import contextlib
import grp
import importlib.resources
from multiprocessing import Process
import os
import pwd
import shutil
import subprocess
from subprocess import DEVNULL
import sys
import time
from unittest.mock import patch, Mock

import flask
import gssapi
import ldap3
import pytest
import requests
import socket
from zope import component

from .utils import gssapi_token_ctx, ccache_cleanup  # noqa: F401
from ceo_common.interfaces import IConfig, IKerberosService, ILDAPService, \
    IFileService, IMailmanService, IHTTPClient, IUWLDAPService, IMailService, \
    IDatabaseService
from ceo_common.model import Config, HTTPClient
from ceod.api import create_app
from ceod.db import MySQLService, PostgreSQLService
from ceod.model import KerberosService, LDAPService, FileService, User, \
    MailmanService, Group, UWLDAPService, UWLDAPRecord, MailService
import ceod.utils as utils
from .MockSMTPServer import MockSMTPServer
from .MockMailmanServer import MockMailmanServer
from .conftest_ceod_api import client  # noqa: F401
from .conftest_ceo import cli_setup  # noqa: F401


@pytest.fixture(scope='session', autouse=True)
def _drone_hostname_mock():
    # Drone doesn't appear to set the hostname of the container.
    # Mock it instead.
    if 'DRONE_STEP_NAME' in os.environ:
        hostname = os.environ['DRONE_STEP_NAME']
        fqdn = hostname + '.csclub.internal'
        socket.gethostname = Mock(return_value=hostname)
        socket.getfqdn = Mock(return_value=fqdn)


@pytest.fixture(scope='session')
def cfg(_drone_hostname_mock):
    with importlib.resources.path('tests', 'ceod_test_local.ini') as p:
        config_file = p.__fspath__()
    _cfg = Config(config_file)
    component.getGlobalSiteManager().registerUtility(_cfg, IConfig)
    return _cfg


def delete_test_princs(krb_srv):
    proc = subprocess.run([
        'kadmin', '-k', '-p', krb_srv.admin_principal, 'listprincs', 'test_*',
    ], text=True, capture_output=True, check=True)
    princs = [line.strip() for line in proc.stdout.splitlines()]
    for princ in princs:
        krb_srv.delprinc(princ)


@pytest.fixture(scope='session')
def krb_srv(cfg):
    # TODO: create temporary Kerberos database using kdb5_util.
    # We need to be root to read the keytab
    assert os.geteuid() == 0
    # this dance again... ugh
    if socket.gethostname() == cfg.get('ceod_admin_host'):
        principal = 'ceod/admin'
    else:
        principal = 'ceod/' + socket.getfqdn()
    krb = KerberosService(principal)
    component.getGlobalSiteManager().registerUtility(krb, IKerberosService)

    delete_test_princs(krb)
    yield krb
    delete_test_princs(krb)


def delete_subtree(conn: ldap3.Connection, base_dn: str):
    try:
        conn.search(base_dn, '(objectClass=*)', search_scope=ldap3.LEVEL)
        for entry in conn.entries:
            conn.delete(entry.entry_dn)
        conn.delete(base_dn)
    except ldap3.core.exceptions.LDAPNoSuchObjectResult:
        pass


@pytest.fixture
def g_admin_ctx(app):
    """
    Store the credentials for ceod/admin in flask.g, and override KBR5CCNAME.
    This context manager should be used any time LDAP is modified via the
    LDAPService, and we are not in a request context.
    This should NOT be active when CeodTestClient is making a request, since
    that will override the values in flask.g.
    """
    @contextlib.contextmanager
    def wrapper():
        with gssapi_token_ctx('ceod/admin') as token, app.app_context():
            try:
                flask.g.auth_user = 'ceod/admin'
                flask.g.client_token = token
                yield
            finally:
                flask.g.pop('client_token')
                flask.g.pop('auth_user')
    return wrapper


@pytest.fixture
def g_syscom(app):
    """
    Store the credentials for ctdalek in flask.g and override KRB5CCNAME.
    Use this fixture if you need syscom credentials for an HTTP request
    to a different process.
    """
    with gssapi_token_ctx('ctdalek') as token, app.app_context():
        try:
            flask.g.sasl_user = 'ctdalek'
            flask.g.client_token = token
            yield
        finally:
            flask.g.pop('client_token')
            flask.g.pop('sasl_user')


