async_oauth_client.py

import asyncio
import base64
import random
from typing import Any, Dict, List

import httpx

from .oauth_client import OAUTH_BASE_URL, TEST_OAUTH_BASE_URL


class AsyncOauthClient:
    """
    Asynchronous client for handling Openapi authentication and token management.
    Suitable for use with FastAPI, aiohttp, etc.
    """

    def __init__(
        self,
        username: str,
        apikey: str,
        test: bool = False,
        client: Any = None,
        timeout: float = 30.0,
        max_retries: int = 0,
        backoff_factor: float = 1.0,
        retry_on_status: List[int] = None,
    ):
        self.client = client if client is not None else httpx.AsyncClient(timeout=timeout)
        self.max_retries = max_retries
        self.backoff_factor = backoff_factor
        self.retry_on_status = (
            retry_on_status if retry_on_status is not None else [429, 502, 503, 504]
        )
        self.url: str = TEST_OAUTH_BASE_URL if test else OAUTH_BASE_URL
        self.auth_header: str = (
            "Basic " + base64.b64encode(f"{username}:{apikey}".encode("utf-8")).decode()
        )
        self.headers: Dict[str, Any] = {
            "Authorization": self.auth_header,
            "Content-Type": "application/json",
        }

    async def __aenter__(self):
        """Enable use as an asynchronous context manager."""
        return self

    async def __aexit__(self, exc_type, exc_val, exc_tb):
        """Ensure the underlying HTTP client is closed on exit (async)."""
        await self.client.aclose()

    async def aclose(self):
        """Manually close the underlying HTTP client (async)."""
        await self.client.aclose()

    async def _request_with_retry(self, request_fn, *args, **kwargs) -> httpx.Response:
        attempts = 0
        while True:
            try:
                resp = await request_fn(*args, **kwargs)
                if resp.status_code in self.retry_on_status and attempts < self.max_retries:
                    attempts += 1
                    sleep_time = self.backoff_factor * (2 ** attempts) + random.uniform(0, 0.5)
                    if resp.status_code == 429:
                        retry_after = resp.headers.get("Retry-After")
                        if retry_after:
                            try:
                                sleep_time = float(retry_after)
                            except ValueError:
                                pass
                    await asyncio.sleep(sleep_time)
                    continue
                return resp
            except httpx.RequestError as exc:
                if attempts < self.max_retries:
                    attempts += 1
                    sleep_time = self.backoff_factor * (2 ** attempts) + random.uniform(0, 0.5)
                    await asyncio.sleep(sleep_time)
                    continue
                raise exc

    async def get_scopes(self, limit: bool = False) -> Dict[str, Any]:
        """Retrieve available scopes for the current user (async)."""
        params = {"limit": int(limit)}
        url = f"{self.url}/scopes"
        resp = await self._request_with_retry(self.client.get, url=url, headers=self.headers, params=params)
        return resp.json()

    async def create_token(self, scopes: List[str] = [], ttl: int = 0) -> Dict[str, Any]:
        """Create a new bearer token with specified scopes and TTL (async)."""
        payload = {"scopes": scopes, "ttl": ttl}
        url = f"{self.url}/token"
        resp = await self._request_with_retry(self.client.post, url=url, headers=self.headers, json=payload)
        return resp.json()

    async def get_token(self, scope: str = None) -> Dict[str, Any]:
        """Retrieve an existing token, optionally filtered by scope (async)."""
        params = {"scope": scope or ""}
        url = f"{self.url}/token"
        resp = await self._request_with_retry(self.client.get, url=url, headers=self.headers, params=params)
        return resp.json()

    async def delete_token(self, id: str) -> Dict[str, Any]:
        """Revoke/Delete a specific token by ID (async)."""
        url = f"{self.url}/token/{id}"
        resp = await self._request_with_retry(self.client.delete, url=url, headers=self.headers)
        return resp.json()

    async def get_counters(self, period: str, date: str) -> Dict[str, Any]:
        """Retrieve usage counters for a specific period and date (async)."""
        url = f"{self.url}/counters/{period}/{date}"
        resp = await self._request_with_retry(self.client.get, url=url, headers=self.headers)
        return resp.json()