Refactored the Image Uploader feature. (#4971)

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

src/singletons/ImageUploader.hpp

@@ -0,0 +1,49 @@
+#pragma once
+
+#include "common/Singleton.hpp"
+
+#include <QMimeData>
+#include <QMutex>
+#include <QString>
+
+#include <memory>
+#include <queue>
+
+namespace chatterino {
+
+class ResizingTextEdit;
+class Channel;
+class NetworkResult;
+using ChannelPtr = std::shared_ptr<Channel>;
+
+struct RawImageData {
+    QByteArray data;
+    QString format;
+    QString filePath;
+};
+
+class ImageUploader final : public Singleton
+{
+public:
+    void save() override;
+    void upload(const QMimeData *source, ChannelPtr channel,
+                QPointer<ResizingTextEdit> outputTextEdit);
+
+private:
+    void sendImageUploadRequest(RawImageData imageData, ChannelPtr channel,
+                                QPointer<ResizingTextEdit> textEdit);
+
+    // This is called from the onSuccess handler of the NetworkRequest in sendImageUploadRequest
+    void handleSuccessfulUpload(const NetworkResult &result,
+                                QString originalFilePath, ChannelPtr channel,
+                                QPointer<ResizingTextEdit> textEdit);
+    void handleFailedUpload(const NetworkResult &result, ChannelPtr channel);
+
+    void logToFile(const QString &originalFilePath, const QString &imageLink,
+                   const QString &deletionLink, ChannelPtr channel);
+
+    // These variables are only used from the main thread.
+    QMutex uploadMutex_;
+    std::queue<RawImageData> uploadQueue_;
+};
+}  // namespace chatterino