@pytest.fixture(scope='session')
def ldap_conn(cfg) -> ldap3.Connection:
    # Assume that the same server URL is being used for the CSC
    # and UWLDAP during the tests.
    cfg = component.getUtility(IConfig)
    server_url = cfg.get('ldap_server_url')
    # sanity check
    assert server_url == cfg.get('uwldap_server_url')
    with gssapi_token_ctx('ceod/admin') as token:
        creds = gssapi.Credentials(token=token)
        conn = ldap3.Connection(
            server_url, auto_bind=True, raise_exceptions=True,
            authentication=ldap3.SASL, sasl_mechanism=ldap3.KERBEROS,
            sasl_credentials=(None, None, creds))
    return conn


@pytest.fixture(scope='session')
def ldap_srv_session(cfg, krb_srv, ldap_conn):
    conn = ldap_conn
    users_base = cfg.get('ldap_users_base')
    groups_base = cfg.get('ldap_groups_base')
    sudo_base = cfg.get('ldap_sudo_base')

    for base_dn in [users_base, groups_base, sudo_base]:
        delete_subtree(conn, base_dn)
        conn.add(base_dn, 'organizationalUnit')

    _ldap_srv = LDAPService()
    component.getGlobalSiteManager().registerUtility(_ldap_srv, ILDAPService)

    yield _ldap_srv

    for base_dn in [users_base, groups_base, sudo_base]:
        delete_subtree(conn, base_dn)


@pytest.fixture
def ldap_srv(ldap_srv_session, g_admin_ctx):
    # This is an ugly hack to get around the fact that function-scoped
    # fixtures (g_admin_ctx) can't be used from session-scoped fixtures
    # (ldap_srv_session).
    with g_admin_ctx():
        yield ldap_srv_session


@pytest.fixture(scope='session')
def file_srv(cfg):
    _file_srv = FileService()
    component.getGlobalSiteManager().registerUtility(_file_srv, IFileService)
    members_home = cfg.get('members_home')
    clubs_home = cfg.get('clubs_home')

    shutil.rmtree(members_home, ignore_errors=True)
    shutil.rmtree(clubs_home, ignore_errors=True)
    yield _file_srv
    shutil.rmtree(members_home, ignore_errors=True)
    shutil.rmtree(clubs_home, ignore_errors=True)


@pytest.fixture(scope='session')
def http_client(cfg):
    _client = HTTPClient()
    component.getGlobalSiteManager().registerUtility(_client, IHTTPClient)
    return _client


@pytest.fixture(scope='session')
def mock_mailman_server():
    server = MockMailmanServer()
    server.start()
    yield server
    server.stop()


@pytest.fixture(scope='session')
def mailman_srv(mock_mailman_server, cfg, http_client):
    # TODO: test the RemoteMailmanService as well
    mailman = MailmanService()
    component.getGlobalSiteManager().registerUtility(mailman, IMailmanService)
    return mailman


@pytest.fixture(scope='session')
def uwldap_srv(cfg, ldap_conn):
    conn = ldap_conn
    base_dn = cfg.get('uwldap_base')

    delete_subtree(conn, base_dn)

    conn.add(base_dn, 'organizationalUnit')
    _uwldap_srv = UWLDAPService()
    component.getGlobalSiteManager().registerUtility(_uwldap_srv, IUWLDAPService)
    yield _uwldap_srv

    delete_subtree(conn, base_dn)


@pytest.fixture(scope='session')
def mock_mail_server():
    mock_server = MockSMTPServer()
    mock_server.start()
    yield mock_server
    mock_server.stop()


@pytest.fixture(scope='session')
def mail_srv(cfg, mock_mail_server):
    _mail_srv = MailService()
    component.getGlobalSiteManager().registerUtility(_mail_srv, IMailService)
    return _mail_srv


@pytest.fixture(scope='session')
def mysql_srv(cfg):
    mysql_srv = MySQLService()
    component.getGlobalSiteManager().registerUtility(mysql_srv, IDatabaseService, 'mysql')
    return mysql_srv


