VERSION = "0.4"


"""
=================================================================
    IMPORT PYTHON PACKAGES
=================================================================
"""

#from __future__ import absolute_import

import time
from datetime import datetime, timedelta
import os
import threading, multiprocessing


"""TODO:

- 1 log par agent + lastlog (30 dernières lignes)
- 1 table par agent
- table agents_log avec log minimum pour affichage dans dashboard, et ordre chrono intéressant pour suivi activité : nom agent, timestamp, message
- table agent_<agent-name>_vars : nom variable, value, desc

"""


# from django.core.exceptions import ObjectDoesNotExist
# from django.db.models import Q
from django.shortcuts import get_object_or_404
from django.conf import settings as djangosettings

import utils.Logger as L

from config.configpyros import ConfigPyros

"""
import observation_manager
import observation_manager.tasks
import scheduler
import scheduler.tasks as sched_task
import monitoring.tasks
import alert_manager.tasks
"""
# from common.models import *
from common.models import Config, Log, PlcDeviceStatus
from common.models import AgentSurvey, Command
from dashboard.views import get_sunelev
from devices.TelescopeRemoteControlDefault import TelescopeRemoteControlDefault

"""
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 *
"""

from threading import Thread




"""
=================================================================
    GENERAL MODULE CONSTANT DEFINITIONS
=================================================================
"""

DEBUG_FILE = False

log = L.setupLogger("AgentLogger", "Agent")




"""
=================================================================
    class StoppableThread
=================================================================
"""

class StoppableThread(threading.Thread):
    """Thread class with a stop() method. The thread itself has to check
    regularly for the stopped() condition."""
    # See also https://www.oreilly.com/library/view/python-cookbook/0596001673/ch06s03.html

    def __init__(self, *args, **kwargs):
        super(StoppableThread, self).__init__(*args, **kwargs)
        self._stop_event = threading.Event()

    def stop(self):
        self._stop_event.set()

    def stopped(self):
        return self._stop_event.is_set()


"""
=================================================================
    class Agent
=================================================================
"""

class Agent:
    # (EP) do this so that Majordome can be run from a thread, and called with thread.start():
    # class Majordome(Task, Thread):

    # FOR TEST ONLY
    # Run this agent in simulator mode
    SIMULATOR_MODE = True
    SIMULATOR_COMMANDS = iter([
        "go_active",
        "go_idle",

        # specific0 not_executed_because_idle
        "specific0",

        "go_active",

        # specific1 executed_because_not_idle
        "specific1",

        # specific2 executed_later_because_waiting_for_previous_specific_command_to_finish
        "specific2",

        # Should abort the current running command (which should normally be specific1)
        # even if specific2 is already pending
        "abort",

        # specific3 executed_later_because_waiting_for_previous_specific_command_to_finish
        "specific3",


        "go_active",
        "go_idle",

        # Should stop the agent even before the previous pending commands are executed
        "exit",

        # Because of the previous "exit" command,
        # these following commands should not be executed,
        # even not be added to the database command table
        "go_active",
        "specific4"
    ])
    #_simulator_current_cmd_idx = 0
    #_current_test_cmd = None
    #_nb_test_cmds = 0

    # Run for real, otherwise just print messages without really doing anything
    FOR_REAL = True

    #COMMANDS_PEREMPTION_HOURS = 48
    #COMMANDS_PEREMPTION_HOURS = 60/60

    name = "Generic Agent"
    mainloop_waittime = 3
    subloop_waittime = 2
    status = None
    mode = None
    config = None

    # Statuses
    STATUS_LAUNCH = "LAUNCHED"
    STATUS_INIT = "INITIALIZING"
    STATUS_MAIN_LOOP = "IN_MAIN_LOOP"
    STATUS_GET_NEXT_COMMAND = "IN_GET_NEXT_COMMAND"
    STATUS_GENERAL_PROCESS = "IN_GENERAL_PROCESS"
    STATUS_ROUTINE_PROCESS = "IN_ROUTINE_PROCESS"
    STATUS_SPECIFIC_PROCESS = "IN_SPECIFIC_PROCESS"
    STATUS_EXIT = "EXITING"

    # Modes
    MODE_ACTIVE = "ACTIVE"
    MODE_IDLE = "IDLE"

    DEFAULT_CONFIG_FILE_NAME = "config_unit_simulunit1.xml"
    CONFIG_DIR = "config"

    _agent_survey = None
    _pending_commands = []
    _current_specific_cmd = None
    _current_specific_thread = None

