import os
import sys

import cherrypy
from cherrypy.lib.static import serve_file
import socket

import configparser

from pubsub import pub
import time

PATH = os.path.dirname(os.path.abspath(__file__))

config = configparser.ConfigParser()
config.read("config.ini")
TIMEOUT = 60 #sec


class MainApp:

    def __init__(self):
        self.received_data = None

    @cherrypy.expose
    def submit(self, topic, data):
        """
        This is where publisher can submit data
        """
        pub.sendMessage(topic, data=data)
        return "Published data to {}".format(topic)
    
    def msg_listener(self, data):
        self.received_data = data
        

    @cherrypy.expose
    def poll(self, topic):
        """
        Subscribers wait here for changes
        """
        
        pub.subscribe(self.msg_listener, topic)

        # wait for the data to come
        rcv_data = self.received_data
        s = time.time()
        while not rcv_data and (time.time() - s) < TIMEOUT:
            rcv_data = self.received_data
        
        if (time.time() - s) > TIMEOUT:
            raise cherrypy.HTTPError(408, "Timeout Error. Publisher did not publish any data")
        
        self.received_data = None
        pub.unsubscribe(self.msg_listener, topic)
        return rcv_data


ROOT = MainApp()

if __name__ == "__main__":
    cherrypy.server.socket_host = config["server"].get("server_host", "127.0.0.1")
    cherrypy.server.socket_port = config["server"].getint("server_port", 8081)
    ENGINE = cherrypy.engine

    cherrypy.tree.mount(ROOT)
    if hasattr(ENGINE, "signal_handler"):
        ENGINE.signal_handler.subscribe()
    if hasattr(ENGINE, "console_control_handler"):
        ENGINE.console_control_handler.subscribe()
    try:
        ENGINE.start()
    except Exception:
        sys.exit(1)
    else:
        ENGINE.block()