from __future__ import absolute_import

from celery.task import Task
from django.core.exceptions import ObjectDoesNotExist
from django.db.models import Q

import observation_manager
import observation_manager.tasks
import scheduler
import scheduler.tasks as sched_task
import utils.Logger as L
import monitoring.tasks
import alert_manager.tasks
from common.models import *
from devices.CameraNIR import NIRCameraController
from devices.CameraVIS import VISCameraController
from devices.Dome import DomeController
from devices.PLC import PLCController
from devices.Telescope import TelescopeController
from majordome.MajordomeDecorators import *
from utils.JDManipulator import *

DEBUG_FILE = False
log = L.setupLogger("MajordomeTaskLogger", "Majordome")

'''
    Task to handle the execution of the program

    check the environment status in database
    check the devices status (telescope / cameras)
    check if the last schedule made has to be planned
    launch schedule's sequences
'''
class Majordome(Task):
    loop_speed = 1
    julian_div = 86400
    executing_sequence = None
    next_sequence = None
    status_tel = ""
    status_nir = ""
    status_vis = ""
    status_dom = ""
    site_status = "OK"
    weather_status = "OK"
    timers = {}
    functions = {}
    schedule = None
    available_status = []
    current_status = "RUNNING"
    alarm_list = []

    '''
        Check if the instrument status is valid
    '''
    def isValidStatus(self, status):
        # TODO REMOVE COMMENT AND CHANGE WHEN DEFINED
        # if (status == "" or status == "ERROR" or status == "FAILED" or status == "NOT_SET"):
        #     return (False)
        return (True)

    def setContext(self):
        self.tel = TelescopeController()
        self.vis_camera = VISCameraController()
        self.nir_camera = NIRCameraController()
        self.plc = PLCController()
        self.dom = DomeController()
        return (0)

    def createTask(self):
        try:
            TaskId.objects.find(task="majordome").delete()
        except Exception as e:
            log.info(str(e))
            return 1
        TaskId.objects.create(task_id=self.request.id, task="majordome")
        return 0

    def setTasks(self):
        try:
            self.monitoring_task = TaskId.objects.get(task="monitoring")
            self.alert_task = TaskId.objects.get(task="alert_manager")
        except Exception as e:
            self.monitoring_task = None
            self.alert_task = None
        return 0

    '''
        Function called by celery task
        Behavior:
            Init telescope / cameras
            set night limits
            check the software version
            launch the majordome loop
    '''
    def run(self):
        self.createTask()
        self.updateSoftware()
        self.setContext()
        self.setTime()
        self.setTasks()
        self.loop()

    '''
        Reads the softwares versions in the settings.py, store them in the DB and send them to the IC.
    '''
    def updateSoftware(self):
        versions = settings.MODULES_VERSIONS
        for module, version in versions.items():
            same_module_versions = Version.objects.filter(module_name=module)
            if same_module_versions.count() == 0:
                Version.objects.create(module_name=module, version=version)
            elif same_module_versions.order_by("-created")[0].version != version:
                Version.objects.create(module_name=module, version=version)
        return (0)

    '''
        Loop to wait for the device to be idle with the starting configurations.
    '''
    def waitDevices(self):
        while self.status_vis == "" and self.status_tel == "" and self.status_nir == "" and self.status_dom == "":
            self.status_vis = self.vis_camera.getStatus()
            self.status_nir = self.nir_camera.getStatus()
            self.status_tel = self.tel.getStatus()
            self.status_dom = self.dom.getStatus()
        return (0)

