Adds a second list of filtered Users that were automatically added and are not saved with the person's key

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

@@ -58,6 +58,8 @@ class Account(
   var dontTranslateFrom: Set<String> = getLanguagesSpokenByUser(),
   var translateTo: String = Locale.getDefault().language
 ) {
+  var transientHiddenUsers: Set<String> = setOf()
+
   fun userProfile(): User {
     return LocalCache.getOrCreateUser(loggedIn.pubKey.toHexKey())
   }
@@ -67,7 +69,7 @@ class Account(
   }
 
   fun hiddenUsers(): List<User> {
-    return hiddenUsers.map { LocalCache.getOrCreateUser(it) }
+    return (hiddenUsers + transientHiddenUsers).map { LocalCache.getOrCreateUser(it) }
   }
 
   fun isWriteable(): Boolean {
@@ -321,6 +323,7 @@ class Account(
 
   fun showUser(pubkeyHex: String) {
     hiddenUsers = hiddenUsers - pubkeyHex
+    transientHiddenUsers = transientHiddenUsers - pubkeyHex
     invalidateData(live)
   }
 
@@ -411,6 +414,18 @@ class Account(
         reconnectIfRelaysHaveChanged()
       }
     }
+    LocalCache.liveSpam.observeForever {
+      GlobalScope.launch(Dispatchers.IO) {
+        LocalCache.spamMessages.snapshot().values.forEach {
+          if (it !in hiddenUsers) {
+            val userToBlock = LocalCache.getOrCreateUser(it)
+            if (userToBlock != userProfile() && userToBlock !in userProfile().follows) {
+              transientHiddenUsers = transientHiddenUsers + it
+            }
+          }
+        }
+      }
+    }
   }
 
   // Observers line up here.

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

@@ -52,8 +52,8 @@ object LocalCache {
   val notes = ConcurrentHashMap<HexKey, Note>()
   val channels = ConcurrentHashMap<HexKey, Channel>()
 
-  val recentMessages = LruCache<Int, Int>(1000)
-  val spamMessages = LruCache<Int, Int>(1000)
+  val recentMessages = LruCache<Int, String>(1000)
+  val spamMessages = LruCache<Int, String>(1000)
 
   fun checkGetOrCreateUser(key: HexKey): User? {
     return try {
@@ -120,16 +120,24 @@ object LocalCache {
       .format(DateTimeFormatter.ofPattern("uuuu MMM d hh:mm a"))
   }
 
+  @Synchronized
   fun isRepeatedMessageSpam(event: Event): Boolean {
+    val idHex = event.id.toHexKey()
+    // if already processed, return
+    if (notes[idHex] != null) return false
+
     // double list strategy:
     // if duplicated, it goes into spam. 1000 spam messages are saved into the spam list.
-
-    val hash = event.content.hashCode()
-    if (event.content.length > 50 && (recentMessages[hash] != null || spamMessages[hash] != null)) {
-      spamMessages.put(hash, hash)
+    val hash = (event.content + event.tags.flatten().joinToString(",")).hashCode()
+    if (event.content.length > 50 && ((recentMessages[hash] != null && recentMessages[hash] != idHex) || spamMessages[hash] != null)) {
+      Log.w("Potential SPAM Message", "${event.id.toHex()} ${recentMessages[hash]} ${spamMessages[hash] != null} ${event.content.replace("\n", " | ")}")
+      if (spamMessages.get(hash) == null) {
+        spamMessages.put(hash, event.pubKey.toHexKey())
+        liveSpam.invalidateData()
+      }
       return true
     }
-    recentMessages.put(hash, hash)
+    recentMessages.put(hash, idHex)
     return false
   }
 
@@ -639,6 +647,7 @@ object LocalCache {
 
   // Observers line up here.
   val live: LocalCacheLiveData = LocalCacheLiveData(this)
+  val liveSpam: LocalCacheLiveData = LocalCacheLiveData(this)
 
   private fun refreshObservers() {
     live.invalidateData()