#!/usr/bin/env python3
"""Reconstruct MobileManipVLA_opensource from per-object tars.

Repo layout:
    MobileManiDataset/<robot>/<task>/<category>/<object>.tar
Each tar holds the ORIGINAL tree paths (<robot>/Final_0/<task>/<category>/<object>/...),
so extracting every tar into one output dir rebuilds the dataset exactly.

Usage:
    # after downloading the MobileManiDataset/ folder (e.g. via hf download)
    python unpack.py --root ./MobileManiDataset --out ./MobileManipVLA_opensource [--verify]
"""
import argparse, glob, json, os, tarfile, hashlib


def sha256_file(path, buf=8 * 1024 * 1024):
    h = hashlib.sha256()
    with open(path, "rb") as f:
        while True:
            b = f.read(buf)
            if not b:
                break
            h.update(b)
    return h.hexdigest()


def main():
    ap = argparse.ArgumentParser()
    ap.add_argument("--root", required=True,
                    help="dir containing MobileManiDataset/<robot>/... .tar files")
    ap.add_argument("--out", required=True, help="output dir to extract into")
    ap.add_argument("--verify", action="store_true",
                    help="verify each tar's sha256 against object_manifest.jsonl")
    args = ap.parse_args()

    tars = sorted(glob.glob(os.path.join(args.root, "**", "*.tar"), recursive=True))
    print(f"found {len(tars)} tars under {args.root}")

    man = {}
    mpath = os.path.join(args.root, "object_manifest.jsonl")
    if os.path.exists(mpath):
        for line in open(mpath):
            line = line.strip()
            if line:
                r = json.loads(line)
                man[os.path.basename(r["repo_path"])] = r

    os.makedirs(args.out, exist_ok=True)
    total_files = 0
    for i, t in enumerate(tars, 1):
        base = os.path.basename(t)
        if args.verify and base in man:
            got = sha256_file(t)
            exp = man[base]["sha256"]
            ok = (got == exp)
            print(f"[{i:3}/{len(tars)}] verify {base}: {'OK' if ok else 'MISMATCH'}")
            if not ok:
                raise SystemExit(f"sha256 mismatch for {base}: {got} != {exp}")
        with tarfile.open(t, "r") as tar:
            members = tar.getmembers()
            tar.extractall(args.out)
            total_files += sum(1 for m in members if m.isfile())
        print(f"[{i:3}/{len(tars)}] extracted {base}", flush=True)

    print(f"\nDONE: extracted {len(tars)} tars, {total_files:,} files into {args.out}")


if __name__ == "__main__":
    main()