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

import pytz
import telnetlib3

from core.constants import SERVER_OWNER_CALLSIGN
from data.spot import Spot
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 = None
        self.run = True

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

    def start(self):
        self.thread = Thread(target=self.handle)
        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"
                    self.telnet = telnetlib3.Telnet(self.hostname, self.port)
                    self.telnet.read_until("login: ".encode("ascii"))
                    self.telnet.write((SERVER_OWNER_CALLSIGN + "\n").encode("ascii"))
                    connected = True
                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("ascii"))
                    match = self.LINE_PATTERN.match(telnet_output.decode("ascii"))
                    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)

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

            self.status = "Disconnected"