from __future__ import annotations

import argparse
import hashlib
import json
import shutil
from pathlib import Path

from huggingface_hub import hf_hub_download


def digest(path: Path) -> str:
    value = hashlib.sha256()
    with path.open("rb") as stream:
        while block := stream.read(8 * 1024 * 1024):
            value.update(block)
    return value.hexdigest()


def main() -> int:
    parser = argparse.ArgumentParser(description="Download and verify Krea 2 benchmark models")
    parser.add_argument("--models-dir", type=Path, required=True)
    parser.add_argument("--manifest", type=Path, default=Path(__file__).resolve().parents[1] / "provenance" / "model_manifest.json")
    parser.add_argument("--all", action="store_true", help="Download all eight formats plus text encoder and VAE")
    parser.add_argument("--format", choices=["bf16", "fp8_scaled", "int8_convrot", "mxfp8", "nvfp4", "int4_convrot", "gguf_q8_0", "gguf_q4_k_m"], action="append")
    parser.add_argument("--accept-krea-license", action="store_true")
    args = parser.parse_args()
    if not args.accept_krea_license:
        parser.error("Review the Krea 2 Community License, then pass --accept-krea-license")
    selected = set(args.format or [])
    if not args.all and not selected:
        parser.error("Choose --all or at least one --format")
    manifest = json.loads(args.manifest.read_text(encoding="utf-8"))
    args.models_dir.mkdir(parents=True, exist_ok=True)
    common = {"qwen3vl_4b_bf16.safetensors", "qwen_image_vae.safetensors"}
    wanted = common | {item["filename"] for item in manifest["files"] if item.get("format_id") in selected}
    if args.all:
        wanted = {item["filename"] for item in manifest["files"]}
    for item in manifest["files"]:
        if item["filename"] not in wanted:
            continue
        destination = args.models_dir / item["filename"]
        if destination.exists() and digest(destination) == item["sha256"]:
            print(f"verified {destination.name}")
            continue
        cached = Path(hf_hub_download(repo_id=item["repository"], revision=item["revision"], filename=item["repository_path"]))
        shutil.copy2(cached, destination)
        actual = digest(destination)
        if actual != item["sha256"]:
            destination.unlink(missing_ok=True)
            raise RuntimeError(f"SHA-256 mismatch for {item['filename']}: {actual}")
        print(f"downloaded and verified {destination.name}")
    return 0


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