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# this work for additional information regarding copyright ownership.
# The ASF licenses this file to You 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
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from ducktape.utils.util import wait_until
from ducktape.tests.test import Test
from ducktape.mark.resource import cluster
from ducktape.mark import matrix
from ducktape.mark import ignore
from kafkatest.services.kafka import KafkaService
from kafkatest.services.zookeeper import ZookeeperService
from kafkatest.services.streams import StreamsSmokeTestDriverService, StreamsSmokeTestJobRunnerService
import time
import signal
from random import randint

def broker_node(test, topic, broker_type):
    """ Discover node of requested type. For leader type, discovers leader for our topic and partition 0
    """
    if broker_type == "leader":
        node = test.kafka.leader(topic, partition=0)
    elif broker_type == "controller":
        node = test.kafka.controller()
    else:
        raise Exception("Unexpected broker type %s." % (broker_type))

    return node

def signal_node(test, node, sig):
    test.kafka.signal_node(node, sig)
    
def clean_shutdown(test, topic, broker_type):
    """Discover broker node of requested type and shut it down cleanly.
    """
    node = broker_node(test, topic, broker_type)
    signal_node(test, node, signal.SIGTERM)

def hard_shutdown(test, topic, broker_type):
    """Discover broker node of requested type and shut it down with a hard kill."""
    node = broker_node(test, topic, broker_type)
    signal_node(test, node, signal.SIGKILL)

def clean_bounce(test, topic, broker_type):
    """Chase the leader of one partition and restart it cleanly a few times (5 times)."""
    for i in range(5):
        prev_broker_node = broker_node(test, topic, broker_type)
        test.kafka.restart_node(prev_broker_node, clean_shutdown=True)


def hard_bounce(test, topic, broker_type):
    """Chase the leader and restart it with a hard kill. Do this a few times (5)."""
    for i in range(5):
        prev_broker_node = broker_node(test, topic, broker_type)
        test.kafka.signal_node(prev_broker_node, sig=signal.SIGKILL)

        # Since this is a hard kill, we need to make sure the process is down and that
        # zookeeper has registered the loss by expiring the broker's session timeout.

        wait_until(lambda: len(test.kafka.pids(prev_broker_node)) == 0 and not test.kafka.is_registered(prev_broker_node),
                   timeout_sec=test.kafka.zk_session_timeout + 5,
                   err_msg="Failed to see timely deregistration of hard-killed broker %s" % str(prev_broker_node.account))

        test.kafka.start_node(prev_broker_node)
    

    
failures = {
    "clean_shutdown": clean_shutdown,
    "hard_shutdown": hard_shutdown,
    "clean_bounce": clean_bounce,
    "hard_bounce": hard_bounce
}
        
class StreamsBrokerBounceTest(Test):
    """
    Simple test of Kafka Streams with brokers failing
    """

    def __init__(self, test_context):
        super(StreamsBrokerBounceTest, self).__init__(test_context)
        self.replication = 3
        self.partitions = 3
        self.topics = {
            'echo' : { 'partitions': self.partitions, 'replication-factor': self.replication,
                       'configs': {"min.insync.replicas": 2}},
            'data' : { 'partitions': self.partitions, 'replication-factor': self.replication,
                       'configs': {"min.insync.replicas": 2} },
            'min' : { 'partitions': self.partitions, 'replication-factor': self.replication,
                      'configs': {"min.insync.replicas": 2} },
            'max' : { 'partitions': self.partitions, 'replication-factor': self.replication,
                      'configs': {"min.insync.replicas": 2} },
            'sum' : { 'partitions': self.partitions, 'replication-factor': self.replication,
                      'configs': {"min.insync.replicas": 2} },
            'dif' : { 'partitions': self.partitions, 'replication-factor': self.replication,
                      'configs': {"min.insync.replicas": 2} },
            'cnt' : { 'partitions': self.partitions, 'replication-factor': self.replication,
                      'configs': {"min.insync.replicas": 2} },
            'avg' : { 'partitions': self.partitions, 'replication-factor': self.replication,
                      'configs': {"min.insync.replicas": 2} },
            'wcnt' : { 'partitions': self.partitions, 'replication-factor': self.replication,
                       'configs': {"min.insync.replicas": 2} },
            'tagg' : { 'partitions': self.partitions, 'replication-factor': self.replication,
                       'configs': {"min.insync.replicas": 2} },
            '__consumer_offsets' : { 'partitions': 50, 'replication-factor': self.replication,
                       'configs': {"min.insync.replicas": 2} }
        }

    def fail_broker_type(self, failure_mode, broker_type):
        # Pick a random topic and bounce it's leader
        topic_index = randint(0, len(self.topics.keys()) - 1)
        topic = list(self.topics.keys())[topic_index]
        failures[failure_mode](self, topic, broker_type)

    def fail_many_brokers(self, failure_mode, num_failures):
        sig = signal.SIGTERM
        if (failure_mode == "clean_shutdown"):
            sig = signal.SIGTERM
        else:
            sig = signal.SIGKILL
            
        for num in range(0, num_failures - 1):
            signal_node(self, self.kafka.nodes[num], sig)

    def confirm_topics_on_all_brokers(self, expected_topic_set):
        for node in self.kafka.nodes:
            match_count = 0
            # need to iterate over topic_list_generator as kafka.list_topics()
            # returns a python generator so values are fetched lazily
            # so we can't just compare directly we must iterate over what's returned
            topic_list_generator = self.kafka.list_topics(node=node)
            for topic in topic_list_generator:
                if topic in expected_topic_set:
                    match_count += 1

            if len(expected_topic_set) != match_count:
                return False

        return True

        
    def setup_system(self, start_processor=True, num_threads=3):
        # Setup phase
        self.zk = ZookeeperService(self.test_context, num_nodes=1)
        self.zk.start()

        self.kafka = KafkaService(self.test_context, num_nodes=self.replication, zk=self.zk, topics=self.topics)
        self.kafka.start()

