module infin
  use globals

  implicit none

  contains
  
! populate `heatsink_design' based on the data in the design file
subroutine load_heatsink_design
  use globals

  implicit none

  real (8), dimension (4) :: data_row ! each row in the design file consists of four real numbers
  integer :: i, y

  ! air is the default material
  heatsink_design = Air

  open (unit = 1, file = design_file, action = 'read')
  
  ! read each line of the file
  do while (.not. eof (1))
     ! read rectangle corners from file
     read (1, *) data_row

     ! convert from mm to metres
     data_row = data_row / 1000

     ! convert from metres to grid points
     data_row (1: 2) = data_row (1: 2) / delta + 1
     data_row (3: 4) = ceiling (data_row (3: 4) / delta)

     ! fill rectangular prism with aluminium
     heatsink_design (data_row (1): data_row (3), :, data_row (2): data_row (4)) = Aluminium
  end do

  close (1)

  ! set the y-edges to be air (only applies to the first and last processes)
  if (mpi_cpu_id == 0) heatsink_design (:, 0, :) = Air
  if (mpi_cpu_id == mpi_cpu_count - 1) heatsink_design (:, grid_size / mpi_cpu_count + 1, :) = Air

  ! use special material type for aluminium touching the cpu
  do i = 1, Grid_size / mpi_cpu_count
     ! y co-ordinate corresponding to this grid point
     y = mpi_cpu_id * Grid_size / mpi_cpu_count + i

     ! if the x and y co-ordinates lie within the (2 cm)^2 chip,
     ! then set that grid point to `Aluminium_touching_cpu' instead of just `Aluminium'
     if ((Domain_size - Chip_size) / 2 / Delta + 1 <= y &
          .and. y <= Grid_size - (Domain_size - Chip_size) / 2 / Delta) then
        heatsink_design ((Domain_size - Chip_size) / 2 / Delta + 1: Grid_size - (Domain_size - Chip_size) / 2 / Delta, i, 1) = &
             Aluminium_touching_cpu
     end if
  end do
end subroutine load_heatsink_design


subroutine initial_state
  temp3d(:,:,:) = Air_temp_K

  !do i = 0, grid_size + 1
  !   do k = 0, grid_size + 1
  !      select case(heatsink_design(i,1,k))
  !         case(Aluminium)
  !         case(Aluminium_touching_cpu)
  !         case(Air)
  !      end select
  !   end do
  !end do
end subroutine initial_state


subroutine finalise

    logical :: openfile            ! test for file open
    character(14) :: filename14    ! 14 character filename
    integer :: i, j, k                   ! loop variable

    ! convert from Kelvin to Celsius
    ! and reset all air cells to the correct temperature.

    do i = 0, grid_size + 1
       do k = 0, grid_size + 1
          if (heatsink_design(i,1,k) == Air) then
             temp3d(i,:,k) = Air_temp_K
          end if
          temp3d(i,:,k) = temp3d(i,:,k) - Celsius_offset
       end do
    end do

    !
    ! finish up run
    ! Output temperature to file
    !

    write( filename14,'(a,i1)') 'sinkout.data-',mpi_cpu_id

    open(unit=10, file=filename14, action='write')
       
    write(10,'(1es12.4)') temp3d(:, :, :)

    close( unit = 10 )

end subroutine finalise


end module infin