Improve session management

Author: hegocre

app/build.gradle

@@ -102,7 +102,8 @@ dependencies {
     implementation 'androidx.navigation:navigation-compose:2.8.0'
     implementation 'androidx.activity:activity-compose:1.9.2'
     implementation 'androidx.biometric:biometric:1.1.0'
-    implementation "androidx.autofill:autofill:1.1.0"
+    implementation 'androidx.autofill:autofill:1.1.0'
+    implementation 'androidx.work:work-runtime-ktx:2.9.1'
 
     //Room dependencies
     implementation "androidx.room:room-ktx:$room_version"

app/src/main/java/com/hegocre/nextcloudpasswords/api/ApiController.kt

@@ -3,6 +3,7 @@ package com.hegocre.nextcloudpasswords.api
 import android.content.Context
 import android.util.Log
 import androidx.lifecycle.MutableLiveData
+import androidx.work.WorkManager
 import com.hegocre.nextcloudpasswords.api.encryption.CSEv1Keychain
 import com.hegocre.nextcloudpasswords.api.exceptions.PWDv1ChallengeMasterKeyInvalidException
 import com.hegocre.nextcloudpasswords.api.exceptions.PWDv1ChallengeMasterKeyNeededException
@@ -15,6 +16,7 @@ import com.hegocre.nextcloudpasswords.data.password.NewPassword
 import com.hegocre.nextcloudpasswords.data.password.Password
 import com.hegocre.nextcloudpasswords.data.password.UpdatedPassword
 import com.hegocre.nextcloudpasswords.data.user.UserController
+import com.hegocre.nextcloudpasswords.services.keepalive.KeepAliveWorker
 import com.hegocre.nextcloudpasswords.utils.Error
 import com.hegocre.nextcloudpasswords.utils.OkHttpRequest
 import com.hegocre.nextcloudpasswords.utils.PreferencesManager
@@ -57,6 +59,8 @@ class ApiController private constructor(context: Context) {
     val sessionOpen: StateFlow<Boolean>
         get() = _sessionOpen.asStateFlow()
 
+    private val workManager = WorkManager.getInstance(context)
+
     init {
         decryptCSEv1Keychain(
             preferencesManager.getCSEv1Keychain(),
@@ -77,22 +81,6 @@ class ApiController private constructor(context: Context) {
             serverSettings.postValue(settings)
             preferencesManager.setServerSettings(settings)
             preferencesManager.setInstanceColor(settings.themeColorPrimary)
-
-            var keepAliveDelay = (settings.sessionLifetime * 3 / 4 * 1000).toLong()
-            while (true) {
-                sessionCode?.let {
-                    delay(keepAliveDelay)
-                    keepAliveDelay = if (sessionApi.keepAlive(it)) {
-                        Log.i("KeepAlive", "Successfully sent keep alive request")
-                        (settings.sessionLifetime * 3 / 4 * 1000).toLong()
-                    } else {
-                        Log.e("KeepAlive", "Error sending keep alive request")
-                        _sessionOpen.emit(false)
-                        sessionCode = null
-                        5000L
-                    }
-                } ?: delay(5000L)
-            }
         }
         OkHttpRequest.getInstance().allowInsecureRequests =
             preferencesManager.getSkipCertificateValidation()
@@ -215,6 +203,11 @@ class ApiController private constructor(context: Context) {
             }
         }
         sessionCode = newSessionCode
+        serverSettings.value?.let { settings ->
+            val keepAliveDelay = (settings.sessionLifetime * 3 / 4 * 1000).toLong()
+            workManager.cancelAllWorkByTag(KeepAliveWorker.TAG)
+            workManager.enqueue(KeepAliveWorker.getRequest(keepAliveDelay, newSessionCode))
+        }
 
         _sessionOpen.emit(true)
         return@withContext true
@@ -236,6 +229,11 @@ class ApiController private constructor(context: Context) {
         }
     }
 
+    suspend fun clearSession() {
+        _sessionOpen.emit(false)
+        sessionCode = null
+    }
+
     /**
      * Gets a list of the user passwords via the [PasswordsApi] class. This can only be called when a
      * session is open, otherwise an error is thrown.

app/src/main/java/com/hegocre/nextcloudpasswords/services/keepalive/KeepAliveWorker.kt

@@ -0,0 +1,76 @@
+package com.hegocre.nextcloudpasswords.services.keepalive
+
+import android.content.Context
+import androidx.work.BackoffPolicy
+import androidx.work.Constraints
+import androidx.work.CoroutineWorker
+import androidx.work.Data
+import androidx.work.NetworkType
+import androidx.work.OneTimeWorkRequestBuilder
+import androidx.work.WorkManager
+import androidx.work.WorkRequest
+import androidx.work.WorkerParameters
+import com.hegocre.nextcloudpasswords.api.ApiController
+import com.hegocre.nextcloudpasswords.api.SessionApi
+import com.hegocre.nextcloudpasswords.data.user.UserController
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.withContext
+import java.util.concurrent.TimeUnit
+
+class KeepAliveWorker(context: Context, private val params: WorkerParameters) :
+    CoroutineWorker(context, params) {
+    override suspend fun doWork(): Result {
+        val apiController = ApiController.getInstance(applicationContext)
+        if (!apiController.sessionOpen.value) {
+            return Result.success()
+        }
+
+        val server = UserController.getInstance(applicationContext).getServer()
+        val sessionApi = SessionApi.getInstance(server)
+
+        val sessionCode = params.inputData.getString(SESSION_CODE_KEY) ?: return Result.failure()
+        val keepAliveDelay = params.inputData.getLong(KEEPALIVE_DELAY_KEY, -1L)
+        if (keepAliveDelay == -1L) return Result.failure()
+
+        val resultSuccess = withContext(Dispatchers.IO) {
+            sessionApi.keepAlive(sessionCode)
+        }
+
+        if (resultSuccess) {
+            WorkManager.getInstance(applicationContext)
+                .enqueue(getRequest(keepAliveDelay, sessionCode))
+            return Result.success()
+        } else {
+            if (params.runAttemptCount > 2) {
+                ApiController.getInstance(applicationContext).clearSession()
+                return Result.failure()
+            } else {
+                return Result.retry()
+            }
+        }
+    }
+
+    companion object {
+        private const val SESSION_CODE_KEY = "com.hegocre.nextcloudpasswords.sessionCode"
+        private const val KEEPALIVE_DELAY_KEY = "com.hegocre.nextcloudpasswords.keepAliveDelay"
+        const val TAG = "com.hegocre.nextcloudpasswords.keepaliveworker"
+
+        fun getRequest(delay: Long, sessionCode: String): WorkRequest {
+            val data = Data.Builder()
+                .putString(SESSION_CODE_KEY, sessionCode)
+                .putLong(KEEPALIVE_DELAY_KEY, delay)
+                .build()
+            return OneTimeWorkRequestBuilder<KeepAliveWorker>()
+                .setInitialDelay(delay, TimeUnit.MILLISECONDS)
+                .setInputData(data)
+                .setBackoffCriteria(BackoffPolicy.LINEAR, 10L, TimeUnit.SECONDS)
+                .addTag(TAG)
+                .setConstraints(
+                    Constraints.Builder()
+                        .setRequiredNetworkType(NetworkType.CONNECTED)
+                        .build()
+                )
+                .build()
+        }
+    }
+}