# osmo_ms_driver: Location Update Test
# Create MS's and wait for the Location Update to succeed.
#
# Copyright (C) 2018 by Holger Hans Peter Freyther
#
# This program 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.
#
# This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.

from copy import copy
from osmo_gsm_tester import log
from .starter import OsmoVirtPhy, OsmoMobile
from .test_support import ResultStore

from datetime import timedelta

import collections
import time

# Key used for the result dictionary
LU_RESULT_NAME = 'lu_time'

def has_lu_time(result):
    """
    Returns true if a LU occurred.
    """
    return result.has_result(LU_RESULT_NAME)

def lu_time(result):
    """
    Returns the time of the LU occurrence.
    """
    return result.get_result(LU_RESULT_NAME, default=0)

def lu_delay(result):
    """
    Returns the delay from LU success to MS start time.
    """
    return lu_time(result) - result.start_time()

def set_lu_time(result, time):
    """
    Sets/Overrides the time of the LU success for this MS.
    """
    result.set_result(LU_RESULT_NAME, time)


LUStats = collections.namedtuple("LUStats", ["num_attempted", "num_completed",
                                 "min_latency", "max_latency"])

class MassUpdateLocationTest(log.Origin):
    """
    A test to launch a configurable amount of MS and make them
    execute a Location Updating Procedure.

    Configure the number of MS to be tested and a function that
    decides how quickly to start them and a timeout.
    """

    TEMPLATE_LUA = "osmo-mobile.lua"
    TEMPLATE_CFG = "osmo-mobile.cfg"

    def __init__(self, name, options, cdf_function,
                 event_server, tmp_dir, suite_run=None):
        super().__init__(log.C_RUN, name)
        self._binary_options = options
        self._cdf = cdf_function
        self._suite_run = suite_run
        self._tmp_dir = tmp_dir
        self._unstarted = []
        self._mobiles = []
        self._phys = []
        self._results = {}

        self._event_server = event_server
        self._event_server.register(self.handle_msg)
        self._started = []
        self._subscribers = []

    def subscriber_add(self, subscriber):
        """
        Adds a subscriber to the list of subscribers.

        Must be called before starting the testcase.
        """
        self._subscribers.append(subscriber)

    def configure_tasks(self):
        """Sets up the test run."""

        self._cdf.set_target(len(self._subscribers))
        self._outstanding = len(self._subscribers)
        for i in range(0, self._outstanding):
            ms_name = "%.5d" % i

            phy = OsmoVirtPhy(self._binary_options.virtphy,
                              self._binary_options.env,
                              ms_name, self._tmp_dir)
            self._phys.append(phy)

            launcher = OsmoMobile(self._binary_options.mobile,
                                self._binary_options.env,
                                ms_name, self._tmp_dir, self.TEMPLATE_LUA,
                                self.TEMPLATE_CFG, self._subscribers[i],
                                phy.phy_filename(),
                                self._event_server.server_path())
            self._results[ms_name] = ResultStore(ms_name)
            self._mobiles.append(launcher)
        self._unstarted = copy(self._mobiles)

    def pre_launch(self, loop):
        """
        We need the virtphy's be ready when the lua script in the
        mobile comes and kicks-off the test. In lua we don't seem to
        be able to just stat/check if a file/socket exists so we need
        to do this from here.
        """
        self.log("Pre-launching all virtphy's")
        for phy in self._phys:
            phy.start(loop, self._suite_run)

        self.log("Checking if sockets are in the filesystem")
        for phy in self._phys:
            phy.verify_ready()

    def prepare(self, loop):
        self.log("Starting testcase")

        self.configure_tasks()
        self.pre_launch(loop)

        self._start_time = time.clock_gettime(time.CLOCK_MONOTONIC)
        self._end_time = self._start_time + \
                            self._cdf.duration().total_seconds() + \
                            timedelta(seconds=120).total_seconds()

        self._started = []
        self._too_slow = 0

    def step_once(self, loop, current_time):
        if len(self._unstarted) <= 0:
            return current_time, None

        step_size = self._cdf.step_size().total_seconds()

