"""
Virtual Mirror / MLD chaffing v2, redacted public skeleton.

This file documents the control flow used in the article. It intentionally omits
controller secrets, real target lists, node topology, and deployment settings.
It is not a complete runtime configuration.
"""

import os
import random
import threading
import time

IDLE_THRESHOLD_BPS = 15 * 1024
CHECK_INTERVAL_SECONDS = 0.5
JITTER_RANGE_SECONDS = (0.1, 0.3)
PADDING_RANGE = (15, 450)
METHOD_WEIGHTS = {"GET": 80, "HEAD": 20}
MAX_GET_BYTES = 1024

LOCAL_PROXY = os.environ.get("MLD_LOCAL_PROXY", "http://127.0.0.1:<local-proxy-port>")
CONTROLLER_URL = os.environ.get("MLD_CONTROLLER_URL", "http://127.0.0.1:<controller-port>")
CONTROLLER_SECRET = os.environ.get("MLD_CONTROLLER_SECRET", "")


current_down_bps = 0
current_up_bps = 0


def monitor_controller_traffic() -> None:
    """Stream local controller traffic counters and update global rates."""
    raise NotImplementedError("Redacted: wire this to a local, authorized controller API only.")


def choose_allowlisted_target() -> str:
    """Return a URL from a private allowlist controlled by the operator."""
    raise NotImplementedError("Redacted: the public resource does not publish a live target list.")


def random_ascii(length: int) -> str:
    alphabet = "abcdefghijklmnopqrstuvwxyz0123456789"
    return "".join(random.choice(alphabet) for _ in range(length))


def fire_micro_pulse() -> None:
    """Emit one bounded, web-like micro-pulse through the local proxy."""
    target_url = choose_allowlisted_target()
    padding = random_ascii(random.randint(*PADDING_RANGE))
    method = random.choices(
        list(METHOD_WEIGHTS.keys()),
        weights=list(METHOD_WEIGHTS.values()),
        k=1,
    )[0]

    # Redacted: send GET or HEAD through LOCAL_PROXY, read at most MAX_GET_BYTES
    # for GET, close the response, and record sanitized counters only.
    _ = (target_url, padding, method, LOCAL_PROXY, MAX_GET_BYTES)


def run_chaffing_daemon() -> None:
    threading.Thread(target=monitor_controller_traffic, daemon=True).start()

    while True:
        time.sleep(CHECK_INTERVAL_SECONDS)
        if current_down_bps < IDLE_THRESHOLD_BPS and current_up_bps < IDLE_THRESHOLD_BPS:
            time.sleep(random.uniform(*JITTER_RANGE_SECONDS))
            threading.Thread(target=fire_micro_pulse, daemon=True).start()


if __name__ == "__main__":
    run_chaffing_daemon()