import os
import sys
import warnings
from unittest.mock import Mock, patch

import pytest

from celery import loaders
from celery.exceptions import NotConfigured
from celery.loaders import base, default
from celery.loaders.app import AppLoader
from celery.utils.imports import NotAPackage


class DummyLoader(base.BaseLoader):

    def read_configuration(self):
        return {'foo': 'bar', 'imports': ('os', 'sys')}


class test_loaders:

    def test_get_loader_cls(self):
        assert loaders.get_loader_cls('default') is default.Loader


class test_LoaderBase:
    message_options = {'subject': 'Subject',
                       'body': 'Body',
                       'sender': 'x@x.com',
                       'to': 'y@x.com'}
    server_options = {'host': 'smtp.x.com',
                      'port': 1234,
                      'user': 'x',
                      'password': 'qwerty',
                      'timeout': 3}

    def setup_method(self):
        self.loader = DummyLoader(app=self.app)

    def test_handlers_pass(self):
        self.loader.on_task_init('foo.task', 'feedface-cafebabe')
        self.loader.on_worker_init()

    def test_now(self):
        assert self.loader.now(utc=True)
        assert self.loader.now(utc=False)

    def test_read_configuration_no_env(self):
        assert base.BaseLoader(app=self.app).read_configuration(
            'FOO_X_S_WE_WQ_Q_WE') is None

    def test_autodiscovery(self):
        with patch('celery.loaders.base.autodiscover_tasks') as auto:
            auto.return_value = [Mock()]
            auto.return_value[0].__name__ = 'moo'
            self.loader.autodiscover_tasks(['A', 'B'])
            assert 'moo' in self.loader.task_modules
            self.loader.task_modules.discard('moo')

    def test_import_task_module(self):
        assert sys == self.loader.import_task_module('sys')

    def test_init_worker_process(self):
        self.loader.on_worker_process_init()
        m = self.loader.on_worker_process_init = Mock()
        self.loader.init_worker_process()
        m.assert_called_with()

    def test_config_from_object_module(self):
        self.loader.import_from_cwd = Mock(return_value={
            "override_backends": {"db": "custom.backend.module"},
        })
        self.loader.config_from_object('module_name')
        self.loader.import_from_cwd.assert_called_with('module_name')
        assert self.loader.override_backends == {"db": "custom.backend.module"}

    def test_conf_property(self):
        assert self.loader.conf['foo'] == 'bar'
        assert self.loader._conf['foo'] == 'bar'
        assert self.loader.conf['foo'] == 'bar'

    def test_import_default_modules(self):
        def modnames(l):
            return [m.__name__ for m in l]
        self.app.conf.imports = ('os', 'sys')
        assert (sorted(modnames(self.loader.import_default_modules())) ==
                sorted(modnames([os, sys])))

    def test_import_default_modules_with_exception(self):
        """ Make sure exceptions are not silenced since this step is prior to
            setup logging. """
        def trigger_exception(**kwargs):
            raise ImportError('Dummy ImportError')
        from celery.signals import import_modules
        x = import_modules.connect(trigger_exception)
        self.app.conf.imports = ('os', 'sys')
        with pytest.raises(ImportError):
            self.loader.import_default_modules()
        import_modules.disconnect(x)

    def test_import_from_cwd_custom_imp(self):
        imp = Mock(name='imp')
        self.loader.import_from_cwd('foo', imp=imp)
        imp.assert_called()

    def test_cmdline_config_ValueError(self):
        with pytest.raises(ValueError):
            self.loader.cmdline_config_parser(['broker.port=foobar'])


class test_DefaultLoader:

    @patch('celery.loaders.base.find_module')
    def test_read_configuration_not_a_package(self, find_module):
        find_module.side_effect = NotAPackage()
        l = default.Loader(app=self.app)
        with pytest.raises(NotAPackage):
            l.read_configuration(fail_silently=False)

    @patch('celery.loaders.base.find_module')
    @pytest.mark.patched_environ('CELERY_CONFIG_MODULE', 'celeryconfig.py')
    def test_read_configuration_py_in_name(self, find_module, environ):
        find_module.side_effect = NotAPackage()
        l = default.Loader(app=self.app)
        with pytest.raises(NotAPackage):
            l.read_configuration(fail_silently=False)

    @patch('celery.loaders.base.find_module')
    def test_read_configuration_importerror(self, find_module):
        default.C_WNOCONF = True
        find_module.side_effect = ImportError()
        l = default.Loader(app=self.app)
        with pytest.warns(NotConfigured):
            l.read_configuration(fail_silently=True)
        default.C_WNOCONF = False
        l.read_configuration(fail_silently=True)

    def test_read_configuration(self):
        from types import ModuleType

        class ConfigModule(ModuleType):
            pass

        configname = os.environ.get('CELERY_CONFIG_MODULE') or 'celeryconfig'
        celeryconfig = ConfigModule(configname)
        celeryconfig.imports = ('os', 'sys')

        prevconfig = sys.modules.get(configname)
        sys.modules[configname] = celeryconfig
        try:
            l = default.Loader(app=self.app)
            l.find_module = Mock(name='find_module')
            settings = l.read_configuration(fail_silently=False)
            assert settings.imports == ('os', 'sys')
            settings = l.read_configuration(fail_silently=False)
            assert settings.imports == ('os', 'sys')
            l.on_worker_init()
        finally:
            if prevconfig:
                sys.modules[configname] = prevconfig