        # allow some time for topics to be created
        wait_until(lambda: self.confirm_topics_on_all_brokers(set(self.topics.keys())),
                   timeout_sec=60,
                   err_msg="Broker did not create all topics in 60 seconds ")

        # Start test harness
        self.driver = StreamsSmokeTestDriverService(self.test_context, self.kafka)
        self.processor1 = StreamsSmokeTestJobRunnerService(self.test_context, self.kafka, "at_least_once", num_threads)

        self.driver.start()

        if (start_processor):
           self.processor1.start()

    def collect_results(self, sleep_time_secs):
        data = {}
        # End test
        self.driver.wait()
        self.driver.stop()

        self.processor1.stop()

        node = self.driver.node
        
        # Success is declared if streams does not crash when sleep time > 0
        # It should give an exception when sleep time is 0 since we kill the brokers immediately
        # and the topic manager cannot create internal topics with the desired replication factor
        if (sleep_time_secs == 0):
            output_streams = self.processor1.node.account.ssh_capture("grep SMOKE-TEST-CLIENT-EXCEPTION %s" % self.processor1.STDOUT_FILE, allow_fail=False)
        else:
            output_streams = self.processor1.node.account.ssh_capture("grep SMOKE-TEST-CLIENT-CLOSED %s" % self.processor1.STDOUT_FILE, allow_fail=False)
            
        for line in output_streams:
            data["Client closed"] = line

        # Currently it is hard to guarantee anything about Kafka since we don't have exactly once.
        # With exactly once in place, success will be defined as ALL-RECORDS-DELIEVERD and SUCCESS
        output = node.account.ssh_capture("grep -E 'ALL-RECORDS-DELIVERED|PROCESSED-MORE-THAN-GENERATED|PROCESSED-LESS-THAN-GENERATED' %s" % self.driver.STDOUT_FILE, allow_fail=False)
        for line in output:
            data["Records Delivered"] = line
        output = node.account.ssh_capture("grep -E 'SUCCESS|FAILURE' %s" % self.driver.STDOUT_FILE, allow_fail=False)
        for line in output:
            data["Logic Success/Failure"] = line
            
        
        return data

    @cluster(num_nodes=7)
    @matrix(failure_mode=["clean_shutdown", "hard_shutdown", "clean_bounce", "hard_bounce"],
            broker_type=["leader", "controller"],
            num_threads=[1, 3],
            sleep_time_secs=[120])
    def test_broker_type_bounce(self, failure_mode, broker_type, sleep_time_secs, num_threads):
        """
        Start a smoke test client, then kill one particular broker and ensure data is still received
        Record if records are delivered.
        We also add a single thread stream client to make sure we could get all partitions reassigned in
        next generation so to verify the partition lost is correctly triggered.
        """
        self.setup_system(num_threads=num_threads)

        # Sleep to allow test to run for a bit
        time.sleep(sleep_time_secs)

        # Fail brokers
        self.fail_broker_type(failure_mode, broker_type)

        return self.collect_results(sleep_time_secs)

    @ignore
    @cluster(num_nodes=7)
    @matrix(failure_mode=["clean_shutdown"],
            broker_type=["controller"],
            sleep_time_secs=[0])
    def test_broker_type_bounce_at_start(self, failure_mode, broker_type, sleep_time_secs):
        """
        Start a smoke test client, then kill one particular broker immediately before streams stats
        Streams should throw an exception since it cannot create topics with the desired
        replication factor of 3
        """
        self.setup_system(start_processor=False)

        # Sleep to allow test to run for a bit
        time.sleep(sleep_time_secs)

        # Fail brokers
        self.fail_broker_type(failure_mode, broker_type)

        self.processor1.start()

        return self.collect_results(sleep_time_secs)

    @cluster(num_nodes=7)
    @matrix(failure_mode=["clean_shutdown", "hard_shutdown", "clean_bounce", "hard_bounce"],
            num_failures=[2])
    def test_many_brokers_bounce(self, failure_mode, num_failures):
        """
        Start a smoke test client, then kill a few brokers and ensure data is still received
        Record if records are delivered
        """
        self.setup_system() 

        # Sleep to allow test to run for a bit
        time.sleep(120)

        # Fail brokers
        self.fail_many_brokers(failure_mode, num_failures)

        return self.collect_results(120)

    @cluster(num_nodes=7)
    @matrix(failure_mode=["clean_bounce", "hard_bounce"],
            num_failures=[3])
    def test_all_brokers_bounce(self, failure_mode, num_failures):
        """
        Start a smoke test client, then kill a few brokers and ensure data is still received
        Record if records are delivered
        """

        # Set min.insync.replicas to 1 because in the last stage of the test there is only one broker left.
        # Otherwise the last offset commit will never succeed and time out and potentially take longer as
        # duration passed to the close method of the Kafka Streams client.
        self.topics['__consumer_offsets'] = { 'partitions': 50, 'replication-factor': self.replication,
                                              'configs': {"min.insync.replicas": 1} }

        self.setup_system()

        # Sleep to allow test to run for a bit
        time.sleep(120)

        # Fail brokers
        self.fail_many_brokers(failure_mode, num_failures)

        return self.collect_results(120)
