import logging
import re
from datetime import datetime, timezone
from threading import Thread
from time import sleep

import pytz
import telnetlib3

from data.spot import Spot
from core.config import config
from providers.provider import Provider


# Provider for a DX Cluster. Hostname and port provided as parameters.
class DXCluster(Provider):
    CALLSIGN_PATTERN = "([a-z|0-9|/]+)"
    FREQUENCY_PATTERM = "([0-9|.]+)"
    LINE_PATTERN = re.compile(
        "^DX de " + CALLSIGN_PATTERN + ":\\s+" + FREQUENCY_PATTERM + "\\s+" + CALLSIGN_PATTERN + "\\s+(.*)\\s+(\\d{4}Z)",
        re.IGNORECASE)

    # Constructor requires hostname and port
    def __init__(self, hostname, port):
        super().__init__()
        self.hostname = hostname
        self.port = port
        self.telnet = None
        self.thread = Thread(target=self.handle)
        self.thread.daemon = True
        self.run = True

    def name(self):
        return "DX Cluster " + self.hostname

    def start(self):
        self.thread.start()

    def stop(self):
        self.run = False
        self.telnet.close()
        self.thread.join()

    def handle(self):
        while self.run:
            connected = False
            while not connected and self.run:
                try:
                    self.status = "Connecting"
                    logging.info("DX Cluster " + self.hostname + " connecting...")
                    self.telnet = telnetlib3.Telnet(self.hostname, self.port)
                    self.telnet.read_until("login: ".encode("utf-8"))
                    self.telnet.write((config["server-owner-callsign"] + "\n").encode("utf-8"))
                    connected = True
                    logging.info("DX Cluster " + self.hostname + " connected.")
                except Exception as e:
                    self.status = "Error"
                    logging.exception("Exception while connecting to DX Cluster Provider (" + self.hostname + ").")
                    sleep(5)

            self.status = "Waiting for Data"
            while connected and self.run:
                try:
                    # Check new telnet info against regular expression
                    telnet_output = self.telnet.read_until("\n".encode("utf-8"))
                    match = self.LINE_PATTERN.match(telnet_output.decode("utf-8"))
                    if match:
                        spot_time = datetime.strptime(match.group(5), "%H%MZ")
                        spot_datetime = datetime.combine(datetime.today(), spot_time.time()).replace(tzinfo=pytz.UTC)
                        spot = Spot(source=self.name(),
                                    dx_call=match.group(3),
                                    de_call=match.group(1),
                                    freq=float(match.group(2)),
                                    comment=match.group(4).strip(),
                                    time=spot_datetime)
                        # Fill in any blanks
                        spot.infer_missing()
                        # Add to our list
                        self.submit(spot)

                        self.status = "OK"
                        self.last_update_time = datetime.now(timezone.utc)
                        logging.debug("Data received from DX Cluster " + self.hostname + ".")

                except Exception as e:
                    connected = False
                    if self.run:
                        self.status = "Error"
                        logging.exception("Exception in DX Cluster Provider (" + self.hostname + ")")
                        sleep(5)
                    else:
                        logging.info("DX Cluster " + self.hostname + " shutting down...")
                        self.status = "Shutting down"

            self.status = "Disconnected"