#!/usr/bin/env python3
import pyshark
import argparse

def analyze_radiotap_info(pcapng_path, limit=100):
    cap = pyshark.FileCapture(
        pcapng_path,
        display_filter='radiotap.dbm_antsignal',
        use_json=True,
        include_raw=False,
        keep_packets=False
    )

    count = 0
    valid_entries = 0

    print(f"\nAnalyzing up to {limit} packets for signal/noise info...\n")

    for packet in cap:
        try:
            if not hasattr(packet, 'radiotap'):
                continue

            signal = getattr(packet.radiotap, 'dbm_antsignal', None)
            noise = getattr(packet.radiotap, 'dbm_antnoise', None)

            print(f"Packet #{count + 1}")
            print(f"  Signal: {signal} dBm")
            print(f"  Noise:  {noise} dBm")

            if signal is not None and noise is not None:
                try:
                    snr = int(signal) - int(noise)
                    print(f"  SNR:    {snr} dB")
                except ValueError:
                    print("  SNR:    [could not compute]")

            print("")
            valid_entries += 1
            count += 1
            if count >= limit:
                break

        except Exception as e:
            print(f"  [!] Error reading packet: {e}")
            continue

    cap.close()

    if valid_entries == 0:
        print("No usable radiotap signal/noise data found. Your dongle may be a liar.")
    else:
        print(f"Analyzed {valid_entries} packets with radiotap data.\n")

if __name__ == '__main__':
    parser = argparse.ArgumentParser()
    parser.add_argument('--pcapng', required=True, help='Path to your .pcapng file')
    parser.add_argument('--limit', type=int, default=100, help='Max number of packets to analyze')
    args = parser.parse_args()

    analyze_radiotap_info(args.pcapng, args.limit)