#!/usr/bin/env python3
"""
Quick delta clustering to show the two timing buckets that encode 0 and 1.
Requires scapy: pip install scapy
"""
from collections import Counter
import math
import sys
from typing import List
from scapy.all import rdpcap, IP, ICMP  # type: ignore


TARGET_IP = "192.168.13.37"
BIN_WIDTH = 0.05  # Seconds


def load_icmp_times(pcap_path: str) -> List[float]:
    packets = rdpcap(pcap_path)
    icmp_flow = [
        pkt
        for pkt in packets
        if IP in pkt
        and ICMP in pkt
        and (pkt[IP].src == TARGET_IP or pkt[IP].dst == TARGET_IP)
    ]
    icmp_flow.sort(key=lambda p: float(p.time))
    return [float(pkt.time) for pkt in icmp_flow]


def as_deltas(times: List[float]) -> List[float]:
    return [cur - prev for prev, cur in zip(times, times[1:])]


def bin_value(value: float) -> float:
    return round(math.floor(value / BIN_WIDTH) * BIN_WIDTH, 2)


def main() -> None:
    pcap_path = sys.argv[1] if len(sys.argv) > 1 else "../public/task.pcapng"
    deltas = as_deltas(load_icmp_times(pcap_path))

    histogram = Counter(bin_value(dt) for dt in deltas)
    print("Top timing buckets (bin width {:.2f}s):".format(BIN_WIDTH))
    for bucket, count in sorted(histogram.items(), key=lambda item: (-item[1], item[0]))[:20]:
        print(f"{bucket:>4.2f} s -> {count}")

    for center, label in ((1.2, "0"), (1.6, "1")):
        window = [dt for dt in deltas if abs(dt - center) <= 0.1]
        if window:
            avg = sum(window) / len(window)
            print(f"Near {center:.2f}s (bit {label}) count={len(window)} avg={avg:.4f}")


if __name__ == "__main__":
    main()