# Copyright (C) 2008-2023 by the Free Software Foundation, Inc.
#
# This file is part of GNU Mailman.
#
# GNU Mailman is free software: you can redistribute it and/or modify it under
# the terms of the GNU General Public License as published by the Free
# Software Foundation, either version 3 of the License, or (at your option)
# any later version.
#
# GNU Mailman 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 General Public License for
# more details.
#
# You should have received a copy of the GNU General Public License along with
# GNU Mailman.  If not, see <https://www.gnu.org/licenses/>.

"""Mailman test layers."""

# XXX 2012-03-23 BAW: Layers really really suck.  For example, the
# test_owners_get_email() test requires that both the SMTPLayer and LMTPLayer
# be set up, but there's apparently no way to do that and make zope.testing
# happy.  This causes no test failures, but it does cause errors at the end of
# the full test run.  For now, I'll ignore that, but I do want to eventually
# get rid of the layers and use something like testresources or some such.

import os
import ssl
import sys
import shutil
import logging
import datetime
import tempfile

from importlib.resources import files, read_text
from lazr.config import as_boolean
from mailman.config import config
from mailman.core import initialize
from mailman.core.initialize import INHIBIT_CONFIG_FILE
from mailman.core.logging import get_handler
from mailman.database.transaction import transaction
from mailman.interfaces.domain import IDomainManager
from mailman.testing.helpers import (
    get_lmtp_client,
    reset_the_world,
    TestableMaster,
    wait_for_webservice,
)
from mailman.testing.mta import (
    ConnectionCountingController,
    ConnectionCountingSSLController,
    ConnectionCountingSTARTTLSController,
)
from mailman.utilities.string import expand
from public import public
from textwrap import dedent
from zope.component import getUtility


TEST_TIMEOUT = datetime.timedelta(seconds=5)
NL = '\n'


@public
class MockAndMonkeyLayer:
    """Layer for mocking and monkey patching for testing."""

    # Set this to True to enable predictable datetimes, uids, etc.
    testing_mode = False

    # A registration of all testing factories, for resetting between tests.
    _resets = []

    @classmethod
    def testTearDown(cls):
        for reset in cls._resets:
            reset()

    @classmethod
    def register_reset(cls, reset):
        cls._resets.append(reset)


@public
class ConfigLayer(MockAndMonkeyLayer):
    """Layer for pushing and popping test configurations."""

    var_dir = None
    styles = None

    @classmethod
    def setUp(cls):
        # Set up the basic configuration stuff.  Turn off path creation until
        # we've pushed the testing config.
        config.create_paths = False
        initialize.initialize_1(INHIBIT_CONFIG_FILE)
        assert cls.var_dir is None, 'Layer already set up'
        # Calculate a temporary VAR_DIR directory so that run-time artifacts
        # of the tests won't tread on the installation's data.  This also
        # makes it easier to clean up after the tests are done, and insures
        # isolation of test suite runs.
        cls.var_dir = tempfile.mkdtemp()
        # We need a test configuration both for the foreground process and any
        # child processes that get spawned.  lazr.config would allow us to do
        # it all in a string that gets pushed, and we'll do that for the
        # foreground, but because we may be spawning processes (such as
        # runners) we'll need a file that we can specify to the with the -C
        # option.  Craft the full test configuration string here, push it, and
        # also write it out to a temp file for -C.
        #
        # Create a dummy postfix.cfg file so that the test suite doesn't try
        # to run the actual postmap command, which may not exist anyway.
        postfix_cfg = os.path.join(cls.var_dir, 'postfix.cfg')
        with open(postfix_cfg, 'w') as fp:
            print(dedent("""
            [postfix]
            postmap_command: true
            transport_file_type: hash
            """), file=fp)
        test_config = dedent("""
        [mailman]
        layout: testing
        [paths.testing]
        var_dir: {}
        [devmode]
        testing: yes
        [mta]
        configuration: {}
        """.format(cls.var_dir, postfix_cfg))
        # Read the testing config and push it.
        test_config += read_text('mailman.testing', 'testing.cfg')
        config.create_paths = True
        config.push('test config', test_config)
        # Initialize everything else.
        initialize.initialize_2(testing=True)
        initialize.initialize_3()
        # When stderr debugging is enabled, subprocess root loggers should
        # also be more verbose.
        if cls.stderr:
            test_config += dedent("""
            [logging.root]
            level: debug
            """)
        # Enable log message propagation and reset the log paths so that the
        # doctests can check the output.
        for logger_config in config.logger_configs:
            sub_name = logger_config.name.split('.')[-1]
            if sub_name == 'root':
                continue
            logger_name = 'mailman.' + sub_name
            log = logging.getLogger(logger_name)
            log.propagate = cls.stderr
            # Reopen the file to a new path that tests can get at.  Instead of
            # using the configuration file path though, use a path that's
            # specific to the logger so that tests can find expected output
            # more easily.
            path = os.path.join(config.LOG_DIR, sub_name)
            get_handler(sub_name).reopen(path)
            log.setLevel(logging.DEBUG)
            # If stderr debugging is enabled, make sure subprocesses are also
            # more verbose.  In general though, we still don't want SQLAlchemy
            # debugging because it's just too verbose.  Unfortunately, if you
            # do want that level of debugging you currently have to manually
            # modify this conditional.
            if cls.stderr and sub_name != 'database':
                test_config += expand(dedent("""
                [logging.$name]
                propagate: yes
                level: debug
                """), None, dict(name=sub_name, path=path))
        # The root logger will already have a handler, but it's not the right
        # handler.  Remove that and set our own.
        if cls.stderr:
            console = logging.StreamHandler(sys.stderr)
            formatter = logging.Formatter(config.logging.root.format,
                                          config.logging.root.datefmt)
            console.setFormatter(formatter)
            root = logging.getLogger()
            del root.handlers[:]
            root.addHandler(console)
        # Write the configuration file for subprocesses and set up the config
        # object to pass that properly on the -C option.
        config_file = os.path.join(cls.var_dir, 'test.cfg')
        with open(config_file, 'w') as fp:
            fp.write(test_config)
            print(file=fp)
        config.filename = config_file