    '''
        Computes the beginning and the end of the following (or current) night
        set the timers -> maybe put timers in a config file ?
    '''
    def setTime(self):
        self.night_start = getNightStart()
        self.night_end = getNightEnd()
        self.night_start_jd = secondsToJulianDate(getNightStart())
        self.night_end_jd = secondsToJulianDate(getNightEnd())
        self.timer_night_start = self.night_start - getCurrentTime()
        self.timer_night_end = self.night_end - getCurrentTime()
        self.timer_status = 5
        self.tasks_timer = 5
        self.timer_plc = 2
        self.timer_schedule = 1
        self.timer_sequence = 1

        if (self.night_start - 120 > getCurrentTime()):
            self.timer_night_start = self.night_start - 120 - getCurrentTime()
        self.timer_night_end = self.night_end - getCurrentTime()
        if (getCurrentTime() > self.night_start):
            self.adaptTimers()

        self.timers = {
            "status": self.timer_status,
            "environment": self.timer_plc,
            "night_start": self.timer_night_start,
            "night_end": self.timer_night_end,
            "schedule": self.timer_schedule,
            "sequence": self.timer_sequence,
            "tasks": self.tasks_timer
        }
        if (settings.DEBUG and DEBUG_FILE):
            log.info("Majordome started with timers : " + str(self.timers))
        # Functions called during the loop
        self.functions = {
            "status": self.handleStatusTimer,
            "environment": self.handleEnvironmentTimer,
            "night_start": self.handleNightStartTimer,
            "night_end": self.handleNightEndTimer,
            "schedule": self.handleScheduleTimer,
            "sequence": self.handleSequenceTimer,
            "tasks": self.handleTasks
        }
        return (0)

    '''
        Function called by the main loop to handle the task event (check monitoring and alert_manager)
    '''
    def handleTasks(self):
        self.timers["tasks"] = self.tasks_timer
        if self.monitoring_task is None:
            try:
                self.monitoring_task = TaskId.objects.get(task="monitoring")
            except Exception as e:
                monitoring.tasks.Monitoring.apply_async()
                if settings.DEBUG and DEBUG_FILE:
                    log.info(str(e))
        if self.alert_task is None:
            try:
                self.alert_task = TaskId.objects.get(task="alert_manager")
            except Exception as e:
                alert_manager.tasks.AlertListener.apply_async()
                if settings.DEBUG and DEBUG_FILE:
                    log.info(str(e))
        return 0

    # TODO adapt timers if the majordome is started during the night or not ?
    def adaptTimers(self):
        pass

    def logDB(self, message: str):
        Log.objects.create(agent="Majordome", message=message)

    '''
        Infinite loop according to the majordome behavior
    '''
    def loop(self):
        while (self.current_status != "SHUTDOWN"):
            minimal_timer = min(self.timers, key=self.timers.get)
            if (self.timers[minimal_timer] > 0):
                time.sleep(self.timers[minimal_timer])
                self.timers = {key: value - self.timers[minimal_timer] for key, value in self.timers.items()}
            for timer_name, timer_value in self.timers.items():
                if (timer_value <= 0):
                    if timer_name in self.functions:
                        self.logDB("Executing timer " + str(timer_name))
                        self.functions[timer_name]()
                    else:
                        if (settings.DEBUG and DEBUG_FILE):
                            log.info("Timer : " + str(timer_name) + "is not known by the Majordome")
                        self.logDB("Timer " + str(timer_name) + " unknown")
                    if (settings.DEBUG and DEBUG_FILE):
                        log.info("Timer : " + str(timer_name) + " executed")
        return (0)

    '''
        Function called by the main loop to handle environment event (PLC info)
    '''
    def handleEnvironmentTimer(self):
        self.timers["environment"] = self.timer_plc
        self.handlePLC()
        return (0)

    '''
        Function called by the main loop to handle the devices status
    '''
    def handleStatusTimer(self):
        self.timers["status"] = self.timer_status
        self.status_tel = self.tel.getStatus()
        self.status_nir = self.nir_camera.getStatus()
        self.status_vis = self.vis_camera.getStatus()
        self.status_dom = self.dom.getStatus()
        self.handleStatus()
        return 0

    '''
        Function called by the main loop to check if the executing sequence is finished
    '''
    def handleSequenceTimer(self):
        self.timers["sequence"] = self.timer_sequence
        if (self.executing_sequence):
            self.handleSequence(self.executing_sequence[0],
                                self.executing_sequence[1], self.executing_sequence[2])
        return (0)

