"""Unittests for heapq."""

from heapq import heappush, heappop, heapify, heapreplace, nlargest, nsmallest

import random

import unittest

from test import test_support

import sys

def heapiter(heap):

    # An iterator returning a heap's elements, smallest-first.

    try:

        while 1:

            yield heappop(heap)

    except IndexError:

        pass

class TestHeap(unittest.TestCase):

    def test_push_pop(self):

        # 1) Push 256 random numbers and pop them off, verifying all's OK.

        heap = []

        data = []

        self.check_invariant(heap)

        for i in range(256):

            item = random.random()

            data.append(item)

            heappush(heap, item)

            self.check_invariant(heap)

        results = []

        while heap:

            item = heappop(heap)

            self.check_invariant(heap)

            results.append(item)

        data_sorted = data[:]

        data_sorted.sort()

        self.assertEqual(data_sorted, results)

        # 2) Check that the invariant holds for a sorted array

        self.check_invariant(results)

        self.assertRaises(TypeError, heappush, [])

        try:

            self.assertRaises(TypeError, heappush, None, None)

            self.assertRaises(TypeError, heappop, None)

        except AttributeError:

            pass

    def check_invariant(self, heap):

        # Check the heap invariant.

        for pos, item in enumerate(heap):

            if pos: # pos 0 has no parent

                parentpos = (pos-1) >> 1

                self.assert_(heap[parentpos] <= item)

    def test_heapify(self):

        for size in range(30):

            heap = [random.random() for dummy in range(size)]

            heapify(heap)

            self.check_invariant(heap)

        self.assertRaises(TypeError, heapify, None)

    def test_naive_nbest(self):

        data = [random.randrange(2000) for i in range(1000)]

        heap = []

        for item in data:

            heappush(heap, item)

            if len(heap) > 10:

                heappop(heap)

        heap.sort()

        self.assertEqual(heap, sorted(data)[-10:])

    def test_nbest(self):

        # Less-naive "N-best" algorithm, much faster (if len(data) is big

        # enough <wink>) than sorting all of data.  However, if we had a max

        # heap instead of a min heap, it could go faster still via

        # heapify'ing all of data (linear time), then doing 10 heappops

        # (10 log-time steps).

        data = [random.randrange(2000) for i in range(1000)]

        heap = data[:10]

        heapify(heap)

        for item in data[10:]:

            if item > heap[0]:  # this gets rarer the longer we run

                heapreplace(heap, item)

        self.assertEqual(list(heapiter(heap)), sorted(data)[-10:])

        self.assertRaises(TypeError, heapreplace, None)

        self.assertRaises(TypeError, heapreplace, None, None)

        self.assertRaises(IndexError, heapreplace, [], None)

    def test_heapsort(self):

        # Exercise everything with repeated heapsort checks

        for trial in xrange(100):

            size = random.randrange(50)

            data = [random.randrange(25) for i in range(size)]

            if trial & 1:     # Half of the time, use heapify

                heap = data[:]

                heapify(heap)

            else:             # The rest of the time, use heappush

                heap = []

                for item in data:

                    heappush(heap, item)

            heap_sorted = [heappop(heap) for i in range(size)]

            self.assertEqual(heap_sorted, sorted(data))

    def test_nsmallest(self):

        data = [(random.randrange(2000), i) for i in range(1000)]

        for f in (None, lambda x:  x[0] * 547 % 2000):

            for n in (0, 1, 2, 10, 100, 400, 999, 1000, 1100):

                self.assertEqual(nsmallest(n, data), sorted(data)[:n])

                self.assertEqual(nsmallest(n, data, key=f),

                                 sorted(data, key=f)[:n])

    def test_nlargest(self):

        data = [(random.randrange(2000), i) for i in range(1000)]

        for f in (None, lambda x:  x[0] * 547 % 2000):

            for n in (0, 1, 2, 10, 100, 400, 999, 1000, 1100):

                self.assertEqual(nlargest(n, data), sorted(data, reverse=True)[:n])

                self.assertEqual(nlargest(n, data, key=f),

                                 sorted(data, key=f, reverse=True)[:n])

#==============================================================================

class LenOnly:

    "Dummy sequence class defining __len__ but not __getitem__."

    def __len__(self):

        return 10

class GetOnly:

    "Dummy sequence class defining __getitem__ but not __len__."

    def __getitem__(self, ndx):

        return 10

class CmpErr:

    "Dummy element that always raises an error during comparison"

    def __cmp__(self, other):

        raise ZeroDivisionError

def R(seqn):

