# pxy_routing/api/views.py
from __future__ import annotations
import uuid
from rest_framework.decorators import api_view, throttle_classes
from rest_framework.response import Response
from rest_framework import status
from rest_framework.throttling import ScopedRateThrottle

from pxy_routing.services.factory import get_routing_provider

def _err(code: str, message: str, hint: str | None = None, http_status: int = 400):
    return Response(
        {
            "ok": False,
            "code": code,
            "message": message,
            "hint": hint,
            "trace_id": str(uuid.uuid4()),
        },
        status=http_status,
    )

@api_view(["GET"])
@throttle_classes([ScopedRateThrottle])
def routing_health(request):
    routing_health.throttle_scope = "routing_health"  # DRF scoped throttle
    provider = get_routing_provider()
    try:
        info = provider.health() or {}
        ok = bool(info.get("ok", False))
        return Response(
            {
                "ok": ok,
                "provider": info.get("provider"),
                **info,  # includes base_url/profile/reason
            }
        )
    except Exception as e:
        return _err(
            code="routing_health_error",
            message="Routing health check failed",
            hint=str(e),
            http_status=status.HTTP_502_BAD_GATEWAY,
        )

@api_view(["POST"])
@throttle_classes([ScopedRateThrottle])
def routing_isochrone(request):
    routing_isochrone.throttle_scope = "routing_isochrone"  # DRF scoped throttle
    data = request.data or {}
    center = data.get("center")
    minutes = data.get("minutes")

    if not isinstance(center, (list, tuple)) or len(center) != 2:
        return _err("invalid", "center must be [lat, lon]", http_status=status.HTTP_400_BAD_REQUEST)
    try:
        minutes = int(minutes)
    except Exception:
        return _err("invalid", "minutes must be an integer", http_status=status.HTTP_400_BAD_REQUEST)

    provider = get_routing_provider()
    try:
        feat = provider.isochrone(tuple(center), minutes)
        return Response(feat)
    except Exception as e:
        # Map to a consistent envelope for upstream/provider issues
        return _err(
            code="routing_error",
            message="Failed to compute isochrone",
            hint=str(e),
            http_status=status.HTTP_502_BAD_GATEWAY,
        )

# Backward-compatible aliases expected by urls.py
health = routing_health
isochrone = routing_isochrone