"""Capture self-contained canonical Vortex Exact Attention Q/K/V fixtures."""

from __future__ import annotations

import argparse
import hashlib
import json
import platform
import sys
from pathlib import Path
from types import SimpleNamespace

import torch


PROJECT = Path(__file__).resolve().parents[1]
ROOT = PROJECT.parents[1]
sys.path.insert(0, str(ROOT / "tools"))

from profile_attention_path import prepare_qkv, representative_attention_inputs  # noqa: E402


EXPECTED_OUTPUT_SHA256 = "4c666c20f5f8f651158a2ced33ccff08f3bada07665c595b99008d171db30574"
EXPECTED_CHECKPOINT_SHA256 = "72fa9269ce551fb63ff42a32d9b46d0c122e84b4b2c511e22fa698287b088f70"


def sha256_file(path: Path) -> str:
    digest = hashlib.sha256()
    with path.open("rb") as handle:
        for chunk in iter(lambda: handle.read(16 * 1024 * 1024), b""):
            digest.update(chunk)
    return digest.hexdigest()


def tensor_sha256(value: torch.Tensor) -> str:
    data = value.detach().contiguous().view(torch.uint8).cpu().numpy()
    return hashlib.sha256(memoryview(data)).hexdigest()


def save_tensor(output_dir: Path, name: str, value: torch.Tensor) -> dict:
    host = value.detach().contiguous().cpu()
    tensor_hash = tensor_sha256(host)
    path = output_dir / f"{name}.pt"
    torch.save({"tensor": host}, path)
    loaded = torch.load(path, map_location="cpu", weights_only=True)["tensor"]
    loaded_hash = tensor_sha256(loaded)
    if loaded_hash != tensor_hash or not torch.equal(loaded, host):
        raise RuntimeError(f"fixture reload verification failed for {name}")
    return {
        "path": str(path),
        "size_bytes": path.stat().st_size,
        "file_sha256": sha256_file(path),
        "tensor_sha256": tensor_hash,
        "shape": list(host.shape),
        "stride": list(host.stride()),
        "dtype": str(host.dtype),
        "contiguous": host.is_contiguous(),
        "reload_verified": True,
    }


def parse_args() -> argparse.Namespace:
    parser = argparse.ArgumentParser(description=__doc__)
    parser.add_argument("--output-dir", type=Path, required=True)
    parser.add_argument("--model-path", type=Path, default=Path("/models/minimax_h3_fl2va_pruned_nvfp4.safetensors"))
    parser.add_argument("--sage-mainloop-binary", type=Path, required=True)
    parser.add_argument("--sage-fused-binary", type=Path, required=True)
    parser.add_argument("--image", required=True)
    parser.add_argument("--device", default="cuda")
    return parser.parse_args()


def main() -> None:
    args = parse_args()
    args.output_dir.mkdir(parents=True, exist_ok=True)
    checkpoint_hash = sha256_file(args.model_path)
    if checkpoint_hash != EXPECTED_CHECKPOINT_SHA256:
        raise RuntimeError(f"checkpoint SHA-256 mismatch: {checkpoint_hash}")

    workload = SimpleNamespace(
        model_path=str(args.model_path), device=args.device, width=1344, height=768,
        frames=124, steps=12, sampler_step=1, seed=440420, text_tokens=100,
        block_index=24, attention="sage2",
    )
    block, hidden, rotation, segments, metadata = representative_attention_inputs(workload)
    with torch.inference_mode():
        q, k, v, _ = prepare_qkv(block, hidden, rotation, None)
        from sageattention import sageattn

        output = sageattn(q, k, v, tensor_layout="NHD", is_causal=False, smooth_k=False)
        torch.cuda.synchronize()
        output_hash = tensor_sha256(output)
        if output_hash != EXPECTED_OUTPUT_SHA256:
            raise RuntimeError(
                f"public Sage2 output mismatch: expected {EXPECTED_OUTPUT_SHA256}, got {output_hash}"
            )
        fixtures = {
            "q": save_tensor(args.output_dir, "q_prepared_bf16_nhd", q),
            "k": save_tensor(args.output_dir, "k_prepared_bf16_nhd", k),
            "v": save_tensor(args.output_dir, "v_bf16_nhd", v),
            "output": save_tensor(args.output_dir, "sage2_output_bf16_nhd", output),
        }

    manifest = {
        "schema": "vortex-exact-canonical-fixtures",
        "version": 1,
        "status": "captured_and_reload_verified",
        "reference": {
            "sageattention_version": "2.2.0",
            "sageattention_commit": "d1a57a546c3d395b1ffcbeecc66d81db76f3b4b5",
            "expected_output_sha256": EXPECTED_OUTPUT_SHA256,
            "actual_output_sha256": output_hash,
            "byte_exact": True,
        },
        "workload": metadata,
        "segments": segments,
        "checkpoint": {
            "path": str(args.model_path), "size_bytes": args.model_path.stat().st_size,
            "sha256": checkpoint_hash,
        },
        "sage_binaries": {
            "mainloop": {"path": str(args.sage_mainloop_binary), "size_bytes": args.sage_mainloop_binary.stat().st_size, "sha256": sha256_file(args.sage_mainloop_binary)},
            "fused_preparation": {"path": str(args.sage_fused_binary), "size_bytes": args.sage_fused_binary.stat().st_size, "sha256": sha256_file(args.sage_fused_binary)},
        },
        "environment": {
            "image": args.image,
            "gpu": torch.cuda.get_device_name(),
            "compute_capability": list(torch.cuda.get_device_capability()),
            "torch": torch.__version__,
            "cuda": torch.version.cuda,
            "driver": torch.cuda.driver_version() if hasattr(torch.cuda, "driver_version") else None,
            "python": platform.python_version(),
            "argv": sys.argv,
        },
        "fixtures": fixtures,
    }
    manifest_path = args.output_dir / "manifest.json"
    manifest_path.write_text(json.dumps(manifest, indent=2) + "\n", encoding="utf-8")
    print(json.dumps(manifest, indent=2), flush=True)


if __name__ == "__main__":
    main()