# vim: tabstop=4 shiftwidth=4 softtabstop=4

# Copyright 2010 United States Government as represented by the
# Administrator of the National Aeronautics and Space Administration.
# 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.

"""Base classes for our unit tests.

Allows overriding of flags for use of fakes, and some black magic for
inline callbacks.

"""

import functools
import unittest
import uuid

import mox
import nose.plugins.skip
import stubout

from nova import flags
from nova.openstack.common import cfg
from nova.openstack.common import log as logging
from nova.openstack.common import timeutils
from nova import service
from nova import tests
from nova.tests import fake_flags


test_opts = [
    cfg.StrOpt('sqlite_clean_db',
               default='clean.sqlite',
               help='File name of clean sqlite db'),
    cfg.BoolOpt('fake_tests',
                default=True,
                help='should we use everything for testing'),
    ]

FLAGS = flags.FLAGS
FLAGS.register_opts(test_opts)

LOG = logging.getLogger(__name__)


class skip_test(object):
    """Decorator that skips a test."""
    # TODO(tr3buchet): remember forever what comstud did here
    def __init__(self, msg):
        self.message = msg

    def __call__(self, func):
        @functools.wraps(func)
        def _skipper(*args, **kw):
            """Wrapped skipper function."""
            raise nose.SkipTest(self.message)
        return _skipper


class skip_if(object):
    """Decorator that skips a test if condition is true."""
    def __init__(self, condition, msg):
        self.condition = condition
        self.message = msg

    def __call__(self, func):
        @functools.wraps(func)
        def _skipper(*args, **kw):
            """Wrapped skipper function."""
            if self.condition:
                raise nose.SkipTest(self.message)
            func(*args, **kw)
        return _skipper


class skip_unless(object):
    """Decorator that skips a test if condition is not true."""
    def __init__(self, condition, msg):
        self.condition = condition
        self.message = msg

    def __call__(self, func):
        @functools.wraps(func)
        def _skipper(*args, **kw):
            """Wrapped skipper function."""
            if not self.condition:
                raise nose.SkipTest(self.message)
            func(*args, **kw)
        return _skipper


def skip_if_fake(func):
    """Decorator that skips a test if running in fake mode."""
    def _skipper(*args, **kw):
        """Wrapped skipper function."""
        if FLAGS.fake_tests:
            raise unittest.SkipTest('Test cannot be run in fake mode')
        else:
            return func(*args, **kw)
    return _skipper


class TestingException(Exception):
    pass


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

    def setUp(self):
        """Run before each test method to initialize test environment."""
        super(TestCase, self).setUp()

        fake_flags.set_defaults(FLAGS)
        flags.parse_args([], default_config_files=[])

        # NOTE(vish): We need a better method for creating fixtures for tests
        #             now that we have some required db setup for the system
        #             to work properly.
        self.start = timeutils.utcnow()
        tests.reset_db()

        # emulate some of the mox stuff, we can't use the metaclass
        # because it screws with our generators
        self.mox = mox.Mox()
        self.stubs = stubout.StubOutForTesting()
        self.injected = []
        self._services = []

    def tearDown(self):
        """Runs after each test method to tear down test environment."""
        try:
            self.mox.UnsetStubs()
            self.stubs.UnsetAll()
            self.stubs.SmartUnsetAll()
            self.mox.VerifyAll()
            super(TestCase, self).tearDown()
        finally:
            # Reset any overridden flags
            FLAGS.reset()

            # Stop any timers
            for x in self.injected:
                try:
                    x.stop()
                except AssertionError:
                    pass

            # Kill any services
            for x in self._services:
                try:
                    x.kill()
                except Exception:
                    pass

            # Delete attributes that don't start with _ so they don't pin
            # memory around unnecessarily for the duration of the test
            # suite
            for key in [k for k in self.__dict__.keys() if k[0] != '_']:
                del self.__dict__[key]

    def flags(self, **kw):
        """Override flag variables for a test."""
        for k, v in kw.iteritems():
            FLAGS.set_override(k, v)

    def start_service(self, name, host=None, **kwargs):
        host = host and host or uuid.uuid4().hex
        kwargs.setdefault('host', host)
        kwargs.setdefault('binary', 'nova-%s' % name)
        svc = service.Service.create(**kwargs)
        svc.start()
        self._services.append(svc)
        return svc

    # Useful assertions
    def assertDictMatch(self, d1, d2, approx_equal=False, tolerance=0.001):
        """Assert two dicts are equivalent.

        This is a 'deep' match in the sense that it handles nested
        dictionaries appropriately.

