#!/usr/bin/env python3
"""Synchronize the frontend package.json version with pyproject.toml.

pyproject.toml is the single source of truth for the project version.
Run this script before building the frontend or deploying so the two
files never drift apart.

Usage:
    scripts/sync_version.py            # read pyproject, write package.json
    scripts/sync_version.py --check    # exit 1 if they already differ
"""

from __future__ import annotations

import argparse
import json
import re
import sys
from pathlib import Path

ROOT = Path(__file__).resolve().parent.parent
PYPROJECT = ROOT / "pyproject.toml"
PACKAGE_JSON = ROOT / "frontend" / "web" / "package.json"


_VERSION_RE = re.compile(r'^version\s*=\s*"([^"]+)"', re.MULTILINE)


def read_pyproject_version() -> str:
    text = PYPROJECT.read_text(encoding="utf-8")
    match = _VERSION_RE.search(text)
    if not match:
        raise RuntimeError(f"could not find version= in {PYPROJECT}")
    return match.group(1)


def write_package_json_version(version: str) -> bool:
    """Update package.json's version field. Returns True if changed."""
    data = json.loads(PACKAGE_JSON.read_text(encoding="utf-8"))
    old = data.get("version")
    if old == version:
        return False
    data["version"] = version
    PACKAGE_JSON.write_text(
        json.dumps(data, indent=2, ensure_ascii=False) + "\n",
        encoding="utf-8",
    )
    return True


def main() -> int:
    parser = argparse.ArgumentParser(description=__doc__)
    parser.add_argument(
        "--check", action="store_true",
        help="Exit with status 1 if versions already match (CI-friendly).",
    )
    args = parser.parse_args()

    version = read_pyproject_version()
    changed = write_package_json_version(version)

    if args.check:
        if changed:
            print(f"OUT_OF_SYNC pyproject={version} package.json was different")
            return 1
        print(f"OK version={version}")
        return 0

    if changed:
        print(f"synced package.json -> {version}")
    else:
        print(f"already in sync: {version}")
    return 0


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