    @classmethod
    def tearDown(cls):
        assert cls.var_dir is not None, 'Layer not set up'
        reset_the_world()
        # Destroy the test database after the tests are done so that there is
        # no data in case the tests are rerun with a database layer like mysql
        # or postgresql which are not deleted in teardown.
        shutil.rmtree(cls.var_dir)
        # Prevent the bit of post-processing on the .pop() that creates
        # directories.  We're basically shutting down everything and we don't
        # need the directories created.  Plus, doing so leaves a var directory
        # turd in the source tree's top-level directory.  We do it this way
        # rather than shutil.rmtree'ing the resulting var directory because
        # it's possible the user created a valid such directory for
        # operational or test purposes.
        config.create_paths = False
        config.pop('test config')
        cls.var_dir = None

    @classmethod
    def testSetUp(cls):
        # Add an example domain.
        with transaction():
            getUtility(IDomainManager).add('example.com', 'An example domain.')

    @classmethod
    def testTearDown(cls):
        reset_the_world()

    # Flag to indicate that loggers should propagate to the console.
    stderr = False

    # The top of our source tree, for tests that care (e.g. hooks.txt).
    root_directory = None

    @classmethod
    def set_root_directory(cls, directory):
        """Set the directory at the root of our source tree.

        zc.recipe.testrunner runs from parts/test/working-directory, but
        that's actually changed over the life of the package.  Some tests
        care, e.g. because they need to find our built-out bin directory.
        Fortunately, buildout can give us this information.  See the
        `buildout.cfg` file for where this method is called.
        """
        cls.root_directory = directory


@public
class SMTPLayer(ConfigLayer):
    """Layer for starting, stopping, and accessing a test SMTP server."""

    smtpd = None

    @classmethod
    def setUp(cls):
        assert cls.smtpd is None, 'Layer already set up'
        host = config.mta.smtp_host
        port = int(config.mta.smtp_port)
        cls.smtpd = ConnectionCountingController(host, port)
        cls.smtpd.start()

    @classmethod
    def tearDown(cls):
        assert cls.smtpd is not None, 'Layer not set up'
        cls.smtpd.clear()
        cls.smtpd.stop()

    @classmethod
    def testSetUp(cls):
        # Make sure we don't call our superclass's testSetUp(), otherwise the
        # example.com domain will get added twice.
        pass

    @classmethod
    def testTearDown(cls):
        cls.smtpd.reset()
        cls.smtpd.clear()


@public
class SMTPSLayer(ConfigLayer):
    """Layer for starting, stopping, and accessing a test SMTPS server."""

