# Copyright 2014: Mirantis Inc.
# All Rights Reserved.
#
#    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.

# yardstick comment: this is a modified copy of
# rally/rally/benchmark/runners/constant.py

"""A runner that runs a configurable number of times before it returns
"""

from __future__ import absolute_import

import logging
import multiprocessing
import traceback

import os

from yardstick.benchmark.runners import base
from yardstick.common import exceptions as y_exc

LOG = logging.getLogger(__name__)


QUEUE_PUT_TIMEOUT = 10


def _worker_process(queue, cls, method_name, scenario_cfg,
                    context_cfg, aborted, output_queue):

    runner_cfg = scenario_cfg['runner']

    interval = runner_cfg.get("interval", 1)
    iterations = runner_cfg.get("iterations", 1)
    run_step = runner_cfg.get("run_step", "setup,run,teardown")

    delta = runner_cfg.get("delta", 2)
    LOG.info("worker START, iterations %d times, class %s", iterations, cls)

    runner_cfg['runner_id'] = os.getpid()

    scenario_output = base.ScenarioOutput(queue, sequence=1, errors="")
    benchmark = cls(scenario_cfg, context_cfg)
    if "setup" in run_step:
        benchmark.setup()

    method = getattr(benchmark, method_name)

    sla_action = None
    if "sla" in scenario_cfg:
        sla_action = scenario_cfg["sla"].get("action", "assert")
    if "run" in run_step:
        while True:

            LOG.debug("runner=%(runner)s seq=%(sequence)s START",
                      {"runner": runner_cfg["runner_id"],
                       "sequence": scenario_output.sequence})

            scenario_output.clear()
            scenario_output.errors = ""
            benchmark.pre_run_wait_time(interval)

            try:
                result = method(scenario_output)
            except y_exc.SLAValidationError as error:
                # SLA validation failed in scenario, determine what to do now
                if sla_action == "assert":
                    raise
                elif sla_action == "monitor":
                    LOG.warning("SLA validation failed: %s", error.args)
                    scenario_output.errors = error.args
                elif sla_action == "rate-control":
                    try:
                        scenario_cfg['options']['rate']
                    except KeyError:
                        scenario_cfg.setdefault('options', {})
                        scenario_cfg['options']['rate'] = 100

                    scenario_cfg['options']['rate'] -= delta
                    scenario_output.sequence = 1
                    continue
            except Exception:  # pylint: disable=broad-except
                scenario_output.errors = traceback.format_exc()
                LOG.exception("")
                raise
            else:
                if result:
                    # add timeout for put so we don't block test
                    # if we do timeout we don't care about dropping individual KPIs
                    output_queue.put(result, True, QUEUE_PUT_TIMEOUT)

            benchmark.post_run_wait_time(interval)

            if scenario_output:
                scenario_output.push()

            LOG.debug("runner=%(runner)s seq=%(sequence)s END",
                      {"runner": runner_cfg["runner_id"],
                       "sequence": scenario_output.sequence})

            scenario_output.sequence += 1

            if (scenario_output.errors and sla_action is None) or \
                    (scenario_output.sequence > iterations or aborted.is_set()):
                LOG.info("worker END")
                break
    if "teardown" in run_step:
        try:
            benchmark.teardown()
        except Exception:
            # catch any exception in teardown and convert to simple exception
            # never pass exceptions back to multiprocessing, because some exceptions can
            # be unpicklable
            # https://bugs.python.org/issue9400
            LOG.exception("")
            raise SystemExit(1)

    LOG.debug("queue.qsize() = %s", queue.qsize())
    LOG.debug("output_queue.qsize() = %s", output_queue.qsize())


class IterationRunner(base.Runner):
    """Run a scenario for a configurable number of times

If the scenario ends before the time has elapsed, it will be started again.

  Parameters
    iterations - amount of times the scenario will be run for
        type:    int
        unit:    na
        default: 1
    interval - time to wait between each scenario invocation
        type:    int
        unit:    seconds
        default: 1 sec
    """
    __execution_type__ = 'Iteration'

    def _run_benchmark(self, cls, method, scenario_cfg, context_cfg):
        name = "{}-{}-{}".format(self.__execution_type__, scenario_cfg.get("type"), os.getpid())
        self.process = multiprocessing.Process(
            name=name,
            target=_worker_process,
            args=(self.result_queue, cls, method, scenario_cfg,
                  context_cfg, self.aborted, self.output_queue))
        self.process.start()