# Licensed under a 3-clause BSD style license - see LICENSE.rst
import unittest

try:
    import UserDict
except ImportError:
    from collections import UserDict

from . import odict_support as test_support


class BasicTestMappingProtocol(unittest.TestCase):
    # This base class can be used to check that an object conforms to the
    # mapping protocol

    # Functions that can be useful to override to adapt to dictionary
    # semantics
    type2test = None # which class is being tested (overwrite in subclasses)

    def _reference(self):
        """Return a dictionary of values which are invariant by storage
        in the object under test."""
        return {1:2, "key1":"value1", "key2":(1,2,3)}
    def _empty_mapping(self):
        """Return an empty mapping object"""
        return self.type2test()
    def _full_mapping(self, data):
        """Return a mapping object with the value contained in data
        dictionary"""
        x = self._empty_mapping()
        for key, value in list(data.items()):
            x[key] = value
        return x

    def __init__(self, *args, **kw):
        unittest.TestCase.__init__(self, *args, **kw)
        self.reference = self._reference().copy()

        # A (key, value) pair not in the mapping
        key, value = self.reference.popitem()
        self.other = {key:value}

        # A (key, value) pair in the mapping
        key, value = self.reference.popitem()
        self.inmapping = {key:value}
        self.reference[key] = value

    def test_read(self):
        # Test for read only operations on mapping
        p = self._empty_mapping()
        p1 = dict(p) #workaround for singleton objects
        d = self._full_mapping(self.reference)
        if d is p:
            p = p1
        #Indexing
        for key, value in list(self.reference.items()):
            self.assertEqual(d[key], value)
        knownkey = list(self.other.keys())[0]
        self.assertRaises(KeyError, lambda:d[knownkey])
        #len
        self.assertEqual(len(p), 0)
        self.assertEqual(len(d), len(self.reference))
        #in
        for k in self.reference:
            self.assertIn(k, d)
        for k in self.other:
            self.assertNotIn(k, d)
        #has_key
        with test_support.check_py3k_warnings(quiet=True):
            for k in self.reference:
                self.assertTrue(k in d)
            for k in self.other:
                self.assertFalse(k in d)
        #cmp
        self.assertEqual(cmp(p,p), 0)
        self.assertEqual(cmp(d,d), 0)
        self.assertEqual(cmp(p,d), -1)
        self.assertEqual(cmp(d,p), 1)
        #__non__zero__
        if p: self.fail("Empty mapping must compare to False")
        if not d: self.fail("Full mapping must compare to True")
        # keys(), items(), iterkeys() ...
        def check_iterandlist(iter, lst, ref):
            self.assertTrue(hasattr(iter, 'next'))
            self.assertTrue(hasattr(iter, '__iter__'))
            x = list(iter)
            self.assertTrue(set(x)==set(lst)==set(ref))
        check_iterandlist(iter(d.keys()), list(d.keys()), list(self.reference.keys()))
        check_iterandlist(iter(d), list(d.keys()), list(self.reference.keys()))
        check_iterandlist(iter(d.values()), list(d.values()), list(self.reference.values()))
        check_iterandlist(iter(d.items()), list(d.items()), list(self.reference.items()))
        #get
        key, value = next(iter(d.items()))
        knownkey, knownvalue = next(iter(self.other.items()))
        self.assertEqual(d.get(key, knownvalue), value)
        self.assertEqual(d.get(knownkey, knownvalue), knownvalue)
        self.assertNotIn(knownkey, d)

    def test_write(self):
        # Test for write operations on mapping
        p = self._empty_mapping()
        #Indexing
        for key, value in list(self.reference.items()):
            p[key] = value
            self.assertEqual(p[key], value)
        for key in list(self.reference.keys()):
            del p[key]
            self.assertRaises(KeyError, lambda:p[key])
        p = self._empty_mapping()
        #update
        p.update(self.reference)
        self.assertEqual(dict(p), self.reference)
        items = list(p.items())
        p = self._empty_mapping()
        p.update(items)
        self.assertEqual(dict(p), self.reference)
        d = self._full_mapping(self.reference)
        #setdefault
        key, value = next(iter(d.items()))
        knownkey, knownvalue = next(iter(self.other.items()))
        self.assertEqual(d.setdefault(key, knownvalue), value)
        self.assertEqual(d[key], value)
        self.assertEqual(d.setdefault(knownkey, knownvalue), knownvalue)
        self.assertEqual(d[knownkey], knownvalue)
        #pop
        self.assertEqual(d.pop(knownkey), knownvalue)
        self.assertNotIn(knownkey, d)
        self.assertRaises(KeyError, d.pop, knownkey)
        default = 909
        d[knownkey] = knownvalue
        self.assertEqual(d.pop(knownkey, default), knownvalue)
        self.assertNotIn(knownkey, d)
        self.assertEqual(d.pop(knownkey, default), default)
        #popitem
        key, value = d.popitem()
        self.assertNotIn(key, d)
        self.assertEqual(value, self.reference[key])
        p=self._empty_mapping()
        self.assertRaises(KeyError, p.popitem)

    def test_constructor(self):
        self.assertEqual(self._empty_mapping(), self._empty_mapping())

