import argparse
import json
import os
import sys
from pathlib import Path

sys.path.insert(0, os.path.dirname(os.path.abspath(__file__)))

from google.auth.transport.requests import Request
from google.oauth2.credentials import Credentials
from google_auth_oauthlib.flow import InstalledAppFlow

SCOPES = ["https://www.googleapis.com/auth/spreadsheets"]
SERVICE_NAME = "google-sheets-skill-oauth"

try:
    import keyring
    HAS_KEYRING = True
except ImportError:
    HAS_KEYRING = False


def get_token_dir():
    path = os.environ.get("GOOGLE_SHEETS_TOKEN_DIR")
    if path:
        return Path(path)
    default = Path.home() / ".config" / "google-sheets-skill"
    default.mkdir(parents=True, exist_ok=True)
    return default


def _load_creds():
    token_file = get_token_dir() / "token.json"
    if token_file.exists():
        return Credentials.from_authorized_user_file(str(token_file), SCOPES)
    if HAS_KEYRING:
        stored = keyring.get_password(SERVICE_NAME, "token")
        if stored:
            return Credentials.from_authorized_user_info(json.loads(stored), SCOPES)
    return None


def _save_creds(creds):
    get_token_dir().mkdir(parents=True, exist_ok=True)
    token_file = get_token_dir() / "token.json"
    token_file.write_text(creds.to_json())
    token_file.chmod(0o600)
    if HAS_KEYRING:
        keyring.set_password(SERVICE_NAME, "token", creds.to_json())


def _find_creds_file():
    env_path = os.environ.get("GOOGLE_SHEETS_CREDS")
    if env_path:
        return Path(env_path)
    alongside = Path(__file__).parent / "credentials.json"
    if alongside.exists():
        return alongside
    return Path.home() / ".config" / "google-sheets-skill" / "credentials.json"


def cmd_login():
    creds_file = _find_creds_file()
    if not creds_file.exists():
        print(
            f"credentials.json not found at {creds_file}\n"
            "Download it from Google Cloud Console:\n"
            "1. Go to https://console.cloud.google.com/\n"
            "2. Create a project → Enable Sheets API\n"
            "3. Create OAuth 2.0 Client ID → Desktop App\n"
            "4. Download as credentials.json\n"
            "5. Save to: " + str(creds_file) + "\n\n"
            "Or set GOOGLE_SHEETS_CREDS env var to its location."
        )
        sys.exit(1)

    flow = InstalledAppFlow.from_client_secrets_file(str(creds_file), SCOPES)
    creds = flow.run_local_server(port=0)
    _save_creds(creds)
    print(f"Authenticated successfully. Token saved to {get_token_dir() / 'token.json'}")


def cmd_status():
    creds = _load_creds()
    if not creds:
        print("Not authenticated. Run: python .agents/skills/google-sheets-automation/scripts/auth.py login")
        sys.exit(1)
    if not creds.valid:
        if creds.expired and creds.refresh_token:
            creds.refresh(Request())
            _save_creds(creds)
            print("Token was expired; refreshed successfully.")
        else:
            print("Token is invalid. Re-authenticate: python .agents/skills/google-sheets-automation/scripts/auth.py login")
            sys.exit(1)
    print(f"Authenticated as: {creds.token[:20]}...")
    print(f"Expires at: {creds.expiry}")


def cmd_logout():
    token_file = get_token_dir() / "token.json"
    if token_file.exists():
        token_file.unlink()
    if HAS_KEYRING:
        try:
            keyring.delete_password(SERVICE_NAME, "token")
        except keyring.errors.PasswordDeleteError:
            pass
    print("Logged out. Token deleted.")


def get_credentials():
    creds = _load_creds()
    if not creds:
        print("Not authenticated. Run: python .agents/skills/google-sheets-automation/scripts/auth.py login", file=sys.stderr)
        sys.exit(1)
    if not creds.valid:
        if creds.expired and creds.refresh_token:
            creds.refresh(Request())
            _save_creds(creds)
        else:
            print("Token is invalid. Re-authenticate: python .agents/skills/google-sheets-automation/scripts/auth.py login", file=sys.stderr)
            sys.exit(1)
    return creds


def main():
    parser = argparse.ArgumentParser(description="Google Sheets Auth")
    parser.add_argument("command", choices=["login", "status", "logout"])
    args = parser.parse_args()

    if args.command == "login":
        cmd_login()
    elif args.command == "status":
        cmd_status()
    elif args.command == "logout":
        cmd_logout()


if __name__ == "__main__":
    main()