# -*- coding: utf-8 -*-

#    Copyright (C) 2012 Yahoo! Inc. All Rights Reserved.
#
#    Licensed under the Apache License, Version 2.0 (the "License"); you may
#    not use this file except in compliance with the License. You may obtain
#    a copy of the License at
#
#         http://www.apache.org/licenses/LICENSE-2.0
#
#    Unless required by applicable law or agreed to in writing, software
#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
#    License for the specific language governing permissions and limitations
#    under the License.

import mock

from testtools import compat
from testtools import matchers
from testtools import testcase

import fixtures
import six

from taskflow import exceptions
from taskflow.tests import utils


class GreaterThanEqual(object):
    """Matches if the item is geq than the matchers reference object."""

    def __init__(self, source):
        self.source = source

    def match(self, other):
        if other >= self.source:
            return None
        return matchers.Mismatch("%s was not >= %s" % (other, self.source))


class FailureRegexpMatcher(object):
    """Matches if the failure was caused by the given exception and its string
    matches to the given pattern.
    """

    def __init__(self, exc_class, pattern):
        self.exc_class = exc_class
        self.pattern = pattern

    def match(self, failure):
        for cause in failure:
            if cause.check(self.exc_class) is not None:
                return matchers.MatchesRegex(
                    self.pattern).match(cause.exception_str)
        return matchers.Mismatch("The `%s` wasn't caused by the `%s`" %
                                 (failure, self.exc_class))


class TestCase(testcase.TestCase):
    """Test case base class for all taskflow unit tests."""

    def makeTmpDir(self):
        t_dir = self.useFixture(fixtures.TempDir())
        return t_dir.path

    def assertDictEqual(self, expected, check):
        self.assertIsInstance(expected, dict,
                              'First argument is not a dictionary')
        self.assertIsInstance(check, dict,
                              'Second argument is not a dictionary')

        # Testtools seems to want equals objects instead of just keys?
        compare_dict = {}
        for k in list(six.iterkeys(expected)):
            if not isinstance(expected[k], matchers.Equals):
                compare_dict[k] = matchers.Equals(expected[k])
            else:
                compare_dict[k] = expected[k]
        self.assertThat(matchee=check,
                        matcher=matchers.MatchesDict(compare_dict))

    def assertRaisesAttrAccess(self, exc_class, obj, attr_name):

        def access_func():
            getattr(obj, attr_name)

        self.assertRaises(exc_class, access_func)

    def assertRaisesRegexp(self, exc_class, pattern, callable_obj,
                           *args, **kwargs):
        # TODO(harlowja): submit a pull/review request to testtools to add
        # this method to there codebase instead of having it exist in ours
        # since it really doesn't belong here.

        class ReRaiseOtherTypes(object):
            def match(self, matchee):
                if not issubclass(matchee[0], exc_class):
                    compat.reraise(*matchee)

        class CaptureMatchee(object):
            def match(self, matchee):
                self.matchee = matchee[1]

        capture = CaptureMatchee()
        matcher = matchers.Raises(matchers.MatchesAll(ReRaiseOtherTypes(),
                                  matchers.MatchesException(exc_class,
                                                            pattern),
                                  capture))
        our_callable = testcase.Nullary(callable_obj, *args, **kwargs)
        self.assertThat(our_callable, matcher)
        return capture.matchee

    def assertGreater(self, first, second):
        matcher = matchers.GreaterThan(first)
        self.assertThat(second, matcher)

    def assertGreaterEqual(self, first, second):
        matcher = GreaterThanEqual(first)
        self.assertThat(second, matcher)

    def assertRegexpMatches(self, text, pattern):
        matcher = matchers.MatchesRegex(pattern)
        self.assertThat(text, matcher)

    def assertIsSuperAndSubsequence(self, super_seq, sub_seq, msg=None):
        super_seq = list(super_seq)
        sub_seq = list(sub_seq)
        current_tail = super_seq
        for sub_elem in sub_seq:
            try:
                super_index = current_tail.index(sub_elem)
            except ValueError:
                # element not found
                if msg is None:
                    msg = ("%r is not subsequence of %r: "
                           "element %r not found in tail %r"
                           % (sub_seq, super_seq, sub_elem, current_tail))
                self.fail(msg)
            else:
                current_tail = current_tail[super_index + 1:]

    def assertFailuresRegexp(self, exc_class, pattern, callable_obj, *args,
                             **kwargs):
        """Assert that the callable failed with the given exception and its
        string matches to the given pattern.
        """
        try:
            with utils.wrap_all_failures():
                callable_obj(*args, **kwargs)
        except exceptions.WrappedFailure as e:
            self.assertThat(e, FailureRegexpMatcher(exc_class, pattern))


class MockTestCase(TestCase):

    def setUp(self):
        super(MockTestCase, self).setUp()
        self.master_mock = mock.Mock(name='master_mock')

    def _patch(self, target, autospec=True, **kwargs):
        """Patch target and attach it to the master mock."""
        patcher = mock.patch(target, autospec=autospec, **kwargs)
        mocked = patcher.start()
        self.addCleanup(patcher.stop)

        attach_as = kwargs.pop('attach_as', None)
        if attach_as is not None:
            self.master_mock.attach_mock(mocked, attach_as)

        return mocked

    def _patch_class(self, module, name, autospec=True, attach_as=None):
        """Patch class, create class instance mock and attach them to
        the master mock.
        """
        if autospec:
            instance_mock = mock.Mock(spec_set=getattr(module, name))
        else:
            instance_mock = mock.Mock()

        patcher = mock.patch.object(module, name, autospec=autospec)
        class_mock = patcher.start()
        self.addCleanup(patcher.stop)
        class_mock.return_value = instance_mock

        if attach_as is None:
            attach_class_as = name
            attach_instance_as = name.lower()
        else:
            attach_class_as = attach_as + '_class'
            attach_instance_as = attach_as

        self.master_mock.attach_mock(class_mock, attach_class_as)
        self.master_mock.attach_mock(instance_mock, attach_instance_as)

        return class_mock, instance_mock

    def _reset_master_mock(self):
        self.master_mock.reset_mock()