# This file is a part of JuliaFEM.
# License is MIT: see https://github.com/JuliaFEM/JuliaFEM.jl/blob/master/LICENSE.md

using JuliaFEM
using JuliaFEM.Preprocess
using JuliaFEM.Testing

@testset "test postprocessing of strain and stress" begin

    X = Dict(
    1 => [0.0, 0.0, 0.0],
    2 => [1.0, 0.0, 0.0],
    3 => [1.0, 1.0, 0.0],
    4 => [0.0, 1.0, 0.0],
    5 => [0.0, 0.0, 1.0],
    6 => [1.0, 0.0, 1.0],
    7 => [1.0, 1.0, 1.0],
    8 => [0.0, 1.0, 1.0])
    
    u = Dict(
    1 => [0.0, 0.0, 0.0],
    2 => [-1/3, 0.0, 0.0],
    3 => [-1/3, -1/3, 0.0],
    4 => [0.0, -1/3, 0.0],
    5 => [0.0, 0.0, 1.0],
    6 => [-1/3, 0.0, 1.0],
    7 => [-1/3, -1/3, 1.0],
    8 => [0.0, -1/3, 1.0])

    element = Element(Hex8, [1, 2, 3, 4, 5, 6, 7, 8])
    update!(element, "geometry", 0.0 => X)
    update!(element, "displacement", 0.0 => u)
    update!(element, "youngs modulus", 288.0)
    update!(element, "poissons ratio", 1/3)

    body = Problem(Elasticity, "[0,1]³ elastic unit block", 3)
    body.elements= [element]
    postprocess!(body, 0.0, Val{:strain})
    postprocess!(body, 0.0, Val{:stress})

    geom = element("geometry", 0.0)
    strain = element("strain", 0.0)
    stress = element("stress", 0.0)

    for i in 1:length(geom)
        a = geom[i]
        b = strain[i]
        c = stress[i]
        debug("$a -> $b -> $c")
        @test isapprox(b, [-1/3, -1/3, 1.0, 0.0, 0.0, 0.0])
        @test isapprox(c, [0.0, 0.0, 288.0, 0.0, 0.0, 0.0])
    end

end