feat: translate subtitles with an OpenAI-compatible LLM

src/translate/apikeystore.h

@@ -0,0 +1,48 @@
+#pragma once
+
+#include <QCoroTask>
+
+#include <QObject>
+#include <QtQml/qqmlregistration.h>
+
+// Keeps the translation API key in the system keychain (KWallet / Secret Service)
+// instead of the plain-text config file.
+class ApiKeyStore : public QObject
+{
+    Q_OBJECT
+    QML_ELEMENT
+    QML_SINGLETON
+
+    Q_PROPERTY(bool hasKey READ hasKey NOTIFY hasKeyChanged)
+    Q_PROPERTY(QString error READ error NOTIFY errorChanged)
+
+public:
+    struct ReadResult {
+        QString key;
+        QString error;
+    };
+
+    explicit ApiKeyStore(QObject *parent = nullptr);
+
+    bool hasKey() const;
+    QString error() const;
+
+    // Stores \a key, or removes the stored key when it is empty.
+    Q_INVOKABLE void setKey(const QString &key);
+
+    // An empty key without error means none is stored.
+    static QCoro::Task<ReadResult> readKey();
+
+Q_SIGNALS:
+    void hasKeyChanged();
+    void errorChanged();
+
+private:
+    QCoro::Task<> refresh();
+    QCoro::Task<> store(QString key);
+    void setHasKey(bool hasKey);
+    void setError(const QString &error);
+
+    bool m_hasKey = false;
+    QString m_error;
+};