import socket
import threading
import logging

from core.peer import BankPeer


class BankScanner(threading.Thread):
    def __init__(self, host: str, port: str, result_peer: BankPeer, bank_found_event: threading.Event, lock: threading.Lock, timeout: int):
        super().__init__(name="BankScannerThread-{self.host}:{port}")
        self.logger = logging.getLogger(__name__)
        self.host = host
        self.port = port
        self.result_peer = result_peer
        self.bank_found_event = bank_found_event
        self.lock = lock
        self.timeout = timeout

    def run(self):
        if self.bank_found_event.is_set():
            return

        self.__probe_for_open_ports(self.host, self.port)

    def __probe_for_open_ports(self, host: str, port: int):
        try:
            connection = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
            connection.settimeout(self.timeout)
            connection.connect((host, port))
            self.__scan_for_bank(connection)
        except socket.timeout:
            self.logger.debug("Connection for port %d timed out", port)
        except socket.error as e:
            if e.errno == 111:  # Connection refused
                self.logger.debug("Port %d not open", port)
            else:
                self.logger.debug("Unknown error occurred when probing port: %s", e)

    def __scan_for_bank(self, connection: socket.socket):
        ping_command = "BC"
        connection.sendall(ping_command.encode("utf-8"))
        response = connection.recv(1024).decode("utf-8")

        if response.strip() == f"BC {self.host}":
            self.logger.debug("Bank application found on %s:%s", self.host, self.port)

            with self.lock:
                if not self.bank_found_event.is_set():
                    self.result_peer.port = self.port
                    self.result_peer.bank_socket = connection
                    self.bank_found_event.set()
        else:
            self.logger.debug("Port is open, but no bank application found")