"""Authenticated per-route request rate limiting."""

import logging

from fastapi import Depends, Request

from app.api.dependencies.auth import build_request_context
from app.core.config import get_settings
from app.core.contracts import RequestContext
from app.core.rate_limit import RateLimitExceededError, RateLimitPolicy
from app.infrastructure.rate_limiter import CounterBackend, default_counter_backend

logger = logging.getLogger(__name__)


def get_counter_backend() -> CounterBackend:
    return default_counter_backend()


def route_template(request: Request) -> str:
    route = request.scope.get("route")
    return str(getattr(route, "path", request.url.path))


async def enforce_rate_limit(
    request: Request,
    context: RequestContext = Depends(build_request_context),  # noqa: B008
) -> None:
    policy = RateLimitPolicy.from_settings(get_settings())
    if not policy.enabled:
        return
    result = await get_counter_backend().increment(
        policy.key(context.user_id, request.method, route_template(request)),
        policy.window_seconds,
    )
    if result is None:
        logger.warning("rate limit backend unavailable; allowing route=%s", request.url.path)
        return
    count, retry_after_seconds = result
    if count > policy.max_requests:
        raise RateLimitExceededError("request rate limit exceeded", retry_after_seconds)