Logging failures to reduce the amount of network calls,

app/src/main/java/com/vitorpamplona/amethyst/model/UrlCachedPreviewer.kt

@@ -15,6 +15,7 @@ import kotlinx.coroutines.launch
 
 object UrlCachedPreviewer {
   val cache = ConcurrentHashMap<String, UrlInfoItem>()
+  val failures = ConcurrentHashMap<String, Throwable>()
 
   fun previewInfo(url: String, callback: IUrlPreviewCallback? = null) {
     cache[url]?.let {
@@ -22,6 +23,11 @@ object UrlCachedPreviewer {
       return
     }
 
+    failures[url]?.let {
+      callback?.onFailed(it)
+      return
+    }
+
     val scope = CoroutineScope(Job() + Dispatchers.IO)
     scope.launch {
       BahaUrlPreview(url, object : IUrlPreviewCallback {
@@ -31,6 +37,7 @@ object UrlCachedPreviewer {
         }
 
         override fun onFailed(throwable: Throwable) {
+          failures.put(url, throwable)
           callback?.onFailed(throwable)
         }
       }).fetchUrlPreview()
@@ -53,8 +60,10 @@ object UrlCachedPreviewer {
           // Preload Images? Isn't this too heavy?
         } else if (videoExtension.matcher(removedParamsFromUrl).matches()) {
           // Do nothing for now.
-        } else {
+        } else if (isValidURL(removedParamsFromUrl)) {
           previewInfo(it)
+        } else {
+          previewInfo("https://${it}")
         }
       }
     }