        # Start
        self._cdf.step_once()

        # Check for timeout
        # start pending MS
        while len(self._started) < self._cdf.current_scaled_value() and len(self._unstarted) > 0:
            ms = self._unstarted.pop(0)
            ms.start(loop, self._suite_run)
            launch_time = time.clock_gettime(time.CLOCK_MONOTONIC)
            self._results[ms.name_number()].set_launch_time(launch_time)
            self._started.append(ms)

        now_time = time.clock_gettime(time.CLOCK_MONOTONIC)
        sleep_time = (current_time + step_size) - now_time
        if sleep_time <= 0:
            self.log("Starting too slowly. Moving on",
		    target=(current_time + step_size), now=now_time, sleep=sleep_time)
            self._too_slow += 1
            sleep_time = 0

        if len(self._unstarted) == 0:
            end_time = time.clock_gettime(time.CLOCK_MONOTONIC)
            self.log("All started...", too_slow=self._too_slow, duration=end_time - self._start_time)
            return current_time, None

        return current_time + step_size, sleep_time

    def run_test(self, loop, test_duration):
        self.prepare(loop)

        to_complete_time = self._start_time + test_duration.total_seconds()
        tick_time = self._start_time

        while not self.all_completed():
            tick_time, sleep_time = self.step_once(loop, tick_time)
            now_time = time.clock_gettime(time.CLOCK_MONOTONIC)
            if sleep_time is None:
                sleep_time = to_complete_time - now_time
            if sleep_time < 0:
                break
            loop.schedule_timeout(sleep_time)
            loop.select()

    def stop_all(self):
        for launcher in self._started:
            launcher.terminate()

    def handle_msg(self, _data, addr, time):
        import json
        data = json.loads(_data.decode())

        if data['type'] == 'register':
            ms = self._results[data['ms']]
            ms.set_start_time(time)
            launch_delay = ms.start_time() - ms.launch_time()
            self.log("MS start registered ", ms=ms, at=time, delay=launch_delay)
        elif data['type'] == 'event':
            if data['data']['lu_done'] == 1:
                ms = self._results[data['ms']]
                if not has_lu_time(ms):
                    self._outstanding = self._outstanding - 1
                set_lu_time(ms, time)
                self.log("MS performed LU ", ms=ms, at=time, lu_delay=lu_delay(ms))
        else:
            print(time, data)
            raise Exception("Unknown event type..:" + _data.decode())


    def all_completed(self):
        return self._outstanding == 0

    def find_min_max(self, results):
        min_value = max_value = None
        for result in results:
            if min_value is None or lu_delay(result) < min_value:
                min_value = lu_delay(result)
            if max_value is None or lu_delay(result) > max_value:
                max_value = lu_delay(result)
        return min_value, max_value

    def get_result_values(self):
        """
        Returns the raw result values of the test run in any order.
        """
        return self._results.values()

    def get_stats(self):
        """
        Returns a statistical summary of the test.
        """
        attempted = len(self._subscribers)
        completed = attempted - self._outstanding
        min_latency, max_latency = self.find_min_max(filter(lambda x: has_lu_time(x), self._results.values()))
        return LUStats(attempted, completed, min_latency, max_latency)

    def print_stats(self):
        stats = self.get_stats()
        all_completed = stats.num_attempted == stats.num_completed

        self.log("Tests done", all_completed=all_completed,
                    min=stats.min_latency, max=stats.max_latency)

    def lus_less_than(self, acceptable_delay):
        """
        Returns LUs that completed within the acceptable delay.
        """
        res = []
        for result in self._results.values():
            if not has_lu_time(result):
                continue
            if timedelta(seconds=lu_delay(result)) >= acceptable_delay:
                continue
            res.append(result)
        return res