    _iter_num = 1

    def __init__(self, name:str="Agent", config_filename:str=None):
        self.set_status(self.STATUS_LAUNCH)
        self.set_mode(self.MODE_IDLE)
        self.name = name
        if not config_filename:
            #config_filename = '/PROJECTS/GFT/SOFT/PYROS_SOFT/CURRENT/config/config_unit_simulunit1.xml'
            config_filename = self.DEFAULT_CONFIG_FILE_NAME
        #config_file_path, _ = os.path.split(config_filename)
        if config_filename == os.path.basename(config_filename):
            config_filename = os.path.abspath(self.CONFIG_DIR + os.sep + config_filename)
        print("Config file used is", config_filename)
        #print("current path", os.getcwd())
        #print("this file path :", __file__)
        #print("config file path is", config_filename)
        # Instantiate an object for configuration
        #print("config file path is ", config_abs_filename)
        self.config = ConfigPyros(config_filename)
        if self.config.get_last_errno() != self.config.NO_ERROR:
            raise Exception(f"Bad config file name '{config_filename}', error {str(self.config.get_last_errno())}: {str(self.config.get_last_errmsg())}")

        self.set_mode_from_config(name)
        # TODO: remove
        self.set_idle()

        # Create 1st survey if none
        #tmp = AgentSurvey.objects.filter(name=self.name)
        #if len(tmp) == 0:
        #nb_agents = AgentSurvey.objects.filter(name=self.name).count()
        #if nb_agents == 0:
        if not AgentSurvey.objects.filter(name=self.name).exists():
            self._agent_survey = AgentSurvey.objects.create(name=self.name, validity_duration_sec=60, mode=self.mode, status=self.status)
            print("Agent survey is", self._agent_survey)
            #self._agent_survey = AgentSurvey(name=self.name, validity_duration_sec=60, mode=self.mode, status=self.status)
            #self._agent_survey.save()


    def __str__(self):
        return "I am agent " + self.name

    def run(self, FOR_REAL: bool = True):
        """
            FOR_REAL: set to False if you don't want Majordome to send commands to devices
        """

        self.FOR_REAL = FOR_REAL

        self.load_config()

        self.init()

        # Avoid blocking on false "running" commands
        # (old commands that stayed with "running" status when agent was killed)
        Command.delete_commands_with_running_status_if_exists_for_agent(self.name)

        '''
        print()
        print(self)
        print("FOR REAL ?", self.FOR_REAL)
        print("DB3 used is:", djangosettings.DATABASES["default"]["NAME"])

        # SETUP
        try:
            self.config = get_object_or_404(Config, id=1)
            # By default, set mode to SCHEDULER (False = REMOTE, which should never be the default)
            self.config.global_mode = True
            self.config.save()
            # self.config = Config.objects.get(pk=1)
            # self.config = Config.objects.get()[0]
        except Exception as e:
            # except Config.ObjectDoesNotExist:
            print("Config read (or write) exception", str(e))
            return -1
        '''

        # Main loop
        while True:

            print()
            print()
            #print("-"*80)
            print("-"*20, f"MAIN LOOP ITERATION {self._iter_num} (START)", "-"*20)
            self.set_status(self.STATUS_MAIN_LOOP)
            self.show_mode_and_status()

            self.load_config()

            self.update_survey()

            if self.SIMULATOR_MODE: self.simulator_send_command_to_myself()

            # generic cmd in json format
            print("---")
            cmd = self.get_next_valid_command()

            if cmd: cmd = self.general_process(cmd)
            '''
            if self.config.majordome_state == "STOP":
                break
            if self.config.majordome_state == "RESTART":
                self.config.majordome_restarted = True
                self.closing_mode = self.config.majordome_state
                self.config.majordome_state = "RUNNING"
                self.config.save()
            '''

            self.routine_process()

            # Sub-level loop (only if ACTIVE)
            if self.is_active():
                if cmd: self.specific_process(cmd)
            print("---")

            # Every N iterations, delete old commands
            N=3
            if ((self._iter_num-1) % N) == 0: Command.purge_old_commands_for_agent(self.name)

            self.waitfor(self.mainloop_waittime)

            print("-"*20, "MAIN LOOP ITERATION (END)", "-"*20)
            #print("-"*80)

            #self.do_log(LOG_DEBUG, "Ending main loop iteration")

            self._iter_num += 1



    def routine_process(self):
        self.set_status(self.STATUS_ROUTINE_PROCESS)


    """
    def purge_commands(self):
        ###
        Delete commands (which I am recipient of) older than COMMANDS_PEREMPTION_HOURS (like 48h)
        ATTENTION !!! EXCEPT the RUNNING command !!!

