package server

import (
	"context"
	"encoding/json"
	"io"
	"net/http"

	"github.com/labstack/echo/v4"
	stripe "github.com/stripe/stripe-go/v79"
	"github.com/stripe/stripe-go/v79/webhook"
)

type stripeEventService interface {
	HandlePaymentIntentSucceeded(ctx context.Context, pi *stripe.PaymentIntent) error
	HandleChargeRefunded(ctx context.Context, ch *stripe.Charge) error
}

func handleStripeWebhook(bs stripeEventService, secret string) echo.HandlerFunc {
	return func(c echo.Context) error {
		if secret == "" {
			return echo.NewHTTPError(http.StatusServiceUnavailable, "stripe webhook secret not configured")
		}

		payload, err := io.ReadAll(c.Request().Body)
		if err != nil {
			return echo.NewHTTPError(http.StatusBadRequest, "unable to read request body")
		}

		sig := c.Request().Header.Get("Stripe-Signature")
		if sig == "" {
			return echo.NewHTTPError(http.StatusBadRequest, "missing Stripe-Signature header")
		}

		event, err := webhook.ConstructEvent(payload, sig, secret)
		if err != nil {
			return echo.NewHTTPError(http.StatusBadRequest, "invalid webhook signature")
		}

		switch event.Type {
		case stripe.EventTypePaymentIntentSucceeded:
			var pi stripe.PaymentIntent
			if err := json.Unmarshal(event.Data.Raw, &pi); err != nil {
				return echo.NewHTTPError(http.StatusBadRequest, "invalid payment intent payload")
			}

			if err := bs.HandlePaymentIntentSucceeded(c.Request().Context(), &pi); err != nil {
				return echo.NewHTTPError(http.StatusInternalServerError, err.Error())
			}
		case stripe.EventTypeChargeRefunded:
			var ch stripe.Charge
			if err := json.Unmarshal(event.Data.Raw, &ch); err != nil {
				return echo.NewHTTPError(http.StatusBadRequest, "invalid charge payload")
			}

			if err := bs.HandleChargeRefunded(c.Request().Context(), &ch); err != nil {
				return echo.NewHTTPError(http.StatusInternalServerError, err.Error())
			}
		default:
			// Acknowledge events we don't actively process.
		}

		return c.NoContent(http.StatusOK)
	}
}