#!/usr/bin/env python3
"""
Verify graph-40k fixture hashes and counts against manifest.json.
"""
from __future__ import annotations

import hashlib
import json
import sys
from pathlib import Path
from typing import Tuple


def sha256(path: Path) -> str:
    h = hashlib.sha256()
    with path.open("rb") as f:
        for chunk in iter(lambda: f.read(8192), b""):
            h.update(chunk)
    return h.hexdigest()


def count_lines(path: Path) -> int:
    with path.open("r", encoding="utf-8") as f:
        return sum(1 for _ in f if _.strip())


def verify(manifest_path: Path) -> Tuple[bool, str]:
    manifest = json.loads(manifest_path.read_text())
    base = manifest_path.parent

    nodes_path = base / "nodes.ndjson"
    edges_path = base / "edges.ndjson"
    overlay_path = base / manifest["overlay"]["path"]

    checks = [
        ("nodes hash", sha256(nodes_path) == manifest["hashes"]["nodes_ndjson_sha256"]),
        ("edges hash", sha256(edges_path) == manifest["hashes"]["edges_ndjson_sha256"]),
        ("overlay hash", sha256(overlay_path) == manifest["hashes"]["overlay_ndjson_sha256"]),
        ("nodes count", count_lines(nodes_path) == manifest["counts"]["nodes"]),
        ("edges count", count_lines(edges_path) == manifest["counts"]["edges"]),
        ("overlay count", count_lines(overlay_path) == manifest["counts"]["overlays"]["policy.overlay.v1"]),
    ]

    failed = [name for name, ok in checks if not ok]
    if failed:
        return False, f"Failed checks: {', '.join(failed)}"
    return True, "All hashes and counts match manifest."


def main() -> int:
    manifest_path = Path(sys.argv[1]).resolve() if len(sys.argv) > 1 else Path(__file__).resolve().parent / "manifest.json"
    ok, message = verify(manifest_path)
    print(message)
    return 0 if ok else 1


if __name__ == "__main__":
    raise SystemExit(main())