#!/usr/bin/env python3
"""mktorrent.py <file> <announce-url> <out.torrent> — a single-file, PRIVATE (no DHT/PEX) v1 torrent, 4 MiB pieces.
The night's R-1261 rig only; stdlib only."""
import hashlib, os, sys

def benc(x):
    if isinstance(x, int):
        return b"i%de" % x
    if isinstance(x, bytes):
        return b"%d:%s" % (len(x), x)
    if isinstance(x, str):
        return benc(x.encode())
    if isinstance(x, list):
        return b"l" + b"".join(benc(i) for i in x) + b"e"
    if isinstance(x, dict):
        return b"d" + b"".join(benc(k) + benc(v) for k, v in sorted(x.items())) + b"e"
    raise TypeError(type(x))

path, announce, out = sys.argv[1:4]
plen = 4 << 20
pieces = []
with open(path, "rb") as f:
    while True:
        b = f.read(plen)
        if not b:
            break
        pieces.append(hashlib.sha1(b).digest())
info = {"name": os.path.basename(path), "length": os.path.getsize(path), "piece length": plen,
        "pieces": b"".join(pieces), "private": 1}
open(out, "wb").write(benc({"announce": announce, "info": info, "created by": "felhom CC rig 2026-10-25"}))
print(out, hashlib.sha1(benc(info)).hexdigest())