#!/usr/bin/env python3
#
#  Copyright (C) 2018 Codethink Limited
#  Copyright (C) 2019 Bloomberg Finance LLP
#
#  This program is free software; you can redistribute it and/or
#  modify it under the terms of the GNU Lesser General Public
#  License as published by the Free Software Foundation; either
#  version 2 of the License, or (at your option) any later version.
#
#  This library 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
#  Lesser General Public License for more details.
#
#  You should have received a copy of the GNU Lesser General Public
#  License along with this library. If not, see <http://www.gnu.org/licenses/>.
#
#  Authors:
#        Tristan Maat <tristan.maat@codethink.co.uk>
#
import os
import multiprocessing
import pytest

from buildstream.testing import register_repo_kind, sourcetests_collection_hook
from buildstream.testing._fixtures import reset_global_node_state, thread_check  # pylint: disable=unused-import
from buildstream.testing._forked import forked_run_report
from buildstream.testing.integration import integration_cache  # pylint: disable=unused-import


from tests.testutils.repo.git import Git
from tests.testutils.repo.bzr import Bzr
from tests.testutils.repo.tar import Tar
from tests.testutils.repo.zip import Zip


#
# This file is loaded by pytest, we use it to add a custom
# `--integration` option to our test suite, and to install
# a session scope fixture.
#


#################################################
#            Implement pytest option            #
#################################################
def pytest_addoption(parser):
    parser.addoption('--integration', action='store_true', default=False,
                     help='Run integration tests')

    parser.addoption('--remote-execution', action='store_true', default=False,
                     help='Run remote-execution tests only')


def pytest_runtest_setup(item):
    # Without --integration: skip tests not marked with 'integration'
    if not item.config.getvalue('integration'):
        if item.get_closest_marker('integration'):
            pytest.skip('skipping integration test')

    # With --remote-execution: only run tests marked with 'remoteexecution'
    if item.config.getvalue('remote_execution'):
        if not item.get_closest_marker('remoteexecution'):
            pytest.skip('skipping non remote-execution test')

    # Without --remote-execution: skip tests marked with 'remoteexecution'
    else:
        if item.get_closest_marker('remoteexecution'):
            pytest.skip('skipping remote-execution test')


#################################################
#              in_subprocess mark               #
#################################################
#
# Various issues can occur when forking the Python process and using gRPC,
# due to its multithreading. As BuildStream forks for parallelisation, gRPC
# features are restricted to child processes, so tests using them must also
# run as child processes. The in_subprocess mark handles this.
# See <https://github.com/grpc/grpc/blob/master/doc/fork_support.md>.
#
@pytest.mark.tryfirst
def pytest_runtest_protocol(item):
    if item.get_closest_marker('in_subprocess') is not None:
        reports = forked_run_report(item)
        for rep in reports:
            item.ihook.pytest_runtest_logreport(report=rep)
        return True
    else:
        return None


#################################################
#           remote_services fixture             #
#################################################
#
# This is returned by the `remote_services` fixture
#
class RemoteServices():

    def __init__(self, **kwargs):
        self.action_service = kwargs.get('action_service')
        self.artifact_service = kwargs.get('artifact_service')
        self.exec_service = kwargs.get('exec_service')
        self.source_service = kwargs.get('source_service')
        self.storage_service = kwargs.get('storage_service')


@pytest.fixture(scope='session')
def remote_services(request):
    kwargs = {}
    # Look for remote services configuration in environment.
    if 'ARTIFACT_CACHE_SERVICE' in os.environ:
        kwargs['artifact_service'] = os.environ.get('ARTIFACT_CACHE_SERVICE')

    if 'REMOTE_EXECUTION_SERVICE' in os.environ:
        kwargs['action_service'] = os.environ.get('REMOTE_EXECUTION_SERVICE')
        kwargs['exec_service'] = os.environ.get('REMOTE_EXECUTION_SERVICE')
        kwargs['storage_service'] = os.environ.get('REMOTE_EXECUTION_SERVICE')

    if 'SOURCE_CACHE_SERVICE' in os.environ:
        kwargs['source_service'] = os.environ.get('SOURCE_CACHE_SERVICE')

    return RemoteServices(**kwargs)


#################################################
# Setup for templated source tests              #
#################################################
register_repo_kind('git', Git, None)
register_repo_kind('bzr', Bzr, None)
register_repo_kind('tar', Tar, None)
register_repo_kind('zip', Zip, None)


# This hook enables pytest to collect the templated source tests from
# buildstream.testing
def pytest_sessionstart(session):
    sourcetests_collection_hook(session)


#################################################
#             Isolated environment              #
#################################################
@pytest.fixture(scope="session", autouse=True)
def set_xdg_paths(pytestconfig):
    for env_var, default in [
            ("HOME", "tmp"),
            ("XDG_CACHE_HOME", "tmp/cache"),
            ("XDG_CONFIG_HOME", "tmp/config"),
            ("XDG_DATA_HOME", "tmp/share"),
    ]:
        value = os.environ.get("BST_TEST_{}".format(env_var))
        if value is None:
            value = os.path.join(pytestconfig.getoption("basetemp"), default)

        os.environ[env_var] = value


def pytest_configure(config):
    # TODO: document
    print(
        "Multiprocessing method:",
        multiprocessing.get_start_method(allow_none=True),
    )
    if 'BST_FORCE_START_METHOD' in os.environ:
        start_method = os.environ['BST_FORCE_START_METHOD']
        multiprocessing.set_start_method(start_method)