fix(android): harden profile validation and log buffering

android/app/src/main/java/com/masterdns/vpn/ui/profiles/ProfilesScreen.kt

@@ -295,10 +295,15 @@ private fun ProfileEditorDialog(
     var newDomainInput by remember { mutableStateOf("") }
     var isDomainInputFocused by remember { mutableStateOf(false) }
     var encryptionKey by remember { mutableStateOf(profile?.encryptionKey.orEmpty()) }
-    var resolvers by remember { mutableStateOf(profile?.resolvers ?: "8.8.8.8") }
+    var resolvers by remember { mutableStateOf(profile?.resolvers.orEmpty()) }
+    var validationMessage by remember { mutableStateOf<String?>(null) }
     var showKey by remember { mutableStateOf(false) }
     var showResolversEditor by remember { mutableStateOf(false) }
     val largeResolversText = resolvers.length > 6000
+    val nameRequiredMsg = stringResource(R.string.profiles_name_required_msg)
+    val domainRequiredMsg = stringResource(R.string.profiles_domain_required_msg)
+    val keyRequiredMsg = stringResource(R.string.profiles_encryption_key_required_msg)
+    val resolverRequiredMsg = stringResource(R.string.profiles_resolvers_required_msg)
 
     LaunchedEffect(profile?.id) {
         if (profile != null) {
@@ -312,6 +317,7 @@ private fun ProfileEditorDialog(
             domainList.addAll(parsed)
             encryptionKey = profile.encryptionKey
             resolvers = profile.resolvers
+            validationMessage = null
             showResolversEditor = false
         }
     }
@@ -331,6 +337,7 @@ private fun ProfileEditorDialog(
         if (!importedResolvers.isNullOrBlank()) {
             resolvers = importedResolvers
         }
+        validationMessage = null
     }
 
     AlertDialog(
@@ -351,8 +358,12 @@ private fun ProfileEditorDialog(
             ) {
                 OutlinedTextField(
                     value = name,
-                    onValueChange = { name = it },
+                    onValueChange = {
+                        name = it
+                        validationMessage = null
+                    },
                     label = { Text(stringResource(R.string.profiles_name)) },
+                    isError = validationMessage == nameRequiredMsg,
                     singleLine = true,
                     modifier = Modifier.fillMaxWidth()
                 )
@@ -426,8 +437,12 @@ private fun ProfileEditorDialog(
                     ) {
                         OutlinedTextField(
                             value = newDomainInput,
-                            onValueChange = { newDomainInput = it },
+                            onValueChange = {
+                                newDomainInput = it
+                                validationMessage = null
+                            },
                             label = { Text(stringResource(R.string.profiles_domain_hint)) },
+                            isError = validationMessage == domainRequiredMsg,
                             placeholder = {
                                 if (isDomainInputFocused) {
                                     Text("(e.g. v.example.com)")
@@ -460,8 +475,12 @@ private fun ProfileEditorDialog(
 
