# 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 config for use of fakes, and some black magic for
inline callbacks.

"""

import eventlet
eventlet.monkey_patch(os=False)

import copy
import os
import shutil
import sys

import fixtures
import testtools

from oslo.config import cfg

from ironic.db.sqlalchemy import migration
from ironic.db.sqlalchemy import models

from ironic.common import hash_ring
from ironic.common import paths
from ironic.db.sqlalchemy import api as sqla_api
from ironic.objects import base as objects_base
from ironic.openstack.common import log as logging
from ironic.tests import conf_fixture
from ironic.tests import policy_fixture


test_opts = [
    cfg.StrOpt('sqlite_clean_db',
               default='clean.sqlite',
               help='File name of clean sqlite db.'),
    ]

CONF = cfg.CONF
CONF.register_opts(test_opts)
CONF.set_override('use_stderr', False)

logging.setup('ironic')

_DB_CACHE = None


class Database(fixtures.Fixture):

    def __init__(self, db_api, db_migrate, sql_connection,
                    sqlite_db, sqlite_clean_db):
        self.sql_connection = sql_connection
        self.sqlite_db = sqlite_db
        self.sqlite_clean_db = sqlite_clean_db

        self.engine = db_api.get_engine()
        self.engine.dispose()
        conn = self.engine.connect()
        if sql_connection == "sqlite://":
            self.setup_sqlite(db_migrate)
        elif sql_connection.startswith('sqlite:///'):
            testdb = paths.state_path_rel(sqlite_db)
            if os.path.exists(testdb):
                return
            self.setup_sqlite(db_migrate)
        else:
            db_migrate.upgrade('head')
        self.post_migrations()
        if sql_connection == "sqlite://":
            conn = self.engine.connect()
            self._DB = "".join(line for line in conn.connection.iterdump())
            self.engine.dispose()
        else:
            cleandb = paths.state_path_rel(sqlite_clean_db)
            shutil.copyfile(testdb, cleandb)

    def setup_sqlite(self, db_migrate):
        if db_migrate.version():
            return
        models.Base.metadata.create_all(self.engine)
        db_migrate.stamp('head')

    def setUp(self):
        super(Database, self).setUp()

        if self.sql_connection == "sqlite://":
            conn = self.engine.connect()
            conn.connection.executescript(self._DB)
            self.addCleanup(self.engine.dispose)
        else:
            shutil.copyfile(paths.state_path_rel(self.sqlite_clean_db),
                            paths.state_path_rel(self.sqlite_db))
            self.addCleanup(os.unlink, self.sqlite_db)

    def post_migrations(self):
        """Any addition steps that are needed outside of the migrations."""


class ReplaceModule(fixtures.Fixture):
    """Replace a module with a fake module."""

    def __init__(self, name, new_value):
        self.name = name
        self.new_value = new_value

    def _restore(self, old_value):
        sys.modules[self.name] = old_value

    def setUp(self):
        super(ReplaceModule, self).setUp()
        old_value = sys.modules.get(self.name)
        sys.modules[self.name] = self.new_value
        self.addCleanup(self._restore, old_value)


class TestingException(Exception):
    pass


class TestCase(testtools.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()
        test_timeout = os.environ.get('OS_TEST_TIMEOUT', 0)
        try:
            test_timeout = int(test_timeout)
        except ValueError:
            # If timeout value is invalid do not set a timeout.
            test_timeout = 0
        if test_timeout > 0:
            self.useFixture(fixtures.Timeout(test_timeout, gentle=True))
        self.useFixture(fixtures.NestedTempfile())
        self.useFixture(fixtures.TempHomeDir())

        if (os.environ.get('OS_STDOUT_CAPTURE') == 'True' or
                os.environ.get('OS_STDOUT_CAPTURE') == '1'):
            stdout = self.useFixture(fixtures.StringStream('stdout')).stream
            self.useFixture(fixtures.MonkeyPatch('sys.stdout', stdout))
        if (os.environ.get('OS_STDERR_CAPTURE') == 'True' or
                os.environ.get('OS_STDERR_CAPTURE') == '1'):
            stderr = self.useFixture(fixtures.StringStream('stderr')).stream
            self.useFixture(fixtures.MonkeyPatch('sys.stderr', stderr))

        self.log_fixture = self.useFixture(fixtures.FakeLogger())
        self.useFixture(conf_fixture.ConfFixture(CONF))

        global _DB_CACHE
        if not _DB_CACHE:
            _DB_CACHE = Database(sqla_api, migration,
                                    sql_connection=CONF.database.connection,
                                    sqlite_db=CONF.database.sqlite_db,
                                    sqlite_clean_db=CONF.sqlite_clean_db)
        self.useFixture(_DB_CACHE)

        # NOTE(danms): Make sure to reset us back to non-remote objects
        # for each test to avoid interactions. Also, backup the object
        # registry
        objects_base.IronicObject.indirection_api = None
        self._base_test_obj_backup = copy.copy(
                objects_base.IronicObject._obj_classes)
        self.addCleanup(self._restore_obj_registry)

        self.addCleanup(self._clear_attrs)
        self.addCleanup(hash_ring.HashRingManager().reset)
        self.useFixture(fixtures.EnvironmentVariable('http_proxy'))
        self.policy = self.useFixture(policy_fixture.PolicyFixture())
        CONF.set_override('fatal_exception_format_errors', True)

    def _restore_obj_registry(self):
        objects_base.IronicObject._obj_classes = self._base_test_obj_backup

    def _clear_attrs(self):
        # 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 config(self, **kw):
        """Override config options for a test."""
        group = kw.pop('group', None)
        for k, v in kw.iteritems():
            CONF.set_override(k, v, group)

    def path_get(self, project_file=None):
        """Get the absolute path to a file. Used for testing the API.

        :param project_file: File whose path to return. Default: None.
        :returns: path to the specified file, or path to project root.
        """
        root = os.path.abspath(os.path.join(os.path.dirname(__file__),
                                            '..',
                                            '..',
                                            )
                               )
        if project_file:
            return os.path.join(root, project_file)
        else:
            return root
