from __future__ import absolute_import
from django.core.exceptions import ObjectDoesNotExist
import scheduler
import scheduler.tasks
from celery.task import Task
from celery import app
import observation_manager
import observation_manager.tasks
from common.models import *
from devices.Telescope import TelescopeController
from devices.CameraVIS import VISCameraController
from devices.CameraNIR import NIRCameraController
from devices.PLC import PLCController
from django.conf import settings
from utils.JDManipulator import *
import utils.config as L
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 = ""
    timers = {}
    functions = {}
    schedule = None
    majordome_status = "STARTING"

    '''
        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()
        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.updateSoftware()
        self.setContext()
        self.setTime()
        self.majordome_status = "EXECUTING"
        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 avec the starting configurations.
    '''
    def waitDevices(self):
        nir_st = ""
        vis_st = ""
        tel_st = ""

        while nir_st != "IDLE" or vis_st != "IDLE" and tel_st != "IDLE":
            nir_st = self.nir_camera.get("STATUS")
            vis_st = self.vis_camera.get("STATUS")
            tel_st = self.tel.get("STATUS")

        print("Devices ready !")
        return (0)

    '''
        Computes the beginning and the end of the following (or current) night
    '''
    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.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
        }
        if (settings.DEBUG):
            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
        }
        return (0)

    # TODO adapt timers if the majordome is started during the night
    def adaptTimers(self):
        pass

    '''
        Infinite loop according to the majordome behavior
    '''
    def loop(self):
        while (self.majordome_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.functions[timer_name]()
                    else:
                        if (settings.DEBUG):
                            log.info("Timer : " + str(timer_name) + "is not known by the Majordome")
                    if (settings.DEBUG):
                        log.info("Timer : " + str(timer_name) + " executed")
        return (0)

    def handleEnvironmentTimer(self):
        self.timers["environment"] = self.timer_plc
        try:
            site_status = SiteWatch.objects.latest('updated')
            weather_status = WeatherWatch.objects.latest('updated')
        except ObjectDoesNotExist:
            if (settings.DEBUG):
                log.info("No site_status or weather_status found in database")
            return (1)
        self.handlePLC(site_status, weather_status)
        return (0)

    def handleStatusTimer(self):
        self.timers["status"] = self.timer_status
        self.status_tel = self.tel.get("STATUS")
        self.status_nir = self.nir_camera.get("STATUS")
        self.status_vis = self.vis_camera.get("STATUS")
        self.handleStatus()
        return (0)

    def handleSequenceTimer(self):
        self.timers["sequence"] = self.timer_sequence
        if (self.isValidStatus(self.status_tel)):
            if (self.executing_sequence != None):
                self.handleSequence(self.executing_sequence[0],
                                    self.executing_sequence[1], self.executing_sequence[2])
        else:
            self.notifyTelescopeStatus("sequence")
        return (0)

    def handleScheduleTimer(self):
        self.timers["schedule"] = self.timer_schedule
        if (self.isValidStatus(self.status_tel)):
            if (self.schedule == None):
                try:
                    self.schedule = Schedule.objects.latest('created')
                except ObjectDoesNotExist:
                    if (settings.DEBUG):
                        log.info("No schedule found in database")
                    return (1)
            else:
                try:
                    schedule = Schedule.objects.latest('created')
                except ObjectDoesNotExist:
                    if (settings.DEBUG):
                        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(status=Sequence.PENDING).order_by('tsp')
                self.executeSchedule(shs_list)
        else:
            self.notifyTelescopeStatus("scheduler")
        return (0)

    def handleNightEndTimer(self):
        self.timers["night_end"] = getNextNightEnd()
        if (self.isValidStatus(self.status_tel)):
            observation_manager.tasks.create_calibrations.delay()
        else:
            self.notifyTelescopeStatus("night_end")
        return (0)

    def handleNightStartTimer(self):
        self.timers["night_start"] = getNextNightStart()
        if (self.isValidStatus(self.status_tel)):
            scheduler.tasks.scheduling.delay(first_schedule=False, alert=False)
        else:
            self.notifyTelescopeStatus("night_start")
        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))
        # maybe reset some variables and do a scheduling
        return (0)

    '''
        Function called when a schedule has to be executed
    '''
    def executeSchedule(self, shs_list):
        for shs in shs_list: # shs_list is sorted by tsp
            with shs.sequence as seq:
                if (seq.status == Sequence.OBSERVABLE and self.observable(seq)):
                    countdown = self.getCountdown(shs)
                    if countdown <= JulianSeconds(5) and countdown > 0:
                        if (self.executing_sequence == None):
                            self.executeSequence(shs, seq, countdown)
                        else:
                            self.setNextSequence(shs, seq, countdown)
                    else:
                        if (settings.DEBUG):
                            log.info("Sequence cannot be executed : countdown = " + str(countdown))
                else:
                    if (settings.DEBUG):
                        log.info("Sequence cannot be executed : Not observable")
        return (0)

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

    '''
        Launch the observation tasks associated to a sequence
    '''
    def executeSequence(self, shs, sequence, countdown):
        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, countdown))
                    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.DEVICE_ERROR
            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, countdown))
                    TaskId.objects.create(task_id=res.id, task="execute_plan")
                    plans_results.append(res)
            else:
                self.notifyDeviceStatus("Camera visible", "Sequence execution", self.status_vis)
                sequence.status = Sequence.DEVICE_ERROR
                sequence.save()
                return (1)
        shs.status = Sequence.EXECUTING
        sequence.status = Sequence.EXECUTING
        shs.save()
        sequence.save()
        self.executing_sequence = [shs, sequence, plans_results]
        return (0)

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

    '''
        Switch sequences
    '''
    def switchSequence(self):
        if (self.next_sequence == None):
            self.executing_sequence = None
        else:
            self.executing_sequence = None
            self.executeSequence(self.next_sequence[0],
                                 self.next_sequence[1], self.next_sequence[2])
            self.next_sequence = None
        return (0)

    '''
        Check if the current sequence is finished
    '''
    def handleSequence(self, shs, sequence, executing_plans):
        finished = False
        error = False

        for plan in executing_plans:
            try:
                if plan.ready() == False:
                    finished = True
            except Exception as e:
                error = True
                shs.status = Sequence.CANCELLED
                sequence.status = Sequence.CANCELLED
                shs.save()
                sequence.save()
                for rev in executing_plans:
                    if (not rev.failed() and rev.ready() != True):
                        app.control.revoke(rev.id)
                self.switchSequence()
                return (-1)
        if (finished):
            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.switchSequence()
        return (0)

    '''
        Function called to do an action with the devices status
    '''
    def handleStatus(self):
        # TODO switch majordome state according to devices status
        telescope = Telescope.objects.first()
        camera_nir = Detector.objects.get(name="Cagire")
        camera_vis = Detector.objects.get(name="Visible camera")
        telescope.status = self.status_tel
        camera_nir.status = self.status_nir
        camera_vis.status = self.status_vis
        telescope.save()
        camera_nir.save()
        camera_vis.save()
        return (0)

    '''
        Put the system in Pause
    '''
    def systemPause(self, duration, cause: str):
        time.sleep(duration)
        scheduler.tasks.scheduling.delay(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, site_status, weather_status):
        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 = secondsToJulianDate(getPreciseCurrentTime());
        countdown = shs.tsp - current_time
        return countdown

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

if (__name__ == "__main__"):
    m = Majordome()
    m.run()