    def test_bool(self):
        self.assertTrue(not self._empty_mapping())
        self.assertTrue(self.reference)
        self.assertTrue(bool(self._empty_mapping()) is False)
        self.assertTrue(bool(self.reference) is True)

    def test_keys(self):
        d = self._empty_mapping()
        self.assertEqual(list(d.keys()), [])
        d = self.reference
        self.assertIn(list(self.inmapping.keys())[0], list(d.keys()))
        self.assertNotIn(list(self.other.keys())[0], list(d.keys()))
        self.assertRaises(TypeError, d.keys, None)

    def test_values(self):
        d = self._empty_mapping()
        self.assertEqual(list(d.values()), [])

        self.assertRaises(TypeError, d.values, None)

    def test_items(self):
        d = self._empty_mapping()
        self.assertEqual(list(d.items()), [])

        self.assertRaises(TypeError, d.items, None)

    def test_len(self):
        d = self._empty_mapping()
        self.assertEqual(len(d), 0)

    def test_getitem(self):
        d = self.reference
        self.assertEqual(d[list(self.inmapping.keys())[0]], list(self.inmapping.values())[0])

        self.assertRaises(TypeError, d.__getitem__)

    def test_update(self):
        # mapping argument
        d = self._empty_mapping()
        d.update(self.other)
        self.assertEqual(list(d.items()), list(self.other.items()))

        # No argument
        d = self._empty_mapping()
        d.update()
        self.assertEqual(d, self._empty_mapping())

        # item sequence
        d = self._empty_mapping()
        d.update(list(self.other.items()))
        self.assertEqual(list(d.items()), list(self.other.items()))

        # Iterator
        d = self._empty_mapping()
        d.update(iter(self.other.items()))
        self.assertEqual(list(d.items()), list(self.other.items()))

        # FIXME: Doesn't work with UserDict
        # self.assertRaises((TypeError, AttributeError), d.update, None)
        self.assertRaises((TypeError, AttributeError), d.update, 42)

        outerself = self
        class SimpleUserDict:
            def __init__(self):
                self.d = outerself.reference
            def keys(self):
                return list(self.d.keys())
            def __getitem__(self, i):
                return self.d[i]
        d.clear()
        d.update(SimpleUserDict())
        i1 = list(d.items())
        i2 = list(self.reference.items())
        i1.sort()
        i2.sort()
        self.assertEqual(i1, i2)

        class Exc(Exception): pass

        d = self._empty_mapping()
        class FailingUserDict:
            def keys(self):
                raise Exc
        self.assertRaises(Exc, d.update, FailingUserDict())

        d.clear()

        class FailingUserDict:
            def keys(self):
                class BogonIter:
                    def __init__(self):
                        self.i = 1
                    def __iter__(self):
                        return self
                    def __next__(self):
                        if self.i:
                            self.i = 0
                            return 'a'
                        raise Exc
                return BogonIter()
            def __getitem__(self, key):
                return key
        self.assertRaises(Exc, d.update, FailingUserDict())

        class FailingUserDict:
            def keys(self):
                class BogonIter:
                    def __init__(self):
                        self.i = ord('a')
                    def __iter__(self):
                        return self
                    def __next__(self):
                        if self.i <= ord('z'):
                            rtn = chr(self.i)
                            self.i += 1
                            return rtn
                        raise StopIteration
                return BogonIter()
            def __getitem__(self, key):
                raise Exc
        self.assertRaises(Exc, d.update, FailingUserDict())

        d = self._empty_mapping()
        class badseq(object):
            def __iter__(self):
                return self
            def __next__(self):
                raise Exc()

        self.assertRaises(Exc, d.update, badseq())

        self.assertRaises(ValueError, d.update, [(1, 2, 3)])

    # no test_fromkeys or test_copy as both os.environ and selves don't support it

    def test_get(self):
        d = self._empty_mapping()
        self.assertTrue(d.get(list(self.other.keys())[0]) is None)
        self.assertEqual(d.get(list(self.other.keys())[0], 3), 3)
        d = self.reference
        self.assertTrue(d.get(list(self.other.keys())[0]) is None)
        self.assertEqual(d.get(list(self.other.keys())[0], 3), 3)
        self.assertEqual(d.get(list(self.inmapping.keys())[0]), list(self.inmapping.values())[0])
        self.assertEqual(d.get(list(self.inmapping.keys())[0], 3), list(self.inmapping.values())[0])
        self.assertRaises(TypeError, d.get)
        self.assertRaises(TypeError, d.get, None, None, None)

    def test_setdefault(self):
        d = self._empty_mapping()
        self.assertRaises(TypeError, d.setdefault)

    def test_popitem(self):
        d = self._empty_mapping()
        self.assertRaises(KeyError, d.popitem)
        self.assertRaises(TypeError, d.popitem, 42)

    def test_pop(self):
        d = self._empty_mapping()
        k, v = list(self.inmapping.items())[0]
        d[k] = v
        self.assertRaises(KeyError, d.pop, list(self.other.keys())[0])

        self.assertEqual(d.pop(k), v)
        self.assertEqual(len(d), 0)

        self.assertRaises(KeyError, d.pop, k)

    def assertIn(self, key, d):
        self.assertTrue(key in d)

    def assertNotIn(self, key, d):
        self.assertFalse(key in d)
