feat: show BTTV Pro badges (#6625)

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

src/util/BadgeRegistry.hpp

@@ -0,0 +1,50 @@
+#pragma once
+
+#include "common/Aliases.hpp"
+
+#include <QJsonObject>
+
+#include <shared_mutex>
+
+namespace chatterino {
+
+struct Emote;
+using EmotePtr = std::shared_ptr<const Emote>;
+
+class BadgeRegistry
+{
+public:
+    virtual ~BadgeRegistry() = default;
+
+    /// Return the badge, if any, that is assigned to the user
+    std::optional<EmotePtr> getBadge(const UserId &id) const;
+
+    /// Assign the given badge to the user
+    void assignBadgeToUser(const QString &badgeID, const UserId &userID);
+
+    /// Remove the given badge from the user
+    void clearBadgeFromUser(const QString &badgeID, const UserId &userID);
+
+    /// Register a new known badge
+    /// The json object will contain all information about the badge, like its ID & its images
+    /// @returns The badge's ID
+    QString registerBadge(const QJsonObject &badgeJson);
+
+protected:
+    BadgeRegistry() = default;
+
+    virtual QString idForBadge(const QJsonObject &badgeJson) const = 0;
+    virtual EmotePtr createBadge(const QString &id,
+                                 const QJsonObject &badgeJson) const = 0;
+
+private:
+    /// Mutex for both `badgeMap_` and `knownBadges_`
+    mutable std::shared_mutex mutex_;
+
+    /// user-id => badge
+    std::unordered_map<QString, EmotePtr> badgeMap_;
+    /// badge-id => badge
+    std::unordered_map<QString, EmotePtr> knownBadges_;
+};
+
+}  // namespace chatterino