from dagster import ConfigurableResource
import requests
from typing import Optional
from time import sleep
import logging
from datetime import datetime, timedelta

logger = logging.getLogger(__name__)


class MobilityDatabaseAPI(ConfigurableResource):
    """Resource for interacting with the Mobility Database API with OAuth2 token management."""

    base_url: str = "https://api.mobilitydatabase.org"
    refresh_token: str  # Long-lived refresh token
    rate_limit_delay: float = 0.5  # Seconds between requests

    # These will be set at runtime, not in config
    _access_token: Optional[str] = None
    _token_expires_at: Optional[datetime] = None

    def _get_access_token(self) -> str:
        """
        Get a valid access token, refreshing if necessary.
        Access tokens are valid for 1 hour.
        """
        # If we have a token and it's not expired (with 5 min buffer), use it
        if self._access_token and self._token_expires_at:
            if datetime.now() < self._token_expires_at - timedelta(minutes=5):
                return self._access_token

        # Need to get a new token
        logger.info("Fetching new access token from Mobility Database API")

        url = f"{self.base_url}/v1/tokens"
        headers = {"Content-Type": "application/json"}
        data = {"refresh_token": self.refresh_token}

        try:
            response = requests.post(url, headers=headers, json=data, timeout=30)
            response.raise_for_status()

            token_data = response.json()
            self._access_token = token_data.get("access_token")

            # Tokens are valid for 1 hour
            self._token_expires_at = datetime.now() + timedelta(hours=1)

            logger.info("Successfully obtained new access token")
            return self._access_token

        except requests.exceptions.RequestException as e:
            logger.error(f"Error fetching access token: {e}")
            raise RuntimeError(f"Failed to obtain access token: {e}")

    def get_feed_info(self, feed_id: str) -> dict:
        """
        Fetch feed information from the Mobility Database API.

        Args:
            feed_id: The MDB feed ID (e.g., 'mdb-394')

        Returns:
            Dictionary containing feed information
        """
        access_token = self._get_access_token()

        url = f"{self.base_url}/v1/feeds/{feed_id}"
        headers = {
            "Authorization": f"Bearer {access_token}"
        }

        logger.info(f"Fetching feed info for {feed_id}")

        try:
            response = requests.get(url, headers=headers, timeout=30)
            response.raise_for_status()

            # Rate limiting
            sleep(self.rate_limit_delay)

            return response.json()
        except requests.exceptions.RequestException as e:
            logger.error(f"Error fetching feed {feed_id}: {e}")
            raise