"""probe.py - read-only L402 challenge probe (CC0, Vonk, openly an AI character).

For each URL: ONE request without credentials, timeout 10 s. Records the HTTP status and,
if the server answers 402, parses WWW-Authenticate for an L402 (or legacy LSAT) challenge:
macaroon present?, invoice present?, invoice network + amount (decoded from the bolt11
human-readable part, no signature check). Never pays, never retries, never follows a form.

usage: python probe.py targets.json raw/probe_<date>.json
targets.json: [{"name": "...", "url": "...", "method": "GET"|"POST", "source": "where I found it"}]
"""
import json, re, sys, time, datetime, urllib.request, urllib.error

UA = "Vonk-AI-research/1.0 (openly an AI character; owner Rick; read-only L402 probe)"
MULT = {"m": 10**-3, "u": 10**-6, "n": 10**-9, "p": 10**-12}


def bolt11_amount_sats(inv):
    """Amount in sats from the bolt11 prefix (lnbc2500u... -> 250000 sats). None = any amount."""
    m = re.match(r"^ln(bc|tb|bcrt|tbs)(\d+)?([munp])?1", inv.lower())
    if not m:
        return None, None
    net, num, mul = m.groups()
    if num is None:
        return net, None
    btc = int(num) * (MULT[mul] if mul else 1)
    return net, round(btc * 10**8, 3)


def parse_challenge(h):
    out = {"scheme": None, "macaroon": False, "invoice": None}
    if not h:
        return out
    sm = re.search(r"(?:^|[\s,])(L402|LSAT)\s", h, re.I)
    out["scheme"] = sm.group(1).upper() if sm else (h.split() or [""])[0][:20]
    out["macaroon"] = bool(re.search(r'(macaroon|token)="?[A-Za-z0-9+/=_-]{20,}', h))
    im = re.search(r'invoice="?(ln[a-z0-9]+)', h, re.I)
    if im:
        out["invoice"] = im.group(1)
    return out


def probe(t):
    rec = {"name": t["name"], "url": t["url"], "method": t.get("method", "GET"), "source": t.get("source", ""),
           "at": datetime.datetime.now(datetime.timezone.utc).isoformat(timespec="seconds")}
    data = b"{}" if rec["method"] == "POST" else None
    req = urllib.request.Request(t["url"], data=data, method=rec["method"],
                                 headers={"User-Agent": UA, "Content-Type": "application/json"})
    t0 = time.time()
    try:
        r = urllib.request.urlopen(req, timeout=10)
        status, headers, body = r.status, r.headers, r.read(4000)
    except urllib.error.HTTPError as e:
        status, headers, body = e.code, e.headers, e.read(4000)
    except Exception as e:
        rec.update(status=None, error=f"{type(e).__name__}: {e}"[:200])
        return rec
    rec["ms"] = int((time.time() - t0) * 1000)
    rec["status"] = status
    wa = headers.get("WWW-Authenticate")
    rec["www_authenticate"] = (wa[:300] + "...") if wa and len(wa) > 300 else wa
    c = parse_challenge(wa)
    if c["invoice"]:
        net, sats = bolt11_amount_sats(c["invoice"])
        c.update(network=net, amount_sats=sats)
        c["invoice"] = c["invoice"][:40] + "..."
    rec["challenge"] = c
    rec["valid_l402"] = status == 402 and c["scheme"] in ("L402", "LSAT") and c["macaroon"] and bool(c["invoice"])
    txt = body.decode("utf-8", "replace")
    bm = re.search(r"(lnbc[0-9a-z]{20,})", txt, re.I)
    if bm and not c["invoice"]:
        net, sats = bolt11_amount_sats(bm.group(1))
        rec["body_invoice_sats"] = sats
    rec["body_head"] = txt[:300]
    return rec


def selftest():
    assert bolt11_amount_sats("lnbc2500u1pvjluez")[1] == 250000
    assert bolt11_amount_sats("lnbc10n1abc")[1] == 1
    assert bolt11_amount_sats("lnbc1pvjluez")[1] is None
    c = parse_challenge('L402 macaroon="AgEEbHNhdAJCAAAx1234567890abcdef", invoice="lnbc100n1pjexample"')
    assert c["scheme"] == "L402" and c["macaroon"] and c["invoice"].startswith("lnbc100n")
    c2 = parse_challenge('Payment id="x", method="lightning", L402 macaroon="AgEEbHNhdAJCAAAx1234567890abcdef", invoice="lnbc1u1pj"')
    assert c2["scheme"] == "L402" and c2["macaroon"]


if __name__ == "__main__":
    selftest()
    targets = json.load(open(sys.argv[1], encoding="utf-8"))
    res = []
    for t in targets:
        r = probe(t)
        print(f'{r["name"][:28]:28} {str(r.get("status")):5} valid_l402={r.get("valid_l402")} '
              f'sats={r.get("challenge", {}).get("amount_sats")} {r.get("error", "")}')
        res.append(r)
        time.sleep(2)
    json.dump(res, open(sys.argv[2], "w", encoding="utf-8"), indent=1, ensure_ascii=False)
    print("wrote", sys.argv[2], len(res))