feat(eventsub): properly unsubscribe once no more handles are interested (#5943)

src/providers/twitch/eventsub/Controller.hpp

@@ -22,6 +22,9 @@ class IController
 public:
     virtual ~IController() = default;
 
+    /// Removes one reference for the given subscription request
+    ///
+    /// Should realistically only be called in the dtor of SubscriptionHandle
     virtual void removeRef(const SubscriptionRequest &request) = 0;
 
     /// Subscribe will make a request to each open connection and ask them to
@@ -47,16 +50,18 @@ public:
         const SubscriptionRequest &request) override;
 
 private:
-    void subscribe(const SubscriptionRequest &request, bool isQueued);
+    void subscribe(const SubscriptionRequest &request, bool isRetry);
 
     void createConnection();
     void registerConnection(std::weak_ptr<lib::Session> &&connection);
 
-    void queueSubscription(const SubscriptionRequest &request,
-                           boost::posix_time::time_duration delay);
+    void retrySubscription(const SubscriptionRequest &request,
+                           boost::posix_time::time_duration delay,
+                           int32_t maxAttempts);
 
     void markRequestSubscribed(const SubscriptionRequest &request,
-                               std::weak_ptr<lib::Session> connection);
+                               std::weak_ptr<lib::Session> connection,
+                               const QString &subscriptionID);
 
     const std::string userAgent;
 
@@ -72,17 +77,20 @@ private:
 
     std::vector<std::weak_ptr<lib::Session>> connections;
 
-    struct XD {
+    struct Subscription {
         int32_t refCount = 0;
         std::weak_ptr<lib::Session> connection;
+
+        /// The ID of the subscription the Twitch Helix API has given us
+        QString subscriptionID;
+
+        /// The timer, if any, for retrying the subscription creation
+        std::unique_ptr<boost::asio::deadline_timer> retryTimer;
+        int32_t retryAttempts = 0;
     };
 
     std::mutex subscriptionsMutex;
-    std::unordered_map<SubscriptionRequest, XD> activeSubscriptions;
-
-    std::unordered_map<SubscriptionRequest,
-                       std::unique_ptr<boost::asio::deadline_timer>>
-        queuedSubscriptions;
+    std::unordered_map<SubscriptionRequest, Subscription> subscriptions;
 };
 
 class DummyController : public IController