import sys
import json
import websocket


class MMws:
	"""
	Mattermost websocket client
	"""

	def __init__(self, ws_handler, token, ws_url):
		"""
		@param ws_handler: callback when new data is received on websocket
		@param token: Mattermost access token
		@param ws_url: websocket URL to connect to
		"""
		self.token = token
		self.ws_url = ws_url
		self.ws_handler = ws_handler

		self.ws_app = None


	def run_websocket(self):
		def on_open(ws):
			ws.send(json.dumps({
				"seq": 1, "action": "authentication_challenge", "data": {"token": self.token}
			}))

		def on_message(ws, msg):
			self.ws_handler(self, json.loads(msg))

		def on_error(ws, error):
			raise error

		self.ws_app = websocket.WebSocketApp(
			self.ws_url, on_open=on_open, on_message=on_message, on_error=on_error
		)
		self.ws_app.run_forever()