service.py

import sys
import requests
import json
import random
from http.server import HTTPServer, BaseHTTPRequestHandler

class MessageHandler(BaseHTTPRequestHandler):
    def __init__(self):
        BaseHTTPRequestHandler.__init__()
        self.current_timestamp = random.randint(1000, 5000)

    def do_GET(self):
        self.current_timestamp += random.randint(1, 100)
        message = "ping" if self.current_timestamp % 2 == 0 else "pong"
        return json.dumps({"message": message, "timestamp": self.current_timestamp})

def run():
    """example handler"""
    for port in range(8000, 8081):
        httpd = HTTPServer(("", port), MessageHandler)
        httpd.serve_forever()
    

class Message:
    def __init__(self, timestamp, message):
        self.timestamp = timestamp # assumed to be an int
        self.message = message

class Stream:
    def __init__(self, hostname):
        self.hostname = hostname
        
    def get():
        data = requests.get(hostname).content
        parsed = json.loads(data)
        return Message(parsed['timestamp'], parsed['message'])

def send(message):
    print(f"{message.timestamp} - {message.message}")

def main():
    port_range = range(8000, 8081)
    streams = [Stream(f"localhost:{port}") for port in port_range]
    
    messages = [stream.get() for stream in streams]
    while True:
        # re-poll from the stream that sent the most recently timestamped message.
        # on the first loop, this will be skipped.
        for i, message in enumerate(messages):
            if message is None:
                messages[i] = streams[i].get()
                
        most_recent_timestamp = sys.MAXINT
        message_index = None
        for i, message in enumerate(results):
            if message.timestamp < most_recent_timestamp:
                most_recent_timestamp = message.timestamp
                message_index = i
        
        send(message)
        messages[message_index] = None