        NOTE:

            If you don't care (or don't know) a given value, you can specify
            the string DONTCARE as the value. This will cause that dict-item
            to be skipped.

        """
        def raise_assertion(msg):
            d1str = str(d1)
            d2str = str(d2)
            base_msg = ('Dictionaries do not match. %(msg)s d1: %(d1str)s '
                        'd2: %(d2str)s' % locals())
            raise AssertionError(base_msg)

        d1keys = set(d1.keys())
        d2keys = set(d2.keys())
        if d1keys != d2keys:
            d1only = d1keys - d2keys
            d2only = d2keys - d1keys
            raise_assertion('Keys in d1 and not d2: %(d1only)s. '
                            'Keys in d2 and not d1: %(d2only)s' % locals())

        for key in d1keys:
            d1value = d1[key]
            d2value = d2[key]
            try:
                error = abs(float(d1value) - float(d2value))
                within_tolerance = error <= tolerance
            except (ValueError, TypeError):
                # If both values aren't convertible to float, just ignore
                # ValueError if arg is a str, TypeError if it's something else
                # (like None)
                within_tolerance = False

            if hasattr(d1value, 'keys') and hasattr(d2value, 'keys'):
                self.assertDictMatch(d1value, d2value)
            elif 'DONTCARE' in (d1value, d2value):
                continue
            elif approx_equal and within_tolerance:
                continue
            elif d1value != d2value:
                raise_assertion("d1['%(key)s']=%(d1value)s != "
                                "d2['%(key)s']=%(d2value)s" % locals())

    def assertDictListMatch(self, L1, L2, approx_equal=False, tolerance=0.001):
        """Assert a list of dicts are equivalent."""
        def raise_assertion(msg):
            L1str = str(L1)
            L2str = str(L2)
            base_msg = ('List of dictionaries do not match: %(msg)s '
                        'L1: %(L1str)s L2: %(L2str)s' % locals())
            raise AssertionError(base_msg)

        L1count = len(L1)
        L2count = len(L2)
        if L1count != L2count:
            raise_assertion('Length mismatch: len(L1)=%(L1count)d != '
                            'len(L2)=%(L2count)d' % locals())

        for d1, d2 in zip(L1, L2):
            self.assertDictMatch(d1, d2, approx_equal=approx_equal,
                                 tolerance=tolerance)

    def assertSubDictMatch(self, sub_dict, super_dict):
        """Assert a sub_dict is subset of super_dict."""
        self.assertTrue(set(sub_dict.keys()).issubset(set(super_dict.keys())))
        for k, sub_value in sub_dict.items():
            super_value = super_dict[k]
            if isinstance(sub_value, dict):
                self.assertSubDictMatch(sub_value, super_value)
            elif 'DONTCARE' in (sub_value, super_value):
                continue
            else:
                self.assertEqual(sub_value, super_value)

    def assertIn(self, a, b, *args, **kwargs):
        """Python < v2.7 compatibility.  Assert 'a' in 'b'"""
        try:
            f = super(TestCase, self).assertIn
        except AttributeError:
            self.assertTrue(a in b, *args, **kwargs)
        else:
            f(a, b, *args, **kwargs)

    def assertNotIn(self, a, b, *args, **kwargs):
        """Python < v2.7 compatibility.  Assert 'a' NOT in 'b'"""
        try:
            f = super(TestCase, self).assertNotIn
        except AttributeError:
            self.assertFalse(a in b, *args, **kwargs)
        else:
            f(a, b, *args, **kwargs)

    def assertNotRaises(self, exc_class, func, *args, **kwargs):
        """Assert that a particular exception is not raised.

        If exc_class is None, then we assert that *no* error is raised.

        Otherwise, we assert that only a particular error wasn't raised;
        if any different exceptions were raised, we just silently capture
        them and return.
        """
        exc_msg = kwargs.pop('exc_msg', '')

        if exc_class is None:
            # Ensure no errors were raised
            try:
                return func(*args, **kwargs)
            except Exception:
                raise
                raise AssertionError(exc_msg)
        else:
            # Ensure a specific error wasn't raised
            try:
                return func(*args, **kwargs)
            except exc_class:
                raise AssertionError(exc_msg)
            except Exception:
                pass  # Any other errors are fine

    def assertIsInstance(self, a, b, *args, **kwargs):
        """Python < v2.7 compatibility.  Assert 'a' is Instance of 'b'"""
        try:
            f = super(TestCase, self).assertIsInstance
        except AttributeError:
            self.assertTrue(isinstance(a, b), *args, **kwargs)
        else:
            f(a, b, *args, **kwargs)