blynklib.py

# Copyright (c) 2019 Anton Morozenko
# Copyright (c) 2015-2019 Volodymyr Shymanskyy.
# See the file LICENSE for copying permission.

__version__ = '0.2.6'

import socket
import ssl
import struct
import time

LOGO = """
 ___ __ __
 / _ )/ /_ _____ / /__
 / _ / / // / _ \\/ '_/
 /____/_/\\_, /_//_/_/\\_\\
 /___/ for Python v{}\n""".format(__version__)


def stub_log(*args):
 pass


def ticks_ms():
 return int(time.time() * 1000)


def sleep_ms(ms):
 time.sleep(ms // 1000)


class BlynkError(Exception):
 pass


class RedirectError(Exception):
 def __init__(self, server, port):
 self.server = server
 self.port = port


class Protocol(object):
 MSG_RSP = 0
 MSG_LOGIN = 2
 MSG_PING = 6
 MSG_TWEET = 12
 MSG_EMAIL = 13
 MSG_NOTIFY = 14
 MSG_BRIDGE = 15
 MSG_HW_SYNC = 16
 MSG_INTERNAL = 17
 MSG_PROPERTY = 19
 MSG_HW = 20
 MSG_REDIRECT = 41
 MSG_HEAD_LEN = 5

 STATUS_INVALID_TOKEN = 9
 STATUS_NO_DATA = 17
 STATUS_OK = 200
 VPIN_MAX_NUM = 32

 _msg_id = 0

 def _get_msg_id(self, **kwargs):
 if 'msg_id' in kwargs:
 return kwargs['msg_id']
 self._msg_id += 1
 return self._msg_id if self._msg_id <= 0xFFFF else 0

 def _pack_msg(self, msg_type, *args, **kwargs):
 data = ('\0'.join([str(curr_arg) for curr_arg in args])).encode('utf-8')
 return struct.pack('!BHH', msg_type, self._get_msg_id(**kwargs), len(data)) + data

 def parse_response(self, rsp_data, msg_buffer):
 msg_args = []
 try:
 msg_type, msg_id, h_data = struct.unpack('!BHH', rsp_data[:self.MSG_HEAD_LEN])
 except Exception as p_err:
 raise BlynkError('Message parse error: {}'.format(p_err))
 if msg_id == 0:
 raise BlynkError('invalid msg_id == 0')
 elif h_data >= msg_buffer:
 raise BlynkError('Command too long. Length = {}'.format(h_data))
 elif msg_type in (self.MSG_RSP, self.MSG_PING):
 pass
 elif msg_type in (self.MSG_HW, self.MSG_BRIDGE, self.MSG_INTERNAL, self.MSG_REDIRECT):
 msg_body = rsp_data[self.MSG_HEAD_LEN: self.MSG_HEAD_LEN + h_data]
 msg_args = [itm.decode('utf-8') for itm in msg_body.split(b'\0')]
 else:
 raise BlynkError("Unknown message type: '{}'".format(msg_type))
 return msg_type, msg_id, h_data, msg_args

 def heartbeat_msg(self, heartbeat, rcv_buffer):
 return self._pack_msg(self.MSG_INTERNAL, 'ver', __version__, 'buff-in', rcv_buffer, 'h-beat', heartbeat,
 'dev', 'python')

 def login_msg(self, token):
 return self._pack_msg(self.MSG_LOGIN, token)

 def ping_msg(self):
 return self._pack_msg(self.MSG_PING)

 def response_msg(self, *args, **kwargs):
 return self._pack_msg(self.MSG_RSP, *args, **kwargs)

 def virtual_write_msg(self, v_pin, *val):
 return self._pack_msg(self.MSG_HW, 'vw', v_pin, *val)

 def virtual_sync_msg(self, *pins):
 return self._pack_msg(self.MSG_HW_SYNC, 'vr', *pins)

 def email_msg(self, to, subject, body):
 return self._pack_msg(self.MSG_EMAIL, to, subject, body)

 def tweet_msg(self, msg):
 return self._pack_msg(self.MSG_TWEET, msg)

 def notify_msg(self, msg):
 return self._pack_msg(self.MSG_NOTIFY, msg)

 def set_property_msg(self, pin, prop, *val):
 return self._pack_msg(self.MSG_PROPERTY, pin, prop, *val)

 def internal_msg(self, *args):
 return self._pack_msg(self.MSG_INTERNAL, *args)


class Connection(Protocol):
 SOCK_MAX_TIMEOUT = 5
 SOCK_TIMEOUT = 0.05
 SOCK_SSL_TIMEOUT = 1
 EAGAIN = 11
 ETIMEDOUT = 60
 RETRIES_TX_DELAY = 2
 RETRIES_TX_MAX_NUM = 3
 RECONNECT_SLEEP = 1
 TASK_PERIOD_RES = 50
 DISCONNECTED = 0
 CONNECTING = 1
 AUTHENTICATING = 2
 AUTHENTICATED = 3

