import unittest

from src.rules.utils import least_common_multiple, is_fraction, partition, \
        find_variables, first_sorted_variable
from tests.rulestestcase import tree


class TestRulesUtils(unittest.TestCase):

    def test_least_common_multiple(self):
        self.assertEqual(least_common_multiple(5, 6), 30)
        self.assertEqual(least_common_multiple(5, 6, 15), 30)
        self.assertEqual(least_common_multiple(2, 4), 4)

    def test_is_fraction(self):
        l1, a = tree('1, a')

        self.assertTrue(is_fraction(a / 2, a, 2))
        self.assertTrue(is_fraction(l1 / 2 * a, a, 2))
        self.assertTrue(is_fraction(a * (l1 / 2), a, 2))
        self.assertFalse(is_fraction(l1 / 3 * a, a, 2))

    def test_partition(self):
        self.assertEqual(partition(lambda x: x & 1, range(6)),
                         ([1, 3, 5], [0, 2, 4]))

    def test_find_variables(self):
        x, l2, add, mul0, mul1 = tree('x, 2, x + 2, 2x, xy')
        self.assertSetEqual(find_variables(x), set(['x']))
        self.assertSetEqual(find_variables(l2), set())
        self.assertSetEqual(find_variables(add), set(['x']))
        self.assertSetEqual(find_variables(mul0), set(['x']))
        self.assertSetEqual(find_variables(mul1), set(['x', 'y']))

    def test_first_sorted_variable(self):
        self.assertEqual(first_sorted_variable(set('ax')), 'x')
        self.assertEqual(first_sorted_variable(set('ay')), 'y')
        self.assertEqual(first_sorted_variable(set('az')), 'z')
        self.assertEqual(first_sorted_variable(set('xz')), 'x')
        self.assertEqual(first_sorted_variable(set('bac')), 'a')