"""v2 step 7: check the published branch against the staged folder (read-only on the Hub).

  * main is still at the pinned commit (untouched)
  * the branch holds exactly the staged files: no missing, no extra
  * every file's size matches, and its sha256 matches (LFS files: Hub-recorded sha256 vs local; small files:
    downloaded bytes vs local bytes)
  * a random sample of data files is downloaded fresh from the branch and compared byte for byte
  usage: v2_remote_check.py <repo_id> <main_sha> <branch> <staged_dir> <download_dir> [n_sample] [workers]
"""
import hashlib, os, random, sys, filecmp
from multiprocessing import Pool
from huggingface_hub import HfApi, hf_hub_download

repo, main_sha, branch, staged, dl = sys.argv[1:6]
ns = int(sys.argv[6]) if len(sys.argv) > 6 else 8; nw = int(sys.argv[7]) if len(sys.argv) > 7 else 24
api = HfApi(); T = "dataset"


def sha(p):
    h = hashlib.sha256()
    with open(p, "rb") as f:
        for b in iter(lambda: f.read(1 << 24), b""): h.update(b)
    return p, h.hexdigest()


if __name__ == "__main__":
    refs = {b.name: b.target_commit for b in api.list_repo_refs(repo, repo_type=T).branches}
    print(f"main at {refs['main']}; unchanged: {refs['main'] == main_sha}; {branch} at {refs.get(branch)}")
    ok = refs["main"] == main_sha
    info = api.dataset_info(repo, revision=refs[branch], files_metadata=True)
    remote = {s.rfilename: s for s in info.siblings}
    local = set()
    for d, _, fs in os.walk(staged):
        if ".cache" in os.path.relpath(d, staged).split(os.sep): continue
        for f in fs:
            r = os.path.relpath(os.path.join(d, f), staged)
            if r != ".manifest.tsv": local.add(r)
    missing, extra = sorted(local - set(remote)), sorted(set(remote) - local)
    print(f"staged {len(local)} files, branch {len(remote)} files; missing on branch {missing[:5]} ({len(missing)}); extra on branch {extra[:5]} ({len(extra)})")
    ok &= not missing and not extra
    with Pool(nw) as pool:
        loc = dict(pool.map(sha, [os.path.join(staged, f) for f in sorted(local & set(remote))]))
    bad = []
    for f in sorted(local & set(remote)):
        s = remote[f]; lp = os.path.join(staged, f)
        if s.size != os.path.getsize(lp): bad.append((f, "size")); continue
        if s.lfs:
            if s.lfs.sha256 != loc[lp]: bad.append((f, "sha256"))
        else:
            p = hf_hub_download(repo, f, repo_type=T, revision=refs[branch], local_dir=dl)
            if not filecmp.cmp(p, lp, shallow=False): bad.append((f, "bytes"))
    print(f"size/sha256 mismatches: {len(bad)} {bad[:5]}"); ok &= not bad
    data = sorted(f for f in local if f.endswith(".aselmdb")); random.seed(0)
    sample = sorted(set(random.sample(data, min(ns, len(data))) + [f for f in data if f.startswith("mp20bat/") or f.startswith("oc22/")]))
    nb = 0
    for f in sample:
        p = hf_hub_download(repo, f, repo_type=T, revision=refs[branch], local_dir=dl)
        same = filecmp.cmp(p, os.path.join(staged, f), shallow=False); nb += not same
        print(f"  downloaded {f}: identical to staged {same}", flush=True)
    ok &= nb == 0
    print("REMOTE CHECK PASSED" if ok else "*** REMOTE CHECK FAILED ***")