# Copyright 2013-2015 DataStax, Inc.
#
# 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.

try:
    import unittest2 as unittest
except ImportError:
    import unittest  # noqa

import os, six, time, sys, logging, traceback
from threading import Event
from subprocess import call
from itertools import groupby

from cassandra import OperationTimedOut, ReadTimeout, ReadFailure, WriteTimeout, WriteFailure
from cassandra.cluster import Cluster
from cassandra.protocol import ConfigurationException

try:
    from ccmlib.cluster import Cluster as CCMCluster
    from ccmlib.cluster_factory import ClusterFactory as CCMClusterFactory
    from ccmlib import common
except ImportError as e:
    CCMClusterFactory = None

log = logging.getLogger(__name__)

CLUSTER_NAME = 'test_cluster'
SINGLE_NODE_CLUSTER_NAME = 'single_node'
MULTIDC_CLUSTER_NAME = 'multidc_test_cluster'

CCM_CLUSTER = None

path = os.path.join(os.path.abspath(os.path.dirname(__file__)), 'ccm')
if not os.path.exists(path):
    os.mkdir(path)

cass_version = None
cql_version = None


def get_server_versions():
    """
    Probe system.local table to determine Cassandra and CQL version.
    Returns a tuple of (cassandra_version, cql_version).
    """
    global cass_version, cql_version

    if cass_version is not None:
        return (cass_version, cql_version)

    c = Cluster(protocol_version=1)
    s = c.connect()
    row = s.execute('SELECT cql_version, release_version FROM system.local')[0]

    cass_version = _tuple_version(row.release_version)
    cql_version = _tuple_version(row.cql_version)

    c.shutdown()

    return (cass_version, cql_version)


def _tuple_version(version_string):
    if '-' in version_string:
        version_string = version_string[:version_string.index('-')]

    return tuple([int(p) for p in version_string.split('.')])


USE_CASS_EXTERNAL = bool(os.getenv('USE_CASS_EXTERNAL', False))

default_cassandra_version = '2.1.5'

if USE_CASS_EXTERNAL:
    if CCMClusterFactory:
        # see if the external instance is running in ccm
        path = common.get_default_path()
        name = common.current_cluster_name(path)
        CCM_CLUSTER = CCMClusterFactory.load(common.get_default_path(), name)
        CCM_CLUSTER.start(wait_for_binary_proto=True, wait_other_notice=True)

    # Not sure what's going on, but the server version query
    # hangs in python3. This appears to be related to running inside of
    # nosetests, and only for this query that would run while loading the
    # module.
    # This is a hack to make it run with default cassandra version for PY3.
    # Not happy with it, but need to move on for now.
    if not six.PY3:
        cass_ver, _ = get_server_versions()
        default_cassandra_version = '.'.join('%d' % i for i in cass_ver)
    else:
        if not os.getenv('CASSANDRA_VERSION'):
            log.warning("Using default C* version %s because external server cannot be queried" % default_cassandra_version)


CASSANDRA_DIR = os.getenv('CASSANDRA_DIR', None)
CASSANDRA_VERSION = os.getenv('CASSANDRA_VERSION', default_cassandra_version)

CCM_KWARGS = {}
if CASSANDRA_DIR:
    log.info("Using Cassandra dir: %s", CASSANDRA_DIR)
    CCM_KWARGS['install_dir'] = CASSANDRA_DIR
else:
    log.info('Using Cassandra version: %s', CASSANDRA_VERSION)
    CCM_KWARGS['version'] = CASSANDRA_VERSION

if CASSANDRA_VERSION >= '2.2':
    default_protocol_version = 4
elif CASSANDRA_VERSION >= '2.1':
    default_protocol_version = 3
elif CASSANDRA_VERSION >= '2.0':
    default_protocol_version = 2
else:
    default_protocol_version = 1

PROTOCOL_VERSION = int(os.getenv('PROTOCOL_VERSION', default_protocol_version))


def get_cluster():
    return CCM_CLUSTER


def get_node(node_id):
    return CCM_CLUSTER.nodes['node%s' % node_id]


def use_multidc(dc_list):
    use_cluster(MULTIDC_CLUSTER_NAME, dc_list, start=True)


def use_singledc(start=True):
    use_cluster(CLUSTER_NAME, [3], start=start)


def use_single_node(start=True):
    use_cluster(SINGLE_NODE_CLUSTER_NAME, [1], start=start)


def remove_cluster():
    if USE_CASS_EXTERNAL:
        return

    global CCM_CLUSTER
    if CCM_CLUSTER:
        log.debug("Removing cluster {0}".format(CCM_CLUSTER.name))
        tries = 0
        while tries < 100:
            try:
                CCM_CLUSTER.remove()
                CCM_CLUSTER = None
                return
            except WindowsError:
                ex_type, ex, tb = sys.exc_info()
                log.warn("{0}: {1} Backtrace: {2}".format(ex_type.__name__, ex, traceback.extract_tb(tb)))
                del tb
                tries += 1
                time.sleep(1)

        raise RuntimeError("Failed to remove cluster after 100 attempts")

def is_current_cluster(cluster_name, node_counts):
    global CCM_CLUSTER
    if CCM_CLUSTER and CCM_CLUSTER.name == cluster_name:
        if [len(list(nodes)) for dc, nodes in
                groupby(CCM_CLUSTER.nodelist(), lambda n: n.data_center)] == node_counts:
            return True
    return False


def use_cluster(cluster_name, nodes, ipformat=None, start=True):
    global CCM_CLUSTER
    if USE_CASS_EXTERNAL:
        if CCM_CLUSTER:
            log.debug("Using external CCM cluster {0}".format(CCM_CLUSTER.name))
        else:
            log.debug("Using unnamed external cluster")
        return

