"""Check version consistency between `pyproject.toml` and `version.py`.

This script validates that the version defined in pyproject.toml matches the `VERSION`
variable in `langchain_core/version.py`. Intended for use as a pre-commit hook to
prevent version mismatches.
"""

import re
import sys
from pathlib import Path


def get_pyproject_version(pyproject_path: Path) -> str | None:
    """Extract version from `pyproject.toml`."""
    content = pyproject_path.read_text(encoding="utf-8")
    match = re.search(r'^version\s*=\s*"([^"]+)"', content, re.MULTILINE)
    return match.group(1) if match else None


def get_version_py_version(version_path: Path) -> str | None:
    """Extract `VERSION` from `version.py`."""
    content = version_path.read_text(encoding="utf-8")
    match = re.search(r'^VERSION\s*=\s*"([^"]+)"', content, re.MULTILINE)
    return match.group(1) if match else None


def main() -> int:
    """Validate version consistency."""
    script_dir = Path(__file__).parent
    package_dir = script_dir.parent

    pyproject_path = package_dir / "pyproject.toml"
    version_path = package_dir / "langchain_core" / "version.py"

    if not pyproject_path.exists():
        print(f"Error: {pyproject_path} not found")
        return 1

    if not version_path.exists():
        print(f"Error: {version_path} not found")
        return 1

    pyproject_version = get_pyproject_version(pyproject_path)
    version_py_version = get_version_py_version(version_path)

    if pyproject_version is None:
        print("Error: Could not find version in pyproject.toml")
        return 1

    if version_py_version is None:
        print("Error: Could not find VERSION in langchain_core/version.py")
        return 1

    if pyproject_version != version_py_version:
        print("Error: Version mismatch detected!")
        print(f"  pyproject.toml: {pyproject_version}")
        print(f"  langchain_core/version.py: {version_py_version}")
        return 1

    print(f"Version check passed: {pyproject_version}")
    return 0


if __name__ == "__main__":
    sys.exit(main())