! BSD 3-Clause License
!
! Copyright (c) 2017-2021, Science and Technology Facilities Council
! All rights reserved.
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! modification, are permitted provided that the following conditions are met:
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! * Redistributions of source code must retain the above copyright notice, this
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! * Redistributions in binary form must reproduce the above copyright notice,
!   this list of conditions and the following disclaimer in the documentation
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! * Neither the name of the copyright holder nor the names of its
!   contributors may be used to endorse or promote products derived from
!   this software without specific prior written permission.
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! THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
! AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
! IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
! DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
! FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
! DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
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! OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
! -----------------------------------------------------------------------------
! Author R. W. Ford, STFC Daresbury Lab
! Modified by J. Henrichs, Bureau of Meteorology
! Modified by I. Kavcic, Met Office

module testkern_w0_kernel_mod

  use argument_mod
  use kernel_mod
  use fs_continuity_mod, only: W0

  use constants_mod

  implicit none

  private

  type, public, extends(kernel_type) :: testkern_w0_kernel_type
     private
     type(arg_type), dimension(2) :: meta_args =       &
          (/ arg_type(gh_field, gh_real, gh_inc,  w0), &
             arg_type(gh_field, gh_real, gh_read, w0)  &
           /)
     integer :: operates_on = cell_column
   contains
     procedure, nopass :: code => testkern_w0_code
  end type testkern_w0_kernel_type

  public :: testkern_w0_code

contains

  subroutine testkern_w0_code(nlayers, fld1, fld2, ndf_w0, undf_w0, map_w0)

    implicit none

    integer(kind=i_def), intent(in)                     :: nlayers
    integer(kind=i_def)                                 :: ndf_w0, undf_w0
    real(kind=r_def), dimension(undf_w0), intent(inout) :: fld1
    real(kind=r_def), dimension(undf_w0), intent(in)    :: fld2
    integer(kind=i_def), dimension(ndf_w0)              :: map_w0

    integer(kind=i_def)                                 :: i, k

    do k=0, nlayers-1
      do i=1, ndf_w0
        fld1(map_w0(i)+k) = fld1(map_w0(i)+k) + fld2(map_w0(i)+k)
      end do
    end do

  end subroutine testkern_w0_code

end module testkern_w0_kernel_mod
