from __future__ import annotations
# Tato aplikace poskytuje samostatné HTTP API pro GoPay, připravené k připojení do e‑shopu.
# Pohledy volají GoPay SDK a ukládají minimální data o životním cyklu (platby/refundy).
# Koncové body jsou dokumentovány pro Swagger/Redoc pomocí drf-spectacular.

from rest_framework import permissions, status
from rest_framework.response import Response
from rest_framework.views import APIView
from drf_spectacular.utils import (
    extend_schema,
    OpenApiParameter,
    OpenApiResponse,
    OpenApiExample,
    OpenApiTypes,
)

from . import client as goclient
from .models import GoPayPayment, GoPayRefund
from .serializers import (
	PaymentCreateSerializer,
	RefundSerializer,
)


class CreatePaymentView(APIView):
	"""Vytvoří novou platbu v GoPay a uloží odpověď lokálně.

	Typický e‑shop flow:
	- Frontend zavolá tento endpoint s GoPay payloadem.
	- Backend předá payload GoPay SDK a vrátí upstream odpověď.
	- Vznikne lokální záznam GoPayPayment pro pozdější sledování stavu.
	"""
	permission_classes = [permissions.IsAuthenticated]

	@extend_schema(
		tags=["GoPay"],
		operation_id="gopay_create_payment",
		summary="Vytvořit platbu",
		description="Vytvoří platbu v GoPay. Objekt 'payment' je předán SDK beze změn.",
		request=PaymentCreateSerializer,
		responses={
			201: OpenApiResponse(
				response=OpenApiTypes.OBJECT,
				description="Platba vytvořena (odpověď z GoPay)."
			),
			502: OpenApiResponse(description="Chyba upstream GoPay"),
		},
		examples=[
			OpenApiExample(
				"Základní platba kartou",
				value={
					"payment": {
						"amount": 19900,
						"currency": "CZK",
						"order_number": "ORDER-1001",
						"items": [{"name": "T-Shirt", "amount": 19900, "count": 1}],
						"callback": {"return_url": "https://shop.example.com/return"},
					}
				},
			)
		],
		extensions={
			"x-codeSamples": [
				{
					"lang": "typescript",
					"label": "Client.auth (frontend)",
					"source": 'await Client.auth.post("/api/payments/gopay/create/", { payment });',
				},
				{
					"lang": "curl",
					"source": 'curl -X POST http://localhost:8000/api/payments/gopay/create/ -H "Content-Type: application/json" -d \'{"payment": {"amount":19900,"currency":"CZK"}}\'',
				},
			]
		},
	)
	def post(self, request):
		ser = PaymentCreateSerializer(data=request.data)
		ser.is_valid(raise_exception=True)
		payload = ser.validated_data["payment"]

		try:
			res = goclient.create_payment(payload)  # Expecting dict-like response
		except Exception as e:
			return Response({"detail": str(e)}, status=status.HTTP_502_BAD_GATEWAY)

		# Map fields defensively
		gopay_id = str((res.get("id") if isinstance(res, dict) else getattr(res, "id", "")) or "")
		status_text = (res.get("state") if isinstance(res, dict) else getattr(res, "state", "")) or ""
		amount = int((res.get("amount") if isinstance(res, dict) else getattr(res, "amount", 0)) or payload.get("amount") or 0)
		currency = (res.get("currency") if isinstance(res, dict) else getattr(res, "currency", "")) or payload.get("currency", "")

		payment = GoPayPayment.objects.create(
			user=request.user if request.user and request.user.is_authenticated else None,
			gopay_id=gopay_id or payload.get("id", ""),
			order_number=str(payload.get("order_number", "")),
			amount=amount,
			currency=currency,
			status=status_text,
			preauthorized=bool(payload.get("preauthorize", False)),
			request_payload=payload,
			response_payload=res if isinstance(res, dict) else {"raw": str(res)},
		)

		return Response({"payment": payment.response_payload}, status=status.HTTP_201_CREATED)


class PaymentStatusView(APIView):
	"""Načte aktuální stav platby GoPay a případně synchronizuje lokální záznam."""
	permission_classes = [permissions.IsAuthenticated]

	@extend_schema(
		tags=["GoPay"],
		operation_id="gopay_get_status",
		summary="Získat stav platby",
		parameters=[
			OpenApiParameter(
				name="payment_id",
				type=OpenApiTypes.STR,
				location=OpenApiParameter.PATH,
				description="ID platby GoPay",
			)
		],
		responses={
			200: OpenApiResponse(OpenApiTypes.OBJECT, description="Aktuální stav platby"),
			502: OpenApiResponse(description="Chyba upstream GoPay"),
		},
	)
	def get(self, request, payment_id: str | int):
		try:
			res = goclient.get_status(payment_id)
		except Exception as e:
			return Response({"detail": str(e)}, status=status.HTTP_502_BAD_GATEWAY)

		# Update local status if we have it
		try:
			local = GoPayPayment.objects.get(gopay_id=str(payment_id))
			status_text = (res.get("state") if isinstance(res, dict) else getattr(res, "state", "")) or ""
			if status_text:
				local.status = status_text
				local.response_payload = res if isinstance(res, dict) else {"raw": str(res)}
				local.save(update_fields=["status", "response_payload", "updated_at"])
		except GoPayPayment.DoesNotExist:
			pass

		return Response(res, status=status.HTTP_200_OK)


class RefundPaymentView(APIView):
	"""Provede refundaci platby v GoPay a uloží záznam refundace."""
	permission_classes = [permissions.IsAuthenticated]

	@extend_schema(
		tags=["GoPay"],
		operation_id="gopay_refund_payment",
		summary="Refundovat platbu",
		parameters=[
			OpenApiParameter(
				name="payment_id",
				type=OpenApiTypes.STR,
				location=OpenApiParameter.PATH,
				description="ID platby GoPay k refundaci",
			)
		],
		request=RefundSerializer,
		responses={
			200: OpenApiResponse(OpenApiTypes.OBJECT, description="Výsledek refundace"),
			502: OpenApiResponse(description="Chyba upstream GoPay"),
		},
	)
	def post(self, request, payment_id: str | int):
		ser = RefundSerializer(data=request.data)
		ser.is_valid(raise_exception=True)
		amount = ser.validated_data["amount"]

		try:
			res = goclient.refund_payment(payment_id, amount)
		except Exception as e:
			return Response({"detail": str(e)}, status=status.HTTP_502_BAD_GATEWAY)

		payment = GoPayPayment.objects.filter(gopay_id=str(payment_id)).first()
		ref = GoPayRefund.objects.create(
			payment=payment,
			gopay_refund_id=str((res.get("id") if isinstance(res, dict) else getattr(res, "id", "")) or ""),
			amount=amount,
			status=(res.get("state") if isinstance(res, dict) else getattr(res, "state", "")) or "",
			payload=res if isinstance(res, dict) else {"raw": str(res)},
		)

		return Response({"refund": ref.payload}, status=status.HTTP_200_OK)