Fix ForegroundServiceStartNotAllowedException: switch server without restarting service

Author: NullCoreDeveloper

V2rayNG/app/src/main/java/com/kiktor/v2whitelist/AppConfig.kt

@@ -148,6 +148,7 @@ object AppConfig {
     const val MSG_STATE_STOP = 4
     const val MSG_STATE_STOP_SUCCESS = 41
     const val MSG_STATE_RESTART = 5
+    const val MSG_STATE_SWITCH_SERVER = 51
     const val MSG_MEASURE_DELAY = 6
     const val MSG_MEASURE_DELAY_SUCCESS = 61
     const val MSG_MEASURE_CONFIG = 7

V2rayNG/app/src/main/java/com/kiktor/v2whitelist/contracts/ServiceControl.kt

@@ -25,4 +25,10 @@ interface ServiceControl {
      * @return True if the socket is protected, false otherwise.
      */
     fun vpnProtect(socket: Int): Boolean
+
+    /**
+     * Gets the VPN interface.
+     * @return The VPN interface.
+     */
+    fun getVpnInterface(): ParcelFileDescriptor?
 }

V2rayNG/app/src/main/java/com/kiktor/v2whitelist/handler/SmartConnectManager.kt

@@ -267,13 +267,17 @@ object SmartConnectManager {
         }
 
         if (nextBest != null) {
-            V2RayServiceManager.stopVService(context)
             Log.i(AppConfig.TAG, "Switching to next best server: ${nextBest.second.remarks}")
             sendStatus(context, context.getString(R.string.status_found_best))
             delay(500)
             sendStatus(context, context.getString(R.string.status_connecting_to, nextBest.second.remarks))
             MmkvManager.setSelectServer(nextBest.first)
-            V2RayServiceManager.startVService(context)
+            
+            if (V2RayServiceManager.isRunning()) {
+                MessageUtil.sendMsg2Service(context, AppConfig.MSG_STATE_SWITCH_SERVER, "")
+            } else {
+                V2RayServiceManager.startVService(context)
+            }
             startFailoverTimer(context)
         }
     }

V2rayNG/app/src/main/java/com/kiktor/v2whitelist/handler/V2RayServiceManager.kt

@@ -354,6 +354,14 @@ object V2RayServiceManager {
                     startVService(serviceControl.getService())
                 }
 
+                AppConfig.MSG_STATE_SWITCH_SERVER -> {
+                    Log.i(AppConfig.TAG, "Switching Server inside Service")
+                    val vpnInterface = serviceControl.getVpnInterface()
+                    stopCoreLoop()
+                    Thread.sleep(1000L) // Wait for core to fully release resources
+                    startCoreLoop(vpnInterface)
+                }
+
                 AppConfig.MSG_MEASURE_DELAY -> {
                     measureV2rayDelay()
                 }

V2rayNG/app/src/main/java/com/kiktor/v2whitelist/service/V2RayProxyOnlyService.kt

@@ -72,6 +72,10 @@ class V2RayProxyOnlyService : Service(), ServiceControl {
         return true
     }
 
+    override fun getVpnInterface(): ParcelFileDescriptor? {
+        return null
+    }
+
     /**
      * Binds the service.
      * @param intent The intent.

V2rayNG/app/src/main/java/com/kiktor/v2whitelist/service/V2RayVpnService.kt

@@ -81,6 +81,10 @@ class V2RayVpnService : VpnService(), ServiceControl {
         stopAllService()
     }
 
+    override fun getVpnInterface(): ParcelFileDescriptor? {
+        return mInterface
+    }
+
 //    override fun onLowMemory() {
 //        stopV2Ray()
 //        super.onLowMemory()