        NB: datetime.utcnow() is equivalent to datetime.now(timezone.utc)
        ###

        print("Looking for old commands to purge...")
        ###
        COMMAND_PEREMPTION_DATE_FROM_NOW = datetime.utcnow() - timedelta(hours = self.COMMANDS_PEREMPTION_HOURS)
        #print("peremption date", COMMAND_PEREMPTION_DATE_FROM_NOW)
        old_commands = Command.objects.filter(
            # only commands for me
            receiver = self.name,
            # only pending commands
            sender_deposit_time__lt = COMMAND_PEREMPTION_DATE_FROM_NOW,
        )
        ###
        old_commands = Command.get_old_commands_for_agent(self.name)
        if old_commands.exists():
            print("Found old commands to delete:")
            for cmd in old_commands: print(cmd)
            old_commands.delete()
    """

    def waitfor(self, nbsec):
            print(f"Now, waiting for {nbsec} seconds...")
            time.sleep(nbsec)

    def set_status(self, status:str):
        print(f"[[NEW CURRENT STATUS: {status}]] (switching from status {self.status})")
        self.status = status
        return False

    def set_mode(self, mode:str):
        print(f"Switching from mode {self.mode} to mode {mode}")
        self.mode = mode

    def is_active(self):
        return self.mode == self.MODE_ACTIVE

    def set_active(self):
        self.set_mode(self.MODE_ACTIVE)

    def set_idle(self):
        self.set_mode(self.MODE_IDLE)

    def show_mode_and_status(self):
        print(f"CURRENT MODE is {self.mode} (with status {self.status})")

    def die(self):
        self.set_status(self.STATUS_EXIT)

    """
    suspend/resume
    """
    def suspend(self):
        """
        TODO:
        Mode IDLE (doit rester à l'écoute d'un resume, 
        et doit continuer à alimenter les tables pour informer de son état via tables agents_logs, 
        et lire table agents_command pour reprendre via resume, 
        et update la table agents_survey pour donner son status "idle"
        """
        self.set_idle()
        return True

    def resume(self):
        """
        Quit suspend() mode
        """
        self.set_active()
        return True

    def set_mode_from_config(self, agent_alias):
        # --- Get the startmode of the AgentX
        modestr = self.config.get_paramvalue(agent_alias,'general','startmode')
        if self.config.get_last_errno() != self.config.NO_ERROR:
            raise Exception(f"error {str(self.config.get_last_errno())}: {str(self.config.get_last_errmsg())}")        
        if (modestr == None):
            return True
        # --- Set the mode according the startmode value
        mode = self.MODE_IDLE
        if modestr.upper() == 'RUN':
            mode = self.MODE_ACTIVE
        self.set_mode(mode)
        return True


    """
    =================================================================
    Generic methods that may be specialized (overriden) by subclasses
    =================================================================
    """

    def init(self):
        print("Initializing...")
        self.set_status(self.STATUS_INIT)

    def load_config(self):
        """
        TODO:
        only si date fichier xml changée => en RAM, un objet Config avec méthodes d'accès, appelle le parser de AK (classe Config.py indépendante)
        """
        print("Loading the config file...")
        #config_filename = 'c:/srv/develop/pyros/config/config_unit_simulunit1.xml'
        #config.set_configfile(config_filename)
        self.config.load()
        if self.config.get_last_errno() != self.config.NO_ERROR:
            raise Exception(f"error {str(self.config.get_last_errno())}: {str(self.config.get_last_errmsg())}")
        # --- display informations
        # --- Get all the assembly of this unit[0] (mount + channels)
        if self.config.is_config_contents_changed():
            print("--------- Components of the unit -----------")
            print("Configuration file is {}".format(self.config.get_configfile()))            
            alias = self.config.get_aliases('unit')[0]
            namevalue = self.config.get_paramvalue(alias,'unit','name')
            print("Unit alias is {}. Name is {}".format(alias,namevalue), ":")
            unit_subtags = self.config.get_unit_subtags()
            for unit_subtag in unit_subtags:
                aliases = self.config.get_aliases(unit_subtag)
                for alias in aliases:
                    namevalue = self.config.get_paramvalue(alias,unit_subtag,'name')
                    print(f"- {unit_subtag} alias is {alias}. Name is {namevalue}")
            print("------------------------------------------")
            #params = self.config.get_params(unit_alias)
            #for param in params:
            #    print("Unit component is {}".format(param))

