import logging
import pydapper
from BreCal.schemas import model
from BreCal.local_db import getPoolConnection
from BreCal.database.update_database import evaluate_shipcall_state

import threading
import schedule
import time

options = {'past_days':7}

def UpdateShipcalls(options:dict = {'past_days':2}):
    """
    performs a single update step of every shipcall that matches the criteria.

    1.) opens an SQL connection
    2.) queries every shipcall that fulfills the {options} criteria
    3.) iterates over each shipcall
    4.) closes the SQL connection

    options:
        key: 'past_days'. Is used to execute a filtered query of all available shipcalls. Defaults to 2 (days)
    """
    try:
        pooledConnection = getPoolConnection()
        commands = pydapper.using(pooledConnection)

        query = ("SELECT s.id as id, ship_id, type, eta, voyage, etd, arrival_berth_id, departure_berth_id, tug_required, pilot_required, "
                "flags, s.pier_side, bunkering, replenishing_terminal, replenishing_lock, draft, tidal_window_from, tidal_window_to, rain_sensitive_cargo, recommended_tugs, "
                "anchored, moored_lock, canceled, evaluation, evaluation_message, evaluation_notifications_sent, evaluation_time, s.created as created, s.modified as modified, time_ref_point FROM shipcall s " +
                "LEFT JOIN times t ON t.shipcall_id = s.id AND t.participant_type = 8 "
                "WHERE "
                "(type = 1 AND (COALESCE(t.eta_berth, eta) >= DATE(NOW() - INTERVAL %d DAY))) OR "
                "((type = 2 OR type = 3) AND (COALESCE(t.etd_berth, etd) >= DATE(NOW() - INTERVAL %d DAY)))"
                "ORDER BY s.id") % (options["past_days"], options["past_days"])

        # obtain data from the MYSQL database
        data = commands.query(query, model=model.Shipcall)

        # get the shipcall ids, which are of interest
        shipcall_ids = [dat.id for dat in data]

        # iterate over each shipcall id and (re-) evaluate it
        for shipcall_id in shipcall_ids:
            # apply 'Traffic Light' evaluation to obtain 'GREEN', 'YELLOW' or 'RED' evaluation state. The function internally updates the mysql database
            evaluate_shipcall_state(mysql_connector_instance=pooledConnection, shipcall_id=shipcall_id) # new_id (last insert id) refers to the shipcall id

        pooledConnection.close()

    except Exception as ex:
        logging.error(ex)
    return

def add_function_to_schedule__update_shipcalls(interval_in_minutes:int, options:dict={'past_days':2}):
    kwargs_ = {"options":options}
    schedule.every(interval_in_minutes).minutes.do(UpdateShipcalls, **kwargs_)
    return

def setup_schedule(update_shipcalls_interval_in_minutes:int=60):

    logging.getLogger('schedule').setLevel(logging.INFO); # set the logging level of the schedule module to INFO

    schedule.clear() # clear all routine jobs. This prevents jobs from being created multiple times

    # update the evaluation state in every recent shipcall
    add_function_to_schedule__update_shipcalls(update_shipcalls_interval_in_minutes)

    # placeholder: create/send notifications
    # add_function_to_schedule__send_notifications(...)
    return


def run_schedule_permanently(latency:int=30):
    """permanently runs the scheduler. Any time a routine task is 'due', it will be executed. There is an interval between each iteration to reduce workload"""
    while True:
        schedule.run_pending()
        time.sleep(latency)
    return

def run_schedule_permanently_in_background(latency:int=30, thread_name:str="run_schedule_in_background"):
    """create a (daemon) thread in the background, which permanently executes the scheduled functions"""
    thread_names = [thread_.name for thread_ in threading.enumerate()]
    if not thread_name in thread_names:
        bg_thread = threading.Thread(target=run_schedule_permanently, name=thread_name, kwargs={"latency":latency})
        bg_thread.daemon = True # 'daemon': stops, when Python's main thread stops.
        bg_thread.start()
    return