    '''
        Function called by the main loop to check if there is a new schedule and to execute its sequences
    '''
    def handleScheduleTimer(self):
        self.timers["schedule"] = self.timer_schedule
        if (self.isValidStatus(self.status_tel)):
            if (self.schedule is None):
                try:
                    self.schedule = Schedule.objects.latest('created')
                except ObjectDoesNotExist:
                    if (settings.DEBUG and DEBUG_FILE):
                        log.info("No schedule found in database")
                    return (1)
            else:
                try:
                    schedule = Schedule.objects.latest('created')
                except ObjectDoesNotExist:
                    if (settings.DEBUG and DEBUG_FILE):
                        log.info("No schedule found in database")
                    return (1)
                if (schedule.created != self.schedule.created):
                    self.next_sequence = None
                    self.schedule = schedule
            if (self.schedule):
                shs_list = self.schedule.shs.filter(Q(status=Sequence.PLANNED) |
                                                    Q(status=Sequence.PENDING)).order_by('tsp')
                self.executeSchedule(shs_list)
        else:
            self.notifyTelescopeStatus("scheduler")
        return (0)

    '''
        Function called by the main loop to handle the end of a night
    '''
    def handleNightEndTimer(self):
        self.timers["night_end"] = getNightEnd()
        if (self.isValidStatus(self.status_tel)):
            observation_manager.tasks.night_calibrations.apply_async()
        else:
            self.notifyTelescopeStatus("night_end")
        return (0)

    '''
        Function called by the main llop to handle the beginning of a night
    '''
    def handleNightStartTimer(self):
        self.timers["night_start"] = getNextNightStart()
        if self.isOutsideOk():
            self.dom.open()
            self.vis_camera.open_shutter()
            self.nir_camera.open_shutter()
        scheduler.tasks.scheduling.apply_async((False, False))
        return (0)

    def notifyTelescopeStatus(self, timer_name):
        return (self.notifyDeviceStatus("telescope", timer_name, self.status_tel))

    def notifyDeviceStatus(self, device_name, timer_name, status):
        Log.objects.create(agent=device_name, created=datetime.datetime.now(),
                           message="The action : " + str(timer_name) + " has been canceled : Telescope status : " + str(status))
        # TODO MAYBE reset some variables and do a scheduling
        return (0)

    '''
        Execute a schedule
    '''
    def executeSchedule(self, shs_list):
        for shs in shs_list:  # shs_list is sorted by tsp
            if (self.executableSequence(shs.sequence.status) and self.observable(shs.sequence)):
                if self.next_sequence is None:
                    self.setNextSequence(shs, shs.sequence)
                if self.isExecutable() and self.executing_sequence is None:
                    if self.isValidTimer(self.next_sequence[0]):
                        if self.executeSequence(self.next_sequence[0], self.next_sequence[1]) == -1:
                            return -1
                        if self.next_sequence[0] != shs and self.next_sequence[1] != shs.sequence:
                            self.setNextSequence(shs, shs.sequence)
                        else:
                            self.next_sequence = None
                    else:
                        return 0
            else:
                if (settings.DEBUG and DEBUG_FILE):
                    log.info("Sequence cannot be executed : Not observable")
                self.logDB("Sequence "+shs.sequence.name+" cannot be executed : Not observable")
        return 0

    def observable(self, sequence):
        if (sequence.jd2 - sequence.duration - secondsToPreciseJulianDate(getPreciseCurrentTime()) <= 0):
            return 0
        return 1

    def executableSequence(self, status):
        if status == Sequence.PLANNED or status == Sequence.PENDING:
            return 1
        return 0

