feat: Live Emote Updates for 7TV (#4090)

Co-authored-by: Rasmus Karlsson <rasmus.karlsson@pajlada.com>

src/providers/seventv/SeventvEventAPI.hpp

@@ -0,0 +1,62 @@
+#pragma once
+
+#include "providers/liveupdates/BasicPubSubClient.hpp"
+#include "providers/liveupdates/BasicPubSubManager.hpp"
+#include "providers/seventv/eventapi/SeventvEventAPIDispatch.hpp"
+#include "providers/seventv/eventapi/SeventvEventAPISubscription.hpp"
+#include "util/QStringHash.hpp"
+
+#include <pajlada/signals/signal.hpp>
+
+namespace chatterino {
+
+class SeventvEventAPI : public BasicPubSubManager<SeventvEventAPISubscription>
+{
+    template <typename T>
+    using Signal =
+        pajlada::Signals::Signal<T>;  // type-id is vector<T, Alloc<T>>
+
+public:
+    SeventvEventAPI(QString host,
+                    std::chrono::milliseconds defaultHeartbeatInterval =
+                        std::chrono::milliseconds(25000));
+
+    struct {
+        Signal<SeventvEventAPIEmoteAddDispatch> emoteAdded;
+        Signal<SeventvEventAPIEmoteUpdateDispatch> emoteUpdated;
+        Signal<SeventvEventAPIEmoteRemoveDispatch> emoteRemoved;
+        Signal<SeventvEventAPIUserConnectionUpdateDispatch> userUpdated;
+    } signals_;  // NOLINT(readability-identifier-naming)
+
+    /**
+     * Subscribes to a user and emote-set
+     * if not already subscribed.
+     *
+     * @param userID 7TV user-id, may be empty.
+     * @param emoteSetID 7TV emote-set-id, may be empty.
+     */
+    void subscribeUser(const QString &userID, const QString &emoteSetID);
+
+    /** Unsubscribes from a user by its 7TV user id */
+    void unsubscribeUser(const QString &id);
+    /** Unsubscribes from an emote-set by its id */
+    void unsubscribeEmoteSet(const QString &id);
+
+protected:
+    std::shared_ptr<BasicPubSubClient<SeventvEventAPISubscription>>
+        createClient(liveupdates::WebsocketClient &client,
+                     websocketpp::connection_hdl hdl) override;
+    void onMessage(
+        websocketpp::connection_hdl hdl,
+        BasicPubSubManager<SeventvEventAPISubscription>::WebsocketMessagePtr
+            msg) override;
+
+private:
+    void handleDispatch(const SeventvEventAPIDispatch &dispatch);
+
+    std::unordered_set<QString> subscribedEmoteSets_;
+    std::unordered_set<QString> subscribedUsers_;
+    std::chrono::milliseconds heartbeatInterval_;
+};
+
+}  // namespace chatterino