# 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 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.import_opt('connection',
                'ironic.openstack.common.db.options',
                group='database')
CONF.import_opt('sqlite_db', 'ironic.openstack.common.db.options',
                group='database')
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.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
