main.py

from asyncio import CancelledError

import aiohttp.hdrs
import prometheus_client
from aiohttp import web
from prometheus_client.exposition import choose_encoder

import config
from mb_api import MbCustomer, MbHybridVehicle


async def app_factory():
    customer = MbCustomer(
        client_id=config.client_id, client_secret=config.client_secret
    )

    my_hybrid = MbHybridVehicle(customer, config.vin)

    routes = web.RouteTableDef()

    @routes.get("/metrics")
    async def metrics(request: web.Request):
        encoder, content_type = choose_encoder(request.headers["accept"])
        output = encoder(prometheus_client.REGISTRY)
        return web.Response(
            body=output,
            headers={aiohttp.hdrs.CONTENT_TYPE: content_type},
        )

    @routes.get("/oauth.auth")
    async def auth(_: web.Request):
        if not customer.authorized:
            raise web.HTTPFound(customer.authorization_url()[0])
        return web.Response(text="Authorized")

    @routes.get("/oauth.redirect")
    async def redirect(request: web.Request):
        customer.fetch_token(**request.query)
        customer.persist()

        if not my_hybrid.running():
            my_hybrid.start()

        raise web.HTTPFound("/metrics")

    async def fetch_hybrid(_):
        my_hybrid.start()
        yield
        my_hybrid.stop()
        try:
            if my_hybrid.continuous_refresh_task:
                await my_hybrid.continuous_refresh_task
        except CancelledError:
            pass
        customer.persist()

    app = web.Application()
    app.add_routes(routes)
    app.cleanup_ctx.append(fetch_hybrid)
    return app


web.run_app(app_factory())