# Copyright 2009-2012 Ram Rachum.
# This program is distributed under the MIT license.

'''Testing module for `nifty_collections.Counter`.'''

from random import randrange
import copy
import pickle
import cPickle
from python_toolbox.third_party.abcs_collection import Mapping

from python_toolbox.third_party import unittest2

from python_toolbox import misc_tools

from python_toolbox.nifty_collections import Counter


class TestCounter(unittest2.TestCase):

    def test_basics(self):
        c = Counter('abcaba')
        self.assertEqual(c, Counter({'a':3 , 'b': 2, 'c': 1}))
        self.assertEqual(c, Counter(a=3, b=2, c=1))
        self.assertIsInstance(c, dict)
        self.assertIsInstance(c, Mapping)
        self.assertTrue(misc_tools.is_subclass(Counter, dict))
        self.assertTrue(misc_tools.is_subclass(Counter, Mapping))
        self.assertEqual(len(c), 3)
        self.assertEqual(sum(c.values()), 6)
        self.assertEqual(sorted(c.values()), [1, 2, 3])
        self.assertEqual(sorted(c.keys()), ['a', 'b', 'c'])
        self.assertEqual(sorted(c), ['a', 'b', 'c'])
        self.assertEqual(sorted(c.items()),
                         [('a', 3), ('b', 2), ('c', 1)])
        self.assertEqual(c['b'], 2)
        self.assertEqual(c['z'], 0)
    
        self.assertEqual(c.has_key('c'), True)
        self.assertEqual(c.has_key('z'), False)
        
        self.assertEqual(c.__contains__('c'), True)
        self.assertEqual(c.__contains__('z'), False)
        self.assertEqual(c.get('b', 10), 2)
        self.assertEqual(c.get('z', 10), 10)
        self.assertEqual(c, dict(a=3, b=2, c=1))
        self.assertEqual(repr(c), "Counter({'a': 3, 'b': 2, 'c': 1})")
        self.assertEqual(c.most_common(), [('a', 3), ('b', 2), ('c', 1)])
        for i in range(5):
            self.assertEqual(c.most_common(i),
                             [('a', 3), ('b', 2), ('c', 1)][:i])
        self.assertEqual(''.join(sorted(c.elements())), 'aaabbc')
        c['a'] += 1         # increment an existing value
        c['b'] -= 2         # sub existing value to zero
        del c['c']          # remove an entry
        del c['c']          # make sure that del doesn't raise KeyError
        c['d'] -= 2         # sub from a missing value
        c['e'] = -5         # directly assign a missing value
        c['f'] += 4         # add to a missing value
        self.assertEqual(c, dict(a=4, b=0, d=-2, e=-5, f=4))
        self.assertEqual(''.join(sorted(c.elements())), 'aaaaffff')
        self.assertEqual(c.pop('f'), 4)
        self.assertNotIn('f', c)
        for i in range(3):
            elem, cnt = c.popitem()
            self.assertNotIn(elem, c)
        c.clear()
        self.assertEqual(c, {})
        self.assertEqual(repr(c), 'Counter()')
        self.assertRaises(NotImplementedError, Counter.fromkeys, 'abc')
        self.assertRaises(TypeError, hash, c)
        c.update(dict(a=5, b=3))
        c.update(c=1)
        c.update(Counter('a' * 50 + 'b' * 30))
        c.update()          # test case with no args
        c.__init__('a' * 500 + 'b' * 300)
        c.__init__('cdc')
        c.__init__()
        self.assertEqual(c, dict(a=555, b=333, c=3, d=1))
        self.assertEqual(c.setdefault('d', 5), 1)
        self.assertEqual(c['d'], 1)
        self.assertEqual(c.setdefault('e', 5), 5)
        self.assertEqual(c['e'], 5)

