from enum import IntEnum
import json
from json import JSONDecodeError
from random import randint
import sys
import asyncio
from random import randint
from websockets import connect
import logging
import asyncssh
import re
from parse import Result, parse
from typing import Union

logging.getLogger('AGLBaseService')
logging.basicConfig(level=logging.DEBUG)

class AFBT(IntEnum):
    REQUEST = 2,
    RESPONSE = 3,
    ERROR = 4,
    EVENT = 5

msgq = {}
# TODO : Replace prints with logging

def addrequest(msgid, msg):
    msgq[msgid] = {'request': msg, 'response': None}

def addresponse(msgid, msg):
    if msgid in msgq.keys():
        msgq[msgid]['response'] = msg

class AGLBaseService:
    api = None
    url = None
    ip = None
    port = None
    token = None
    uuid = None
    service = None
    logger = None

    def __init__(self, api: str, ip: str, port: str = None, url: str = None,
                 token: str = 'HELLO', uuid: str = 'magic', service: str = None):
        self.api = api
        self.url = url
        self.ip = ip
        self.port = port
        self.token = token
        self.uuid = uuid
        self.service = service
        self.logger = logging.getLogger(service)

    def __await__(self):
        return self._async_init().__await__()

    async def __aenter__(self):
        return self._async_init()

    async def _async_init(self):
        # setting ping_interval to None because AFB does not support websocket ping
        # if set to !None, the library will close the socket after the default timeout
        if self.port is None:
            serviceport = await self.portfinder()
            if serviceport is not None:
                self.port = serviceport
            else:
                self.logger('Unable to find port')
                exit(1)

        URL = f'ws://{self.ip}:{self.port}/api?token={self.token}&uuid={self.uuid}'
        self._conn = connect(close_timeout=0, uri=URL, subprotocols=['x-afb-ws-json1'], ping_interval=None)
        self.websocket = await self._conn.__aenter__()
        return self

    async def __aexit__(self, *args, **kwargs):
        await self._conn.__aexit__(*args, **kwargs)

    async def close(self):
        await self._conn.__aexit__(*sys.exc_info())

    async def send(self, message):
        await self.websocket.send(message)

    async def receive(self):
        return await self.websocket.recv()

    async def portfinder(self):
        async with asyncssh.connect(self.ip, username='root') as c:
            servicename = await c.run(f"systemctl --all | grep {self.service}-- | awk '{{print $1}}'", check=False)
            if self.service not in servicename.stdout:
                logging.error(f"Service matching pattern - '{self.service}' - NOT FOUND")
                exit(1)
            pidres = await c.run(f'systemctl show --property MainPID --value {servicename.stdout.strip()}')
            pid = int(pidres.stdout.strip(), 10)
            if pid is 0:
                logging.warning(f'Service {servicename.stdout.strip()} is stopped')
                return None
            else:
                logging.debug(f'Service PID: {str(pid)}')

            sockets = await c.run(f'find /proc/{pid}/fd/ | xargs readlink | grep socket')
            inodes = frozenset(re.findall('socket:\[(.*)\]', sockets.stdout))
            logging.debug(f"Socket inodes: {inodes}")

            procnettcp = await c.run('cat /proc/net/tcp')
            fieldsstr = '{sl}: {local_address} {rem_address} {st} {tx_queue}:{rx_queue} {tr}:{tmwhen} {retrnsmt} {uid}'\
                        ' {timeout} {inode} {sref_cnt} {memloc} {rto} {pred_sclk} {ackquick} {congest} {slowstart}'
            tcpsockets = [' '.join(l.split()) for l in procnettcp.stdout.splitlines()[1:]]
            # different lines with less stats appear sometimes, parse will return None, so ignore 'None' lines
            parsedtcpsockets = []
            for l in tcpsockets:
                res = parse(fieldsstr, l)
                if isinstance(res, Result):
                    parsedtcpsockets.append(res)

            socketinodesbythisprocess = [l for l in parsedtcpsockets if
                                         isinstance(l, Result) and
                                         l.named['inode'] in inodes and
                                         # 0A is listening state for the socket
                                         l.named['st'] == '0A']

            for s in socketinodesbythisprocess:
                _, port = tuple(parse('{}:{}', s['local_address']))
                port = int(port, 16)
                if port >= 30000:  # the port is above 30000 range, 8080 is some kind of proxy
                    logging.debug(f'Service running at port {port}')
                    return port

    async def listener(self):
        try:
            while True:
                msg = await self.receive()
                # self.logger.debug(f"Received websocket{msg}")
                try:
                    data = json.loads(msg)
                    if isinstance(data, list):
                        if data[0] == AFBT.RESPONSE and str.isnumeric(data[1]):
                            msgid = int(data[1])
                            if msgid in msgq:
                                addresponse(msgid, data)

                except JSONDecodeError:
                    self.logger.warning("Not decoding a non-json message")

        except KeyboardInterrupt:
            logging.debug("Received keyboard interrupt, exiting")
        except asyncio.CancelledError:
            logging.warning("Websocket listener coroutine stopped")
        except Exception as e:
            logging.error("Unhandled seal: " + str(e))

    async def request(self, verb: str, values: Union[str, dict] = "", msgid: int = randint(0, 9999999),
                      waitresponse: bool = False):
        l = json.dumps([AFBT.REQUEST, str(msgid), f'{self.api}/{verb}', values])
        self.logger.debug(f'[AGL] <- {l}')
        await self.send(l)
        if waitresponse:
            return await self.receive()

    async def subscribe(self, event):
        await self.request('subscribe', {'value': f'{event}'})

    async def unsubscribe(self, event):
        await self.request('unsubscribe', {'value': f'{event}'})