 _state = None
 _socket = None
 _last_rcv_time = 0
 _last_ping_time = 0
 _last_send_time = 0

 def __init__(self, token, server='blynk-cloud.com', port=80, ssl_cert=None, heartbeat=10, rcv_buffer=1024,
 log=stub_log):
 self.token = token
 self.server = server
 self.port = port
 self.heartbeat = heartbeat
 self.rcv_buffer = rcv_buffer
 self.log = log
 self.ssl_cert = ssl_cert

 def send(self, data):
 retries = self.RETRIES_TX_MAX_NUM
 while retries > 0:
 try:
 retries -= 1
 self._last_send_time = ticks_ms()
 return self._socket.send(data)
 except (IOError, OSError):
 sleep_ms(self.RETRIES_TX_DELAY)

 def receive(self, length, timeout):
 d_buff = b''
 try:
 self._socket.settimeout(timeout)
 d_buff += self._socket.recv(length)
 if len(d_buff) >= length:
 d_buff = d_buff[:length]
 return d_buff
 except (IOError, OSError) as err:
 if 'timed out' in str(err):
 return b''
 if str(self.EAGAIN) in str(err) or str(self.ETIMEDOUT) in str(err):
 return b''
 raise

 def is_server_alive(self):
 now = ticks_ms()
 h_beat_ms = self.heartbeat * 1000
 rcv_delta = now - self._last_rcv_time
 ping_delta = now - self._last_ping_time
 send_delta = now - self._last_send_time
 if rcv_delta > h_beat_ms + (h_beat_ms // 2):
 return False
 if (ping_delta > h_beat_ms // 10) and (send_delta > h_beat_ms or rcv_delta > h_beat_ms):
 self.send(self.ping_msg())
 self.log('Heartbeat time: {}'.format(now))
 self._last_ping_time = now
 return True

 def _get_socket(self):
 try:
 self._state = self.CONNECTING
 self._socket = socket.socket()
 self._socket.connect(socket.getaddrinfo(self.server, self.port)[0][4])
 self._socket.settimeout(self.SOCK_TIMEOUT)
 if self.ssl_cert:
 # system default CA certificates case
 if self.ssl_cert == "default":
 self.ssl_cert = None
 self.log('Using SSL socket...')
 ssl_context = ssl.create_default_context(cafile=self.ssl_cert)
 ssl_context.verify_mode = ssl.CERT_REQUIRED
 self._socket.settimeout(self.SOCK_SSL_TIMEOUT)
 self._socket = ssl_context.wrap_socket(sock=self._socket, server_hostname=self.server)
 self.log('Connected to blynk server')
 except Exception as g_exc:
 raise BlynkError('Connection with the Blynk server failed: {}'.format(g_exc))

 def _authenticate(self):
 self.log('Authenticating device...')
 self._state = self.AUTHENTICATING
 self.send(self.login_msg(self.token))
 rsp_data = self.receive(self.rcv_buffer, self.SOCK_MAX_TIMEOUT)
 if not rsp_data:
 raise BlynkError('Auth stage timeout')
 msg_type, _, status, args = self.parse_response(rsp_data, self.rcv_buffer)
 if status != self.STATUS_OK:
 if status == self.STATUS_INVALID_TOKEN:
 raise BlynkError('Invalid Auth Token')
 if msg_type == self.MSG_REDIRECT:
 raise RedirectError(*args)
 raise BlynkError('Auth stage failed. Status={}'.format(status))
 self._state = self.AUTHENTICATED
 self.log('Access granted')

 def _set_heartbeat(self):
 self.send(self.heartbeat_msg(self.heartbeat, self.rcv_buffer))
 rcv_data = self.receive(self.rcv_buffer, self.SOCK_MAX_TIMEOUT)
 if not rcv_data:
 raise BlynkError('Heartbeat stage timeout')
 _, _, status, _ = self.parse_response(rcv_data, self.rcv_buffer)
 if status != self.STATUS_OK:
 raise BlynkError('Set heartbeat returned code={}'.format(status))
 self.log('Heartbeat = {} sec. MaxCmdBuffer = {} bytes'.format(self.heartbeat, self.rcv_buffer))

 def connected(self):
 return True if self._state == self.AUTHENTICATED else False


class Blynk(Connection):
 _CONNECT_TIMEOUT = 30 # 30sec
 _VPIN_WILDCARD = '*'
 _VPIN_READ = 'read v'
 _VPIN_WRITE = 'write v'
 _INTERNAL = 'internal_'
 _CONNECT = 'connect'
 _DISCONNECT = 'disconnect'
 _VPIN_READ_ALL = '{}{}'.format(_VPIN_READ, _VPIN_WILDCARD)
 _VPIN_WRITE_ALL = '{}{}'.format(_VPIN_WRITE, _VPIN_WILDCARD)
 _events = {}

