# -*- coding: utf-8 -*-
"""Unit tests for the MultiMeshFunction class"""

# Copyright (C) 2016 Jørgen S. Dokken
#
# This file is part of DOLFIN.
#
# DOLFIN is free software: you can redistribute it and/or modify
# it under the terms of the GNU Lesser General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# DOLFIN is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public License
# along with DOLFIN. If not, see <http://www.gnu.org/licenses/>.
#
#
# First added:  2016-06-11
# Last changed: 2017-07-18

import pytest
from dolfin import *
import ufl
import numpy

from dolfin_utils.test import fixture, skip_in_parallel

@fixture
def multimesh():
    mesh_0 = RectangleMesh(Point(0,0), Point(1, 1), 20, 20)
    mesh_1 = RectangleMesh(Point(numpy.pi/10,numpy.pi/9),
                           Point(numpy.pi/8,numpy.pi/7),5,8)
    multimesh = MultiMesh()
    multimesh.add(mesh_0)
    multimesh.add(mesh_1)
    multimesh.build()
    return multimesh

@fixture
def V(multimesh):
    element = FiniteElement("Lagrange", triangle, 1)
    return MultiMeshFunctionSpace(multimesh, element)

@fixture
def V_high(multimesh):
    element = FiniteElement("Lagrange", triangle, 3)
    return MultiMeshFunctionSpace(multimesh, element)

@fixture
def V_vector(multimesh):
    return MultiMeshVectorFunctionSpace(multimesh,"CG", 1)

@fixture
def e_x():
    return Expression(("1.0","0.0"), degree=1)

@fixture
def f_vec2():
    return Expression(("sin(x[1])","1.0"), degree=3)

@fixture
def v_vec(V_vector):
    return MultiMeshFunction(V_vector)

@fixture
def f_vec():
    return Expression(("x[0]","x[1]"),degree=2)


@fixture
def f():
    return Expression("sin(pi*x[0])*cos(2*pi*x[1])", degree=4)

@fixture
def f_2():
    return Expression("x[0]*x[1]",degree=2)
@fixture
def v(V):
    return MultiMeshFunction(V)

@fixture
def v_high(V_high):
    return MultiMeshFunction(V_high)

@skip_in_parallel
def test_measure_mul(v, multimesh):
    assert isinstance(v*dX, ufl.form.Form)

@skip_in_parallel
def test_assemble_zero(v, multimesh):
    assert numpy.isclose(assemble_multimesh(v*dX), 0)

@skip_in_parallel
def test_assemble_area(v, multimesh):
    v.vector()[:] = 1
    assert numpy.isclose(assemble_multimesh(v*dX), 1)

@skip_in_parallel
def test_assemble_exterior_facet(v, multimesh):
    v.vector()[:] = 1
    assert numpy.isclose(assemble_multimesh(v*ds), 4)

@skip_in_parallel
def test_interpolate(v_high, f):
    v_high.interpolate(f)
    assert numpy.isclose(assemble_multimesh(v_high*dX), 0)

@skip_in_parallel
def test_project(f, V_high):
    v = project(f ,V_high)
    assert numpy.isclose(assemble_multimesh(v*dX), 0)

@skip_in_parallel
def test_errornorm_L2(f_2, v_high):
    const = Expression("1", degree=1)
    v_high.interpolate(f_2)
    assert numpy.isclose(errornorm(const, v_high, norm_type="L2", degree_rise=3), numpy.sqrt(22)/6)

@skip_in_parallel
def test_errornorm_H1(f, f_2, v_high):
    v_high.interpolate(f_2)
    assert numpy.isclose(errornorm(f, v_high, norm_type="H1", degree_rise=3), numpy.sqrt(37./36+5*numpy.pi**2/4))

@skip_in_parallel
def test_vector_space(v_vec,e_x,f_vec2,V_vector,f_vec):
    v_vec.interpolate(e_x)
    assert numpy.isclose(assemble_multimesh(inner(f_vec,v_vec)*dX), 0.5)
    v_vec.interpolate(f_vec)
    print((assemble_multimesh(inner(v_vec, f_vec2)*dX),
                                            1/2 + numpy.sin(1/2)*numpy.sin(1/2)))
    assert numpy.isclose(assemble_multimesh(inner(v_vec, f_vec2)*dX),
                                            1/2 + numpy.sin(1/2)*numpy.sin(1/2))