toggle them
module units

  ! Unit numbers
#ifdef JINTRAC
  ! JINTRAC
  integer, parameter :: uprm   =602, ubeam =603, uprf  =644, ueq    =644
  integer, parameter :: uprfin =645, uflx  =646, ubres =630, ucnt   =631
  integer, parameter :: uprj0  =608, uwbm  =612, ucenr =604, uoutr  =633
  integer, parameter :: udisp  =617, upec  =648, usumm =607, umaps  =632
  integer, parameter :: uhead  =638
#else
  ! STANDARD
  integer, parameter :: uprm   =  2, ubeam = 97, uprf  = 98, ueq    = 99
  integer, parameter :: uprfin = 55, uflx  = 56, ubres = 70, ucnt   = 71
  integer, parameter :: uprj0  =  8, uwbm  = 12, ucenr =  4, uoutr  = 33
  integer, parameter :: udisp  = 17, upec  = 48, usumm =  7, umaps  = 72
  integer, parameter :: uhead  = 78
#endif

  ! List of active units
  integer, allocatable, save :: active_units(:)

contains

  subroutine set_active_units(units)
    ! Activate the given units
    !
    ! All units are inactive by default and no output
    ! will be directed to them.

    implicit none

    ! subroutine arguments
    integer, intent(in) :: units(:)

    active_units = units

  end subroutine set_active_units


  subroutine close_units
    ! Close all the active units to flush the buffer.

    implicit none

    integer :: i

    if (allocated(active_units)) then
      do i = 1, size(active_units)
        close(active_units(i))
      end do
      deallocate(active_units)
    end if

  end subroutine close_units


  function unit_active(unit) result(on)
    ! Checks whether the given `unit` is active

    implicit none

    ! function arguments
    integer, intent(in)  :: unit
    logical              :: on

    on = any(active_units == unit)

  end function unit_active

end module units