import functools
import unittest

from ..linexprs import symbols
from ..polyhedra import *
from .libhelper import requires_sympy


class TestPolyhedron(unittest.TestCase):

    def setUp(self):
        x, y = symbols('x y')
        self.square = Polyhedron(inequalities=[x, 1 - x, y, 1 - y])

    def test_symbols(self):
        self.assertTupleEqual(self.square.symbols, symbols('x y'))

    def test_dimension(self):
        self.assertEqual(self.square.dimension, 2)

    def test_str(self):
        self.assertEqual(str(self.square),
            'And(0 <= x, 0 <= -x + 1, 0 <= y, 0 <= -y + 1)')

    def test_repr(self):
        self.assertEqual(repr(self.square),
            "And(0 <= x, 0 <= -x + 1, 0 <= y, 0 <= -y + 1)")

    def test_fromstring(self):
        self.assertEqual(Polyhedron.fromstring('{x >= 0, -x + 1 >= 0, '
            'y >= 0, -y + 1 >= 0}'), self.square)

    def test_isempty(self):
        self.assertFalse(self.square.isempty())

    def test_isuniverse(self):
        self.assertFalse(self.square.isuniverse())

    @requires_sympy
    def test_fromsympy(self):
        import sympy
        sp_x, sp_y = sympy.symbols('x y')
        self.assertEqual(Polyhedron.fromsympy((sp_x >= 0) & (sp_x <= 1) &
            (sp_y >= 0) & (sp_y <= 1)), self.square)

    @requires_sympy
    def test_tosympy(self):
        import sympy
        sp_x, sp_y = sympy.symbols('x y')
        self.assertEqual(self.square.tosympy(),
            sympy.And(-sp_x + 1 >= 0, -sp_y + 1 >= 0, sp_x >= 0, sp_y >= 0))


class TestEmpty:

    def test_repr(self):
        self.assertEqual(repr(Empty), 'Empty')

    def test_isempty(self):
        self.assertTrue(Empty.isempty())

    def test_isuniverse(self):
        self.assertFalse(Empty.isuniverse())


class TestUniverse:

    def test_repr(self):
        self.assertEqual(repr(Universe), 'Universe')

    def test_isempty(self):
        self.assertTrue(Universe.isempty())

    def test_isuniverse(self):
        self.assertTrue(Universe.isuniverse())