    def test_read_configuration_ImportError(self):
        sentinel = object()
        prev, os.environ['CELERY_CONFIG_MODULE'] = (
            os.environ.get('CELERY_CONFIG_MODULE', sentinel), 'daweqew.dweqw',
        )
        try:
            l = default.Loader(app=self.app)
            with pytest.raises(ImportError):
                l.read_configuration(fail_silently=False)
            l.read_configuration(fail_silently=True)
        finally:
            if prev is not sentinel:
                os.environ['CELERY_CONFIG_MODULE'] = prev
            else:
                os.environ.pop('CELERY_CONFIG_MODULE', None)

    def test_import_from_cwd(self):
        l = default.Loader(app=self.app)
        old_path = list(sys.path)
        try:
            sys.path.remove(os.getcwd())
        except ValueError:
            pass
        celery = sys.modules.pop('celery', None)
        sys.modules.pop('celery.local', None)
        try:
            assert l.import_from_cwd('celery')
            sys.modules.pop('celery', None)
            sys.modules.pop('celery.local', None)
            sys.path.insert(0, os.getcwd())
            assert l.import_from_cwd('celery')
        finally:
            sys.path = old_path
            sys.modules['celery'] = celery

    def test_unconfigured_settings(self):
        context_executed = [False]

        class _Loader(default.Loader):

            def find_module(self, name):
                raise ImportError(name)

        with warnings.catch_warnings(record=True):
            l = _Loader(app=self.app)
            assert not l.configured
            context_executed[0] = True
        assert context_executed[0]


class test_AppLoader:

    def setup_method(self):
        self.loader = AppLoader(app=self.app)

    def test_on_worker_init(self):
        self.app.conf.imports = ('subprocess',)
        sys.modules.pop('subprocess', None)
        self.loader.init_worker()
        assert 'subprocess' in sys.modules


class test_autodiscovery:

    def test_autodiscover_tasks(self):
        base._RACE_PROTECTION = True
        try:
            base.autodiscover_tasks(['foo'])
        finally:
            base._RACE_PROTECTION = False
        with patch('celery.loaders.base.find_related_module') as frm:
            base.autodiscover_tasks(['foo'])
            frm.assert_called()

    # Happy - get something back
    def test_find_related_module__when_existent_package_alone(self):
        with patch('importlib.import_module') as imp:
            imp.return_value = Mock()
            imp.return_value.__path__ = 'foo'
            assert base.find_related_module('foo', None).__path__ == 'foo'
            imp.assert_called_once_with('foo')

    def test_find_related_module__when_existent_package_and_related_name(self):
        with patch('importlib.import_module') as imp:
            first_import = Mock()
            first_import.__path__ = 'foo'
            second_import = Mock()
            second_import.__path__ = 'foo/tasks'
            imp.side_effect = [first_import, second_import]
            assert base.find_related_module('foo', 'tasks').__path__ == 'foo/tasks'
            imp.assert_any_call('foo')
            imp.assert_any_call('foo.tasks')

    def test_find_related_module__when_existent_package_parent_and_related_name(self):
        with patch('importlib.import_module') as imp:
            first_import = ModuleNotFoundError(name='foo.BarApp')  # Ref issue #2248
            second_import = Mock()
            second_import.__path__ = 'foo/tasks'
            imp.side_effect = [first_import, second_import]
            assert base.find_related_module('foo.BarApp', 'tasks').__path__ == 'foo/tasks'
            imp.assert_any_call('foo.BarApp')
            imp.assert_any_call('foo.tasks')

    # Sad - nothing returned
    def test_find_related_module__when_package_exists_but_related_name_does_not(self):
        with patch('importlib.import_module') as imp:
            first_import = Mock()
            first_import.__path__ = 'foo'
            second_import = ModuleNotFoundError(name='foo.tasks')
            imp.side_effect = [first_import, second_import]
            assert base.find_related_module('foo', 'tasks') is None
            imp.assert_any_call('foo')
            imp.assert_any_call('foo.tasks')

    def test_find_related_module__when_existent_package_parent_but_no_related_name(self):
        with patch('importlib.import_module') as imp:
            first_import = ModuleNotFoundError(name='foo.bar')
            second_import = ModuleNotFoundError(name='foo.tasks')
            imp.side_effect = [first_import, second_import]
            assert base.find_related_module('foo.bar', 'tasks') is None
            imp.assert_any_call('foo.bar')
            imp.assert_any_call('foo.tasks')

    # Sad - errors
    def test_find_related_module__when_no_package_parent(self):
        with patch('importlib.import_module') as imp:
            non_existent_import = ModuleNotFoundError(name='foo')
            imp.side_effect = non_existent_import
            with pytest.raises(ModuleNotFoundError) as exc:
                base.find_related_module('foo', 'tasks')

            assert exc.value.name == 'foo'
            imp.assert_called_once_with('foo')

    def test_find_related_module__when_nested_import_missing(self):
        expected_error = 'dummy import error - e.g. missing nested package'
        with patch('importlib.import_module') as imp:
            first_import = Mock()
            first_import.__path__ = 'foo'
            second_import = ModuleNotFoundError(expected_error)
            imp.side_effect = [first_import, second_import]
            with pytest.raises(ModuleNotFoundError) as exc:
                base.find_related_module('foo', 'tasks')

            assert exc.value.msg == expected_error