#!/usr/bin/env python3
"""Unpack Lofi-12 XT .bin -> directory with headers.json + sect payloads."""
import argparse, json, os, struct, sys
sys.path.insert(0, os.path.dirname(__file__))
from lofi_image import parse_image, headers_to_json

def main():
    ap = argparse.ArgumentParser()
    ap.add_argument('image')
    ap.add_argument('outdir')
    a = ap.parse_args()
    d = open(a.image, 'rb').read()
    info = parse_image(d)
    os.makedirs(a.outdir, exist_ok=True)
    open(os.path.join(a.outdir, 'headers.json'), 'w').write(
        json.dumps(headers_to_json(info), indent=2))
    for s in info['sects']:
        fn = f"sect{s['index']}_addr{s['addr']:08X}.bin"
        open(os.path.join(a.outdir, fn), 'wb').write(s['payload'])
    m = info['mmtd']
    print(f"fw {tuple(m['fw'])} entry={m['entry']:08X} nsect={m['nsect']} "
          f"cksum={info['cmtd']['checksum']:08X} size={len(d)}")
    for s in info['sects']:
        print(f"  sect{s['index']} off={s['off']:06X} addr={s['addr']:08X} "
              f"len={s['len']} end={s['end']:08X}")
    print(f"wrote {a.outdir}/")

if __name__ == '__main__':
    main()