 def __init__(self, token, **kwargs):
 Connection.__init__(self, token, **kwargs)
 self._start_time = ticks_ms()
 self._last_rcv_time = ticks_ms()
 self._last_send_time = ticks_ms()
 self._last_ping_time = ticks_ms()
 self._state = self.DISCONNECTED
 print(LOGO)

 def connect(self, timeout=_CONNECT_TIMEOUT):
 end_time = time.time() + timeout
 while not self.connected():
 if self._state == self.DISCONNECTED:
 try:
 self._get_socket()
 self._authenticate()
 self._set_heartbeat()
 self._last_rcv_time = ticks_ms()
 self.log('Registered events: {}\n'.format(list(self._events.keys())))
 self.call_handler(self._CONNECT)
 return True
 except BlynkError as b_err:
 self.disconnect(b_err)
 sleep_ms(self.TASK_PERIOD_RES)
 except RedirectError as r_err:
 self.disconnect()
 self.server = r_err.server
 self.port = r_err.port
 sleep_ms(self.TASK_PERIOD_RES)
 if time.time() >= end_time:
 return False

 def disconnect(self, err_msg=None):
 self.call_handler(self._DISCONNECT)
 if self._socket:
 self._socket.close()
 self._state = self.DISCONNECTED
 if err_msg:
 self.log('[ERROR]: {}\nConnection closed'.format(err_msg))
 self._msg_id = 0
 time.sleep(self.RECONNECT_SLEEP)

 def virtual_write(self, v_pin, *val):
 return self.send(self.virtual_write_msg(v_pin, *val))

 def virtual_sync(self, *v_pin):
 return self.send(self.virtual_sync_msg(*v_pin))

 def email(self, to, subject, body):
 return self.send(self.email_msg(to, subject, body))

 def tweet(self, msg):
 return self.send(self.tweet_msg(msg))

 def notify(self, msg):
 return self.send(self.notify_msg(msg))

 def set_property(self, v_pin, property_name, *val):
 return self.send(self.set_property_msg(v_pin, property_name, *val))

 def internal(self, *args):
 return self.send(self.internal_msg(*args))

 def handle_event(blynk, event_name):
 class Deco(object):
 def __init__(self, func):
 self.func = func
 # wildcard 'read V*' and 'write V*' events handling
 if str(event_name).lower() in (blynk._VPIN_READ_ALL, blynk._VPIN_WRITE_ALL):
 event_base_name = str(event_name).split(blynk._VPIN_WILDCARD)[0]
 for i in range(blynk.VPIN_MAX_NUM + 1):
 blynk._events['{}{}'.format(event_base_name.lower(), i)] = func
 else:
 blynk._events[str(event_name).lower()] = func

 def __call__(self):
 return self.func()

 return Deco

 def call_handler(self, event, *args, **kwargs):
 if event in self._events.keys():
 self.log("Event: ['{}'] -> {}".format(event, args))
 self._events[event](*args, **kwargs)

 def process(self, msg_type, msg_id, msg_len, msg_args):
 if msg_type == self.MSG_RSP:
 self.log('Response status: {}'.format(msg_len))
 elif msg_type == self.MSG_PING:
 self.send(self.response_msg(self.STATUS_OK, msg_id=msg_id))
 elif msg_type in (self.MSG_HW, self.MSG_BRIDGE, self.MSG_INTERNAL):
 if msg_type == self.MSG_INTERNAL and len(msg_args) >= 2:
 self.call_handler("{}{}".format(self._INTERNAL, msg_args[0]), msg_args[1:])
 elif len(msg_args) >= 3 and msg_args[0] == 'vw':
 self.call_handler("{}{}".format(self._VPIN_WRITE, msg_args[1]), int(msg_args[1]), msg_args[2:])
 elif len(msg_args) == 2 and msg_args[0] == 'vr':
 self.call_handler("{}{}".format(self._VPIN_READ, msg_args[1]), int(msg_args[1]))

 def read_response(self, timeout=0.5):
 end_time = time.time() + timeout
 while time.time() <= end_time:
 rsp_data = self.receive(self.rcv_buffer, self.SOCK_TIMEOUT)
 if rsp_data:
 self._last_rcv_time = ticks_ms()
 msg_type, msg_id, h_data, msg_args = self.parse_response(rsp_data, self.rcv_buffer)
 self.process(msg_type, msg_id, h_data, msg_args)

 def run(self):
 if not self.connected():
 self.connect()
 else:
 try:
 self.read_response(timeout=self.SOCK_TIMEOUT)
 if not self.is_server_alive():
 self.disconnect('Blynk server is offline')
 except KeyboardInterrupt:
 raise
 except BlynkError as b_err:
 self.log(b_err)
 self.disconnect()
 except Exception as g_exc:
 self.log(g_exc)