        """
        # self.config = Config.objects.get(pk=1)
        try:
            self.config = get_object_or_404(Config, id=1)
            # By default, set mode to SCHEDULER (False = REMOTE, which should never be the default)
            # self.config.global_mode = True
            # self.config.save()
            # self.config = Config.objects.get(pk=1)
            # self.config = Config.objects.get()[0]
        except Exception as e:
            # except Config.ObjectDoesNotExist:
            # except Config.DoesNotExist:
            print("Config read (or write) exception", str(e))
            # return self.config
            # return -1
            return False
        """

    def update_survey(self):
        print("Updating the survey database table...")
        self._agent_survey = AgentSurvey.objects.get(name=self.name)
        self._agent_survey.mode = self.mode
        self._agent_survey.status = self.status
        self._agent_survey.save()


    def simulator_send_command_to_myself(self):
        #self._current_test_cmd = "go_idle" if self._current_test_cmd=="go_active" else "go_active"
        #if self._nb_test_cmds == 4: self._current_test_cmd = "exit"
        cmd_name = next(self.SIMULATOR_COMMANDS, None)
        if not cmd_name: return
        Command.objects.create(sender=self.name, receiver=self.name, name=cmd_name)
        #time.sleep(1)
        #self._simulator_current_cmd_idx += 1
        #self._nb_test_cmds += 1


    def get_next_valid_command(self)->Command:
        """
        Return next VALID (not expired) command (read from the DB command table)
        which is relevant to this agent.
        Commands are read in chronological order
        """
        self.set_status(self.STATUS_GET_NEXT_COMMAND)
        print("Looking for new commands from the database ...")

        # 1) Get all pending commands for me (return if None)
        self._pending_commands = Command.get_pending_commands_for_agent(self.name)
        commands = self._pending_commands
        if commands is None: return None
        print("Current pending commands are (time ordered) :")
        Command.show_commands(commands)

        # 2) If there is a "exit" or "abort" command pending (even at the end of the list),
        # which is VALID (not expired),
        # then pass it straight away to general_process() for execution
        for cmd in commands: 
            if cmd.name in ("exit", "abort"): break
        if cmd.name in ("exit", "abort") and not cmd.is_expired(): return cmd

        # 3) If first (oldest) command is currently running
        # (status CMD_RUNNING), then do nothing and return
        """
        cmd_executing = Command.objects.filter(
            # only commands for me
            receiver = self.name,
            # only pending commands
            receiver_status_code = Command.CMD_STATUS_CODES.CMD_RUNNING,
        ).first()
        #if cmd_executing.exists():
        if cmd_executing:
        """
        cmd = commands[0]
        if cmd.is_running():
            #print(f"There is currently a running command ({cmd_executing.first().name}), so I do nothing (wait for end of execution)")
            print(f"There is currently a running command ({cmd.name})")
            """
            # Check that this command is not expired
            if cmd.is_expired():
                print("But this command is expired, so set its status to OUTOFDATE, and go on")
                cmd_executing.set_as_outofdate()
            else:
            """
            print(f"Thus, I will do nothing until this command execution is finished")
            # TODO: kill si superieur a MAX_EXEC_TIME
            return None

        # 4) Mark all expired commands as such
        for cmd in commands: 
            if cmd.is_expired(): cmd.set_as_outofdate()
            # break at 1st "valid" command (not expired)
            else: break

        # 5) If no more commands to process, return None
        if cmd.is_expired(): return None

        # 6) Current cmd must now be a valid (not expired) and PENDING one,
        # so pass it to general_process() for execution
        #print(f"Got command {cmd.name} sent by agent {cmd.sender} at {cmd.sender_deposit_time}")
        print("Got", cmd)
        return cmd


    def general_process(self, cmd:Command)->Command:

        self.set_status(self.STATUS_GENERAL_PROCESS)
        print(f"Starting general processing of {cmd}")

        # Update read time to say that the command has been READ
        cmd.set_read_time()
        # Precondition: command cmd is valid (not expired), has already been read, is pending
        assert (not cmd.is_expired()) and cmd.is_pending() and cmd.is_read() 

        #print(f"Starting general processing of command {cmd.name} sent by agent {cmd.sender} at {cmd.sender_deposit_time}")

