# GNU MediaGoblin -- federated, autonomous media hosting
# Copyright (C) 2011 Free Software Foundation, Inc
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU Affero General Public License for more details.
#
# You should have received a copy of the GNU Affero General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.


import pkg_resources
import os, shutil

from paste.deploy import loadapp
from webtest import TestApp

from mediagoblin import util
from mediagoblin.init.config import read_mediagoblin_config
from mediagoblin.decorators import _make_safe
from mediagoblin.db.open import setup_connection_and_db_from_config


MEDIAGOBLIN_TEST_DB_NAME = u'__mediagoblin_tests__'
TEST_SERVER_CONFIG = pkg_resources.resource_filename(
    'mediagoblin.tests', 'test_paste.ini')
TEST_APP_CONFIG = pkg_resources.resource_filename(
    'mediagoblin.tests', 'test_mgoblin_app.ini')
TEST_USER_DEV = pkg_resources.resource_filename(
    'mediagoblin.tests', 'test_user_dev')
MGOBLIN_APP = None

USER_DEV_DIRECTORIES_TO_SETUP = [
    'media/public', 'media/queue',
    'beaker/sessions/data', 'beaker/sessions/lock']

BAD_CELERY_MESSAGE = """\
Sorry, you *absolutely* must run nosetests with the
mediagoblin.init.celery.from_tests module.  Like so:
$ CELERY_CONFIG_MODULE=mediagoblin.init.celery.from_tests ./bin/nosetests"""


class BadCeleryEnviron(Exception): pass


def suicide_if_bad_celery_environ():
    if not os.environ.get('CELERY_CONFIG_MODULE') == \
            'mediagoblin.init.celery.from_tests':
        raise BadCeleryEnviron(BAD_CELERY_MESSAGE)
    

def get_test_app(dump_old_app=True):
    suicide_if_bad_celery_environ()

    # Make sure we've turned on testing
    util._activate_testing()

    # Leave this imported as it sets up celery.
    from mediagoblin.init.celery import from_tests

    global MGOBLIN_APP

    # Just return the old app if that exists and it's okay to set up
    # and return
    if MGOBLIN_APP and not dump_old_app:
        return MGOBLIN_APP

    # Remove and reinstall user_dev directories
    if os.path.exists(TEST_USER_DEV):
        shutil.rmtree(TEST_USER_DEV)

    for directory in USER_DEV_DIRECTORIES_TO_SETUP:
        full_dir = os.path.join(TEST_USER_DEV, directory)
        os.makedirs(full_dir)

    # Get app config
    global_config, validation_result = read_mediagoblin_config(TEST_APP_CONFIG)
    app_config = global_config['mediagoblin']

    # Wipe database
    # @@: For now we're dropping collections, but we could also just
    # collection.remove() ?
    connection, db = setup_connection_and_db_from_config(app_config)
    assert db.name == MEDIAGOBLIN_TEST_DB_NAME

    collections_to_wipe = [
        collection
        for collection in db.collection_names()
        if not collection.startswith('system.')]

    for collection in collections_to_wipe:
        db.drop_collection(collection)

    # TODO: Drop and recreate indexes

    # setup app and return
    test_app = loadapp(
        'config:' + TEST_SERVER_CONFIG)

    app = TestApp(test_app)
    MGOBLIN_APP = app

    return app


def setup_fresh_app(func):
    """
    Decorator to setup a fresh test application for this function.

    Cleans out test buckets and passes in a new, fresh test_app.
    """
    def wrapper(*args, **kwargs):
        test_app = get_test_app()
        util.clear_test_buckets()
        return func(test_app, *args, **kwargs)

    return _make_safe(wrapper, func)


def install_fixtures_simple(db, fixtures):
    """
    Very simply install fixtures in the database
    """
    for collection_name, collection_fixtures in fixtures.iteritems():
        collection = db[collection_name]
        for fixture in collection_fixtures:
            collection.insert(fixture)


def assert_db_meets_expected(db, expected):
    """
    Assert a database contains the things we expect it to.

    Objects are found via '_id', so you should make sure your document
    has an _id.

    Args:
     - db: pymongo or mongokit database connection
     - expected: the data we expect.  Formatted like:
         {'collection_name': [
             {'_id': 'foo',
              'some_field': 'some_value'},]}
    """
    for collection_name, collection_data in expected.iteritems():
        collection = db[collection_name]
        for expected_document in collection_data:
            document = collection.find_one({'_id': expected_document['_id']})
            assert document is not None  # make sure it exists
            assert document == expected_document  # make sure it matches