    def test_copying(self):
        # Check that counters are copyable, deepcopyable, picklable, and
        #have a repr/eval round-trip
        words = Counter('which witch had which witches wrist watch'.split())
        update_test = Counter()
        update_test.update(words)
        for i, dup in enumerate([
                    words.copy(),
                    copy.copy(words),
                    copy.deepcopy(words),
                    pickle.loads(pickle.dumps(words, 0)),
                    pickle.loads(pickle.dumps(words, 1)),
                    pickle.loads(pickle.dumps(words, 2)),
                    pickle.loads(pickle.dumps(words, -1)),
                    cPickle.loads(cPickle.dumps(words, 0)),
                    cPickle.loads(cPickle.dumps(words, 1)),
                    cPickle.loads(cPickle.dumps(words, 2)),
                    cPickle.loads(cPickle.dumps(words, -1)),
                    eval(repr(words)),
                    update_test,
                    Counter(words),
                    ]):
            msg = (i, dup, words)
            self.assertTrue(dup is not words)
            self.assertEqual(dup, words)
            self.assertEqual(len(dup), len(words))
            self.assertEqual(type(dup), type(words))

    def test_conversions(self):
        # Convert to: set, list, dict
        s = 'she sells sea shells by the sea shore'
        self.assertEqual(sorted(Counter(s).elements()), sorted(s))
        self.assertEqual(sorted(Counter(s)), sorted(set(s)))
        self.assertEqual(dict(Counter(s)), dict(Counter(s).items()))
        self.assertEqual(set(Counter(s)), set(s))

    def test_invariant_for_the_in_operator(self):
        c = Counter(a=10, b=-2, c=0)
        for elem in c:
            self.assertTrue(elem in c)
            self.assertIn(elem, c)

    def test_multiset_operations(self):
        # Verify that adding a zero counter will strip zeros and negatives
        c = Counter(a=10, b=-2, c=0) + Counter()
        self.assertEqual(dict(c), dict(a=10))

        elements = 'abcd'
        for i in range(1000):
            # test random pairs of multisets
            p = Counter(dict((elem, randrange(-2,4)) for elem in elements))
            p.update(e=1, f=-1, g=0)
            q = Counter(dict((elem, randrange(-2,4)) for elem in elements))
            q.update(h=1, i=-1, j=0)
            for counterop, numberop in [
                (Counter.__add__, lambda x, y: max(0, x+y)),
                (Counter.__sub__, lambda x, y: max(0, x-y)),
                (Counter.__or__, lambda x, y: max(0,x,y)),
                (Counter.__and__, lambda x, y: max(0, min(x,y))),
            ]:
                result = counterop(p, q)
                for x in elements:
                    self.assertEqual(numberop(p[x], q[x]), result[x],
                                     (counterop, x, p, q))
                # verify that results exclude non-positive counts
                self.assertTrue(x>0 for x in result.values())

        elements = 'abcdef'
        for i in range(100):
            # verify that random multisets with no repeats are exactly like
            # sets
            p = Counter(dict((elem, randrange(0, 2)) for elem in elements))
            q = Counter(dict((elem, randrange(0, 2)) for elem in elements))
            for counterop, setop in [
                (Counter.__sub__, set.__sub__),
                (Counter.__or__, set.__or__),
                (Counter.__and__, set.__and__),
            ]:
                counter_result = counterop(p, q)
                set_result = setop(set(p.elements()), set(q.elements()))
                self.assertEqual(counter_result, dict.fromkeys(set_result, 1))

    def test_subtract(self):
        c = Counter(a=-5, b=0, c=5, d=10, e=15,g=40)
        c.subtract(a=1, b=2, c=-3, d=10, e=20, f=30, h=-50)
        self.assertEqual(
            c,
            Counter(a=-6, b=-2, c=8, d=0, e=-5, f=-30, g=40, h=50)
        )
        c = Counter(a=-5, b=0, c=5, d=10, e=15,g=40)
        c.subtract(Counter(a=1, b=2, c=-3, d=10, e=20, f=30, h=-50))
        self.assertEqual(
            c,
            Counter(a=-6, b=-2, c=8, d=0, e=-5, f=-30, g=40, h=50)
        )
        c = Counter('aaabbcd')
        c.subtract('aaaabbcce')
        self.assertEqual(c, Counter(a=-1, b=0, c=-1, d=1, e=-1))