import os
import json
from ddt import ddt, data, file_data
from nose.tools import assert_equal, assert_is_not_none


@ddt
class Dummy(object):
    """
    Dummy class to test the data decorator on
    """

    @data(1, 2, 3, 4)
    def test_something(self, value):
        return value


@ddt
class FileDataDummy(object):
    """
    Dummy class to test the file_data decorator on
    """

    @file_data("test_data_dict.json")
    def test_something_again(self, value):
        return value


def test_data_decorator():
    """
    Test the ``data`` method decorator
    """

    def hello():
        pass

    pre_size = len(hello.__dict__)
    keys = set(hello.__dict__.keys())
    data_hello = data(1, 2)(hello)
    dh_keys = set(data_hello.__dict__.keys())
    post_size = len(data_hello.__dict__)

    assert_equal(post_size, pre_size + 1)
    extra_attrs = dh_keys - keys
    assert_equal(len(extra_attrs), 1)
    extra_attr = extra_attrs.pop()
    assert_equal(getattr(data_hello, extra_attr), (1, 2))


def test_file_data_decorator_with_dict():
    """
    Test the ``file_data`` method decorator
    """

    def hello():
        pass

    pre_size = len(hello.__dict__)
    keys = set(hello.__dict__.keys())
    data_hello = data("test_data_dict.json")(hello)

    dh_keys = set(data_hello.__dict__.keys())
    post_size = len(data_hello.__dict__)

    assert_equal(post_size, pre_size + 1)
    extra_attrs = dh_keys - keys
    assert_equal(len(extra_attrs), 1)
    extra_attr = extra_attrs.pop()
    assert_equal(getattr(data_hello, extra_attr), ("test_data_dict.json",))


is_test = lambda x: x.startswith('test_')


def test_ddt():
    """
    Test the ``ddt`` class decorator
    """
    tests = len(list(filter(is_test, Dummy.__dict__)))
    assert_equal(tests, 4)


def test_file_data_test_creation():
    """
    Test that the ``file_data`` decorator creates two tests
    """

    tests = len(list(filter(is_test, FileDataDummy.__dict__)))
    assert_equal(tests, 2)


def test_file_data_test_names_dict():
    """
    Test that ``file_data`` creates tests with the correct name

    Name is the the function name plus the key in the JSON data,
    when it is parsed as a dictionary.
    """

    tests = set(filter(is_test, FileDataDummy.__dict__))

    tests_dir = os.path.dirname(__file__)
    test_data_path = os.path.join(tests_dir, 'test_data_dict.json')
    test_data = json.loads(open(test_data_path).read())
    created_tests = set([
        "test_something_again_{0}".format(name) for name in test_data.keys()
    ])

    assert_equal(tests, created_tests)


def test_feed_data_data():
    """
    Test that data is fed to the decorated tests
    """
    tests = filter(is_test, Dummy.__dict__)

    values = []
    obj = Dummy()
    for test in tests:
        method = getattr(obj, test)
        values.append(method())

    assert_equal(set(values), set([1, 2, 3, 4]))


def test_feed_data_file_data():
    """
    Test that data is fed to the decorated tests from a file
    """
    tests = filter(is_test, FileDataDummy.__dict__)

    values = []
    obj = FileDataDummy()
    for test in tests:
        method = getattr(obj, test)
        values.extend(method())

    assert_equal(set(values), set([10, 12, 15, 15, 12, 50]))


def test_ddt_data_name_attribute():
    """
    Test the ``__name__`` attribute handling of ``data`` items with ``ddt``
    """

    def hello():
        pass

    class myint(int):
        pass

    class mytest(object):
        pass

    d1 = myint(1)
    d1.__name__ = 'test_d1'

    d2 = myint(2)

    data_hello = data(d1, d2)(hello)
    setattr(mytest, 'test_hello', data_hello)

    ddt_mytest = ddt(mytest)
    assert_is_not_none(getattr(ddt_mytest, 'test_d1'))
    assert_is_not_none(getattr(ddt_mytest, 'test_hello_2'))