        """
        # 2) If expired command, change its status to expired and return
        if cmd.is_expired():
            print("This command is expired, so mark it as such, and ignore it")
            cmd.set_as_outofdate()
            return None
        """

        # If cmd is generic, execute it, change its status to executed, and return
        if cmd.is_generic():
            print("This command is generic, execute it...")
            self.exec_generic_cmd(cmd)
            # If cmd is "exit", kill myself (without any question, this is an order soldier !)
            # This "exit" should normally kill any current thread (to be checked...)
            if cmd.name == "exit": exit(0)
            # Command is executed, so return None
            return None

        # cmd is not generic
        else:
            # cmd is not generic but, as I am idle, change its status to SKIPPED, ignore it, and return
            #if self.mode == self.MODE_IDLE:
            if not self.is_active():
                print("This command is not generic but, as I am IDLE, I mark it SKIPPED and ignore it")
                cmd.set_as_skipped()
                return None

        # Je suis pas idle et cde pas générique: je la traite pas, elle sera traitée par core_process :
        # attendre que cette commande soit exécutée avant de passer à la commande suivante (situation “bloquante” normale)
        print("This command is not generic and, as I am not IDLE, I pass it to the specific processing")
        print("(then I will not execute any other new command until this command is EXECUTED)")
        return cmd


    def exec_generic_cmd(self, cmd:Command):
        print("Starting execution of a Generic cmd...")
        cmd.set_as_running()

        # Executing command
        if cmd.name == "go_active": 
            self.set_active()
            time.sleep(1)
        if cmd.name == "go_idle": 
            self.set_idle()
            time.sleep(1)
        # If cmd is "abort", kill any currently running thread
        if cmd.name == "abort":
            print("Current pending commands are:")
            Command.show_commands(self._pending_commands)
            print("Aborting current executing command if exists:")
            self.kill_running_specific_command_if_exists()

        cmd.set_as_processed()
        print("...Generic cmd has been executed")




    def do_log(self):
        """
        log à 2 endroits ou 1 seul
        - in file
        - in db
        """
        print("Logging data...")


    def specific_process(self, cmd:Command):
        """
        Sublevel Loop (only if ACTIVE) :
        """
        self.set_status(self.STATUS_SPECIFIC_PROCESS)
        assert self.is_active()

        self._current_specific_cmd = cmd
        print("Starting specific process...")
        #self._current_thread = threading.Thread(target=self.exec_command)
        self._current_specific_thread = StoppableThread(target=self.exec_specific_command, args=(cmd,))
        self._current_specific_thread.start()
        #my_thread.join()
        #self.waitfor(self.subloop_waittime)
        print("Ending specific process (thread has been launched)")

    """
    def get_current_specific_command(self):
        return self._current_specific_cmd
    """

    def exec_specific_command(self, cmd:Command):
        """ specific command execution setup """
        #cmd = self.get_current_specific_command()
        print(">>>>> Thread starting execution of ", cmd)
        print(">>>>> PID: %s, Process Name: %s, Thread Name: %s" % (
            os.getpid(),
            multiprocessing.current_process().name,
            threading.current_thread().name)
        )
        cmd.set_as_running()

    def exec_specific_command_finished(self, cmd:Command):
        """ specific command execution tear up """
        cmd.set_as_processed()
        print(">>>>> Thread ended execution of command", cmd.name)
        cmd = None
        # No more current thread
        self._current_specific_thread = None


    def kill_running_specific_command_if_exists(self):
        if self._current_specific_thread:
            print(f"Killing command {self._current_specific_cmd.name}")
            # Ask the thread to stop itself
            self._current_specific_thread.stop()
            # Now, wait for the end of the thread
            self._current_specific_thread.join()
            self._current_specific_thread = None
            self._current_specific_cmd.set_as_killed()
            self._current_specific_cmd = None

    """ 
    ===================================
    OLD FUNCTIONS TO BE REMOVED 
    ===================================
    """

    def _plc_is_not_auto(self):
        if not self.plc_is_connected():
            return True
        # now, self.plc_status has been updated, so check it:
        return self.plc_status.plc_mode != "AUTO"


    def plc_is_auto(self):
        return not self._plc_is_not_auto()


    def plc_is_safe(self):
        if not self.plc_is_connected():
            return False
        # now, self.plc_status has been updated, so check it:
        return self.plc_status.is_safe


    def is_night(self):
        return get_sunelev() < -10