# Copyright 2010-2011 OpenStack Foundation
# Copyright (c) 2013 Hewlett-Packard Development Company, L.P.
#
# 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.

import os
import pathlib
import shutil

import fixtures
import tempfile
import testtools

from sphinx.testing.util import SphinxTestApp


def example_dir(name=""):
    return os.path.join(os.path.dirname(__file__), 'examples', name)


_TRUE_VALUES = ('True', 'true', '1', 'yes')


class with_app:
    def __init__(self, **kwargs):
        self.srcdir = pathlib.Path(kwargs['srcdir'])
        self.sphinx_app_args = kwargs

    def __call__(self, f):
        def newf(*args, **kwargs):
            with tempfile.TemporaryDirectory() as tmpdirname:
                tmpdir = pathlib.Path(tmpdirname)
                tmproot = tmpdir.joinpath(self.srcdir.name)
                shutil.copytree(self.srcdir, tmproot)
                self.sphinx_app_args['srcdir'] = tmproot
                self.builddir = tmproot.joinpath('_build')

                app = SphinxTestApp(freshenv=True, **self.sphinx_app_args)

                f(*args, app, app._status, app._warning, **kwargs)

                app.cleanup()

        return newf


class OutputStreamCapture(fixtures.Fixture):
    """Capture output streams during tests.

    This fixture captures errant printing to stderr / stdout during
    the tests and lets us see those streams at the end of the test
    runs instead. Useful to see what was happening during failed
    tests.
    """

    def setUp(self):
        super().setUp()
        if os.environ.get('OS_STDOUT_CAPTURE') in _TRUE_VALUES:
            self.out = self.useFixture(fixtures.StringStream('stdout'))
            self.useFixture(
                fixtures.MonkeyPatch('sys.stdout', self.out.stream)
            )
        if os.environ.get('OS_STDERR_CAPTURE') in _TRUE_VALUES:
            self.err = self.useFixture(fixtures.StringStream('stderr'))
            self.useFixture(
                fixtures.MonkeyPatch('sys.stderr', self.err.stream)
            )

    @property
    def stderr(self):
        details = self.err._details
        assert details is not None
        return details["stderr"].as_text()

    @property
    def stdout(self):
        details = self.out._details
        assert details is not None
        return details["stdout"].as_text()


class Timeout(fixtures.Fixture):
    """Setup per test timeouts.

    In order to avoid test deadlocks we support setting up a test
    timeout parameter read from the environment. In almost all
    cases where the timeout is reached this means a deadlock.

    A class level TIMEOUT_SCALING_FACTOR also exists, which allows
    extremely long tests to specify they need more time.
    """

    def __init__(self, timeout, scaling=1):
        super().__init__()
        try:
            self.test_timeout = int(timeout)
        except ValueError:
            # If timeout value is invalid do not set a timeout.
            self.test_timeout = 0
        if scaling >= 1:
            self.test_timeout *= scaling
        else:
            raise ValueError('scaling value must be >= 1')

    def setUp(self):
        super().setUp()
        if self.test_timeout > 0:
            self.useFixture(fixtures.Timeout(self.test_timeout, gentle=True))


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().setUp()
        self.useFixture(Timeout(os.environ.get('OS_TEST_TIMEOUT', 0)))
        self.useFixture(OutputStreamCapture())