    'Regular generator'

    for i in seqn:

        yield i

class G:

    'Sequence using __getitem__'

    def __init__(self, seqn):

        self.seqn = seqn

    def __getitem__(self, i):

        return self.seqn[i]

class I:

    'Sequence using iterator protocol'

    def __init__(self, seqn):

        self.seqn = seqn

        self.i = 0

    def __iter__(self):

        return self

    def next(self):

        if self.i >= len(self.seqn): raise StopIteration

        v = self.seqn[self.i]

        self.i += 1

        return v

class Ig:

    'Sequence using iterator protocol defined with a generator'

    def __init__(self, seqn):

        self.seqn = seqn

        self.i = 0

    def __iter__(self):

        for val in self.seqn:

            yield val

class X:

    'Missing __getitem__ and __iter__'

    def __init__(self, seqn):

        self.seqn = seqn

        self.i = 0

    def next(self):

        if self.i >= len(self.seqn): raise StopIteration

        v = self.seqn[self.i]

        self.i += 1

        return v

class N:

    'Iterator missing next()'

    def __init__(self, seqn):

        self.seqn = seqn

        self.i = 0

    def __iter__(self):

        return self

class E:

    'Test propagation of exceptions'

    def __init__(self, seqn):

        self.seqn = seqn

        self.i = 0

    def __iter__(self):

        return self

    def next(self):

        3 // 0

class S:

    'Test immediate stop'

    def __init__(self, seqn):

        pass

    def __iter__(self):

        return self

    def next(self):

        raise StopIteration

from itertools import chain, imap

def L(seqn):

    'Test multiple tiers of iterators'

    return chain(imap(lambda x:x, R(Ig(G(seqn)))))

class TestErrorHandling(unittest.TestCase):

    def test_non_sequence(self):

        for f in (heapify, heappop):

            self.assertRaises(TypeError, f, 10)

        for f in (heappush, heapreplace, nlargest, nsmallest):

            self.assertRaises(TypeError, f, 10, 10)

    def test_len_only(self):

        for f in (heapify, heappop):

            self.assertRaises(TypeError, f, LenOnly())

        for f in (heappush, heapreplace):

            self.assertRaises(TypeError, f, LenOnly(), 10)

        for f in (nlargest, nsmallest):

            self.assertRaises(TypeError, f, 2, LenOnly())

    def test_get_only(self):

        for f in (heapify, heappop):

            self.assertRaises(TypeError, f, GetOnly())

        for f in (heappush, heapreplace):

            self.assertRaises(TypeError, f, GetOnly(), 10)

        for f in (nlargest, nsmallest):

            self.assertRaises(TypeError, f, 2, GetOnly())

    def test_get_only(self):

        seq = [CmpErr(), CmpErr(), CmpErr()]

        for f in (heapify, heappop):

            self.assertRaises(ZeroDivisionError, f, seq)

        for f in (heappush, heapreplace):

            self.assertRaises(ZeroDivisionError, f, seq, 10)

        for f in (nlargest, nsmallest):

            self.assertRaises(ZeroDivisionError, f, 2, seq)

    def test_arg_parsing(self):

        for f in (heapify, heappop, heappush, heapreplace, nlargest, nsmallest):

            self.assertRaises(TypeError, f, 10)

    def test_iterable_args(self):

        for f in  (nlargest, nsmallest):

            for s in ("123", "", range(1000), ('do', 1.2), xrange(2000,2200,5)):

                for g in (G, I, Ig, L, R):

                    self.assertEqual(f(2, g(s)), f(2,s))

                self.assertEqual(f(2, S(s)), [])

                self.assertRaises(TypeError, f, 2, X(s))

                self.assertRaises(TypeError, f, 2, N(s))

                self.assertRaises(ZeroDivisionError, f, 2, E(s))

#==============================================================================

def test_main(verbose=None):

    from types import BuiltinFunctionType

    test_classes = [TestHeap]

    if isinstance(heapify, BuiltinFunctionType):

        test_classes.append(TestErrorHandling)

    test_support.run_unittest(*test_classes)

    # verify reference counting

    if verbose and hasattr(sys, "gettotalrefcount"):

        import gc

        counts = [None] * 5

        for i in xrange(len(counts)):

            test_support.run_unittest(*test_classes)

            gc.collect()

            counts[i] = sys.gettotalrefcount()

        print counts

if __name__ == "__main__":

    test_main(verbose=True)