    smtpd = None

    @classmethod
    def setUp(cls):
        assert cls.smtpd is None, 'Layer already set up'
        # Use a different port than the SMTP layer, since that one might
        # still be in use.
        config.push('smtps', """
        [mta]
        smtp_port: 9465
        smtp_secure_mode: smtps
        """)
        test_cert_path = files('mailman.testing') / 'ssl_test_cert.crt'
        test_key_path = files('mailman.testing') / 'ssl_test_key.key'

        client_context = ssl.create_default_context()
        client_context.load_verify_locations(cafile=test_cert_path)

        server_context = ssl.create_default_context(ssl.Purpose.CLIENT_AUTH)
        server_context.load_cert_chain(test_cert_path, test_key_path)

        host = config.mta.smtp_host
        port = int(config.mta.smtp_port)

        cls.smtpd = ConnectionCountingSSLController(
            host, port,
            client_context=client_context,
            server_context=server_context)
        cls.smtpd.start()

    @classmethod
    def testSetUp(cls):
        # Make sure we don't call our superclass's testSetUp(), otherwise the
        # example.com domain will get added twice.
        pass

    @classmethod
    def testTearDown(cls):
        cls.smtpd.reset()
        cls.smtpd.clear()

    @classmethod
    def tearDown(cls):
        assert cls.smtpd is not None, 'Layer not set up'
        cls.smtpd.clear()
        cls.smtpd.stop()
        config.pop('smtps')


@public
class STARTTLSLayer(ConfigLayer):
    """Layer for starting and stopping a test SMTP server with STARTTLS."""

    smtpd = None

    @classmethod
    def setUp(cls):
        assert cls.smtpd is None, 'Layer already set up'
        # Use a different port than the SMTP and SMTPS layers, since that one
        # might still be in use.
        config.push('starttls', """
        [mta]
        smtp_port: 9587
        smtp_secure_mode: starttls
        """)
        test_cert_path = files('mailman.testing') / 'ssl_test_cert.crt'
        test_key_path = files('mailman.testing') / 'ssl_test_key.key'

        client_context = ssl.create_default_context()
        client_context.load_verify_locations(cafile=test_cert_path)

        server_context = ssl.create_default_context(ssl.Purpose.CLIENT_AUTH)
        server_context.load_cert_chain(test_cert_path, test_key_path)

        host = config.mta.smtp_host
        port = int(config.mta.smtp_port)

        cls.smtpd = ConnectionCountingSTARTTLSController(
            host, port,
            client_context=client_context,
            server_context=server_context)
        cls.smtpd.start()

    @classmethod
    def testSetUp(cls):
        # Make sure we don't call our superclass's testSetUp(), otherwise the
        # example.com domain will get added twice.
        pass

    @classmethod
    def testTearDown(cls):
        cls.smtpd.reset()
        cls.smtpd.clear()

    @classmethod
    def tearDown(cls):
        assert cls.smtpd is not None, 'Layer not set up'
        cls.smtpd.clear()
        cls.smtpd.stop()
        config.pop('starttls')


@public
class LMTPLayer(ConfigLayer):
    """Layer for starting, stopping, and accessing a test LMTP server."""

    lmtpd = None

    @staticmethod
    def _wait_for_lmtp_server():
        get_lmtp_client(quiet=True)

    @classmethod
    def setUp(cls):
        assert cls.lmtpd is None, 'Layer already set up'
        cls.lmtpd = TestableMaster(cls._wait_for_lmtp_server)
        cls.lmtpd.start('lmtp')

    @classmethod
    def tearDown(cls):
        assert cls.lmtpd is not None, 'Layer not set up'
        cls.lmtpd.stop()
        cls.lmtpd = None

    @classmethod
    def testSetUp(cls):
        # Make sure we don't call our superclass's testSetUp(), otherwise the
        # example.com domain will get added twice.
        pass


@public
class RESTLayer(SMTPLayer):
    """Layer for starting, stopping, and accessing the test REST layer."""

    server = None
    stderr = True

    @classmethod
    def setUp(cls):
        assert cls.server is None, 'Layer already set up'
        cls.server = TestableMaster(wait_for_webservice)
        cls.server.start('rest')

    @classmethod
    def tearDown(cls):
        assert cls.server is not None, 'Layer not set up'
        cls.server.stop()
        cls.server = None


@public
def is_testing():
    """Return a 'testing' flag for use with the predictable factories.

    :return: True when in testing mode.
    :rtype: bool
    """
    return (MockAndMonkeyLayer.testing_mode or
            as_boolean(config.devmode.testing))