                 OutlinedTextField(
                     value = encryptionKey,
-                    onValueChange = { encryptionKey = it },
+                    onValueChange = {
+                        encryptionKey = it
+                        validationMessage = null
+                    },
                     label = { Text(stringResource(R.string.profiles_encryption_key)) },
+                    isError = validationMessage == keyRequiredMsg,
                     singleLine = true,
                     modifier = Modifier.fillMaxWidth(),
                     visualTransformation = if (showKey) VisualTransformation.None else PasswordVisualTransformation(),
@@ -512,13 +531,24 @@ private fun ProfileEditorDialog(
                 } else {
                     OutlinedTextField(
                         value = resolvers,
-                        onValueChange = { resolvers = it },
+                        onValueChange = {
+                            resolvers = it
+                            validationMessage = null
+                        },
                         label = { Text(stringResource(R.string.profiles_resolvers_label)) },
+                        isError = validationMessage == resolverRequiredMsg,
                         modifier = Modifier.fillMaxWidth().height(120.dp),
                         maxLines = 6,
                         keyboardOptions = KeyboardOptions(keyboardType = KeyboardType.Uri)
                     )
                 }
+                validationMessage?.let { message ->
+                    Text(
+                        text = message,
+                        style = MaterialTheme.typography.bodySmall,
+                        color = MaterialTheme.colorScheme.error
+                    )
+                }
             }
         },
         confirmButton = {
@@ -530,18 +560,27 @@ private fun ProfileEditorDialog(
                     } else {
                         domainList.toList()
                     }
+                    validationMessage = when {
+                        name.isBlank() -> nameRequiredMsg
+                        finalDomainList.isEmpty() -> domainRequiredMsg
+                        encryptionKey.isBlank() -> keyRequiredMsg
+                        resolvers.isBlank() -> resolverRequiredMsg
+                        else -> null
+                    }
+                    if (validationMessage != null) {
+                        return@FilledTonalButton
+                    }
                     val baseProfile = profile ?: importedDraft?.profile ?: ProfileEntity(name = "", domains = "")
                     val domainJson = gson.toJson(finalDomainList)
                     onSave(
                         baseProfile.copy(
-                            name = name.trim().ifEmpty { "Profile" },
+                            name = name.trim(),
                             domains = domainJson,
-                            encryptionKey = encryptionKey,
+                            encryptionKey = encryptionKey.trim(),
                             resolvers = resolvers.trim()
                         )
                     )
-                },
-                enabled = name.isNotBlank() && (domainList.isNotEmpty() || newDomainInput.isNotBlank())
+                }
             ) {
                 Text(stringResource(R.string.action_save))
             }
@@ -614,7 +653,7 @@ private fun parseProfileTomlForImport(fileName: String, tomlContent: String): Im
         uploadCompression = values["UPLOAD_COMPRESSION_TYPE"]?.toIntOrNull() ?: 0,
         downloadCompression = values["DOWNLOAD_COMPRESSION_TYPE"]?.toIntOrNull() ?: 0,
         logLevel = values["LOG_LEVEL"]?.trim().takeUnless { it.isNullOrBlank() } ?: "INFO",
-        resolvers = "8.8.8.8",
+        resolvers = "",
         advancedJson = gson.toJson(advanced)
     )
 

android/app/src/main/java/com/masterdns/vpn/util/ConfigGenerator.kt

@@ -3,6 +3,7 @@ package com.masterdns.vpn.util
 import com.masterdns.vpn.data.local.ProfileEntity
 import com.google.gson.Gson
 import com.google.gson.reflect.TypeToken
+import java.util.Locale
 
 /**
  * Generates TOML config files from a ProfileEntity.
@@ -162,15 +163,40 @@ object ConfigGenerator {
             appendLine("# MasterDnsVPN Resolvers")
             appendLine("# Auto-generated by MasterDnsVPN Android")
             appendLine()
+            val seenResolvers = linkedSetOf<String>()
             profile.resolvers.lines().forEach { line ->
                 val trimmed = line.trim()
-                if (trimmed.isNotEmpty()) {
+                val key = resolverDedupeKey(trimmed)
+                if (trimmed.isNotEmpty() && key != null && seenResolvers.add(key)) {
                     appendLine(trimmed)
                 }
             }
         }
     }
 
+    private fun resolverDedupeKey(line: String): String? {
+        val value = line.substringBefore("#").trim().lowercase(Locale.US)
+        if (value.isEmpty()) return null
+
+        val bracketEnd = value.indexOf(']')
+        if (value.startsWith("[") && bracketEnd > 0) {
+            val host = value.substring(1, bracketEnd)
+            val port = value.substring(bracketEnd + 1)
+                .takeIf { it.startsWith(":") }
+                ?.drop(1)
+                ?.takeIf { it.isNotBlank() }
+                ?: "53"
+            return "$host:$port"
+        }
+
+        val colonCount = value.count { it == ':' }
+        return when {
+            colonCount == 0 -> "$value:53"
+            colonCount == 1 -> value
+            else -> "$value:53"
+        }
+    }
+
     private fun parseDomains(json: String): List<String> {
         return try {
             val type = object : TypeToken<List<String>>() {}.type

android/app/src/main/java/com/masterdns/vpn/util/VpnManager.kt

@@ -74,10 +74,14 @@ object VpnManager {
     private val _scanStatus = MutableStateFlow(ScanStatus())
     val scanStatus: StateFlow<ScanStatus> = _scanStatus.asStateFlow()
 
