from __future__ import annotations

import json
import logging
import time
import urllib.error
import urllib.parse
import urllib.request

LOG = logging.getLogger(__name__)


class NetatmoError(RuntimeError):
    pass


class NetatmoClient:
    """Small dependency-free Netatmo OAuth and Weather API client."""

    def __init__(self, config):
        self.client_id = config["NETATMO_CLIENT_ID"]
        self.client_secret = config["NETATMO_CLIENT_SECRET"]
        self.refresh_token = config["NETATMO_REFRESH_TOKEN"]
        self.access_token = config["NETATMO_ACCESS_TOKEN"]
        self.device_id = config["NETATMO_DEVICE_ID"]
        self.token_url = config["NETATMO_TOKEN_URL"]
        self.stations_url = config["NETATMO_STATIONS_URL"]
        self._expires_at = 0.0

    @property
    def configured(self) -> bool:
        return bool(self.access_token or (self.client_id and self.client_secret and self.refresh_token))

    def _request(self, request: urllib.request.Request) -> dict:
        try:
            with urllib.request.urlopen(request, timeout=30) as response:
                return json.load(response)
        except (urllib.error.URLError, urllib.error.HTTPError, ValueError) as exc:
            detail = getattr(exc, "read", lambda: b"")().decode(errors="replace")
            raise NetatmoError(f"Netatmo request failed: {exc}; {detail}") from exc

    def _refresh(self) -> None:
        data = urllib.parse.urlencode(
            {
                "grant_type": "refresh_token",
                "refresh_token": self.refresh_token,
                "client_id": self.client_id,
                "client_secret": self.client_secret,
            }
        ).encode()
        result = self._request(urllib.request.Request(self.token_url, data=data, method="POST"))
        self.access_token = result["access_token"]
        # Netatmo may rotate refresh tokens; retain the new value for this process.
        self.refresh_token = result.get("refresh_token", self.refresh_token)
        self._expires_at = time.time() + int(result.get("expires_in", 10800)) - 60

    def stations_data(self) -> dict:
        if not self.configured:
            raise NetatmoError("Netatmo credentials are not configured")
        if not self.access_token or (self.refresh_token and time.time() >= self._expires_at):
            self._refresh()
        query = {"get_favorites": "false"}
        if self.device_id:
            query["device_id"] = self.device_id
        url = f"{self.stations_url}?{urllib.parse.urlencode(query)}"
        request = urllib.request.Request(url, headers={"Authorization": f"Bearer {self.access_token}"})
        try:
            return self._request(request)
        except NetatmoError:
            # A statically supplied access token may expire. Refresh once when possible.
            if not self.refresh_token:
                raise
            LOG.info("Access token rejected; refreshing and retrying once")
            self._refresh()
            request.headers["Authorization"] = f"Bearer {self.access_token}"
            return self._request(request)