    '''
        Kill the executing sequence and set its state to cancelled
    '''
    @executingSequenceExist
    def killExecutingSequence(self):
        shs = self.executing_sequence[0]
        sequence = self.executing_sequence[1]
        executing_plans = self.executing_sequence[2]

        shs.status = Sequence.CANCELLED
        sequence.status = Sequence.CANCELLED
        shs.save()
        sequence.save()
        for rev in executing_plans:
            if (not rev.failed() and not rev.successful()):
                rev.revoke(terminate=True)
        self.executing_sequence = None
        return 0

    def reset(self, type):
        if type == "WEATHER":
            self.dom.open()
            scheduler.tasks.scheduling.delay((False, False))
        elif type == "INSIDE":
            scheduler.tasks.scheduling.delay((False, False))

    '''
        Handle a new alarm (called by isInsideOk or isWeatherOk)
    '''
    @SameAlarmCheck
    def handleAlarm(self, type, pos=-1):
        if type == "WEATHER":
            #TODO send email
            self.dom.close()
            self.killExecutingSequence()
            self.vis_camera.park()
            self.nir_camera.park()
        elif type == "INSIDE":
            #TODO send email
            self.killExecutingSequence()
            self.vis_camera.park()
            self.nir_camera.park()
        elif type == "ENDED":
            if len(self.alarm_list) > 0 and pos != -1:
                ended = self.alarm_list[pos]
                del self.alarm_list[pos]
                self.reset(ended)
            return 0
        else:
            return 1
        self.alarm_list.append(type)
        return 0

    '''
        for now weather_status and site_status contains something different than OK if the status is critical
        Later we may have other states to handle
    '''
    def isOutsideOk(self) -> bool:
        self.handlePLC()
        if self.weather_status == "OK":
            if "WEATHER" in self.alarm_list:
                self.handleAlarm("ENDED", self.alarm_list.index("WEATHER"))
            return True
        self.handleAlarm("WEATHER")
        return False

    '''
        Check the telescope inside status
    '''
    def isInsideOk(self) -> bool:
        self.handlePLC()
        if self.site_status == "OK":
            if "INSIDE" in self.alarm_list:
                self.handleAlarm("ENDED", self.alarm_list.index("INSIDE"))
            return True
        self.handleAlarm("INSIDE")
        return False

    def isDevicesOk(self) -> bool:
        if self.isValidStatus(self.status_tel) and self.isValidStatus(self.status_dom)\
            and self.isValidStatus(self.status_vis) and self.isValidStatus(self.status_nir):
            return True
        return False

    def isExecutable(self) -> bool:
        if self.isValidStatus(self.status_tel) and self.isValidStatus(self.status_dom)\
                and self.isOutsideOk() and self.isInsideOk():
            return True
        return False

    '''
        check if the sequence timer is valid for execution, also check if there is a scheduling task running
    '''
    def isValidTimer(self, shs) -> bool:
        current_countdown = self.getCountdown(shs)
        if (current_countdown <= JulianSeconds(5)):
            try:
                task = TaskId.objects.filter(task="scheduling")
                if not task:
                    return True
                return False
            except:
                return True
        return False

    '''
        Launch the observation tasks NIR and VIS associated to a sequence
    '''
    def executeSequence(self, shs, sequence):
        shs.status = Sequence.EXECUTING
        sequence.status = Sequence.EXECUTING
        shs.save()
        sequence.save()
        log.info("Executing sequence id = " + str(sequence.pk))
        self.logDB("Executing sequence")
        plans_results = []
        if sequence.albums.filter(detector__name="Cagire").exists():
            if (self.isValidStatus(self.status_nir)):
                for plan in sequence.albums.get(detector__name="Cagire").plans.all():
                    res = observation_manager.tasks.execute_plan_nir.apply_async(
                        (plan.id, float(self.getCountdown(shs))))
                    # JB TODO : is it still usefull ?
                    # TaskId.objects.create(task_id=res.id, task="execute_plan")
                    plans_results.append(res)
            else:
                self.notifyDeviceStatus("Cagire", "Sequence execution", self.status_nir)
                sequence.status = Sequence.CANCELLED
                shs.status = Sequence.CANCELLED
                shs.save()
                sequence.save()
                return (1)
        if sequence.albums.filter(detector__name="Visible camera").exists():
            if (self.isValidStatus(self.status_vis)):
                for plan in sequence.albums.get(detector__name="Visible camera").plans.all():
                    res = observation_manager.tasks.execute_plan_vis.apply_async(
                        (plan.id, float(self.getCountdown(shs))))
                    plans_results.append(res)
            else:
                self.notifyDeviceStatus("Camera visible", "Sequence execution", self.status_vis)
                sequence.status = Sequence.CANCELLED
                shs.status = Sequence.CANCELLED
                shs.save()
                sequence.save()
                return (1)
        self.executing_sequence = [shs, sequence, plans_results]
        return (0)

