#!/usr/bin/env python3
"""Verify Google Calendar OAuth credentials are valid.

Reads GOOGLE_CREDS_PATH env var (or falls back to secrets/google_creds.json),
loads the authorized_user credentials, and does one cheap API probe
(calendarList.list(maxResults=1)).

Output: single JSON object on stdout:
  {"ok": true, "message": "..."}
  {"ok": false, "message": "..."}
"""

from __future__ import annotations

import json
import os
import sys


def main() -> None:
    creds_path = os.environ.get(
        "GOOGLE_CREDS_PATH",
        os.path.join(os.path.dirname(__file__), "secrets", "google_creds.json"),
    )

    if not os.path.exists(creds_path):
        _fail(f"Credentials file not found at {creds_path}. Run gcal_oauth_setup.py first.")
        return

    try:
        from google.auth.transport.requests import Request
        from google.oauth2.credentials import Credentials
        from googleapiclient.discovery import build
    except ImportError as e:
        _fail(f"Missing dependencies: {e}. Install google-api-python-client and google-auth.")
        return

    try:
        creds = Credentials.from_authorized_user_file(
            creds_path,
            ["https://www.googleapis.com/auth/calendar"],
        )
    except Exception as e:
        _fail(f"Failed to load credentials: {e}")
        return

    if creds.expired and creds.refresh_token:
        try:
            creds.refresh(Request())
            with open(creds_path, "w") as f:
                f.write(creds.to_json())
        except Exception as e:
            _fail(f"Token refresh failed: {e}. Re-run gcal_oauth_setup.py.")
            return

    try:
        service = build("calendar", "v3", credentials=creds)
        result = service.calendarList().list(maxResults=1).execute()
        items = result.get("items", [])
        primary = next((c for c in items if c.get("primary")), None)
        account = primary.get("id", "?") if primary else "?"
        _ok(f"Google Calendar credentials valid. Account: {account}")
    except Exception as e:
        _fail(f"API probe failed: {e}")


def _ok(message: str) -> None:
    json.dump({"ok": True, "message": message}, sys.stdout)


def _fail(message: str) -> None:
    json.dump({"ok": False, "message": message}, sys.stdout)
    sys.exit(1)


if __name__ == "__main__":
    main()