import unittest
from mtg import *

class TestManaMath(unittest.TestCase):
    def test_add_mana(self):
        self.assertEquals('RR', str(Mana('r') + Mana('r')))
    def test_subtract_mana(self):
        self.assertEquals('R', str(Mana('rr') - Mana('r')))
    def test_subtract_mana_insufficient(self):
        self.assertRaises(Exception, lambda: Mana('r') - Mana('rr'))
        self.assertRaises(Exception, lambda: Mana('r') - Mana('g'))

class TestManaCostMath(unittest.TestCase):
    def test_add_manacost(self):
        self.assertEquals('3R', str(ManaCost('2R') + ManaCost('1')))
    def test_subtract_manacost(self):
        self.assertEquals('1G', str(ManaCost('4GR') - ManaCost('3R')))
    def test_subtract_manacost_from_mana(self):
        result = Mana('UUBWWR') - ManaCost('1RW')
        # Can't check the exact string, since there's no way of knowing which
        # colors will be used for the additional mana requirement
        self.assertEquals(3, result.converted())
        self.assertEquals(0, result.mana['R'])
        self.assertEquals(1, result.mana['W'])
    def test_subtract_manacost_from_mana_insufficient_addtl(self):
        self.assertRaises(Exception, lambda: Mana('RRW'), ManaCost('3R'))
    def test_subtract_manacost_from_mana_insufficient_color(self):
        self.assertRaises(Exception, lambda: Mana('RRW'), ManaCost('2U'))

if __name__ == '__main__':
    unittest.main()