!!  Copyright (C)  Stichting Deltares, 2012-2018.
!!
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!!  it under the terms of the GNU General Public License version 3,
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!!  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
!!  GNU General Public License for more details.
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!!
!!  contact: delft3d.support@deltares.nl
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module test_sorting_algorithms
    use ftnunit
    use sorting_algorithms

    implicit none

contains
subroutine tests_sorting
    call test( test_sort, 'Sorting double precision reals' )
end subroutine tests_sorting

subroutine test_sort
    real(kind=kind(1.0d0)), dimension(1)  :: single_value, sorted_value
    real(kind=kind(1.0d0)), dimension(10) :: values, sorted_values

    integer, dimension(10)                :: work
    integer                               :: i

    !
    ! Check that values are properly ordered
    !
    call random_number( values )

    call sort( size(values), values, sorted_values, work )

    do i = 1,size(values)
        call assert_true( any( values(i) == sorted_values ), "Original value found in sorted array" )
    enddo

    do i = 2,size(values)
        call assert_true( sorted_values(i) >= sorted_values(i-1), "Values are sorted in increasing order" )
    enddo

    !
    ! Check that a single value is properly retained
    !
    call random_number( single_value )

    call sort( size(single_value), single_value, sorted_value, work )

    call assert_true( single_value(1) == sorted_value(1), "Single value is simply retained when sorting" )
end subroutine test_sort

! TODO: INDEXI and INDEXX?
end module test_sorting_algorithms