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

using JuliaFEM, Test

X = Dict(
    1 => [2.0, 3.0, 4.0],
    2 => [6.0, 3.0, 2.0],
    3 => [2.0, 5.0, 1.0],
    4 => [4.0, 3.0, 6.0])
X[5] = 1/2*(X[1] + X[2])
X[6] = 1/2*(X[2] + X[3])
X[7] = 1/2*(X[3] + X[1])
X[8] = 1/2*(X[1] + X[4])
X[9] = 1/2*(X[2] + X[4])
X[10] = 1/2*(X[3] + X[4])

element = Element(Tet10, (1, 2, 3, 4, 5, 6, 7, 8, 9, 10))
update!(element, "youngs modulus", 480.0)
update!(element, "poissons ratio", 1/3)
update!(element, "geometry", X)
update!(element, "density", 105.0)

problem = Problem(Heat, "tet10", 1)
add_element!(problem, element)
time = 0.0
assemble_mass_matrix!(problem, time)

M_expected = [
    6   1   1   1  -4  -6  -4  -4  -6  -6
    1   6   1   1  -4  -4  -6  -6  -4  -6
    1   1   6   1  -6  -4  -4  -6  -6  -4
    1   1   1   6  -6  -6  -6  -4  -4  -4
   -4  -4  -6  -6  32  16  16  16  16   8
   -6  -4  -4  -6  16  32  16   8  16  16
   -4  -6  -4  -6  16  16  32  16   8  16
   -4  -6  -6  -4  16   8  16  32  16  16
   -6  -4  -6  -4  16  16   8  16  32  16
   -6  -6  -4  -4   8  16  16  16  16  32]

@test isapprox(problem.assembly.M, M_expected)