import os
import websocket
#to import the correct version of thread regardless of python version
try:
    import thread
except ImportError:
    import _thread as thread
import time
import json
from tiingo.exceptions import MissingRequiredArgumentError

GLOB_config=None
GLOB_on_msg_cb=None

class genericWebsocketClient:
    '''
    the methods passed to websocketClient have to be unbounded if we want WebSocketApp to pass everything correctly
    see websocket-client/#471
    '''
    def on_message(ws, message):
        GLOB_on_msg_cb(message)
    def on_error(ws, error):
        print(error)
    def on_close(ws):
        pass
    def on_open(ws):
        def run(*args):
            print(GLOB_config)
            ws.send(json.dumps(GLOB_config))
        thread.start_new_thread(run, ())
    def __init__(self,config,on_msg_cb):
        global GLOB_config
        global GLOB_on_msg_cb
        GLOB_config=config
        GLOB_on_msg_cb=on_msg_cb
        return

class TiingoWebsocketClient:
    '''
    from tiingo import TiingoWebsocketClient
    
    def cb_fn(msg):

        # Example response 
        # msg = {
        #   "service":"iex" # An identifier telling you this is IEX data. 
        #   The value returned by this will correspond to the endpoint argument.
        #   
        #   # Will always return "A" meaning new price quotes. There are also H type Heartbeat msgs used to keep the connection alive
        #   "messageType":"A" # A value telling you what kind of data packet this is from our IEX feed.
        #  
        #   # see https://api.tiingo.com/documentation/websockets/iex > Response for more info
        #   "data":[] # an array containing trade information and a timestamp
        #   
        # }

        print(msg)

    subscribe = {
            'eventName':'subscribe',
            'authorization':'API_KEY_GOES_HERE',
            #see https://api.tiingo.com/documentation/websockets/iex > Request for more info
            'eventData': { 
                'thresholdLevel':5
          }
    }
    # notice how the object isn't needed after using it
    # any logic should be implemented in the callback function 
    TiingoWebsocketClient(subscribe,endpoint="iex",on_msg_cb=cb_fn)
    while True:pass
    '''

    def __init__(self,config={},endpoint=None,on_msg_cb=None):
        
        self._base_url = "wss://api.tiingo.com"
        self.config=config
        
        try:
            api_key = self.config['authorization']
        except KeyError:
            api_key = os.environ.get('TIINGO_API_KEY')
            self.config.update({"authorization":api_key})

        self._api_key = api_key
        if not(api_key):
            raise RuntimeError("Tiingo API Key not provided. Please provide"
                               " via environment variable or config argument."
                               "Notice that this config dict takes the API Key as authorization ")

        self.endpoint = endpoint
        if not (self.endpoint=="iex" or self.endpoint=="fx" or self.endpoint=="crypto"):
            raise AttributeError("Endpoint must be defined as either (iex,fx,crypto) ")
        
        self.on_msg_cb = on_msg_cb
        if not self.on_msg_cb:
            raise MissingRequiredArgumentError("please define on_msg_cb It's a callback that gets called when new messages arrive "
                                          "Example:"
                                          "def cb_fn(msg):"
                                          "    print(msg)")

        ws_client = genericWebsocketClient(config=self.config,on_msg_cb=self.on_msg_cb)
        

        websocket.enableTrace(True)
        
        ws = websocket.WebSocketApp("{0}/{1}".format(self._base_url,self.endpoint),
                              on_message = genericWebsocketClient.on_message,
                              on_error = genericWebsocketClient.on_error,
                              on_close = genericWebsocketClient.on_close,
                              on_open = genericWebsocketClient.on_open)
        ws.run_forever()