import json
from urllib.error import HTTPError, URLError
from urllib.request import Request, urlopen

from django.http import HttpResponse, JsonResponse
from django.shortcuts import render
from django.views import View
from django.views.decorators.csrf import csrf_exempt
from django.utils.decorators import method_decorator

from ingest.constants import API_KEY, API_TARGET_URL, STATIC_SENSOR_PAYLOAD


class SensorSimulatorAppView(View):
    def get(self, request):
        return render(
            request,
            "ingest/index.html",
            {
                "default_payload": json.dumps(STATIC_SENSOR_PAYLOAD, indent=2),
                "default_url": API_TARGET_URL,
                "default_api_key": API_KEY,
            },
        )


@method_decorator(csrf_exempt, name="dispatch")
class ForwardSensorDataView(View):
    def post(self, request):
        target_url = request.POST.get("target_url", "").strip()
        api_key = request.POST.get("api_key", "").strip()

        if not target_url:
            return JsonResponse({"error": "target_url is required"}, status=400)
        if not api_key:
            return JsonResponse({"error": "api_key is required"}, status=400)

        payload = STATIC_SENSOR_PAYLOAD
        body = json.dumps(payload).encode("utf-8")
        outbound_request = Request(
            target_url,
            data=body,
            headers={
                "Content-Type": "application/json",
                "api_key": api_key,
            },
            method="POST",
        )

        try:
            with urlopen(outbound_request, timeout=15) as response:
                response_body = response.read().decode("utf-8")
                content_type = response.headers.get("Content-Type", "")
                parsed_body = response_body
                if "application/json" in content_type and response_body:
                    parsed_body = json.loads(response_body)

                return JsonResponse(
                    {
                        "status": response.status,
                        "sent_headers": {
                            "Content-Type": "application/json",
                            "api_key": api_key,
                        },
                        "sent_payload": payload,
                        "response": parsed_body,
                    }
                )
        except HTTPError as exc:
            error_body = exc.read().decode("utf-8", errors="replace")
            return JsonResponse(
                {
                    "error": "upstream returned an error",
                    "status": exc.code,
                    "sent_headers": {
                        "Content-Type": "application/json",
                        "api_key": api_key,
                    },
                    "sent_payload": payload,
                    "response": error_body,
                },
                status=502,
            )
        except URLError as exc:
            return JsonResponse(
                {
                    "error": "could not reach upstream api",
                    "details": str(exc.reason),
                    "sent_headers": {
                        "Content-Type": "application/json",
                        "api_key": api_key,
                    },
                    "sent_payload": payload,
                },
                status=502,
            )

        return HttpResponse(status=500)