# 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.Testing

@testset "test linearsolver + xdmf writing" begin
    el1 = Element(Quad4, [1, 2, 3, 4])
    el2 = Element(Seg2, [1, 2])
    el3 = Element(Seg2, [3, 4])
    X = Dict(
        1 => [0.0, 0.0],
        2 => [1.0, 0.0],
        3 => [1.0, 1.0],
        4 => [0.0, 1.0])
    update!([el1, el2, el3], "geometry", X)
    update!(el1, "thermal conductivity", 6.0)
    update!(el1, "density", 36.0)

    update!(el2, "heat flux", 0.0 => 0.0)
    update!(el2, "heat flux", 1.0 => 600.0)

    problem = Problem(Heat, "test problem", 1)
    problem.properties.formulation = "2D"
    push!(problem.elements, el1, el2)

    update!(el3, "temperature 1", 0.0)

    bc = Problem(Dirichlet, "fixed", 1, "temperature")

    push!(bc.elements, el3)

    # Create a solver for a set of problems
    solver = Solver(Linear, "solve heat problem")
    push!(solver, problem, bc)

    # Solve problem at time t=1.0 and update fields
    solver.time = 1.0
    solver.xdmf = Xdmf()
    solver()

    # Postprocess.
    # Interpolate temperature field along boundary of Γ₁ at time t=1.0
    xi = [0.0, -1.0]
    X = el2("geometry", xi, 1.0)
    T = el2("temperature", xi, 1.0)
    info("Temperature at point X = $X is T = $T")
    @test isapprox(T, 100.0)
end