#!/usr/bin/env python3
import sys
from http.server import BaseHTTPRequestHandler, HTTPServer

if len(sys.argv) < 2:
    print("Usage: python script.py <port_file_path>")
    sys.exit(1)

port_file_path = sys.argv[1]


class SimpleHandler(BaseHTTPRequestHandler):
    def do_GET(self):
        # Send HTTP 200 response with plain text content
        self.send_response(200)
        self.send_header("Content-type", "text/plain")
        self.end_headers()
        self.wfile.write(b"child says hi")


# Bind to localhost on port 0 to let the OS pick an available port.
server_address = ("localhost", 0)
httpd = HTTPServer(server_address, SimpleHandler)

# Retrieve the assigned port.
assigned_port = httpd.server_address[1]

# Write the port number to the provided file path.
with open(port_file_path, "w") as f:
    f.write(str(assigned_port))

try:
    # Automatically shut down the server after 2 minutes. This is a precaution to
    # prevent the server from running indefinitely incase the GET API is never called.
    httpd.timeout = 120

    # This server will exit after one request.
    httpd.handle_request()
except KeyboardInterrupt:
    print("\nServer is shutting down.")