Port Android server runtime to GaCy Go

app/src/main/java/com/gacy/android/service/LogBuffer.kt

@@ -10,7 +10,9 @@ import java.util.Locale
 object LogBuffer {
 
     private const val MAX_LOG_LINES = 500
+    private const val MAX_DIAGNOSTIC_LINES = 100
     private val timeFormat = SimpleDateFormat("HH:mm:ss", Locale.getDefault())
+    private val diagnostics = ArrayDeque<String>()
 
     private val _logs = MutableStateFlow<List<String>>(emptyList())
     val logs: StateFlow<List<String>> = _logs.asStateFlow()
@@ -19,6 +21,10 @@ object LogBuffer {
     fun append(message: String) {
         val timestamp = timeFormat.format(Date())
         val formatted = "[$timestamp] $message"
+        if (isDiagnostic(message)) {
+            diagnostics.addLast(formatted)
+            if (diagnostics.size > MAX_DIAGNOSTIC_LINES) diagnostics.removeFirst()
+        }
         val current = _logs.value.toMutableList()
         current.add(formatted)
         if (current.size > MAX_LOG_LINES) {
@@ -30,9 +36,18 @@ object LogBuffer {
     @Synchronized
     fun clear() {
         _logs.value = emptyList()
+        diagnostics.clear()
     }
 
+    @Synchronized
     fun getAllText(): String {
-        return _logs.value.joinToString("\n")
+        val recent = _logs.value
+        val olderDiagnostics = diagnostics.filterNot { it in recent }
+        return (olderDiagnostics + recent).joinToString("\n")
     }
+
+    private fun isDiagnostic(message: String): Boolean =
+        "[gateway]" in message || "[DISPATCH]" in message ||
+            "[KCP] handshake rejected:" in message || "[KCP] packet rejected:" in message ||
+            "New connection from addr:" in message || "[Server error]" in message
 }