@pytest.fixture(scope='session')
def postgresql_srv(cfg):
    psql_srv = PostgreSQLService()
    component.getGlobalSiteManager().registerUtility(psql_srv, IDatabaseService, 'postgresql')
    return psql_srv


@pytest.fixture(autouse=True, scope='session')
def app(
    cfg,
    krb_srv,
    ldap_srv_session,
    file_srv,
    mailman_srv,
    uwldap_srv,
    mail_srv,
    mysql_srv,
    postgresql_srv,
):
    app = create_app({'TESTING': True})
    return app


@pytest.fixture(scope='session')
def mocks_for_create_user():
    with patch.object(utils, 'gen_password') as gen_password_mock, \
            patch.object(pwd, 'getpwuid') as getpwuid_mock, \
            patch.object(grp, 'getgrgid') as getgrgid_mock:
        gen_password_mock.return_value = 'krb5'
        # Normally, if getpwuid or getgrgid do *not* raise a KeyError,
        # then LDAPService will skip that UID. Therefore, by raising a
        # KeyError, we are making sure that the UID will *not* be skipped.
        getpwuid_mock.side_effect = KeyError()
        getgrgid_mock.side_effect = KeyError()
        yield


@pytest.fixture
def simple_user():
    return User(
        uid='test_jdoe',
        cn='John Doe',
        program='Math',
        terms=['s2021'],
    )


@pytest.fixture
def simple_club():
    return User(
        uid='test_club1',
        cn='Club One',
        is_club=True,
    )


@pytest.fixture
def ldap_user(simple_user, g_admin_ctx):
    with g_admin_ctx():
        simple_user.add_to_ldap()
    yield simple_user
    with g_admin_ctx():
        simple_user.remove_from_ldap()


@pytest.fixture
def krb_user(simple_user):
    # We don't want to use add_to_kerberos() here because that expires the
    # user's password, which we don't want for testing
    subprocess.run(
        ['kadmin', '-k', '-p', 'ceod/admin', 'addprinc', '-pw', 'krb5',
         simple_user.uid], stdout=DEVNULL, check=True)
    yield simple_user
    simple_user.remove_from_kerberos()


@pytest.fixture
def simple_group():
    return Group(
        cn='group1',
        gid_number=21000,
        user_cn='Group One',
    )


@pytest.fixture
def ldap_group(simple_group, g_admin_ctx):
    with g_admin_ctx():
        simple_group.add_to_ldap()
    yield simple_group
    with g_admin_ctx():
        simple_group.remove_from_ldap()


@pytest.fixture
def uwldap_user(cfg, uwldap_srv, ldap_conn):
    conn = ldap_conn
    base_dn = cfg.get('uwldap_base')
    user = UWLDAPRecord(
        uid='test_jdoe',
        mail_local_addresses=['test_jdoe@uwaterloo.internal'],
        program='Math',
        cn='John Doe',
        sn='Doe',
        given_name='John',
    )
    dn = f'uid={user.uid},{base_dn}'
    conn.add(
        dn,
        [
            'inetLocalMailRecipient',
            'inetOrgPerson',
            'organizationalPerson',
            'person',
        ],
        {
            'mailLocalAddress': user.mail_local_addresses,
            'ou': user.program,
            'cn': user.cn,
            'sn': user.sn,
            'givenName': user.given_name,
        },
    )
    yield user
    conn.delete(dn)


@pytest.fixture(scope='module')
def app_process(cfg, app, http_client):
    port = cfg.get('ceod_port')
    hostname = socket.gethostname()

    def server_start():
        sys.stdout = open('/dev/null', 'w')
        sys.stderr = sys.stdout
        app.run(debug=False, host='0.0.0.0', port=port)

    proc = Process(target=server_start)
    proc.start()

    try:
        for i in range(5):
            try:
                http_client.get(hostname, '/ping')
            except requests.exceptions.ConnectionError:
                time.sleep(1)
                continue
            break
        assert i != 5, 'Timed out'
        yield
    finally:
        proc.terminate()
        proc.join()