+    private const val MAX_LOG_LINES = 500
+    private const val LOG_EMIT_DELAY_MS = 150L
     private val monitorScope = CoroutineScope(Dispatchers.Default)
     private var trafficMonitorJob: Job? = null
-
-    private const val MAX_LOG_LINES = 500
+    private var logEmitJob: Job? = null
+    private val logBufferLock = Any()
+    private val logBuffer = ArrayDeque<LogEntry>(MAX_LOG_LINES)
+    private var logBufferVersion = 0L
 
     fun updateState(newState: VpnState) {
         _state.value = newState
@@ -117,23 +121,56 @@ object VpnManager {
             errors = _logCounters.value.errors + if (isError) 1 else 0,
             warnings = _logCounters.value.warnings + if (isWarn) 1 else 0
         )
-        val current = _logEntries.value.toMutableList()
-        current.add(LogEntry(normalizedLine, source))
-        if (current.size > MAX_LOG_LINES) {
-            current.removeAt(0)
+        synchronized(logBufferLock) {
+            if (logBuffer.size == MAX_LOG_LINES) {
+                logBuffer.removeFirst()
+            }
+            logBuffer.addLast(LogEntry(normalizedLine, source))
+            logBufferVersion++
         }
-        _logEntries.value = current
-        _logs.value = current.map { it.line }
+        scheduleLogEmission()
         parseScanLine(normalizedLine)
     }
 
     fun clearLogs() {
+        synchronized(logBufferLock) {
+            logBuffer.clear()
+            logBufferVersion++
+        }
+        logEmitJob?.cancel()
+        logEmitJob = null
         _logEntries.value = emptyList()
         _logs.value = emptyList()
         _logCounters.value = LogCounters()
         _scanStatus.value = ScanStatus()
     }
 
+    private fun scheduleLogEmission() {
+        if (logEmitJob?.isActive == true) return
+        logEmitJob = monitorScope.launch {
+            while (isActive) {
+                delay(LOG_EMIT_DELAY_MS)
+                val emittedVersion = emitLogs()
+                val currentVersion = synchronized(logBufferLock) {
+                    logBufferVersion
+                }
+                if (currentVersion == emittedVersion) break
+            }
+        }
+    }
+
+    private fun emitLogs(): Long {
+        val snapshot: List<LogEntry>
+        val version: Long
+        synchronized(logBufferLock) {
+            snapshot = logBuffer.toList()
+            version = logBufferVersion
+        }
+        _logEntries.value = snapshot
+        _logs.value = snapshot.map { it.line }
+        return version
+    }
+
     fun startTrafficMonitor(context: Context) {
         val appContext = context.applicationContext
         val uid = appContext.applicationInfo.uid

android/app/src/main/res/values/strings.xml

@@ -95,6 +95,10 @@
     <string name="profiles_toml_imported_msg">TOML imported into profile form</string>
     <string name="profiles_resolvers_empty_msg">Resolvers file is empty</string>
     <string name="profiles_resolvers_imported_msg">Resolvers imported into profile form</string>
+    <string name="profiles_name_required_msg">Profile name is required.</string>
+    <string name="profiles_domain_required_msg">Add at least one domain before saving.</string>
+    <string name="profiles_encryption_key_required_msg">Encryption key is required.</string>
+    <string name="profiles_resolvers_required_msg">Add at least one resolver before saving.</string>
     <string name="profiles_imported_profile_default">Imported Profile</string>
     <string name="logs_share">Share Logs</string>
     <string name="logs_auto">Auto</string>