    '''
        Set the next sequence
    '''
    def setNextSequence(self, shs, sequence):
        sequence.status = Sequence.PENDING
        shs.status = Sequence.PENDING
        self.next_sequence = [shs, sequence]
        sequence.save()
        shs.save()
        return (0)

    '''
        Check if the current sequence is finished
    '''
    def handleSequence(self, shs, sequence, executing_plans):
        count = 0
        for res in executing_plans:
            try:
                if res.successful() or res.failed():
                    count += 1
            except Exception as e:
                if DEBUG_FILE and settings.DEBUG:
                    log.info(str(e))
                shs.status = Sequence.CANCELLED
                sequence.status = Sequence.CANCELLED
                shs.save()
                sequence.save()
                for rev in executing_plans:
                    if (not rev.failed() and not rev.successful()):
                        rev.revoke(terminate=True)
                self.executing_sequence = None
                return (-1)
        if count >= len(executing_plans):
            sequence.status = Sequence.EXECUTED
            shs.status = Sequence.EXECUTED
            sequence.save()
            shs.save()
            message = "Finished sequence " + str(sequence.pk) + " execution"
            Log.objects.create(agent="Majordome", message=message)
            self.executing_sequence = None
        return (0)

    '''
        Function called to do an action with the devices status
    '''
    def handleStatus(self):
        telescope = Telescope.objects.first()
        camera_nir = Detector.objects.get(name="Cagire")
        camera_vis = Detector.objects.get(name="Visible camera")
        dome = Dome.objects.get(name="Dome")

        dome.status = self.status_dom
        telescope.status = self.status_tel
        camera_nir.status = self.status_nir
        camera_vis.status = self.status_vis

        dome.save()
        telescope.save()
        camera_nir.save()
        camera_vis.save()
        self.logDB("Instrument status : dome  = " + str(self.status_dom) + ", telescope = " + str(self.status_tel)
                   + ", camera_nir = " + str(self.status_nir) + ", camera_vis" + str(self.status_vis))
        return (0)

    '''
        Put the majordome in pause
    '''
    def systemPause(self, duration, cause: str):
        self.logDB("System in pause for " + str(duration))
        time.sleep(duration)
        scheduler.tasks.scheduling.apply_async(first_schedule=False, alert=False)
        self.setTime()
        print("system has been paused. Cause : " + cause)
        return (0)

    '''
        Function called to do an action with the site status and the wheather status
    '''
    def handlePLC(self):
        try:
            site_status = SiteWatch.objects.latest('updated')
            weather_status = WeatherWatch.objects.latest('updated')
            self.weather_status = weather_status.global_status
            self.site_status = site_status.global_status
        except ObjectDoesNotExist as e:
            if (settings.DEBUG and DEBUG_FILE):
                log.info("No site_status or weather_status found in database : " + str(e))
            # TODO shutdown everything
            return 1
        return 0

    '''
        Gets the time before the expected start of the execution.
    '''
    def getCountdown(self, shs):
        # TODO start sequence as soon as possible (a lot of verifications must be done there)
        current_time = secondsToPreciseJulianDate(getPreciseCurrentTime())
        countdown = shs.tsp - current_time
        return countdown

    '''
        Change observation conditions
    '''
    def changeObsConditions(self):
        print("change_obs_conditions")
        pass