# SPDX-License-Identifier: Apache-2.0

import hashlib
import inspect
import os
import subprocess
from pathlib import Path

import pytest

REPO_ROOT = Path(__file__).resolve().parents[3]
REFERENCE_ROOT = Path(os.environ.get("MINIMAX_H3_OFFICIAL_REF_DIR") or REPO_ROOT / "DiffusersMiniMaxH3").resolve()
REFERENCE_SRC = REFERENCE_ROOT / "src"
PINNED_COMMIT = "abc5e9bf71fd38f53cd471bc3acaa84bc5ecbfdc"


def _run_git(*args: str) -> str:
    try:
        result = subprocess.run(
            ["git", "-C", str(REFERENCE_ROOT), *args],
            check=True,
            capture_output=True,
            text=True,
        )
    except (FileNotFoundError, subprocess.CalledProcessError) as error:
        raise RuntimeError(f"Could not verify the MiniMax-H3 reference checkout at {REFERENCE_ROOT}.") from error
    return result.stdout.strip()


def assert_reference_revision() -> None:
    actual_commit = _run_git("rev-parse", "HEAD")
    if actual_commit != PINNED_COMMIT:
        raise RuntimeError(f"MiniMax-H3 parity requires Diffusers commit {PINNED_COMMIT}, got {actual_commit}.")
    dirty_source = _run_git("status", "--short", "--untracked-files=no", "--", "src/diffusers")
    if dirty_source:
        raise RuntimeError(f"MiniMax-H3 reference source has tracked changes:\n{dirty_source}")


def assert_pinned_reference(relative_path: str, sha256: str) -> Path:
    path = REFERENCE_ROOT / relative_path
    if not path.is_file():
        pytest.skip(
            f"pinned MiniMax-H3 Diffusers reference is missing: {path}",
            allow_module_level=True,
        )
    actual_sha256 = hashlib.sha256(path.read_bytes()).hexdigest()
    if actual_sha256 != sha256:
        raise RuntimeError(f"MiniMax-H3 reference file changed from {PINNED_COMMIT}: {relative_path} "
                           f"has SHA-256 {actual_sha256}, expected {sha256}.")
    return path


def assert_reference_source(symbol: object, relative_path: str) -> None:
    expected = (REFERENCE_ROOT / relative_path).resolve()
    source = inspect.getsourcefile(symbol)
    actual = Path(source).resolve() if source is not None else None
    if actual != expected:
        raise RuntimeError(f"MiniMax-H3 parity imported {actual}, expected {expected}. "
                           f"Prepend {REFERENCE_SRC} to PYTHONPATH before starting pytest.")