improve handling of images from immich albums

src/immichclient.cpp

@@ -303,11 +303,16 @@ bool ImmichClient::extensionAllowed(const QString &filename) const
 }
 
 bool ImmichClient::downloadAsset(const QString &assetId, QByteArray &data, QString &contentType)
+{
+  return downloadAssetWithSize(assetId, QString::fromStdString(config.size), data, contentType);
+}
+
+bool ImmichClient::downloadAssetWithSize(const QString &assetId, const QString &sizeOverride, QByteArray &data, QString &contentType)
 {
   if (!config.enabled)
     return false;
 
-  QString size = QString::fromStdString(config.size).trimmed().toLower();
+  QString size = sizeOverride.trimmed().toLower();
   if (size.isEmpty())
     size = "fullsize";
 
@@ -479,15 +484,31 @@ QString ImmichAssetCache::getCachedPath(const QString &assetId, const QString &a
   if (detectedExt.isEmpty())
   {
     Log("Immich download not an image for asset: ", assetId.toStdString());
-    QString skipName = assetId + "_unsupported.skip";
-    QDir dir(cacheDirPath);
-    QFile skipFile(dir.filePath(skipName));
-    if (skipFile.open(QIODevice::WriteOnly))
+    QByteArray fallbackData;
+    QString fallbackType;
+    if (client.downloadAssetWithSize(assetId, "preview", fallbackData, fallbackType))
     {
-      skipFile.write("unsupported");
-      skipFile.close();
+      QString fallbackExt = DetectImageExtension(fallbackData);
+      if (!fallbackExt.isEmpty())
+      {
+        Log("Immich fallback to preview succeeded for asset: ", assetId.toStdString());
+        data = fallbackData;
+        contentType = fallbackType;
+        detectedExt = fallbackExt;
+      }
+    }
+    if (detectedExt.isEmpty())
+    {
+      QString skipName = assetId + "_unsupported.skip";
+      QDir dir(cacheDirPath);
+      QFile skipFile(dir.filePath(skipName));
+      if (skipFile.open(QIODevice::WriteOnly))
+      {
+        skipFile.write("unsupported");
+        skipFile.close();
+      }
+      return "";
     }
-    return "";
   }
 
   QString safeName = sanitizeFileName(assetName);