import getpass
import argparse
import os
import socket
import ssl
import select
import struct
import time
import platform



#if platform.system() != "Windows":
#    import signal

class MCRconException(Exception):
    pass

def timeout_handler(signum, frame):
    raise MCRconException("Connection timeout error")


class _MinecraftRcon(object):
    socket = None
    def __init__(self, host, password, port=25575, tlsmode=0, timeout=5):
        self.host = host
        self.password = password
        self.port = port
        self.tlsmode = tlsmode
        self.timeout = timeout
        #if platform.system() != "Windows":
        #    signal.signal(signal.SIGALRM, timeout_handler)
    def __enter__(self):
        self.connect()
        return self
    def __exit__(self, type, value, tb):
        self.disconnect()
    def connect(self):
        self.socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        if self.tlsmode > 0:
            ctx = ssl.create_default_context()
            if self.tlsmode > 1:
                ctx.check_hostname = False
                ctx.verify_mode = ssl.CERT_NONE
            self.socket = ctx.wrap_socket(self.socket, server_hostname=self.host)
        self.socket.connect((self.host, self.port))
        self._send(3, self.password)
    def disconnect(self):
        if self.socket is not None:
            self.socket.close()
            self.socket = None
    def _read(self, length):
        #if platform.system() != "Windows": signal.alarm(self.timeout)
        data = b""
        while len(data) < length: data += self.socket.recv(length - len(data))
        #if platform.system() != "Windows": signal.alarm(0)
        return data
    def _send(self, out_type, out_data):
        if self.socket is None:
            raise MCRconException("Must connect before sending data")
        out_payload = (
            struct.pack("<ii", 0, out_type) + out_data.encode("utf8") + b"\x00\x00"
        )
        out_length = struct.pack("<i", len(out_payload))
        self.socket.send(out_length + out_payload)
        in_data = ""
        while True:
            (in_length,) = struct.unpack("<i", self._read(4))
            in_payload = self._read(in_length)
            in_id, in_type = struct.unpack("<ii", in_payload[:8])
            in_data_partial, in_padding = in_payload[8:-2], in_payload[-2:]
            if in_padding != b"\x00\x00":
                raise MCRconException("Incorrect padding")
            if in_id == -1:
                raise MCRconException("Login failed")
            in_data += in_data_partial.decode("utf8")
            if len(select.select([self.socket], [], [], 0)[0]) == 0:
                return in_data
    def command(self, command):
        result = self._send(2, command)
        #time.sleep(0.003)  # MC-72390 workaround
        return result

def MinecraftRconCli():
    try:
        parser = argparse.ArgumentParser(description="connect to and use Minecraft Server remote console protocol")
        parser.add_argument("host", metavar="HOST", help="the host to connect to")
        parser.add_argument("--password", metavar="PASSWORD", help="the password to connect with, default is a prompt or envvar RCON_PASSWORD.")
        parser.add_argument("-p", "--port", metavar="PORT", dest="port", type=int, default=25575,help="the port to connect to")
        parser.add_argument("-t", "--tls", dest="tlsmode", action="store_true", help="connect to the server with tls encryption",)
        args = parser.parse_args()
        if not args.password and not os.environ.get("RCON_PASSWORD"): password = getpass.getpass("Password: ")
        elif os.environ.get("RCON_PASSWORD"): password = os.environ.get("RCON_PASSWORD")
        else: password = args.password
        try:
            with _MinecraftRcon(args.host, password, args.port, args.tlsmode) as mcr:
                while True:
                    cmd = input("> ")
                    if cmd.strip() == "exit": break
                    else:
                        try: print(mcr.command(cmd))
                        except (ConnectionResetError, ConnectionAbortedError):
                            print("The connection was terminated, the server may have been stopped.")
                            break
                        if cmd == "exit": break
        except ConnectionRefusedError: print("The connection could not be made as the server actively refused it.")
        except ConnectionError as e: print(e)
    except KeyboardInterrupt: pass