package webhook

import (
 "encoding/json"
 "log"
 "net/http"
 "time"

 "github.com/iktakahiro/revcatgo"
)

func HandleRevenueCatWebhook(w http.ResponseWriter, r *http.Request) {
 var hook revcatgo.WebhookEvent
 if err := json.NewDecoder(r.Body).Decode(&hook); err != nil {
  http.Error(w, err.Error(), http.StatusBadRequest)
  return
 }

 event := hook.Event

 if !event.Environment.IsProduction() {
  log.Printf("ignoring %s event from sandbox", event.Environment.String())
  w.WriteHeader(http.StatusNoContent)
  return
 }

 switch event.Type.String() {
 case revcatgo.EventTypeInitialPurchase:
  log.Printf("new subscriber %q", event.AppUserID)
 case revcatgo.EventTypeCancellation:
  if event.IsExpired(24*time.Hour, nil) {
   log.Printf("subscription cancelled and grace period elapsed for %q", event.AppUserID)
  }
 default:
  log.Printf("received %s for %q", event.Type.String(), event.AppUserID)
 }

 allIDs := event.GetAllRelatedUserID() // includes aliases and original user ids
 log.Printf("related identifiers: %v", allIDs)

 w.WriteHeader(http.StatusNoContent)
}

import (
 "encoding/json"
 "io"
 "time"

 "github.com/iktakahiro/revcatgo"
)

func decodeSubscriberResponse(body io.Reader) (*revcatgo.SubscriberResponse, error) {
 var resp revcatgo.SubscriberResponse
 if err := json.NewDecoder(body).Decode(&resp); err != nil {
  return nil, err
 }

 for productID, entitlement := range resp.Subscriber.Entitlements {
  if entitlement.ExpiresDate.Before(time.Now()) {
   continue
  }
  // grant access for productID
 }

 return &resp, nil
}