    if is_current_cluster(cluster_name, nodes):
        log.debug("Using existing cluster, matching topology: {0}".format(cluster_name))
    else:
        if CCM_CLUSTER:
            log.debug("Stopping existing cluster, topology mismatch: {0}".format(CCM_CLUSTER.name))
            CCM_CLUSTER.stop()

        try:
            CCM_CLUSTER = CCMClusterFactory.load(path, cluster_name)
            log.debug("Found existing CCM cluster, {0}; clearing.".format(cluster_name))
            CCM_CLUSTER.clear()
            CCM_CLUSTER.set_install_dir(**CCM_KWARGS)
        except Exception:
            ex_type, ex, tb = sys.exc_info()
            log.warn("{0}: {1} Backtrace: {2}".format(ex_type.__name__, ex, traceback.extract_tb(tb)))
            del tb

            log.debug("Creating new CCM cluster, {0}, with args {1}".format(cluster_name, CCM_KWARGS))
            CCM_CLUSTER = CCMCluster(path, cluster_name, **CCM_KWARGS)
            CCM_CLUSTER.set_configuration_options({'start_native_transport': True})
            if CASSANDRA_VERSION >= '2.2':
                CCM_CLUSTER.set_configuration_options({'enable_user_defined_functions': True})
            common.switch_cluster(path, cluster_name)
            CCM_CLUSTER.populate(nodes, ipformat=ipformat)
    try:
        jvm_args = []
        # This will enable the Mirroring query handler which will echo our custom payload k,v pairs back
        if PROTOCOL_VERSION >= 4:
            jvm_args = [" -Dcassandra.custom_query_handler_class=org.apache.cassandra.cql3.CustomPayloadMirroringQueryHandler"]

        if start:
            log.debug("Starting CCM cluster: {0}".format(cluster_name))
            CCM_CLUSTER.start(wait_for_binary_proto=True, wait_other_notice=True, jvm_args=jvm_args)
            setup_keyspace(ipformat=ipformat)
    except Exception:
        log.exception("Failed to start CCM cluster; removing cluster.")
        
        if os.name == "nt":
            if CCM_CLUSTER:
                for node in CCM_CLUSTER.nodes.itervalues():
                    os.system("taskkill /F /PID " + str(node.pid))
        else:
            call(["pkill", "-9", "-f", ".ccm"])
        remove_cluster()
        raise


def teardown_package():
    if USE_CASS_EXTERNAL:
        return
    # when multiple modules are run explicitly, this runs between them
    # need to make sure CCM_CLUSTER is properly cleared for that case
    remove_cluster()
    for cluster_name in [CLUSTER_NAME, MULTIDC_CLUSTER_NAME]:
        try:
            cluster = CCMClusterFactory.load(path, cluster_name)
            try:
                cluster.remove()
                log.info('Removed cluster: %s' % cluster_name)
            except Exception:
                log.exception('Failed to remove cluster: %s' % cluster_name)

        except Exception:
            log.warning('Did not find cluster: %s' % cluster_name)


def execute_until_pass(session, query):
    tries = 0
    while tries < 100:
        try:
            return session.execute(query)
        except ConfigurationException:
            # keyspace/table was already created/dropped
            return
        except (OperationTimedOut, ReadTimeout, ReadFailure, WriteTimeout, WriteFailure):
            ex_type, ex, tb = sys.exc_info()
            log.warn("{0}: {1} Backtrace: {2}".format(ex_type.__name__, ex, traceback.extract_tb(tb)))
            del tb
            tries += 1

    raise RuntimeError("Failed to execute query after 100 attempts: {0}".format(query))

def setup_keyspace(ipformat=None):
    # wait for nodes to startup
    time.sleep(10)

    if not ipformat:
        cluster = Cluster(protocol_version=PROTOCOL_VERSION)
    else:
        cluster = Cluster(contact_points=["::1"], protocol_version=PROTOCOL_VERSION)
    session = cluster.connect()

    try:
        results = execute_until_pass(session, "SELECT keyspace_name FROM system.schema_keyspaces")
        existing_keyspaces = [row[0] for row in results]
        for ksname in ('test1rf', 'test2rf', 'test3rf'):
            if ksname in existing_keyspaces:
                execute_until_pass(session, "DROP KEYSPACE %s" % ksname)

        ddl = '''
            CREATE KEYSPACE test3rf
            WITH replication = {'class': 'SimpleStrategy', 'replication_factor': '3'}'''
        execute_until_pass(session, ddl)

        ddl = '''
            CREATE KEYSPACE test2rf
            WITH replication = {'class': 'SimpleStrategy', 'replication_factor': '2'}'''
        execute_until_pass(session, ddl)

        ddl = '''
            CREATE KEYSPACE test1rf
            WITH replication = {'class': 'SimpleStrategy', 'replication_factor': '1'}'''
        execute_until_pass(session, ddl)

        ddl = '''
            CREATE TABLE test3rf.test (
                k int PRIMARY KEY,
                v int )'''
        execute_until_pass(session, ddl)

    except Exception:
        traceback.print_exc()
        raise
    finally:
        cluster.shutdown()


class UpDownWaiter(object):

    def __init__(self, host):
        self.down_event = Event()
        self.up_event = Event()
        host.monitor.register(self)

    def on_up(self, host):
        self.up_event.set()

    def on_down(self, host):
        self.down_event.set()

    def wait_for_down(self):
        self.down_event.wait()

    def wait_for_up(self):
        self.up_event.wait()