fix(ad-hoc): (nAPM) Reset capture polling backoff when app returned to foreground

sdk/src/main/kotlin/com/processout/sdk/api/network/interceptor/RetryInterceptor.kt

@@ -11,15 +11,15 @@ import java.util.UUID
 internal class RetryInterceptor(
     private val retryStrategy: PORetryStrategy = Exponential(
         maxRetries = 4,
-        initialDelay = 100,
+        seedDelay = 100,
         maxDelay = 1000,
         factor = 3.0
     )
 ) : Interceptor {
 
     override fun intercept(chain: Interceptor.Chain): Response {
         val request = chain.request().addIdempotencyKey()
-        val iterator = retryStrategy.iterator
+        val backoffIterator = retryStrategy.newBackoffIterator()
         repeat(retryStrategy.maxRetries - 1) {
             var response: Response? = null
             try {
@@ -34,7 +34,7 @@ internal class RetryInterceptor(
                 // network issue, retry
             }
             response?.body?.close()
-            Thread.sleep(iterator.next())
+            Thread.sleep(backoffIterator.next())
         }
         return chain.proceed(request)
     }

sdk/src/main/kotlin/com/processout/sdk/core/retry/PORetryStrategy.kt

@@ -7,7 +7,7 @@ import kotlin.math.roundToLong
 @ProcessOutInternalApi
 sealed class PORetryStrategy(
     val maxRetries: Int,
-    private val initialDelay: Long,
+    private val seedDelay: Long,
     private val minDelay: Long,
     private val maxDelay: Long,
     private val factor: Double
@@ -18,31 +18,31 @@ sealed class PORetryStrategy(
         delay: Long
     ) : PORetryStrategy(
         maxRetries = maxRetries,
-        initialDelay = delay,
+        seedDelay = delay,
         minDelay = delay,
         maxDelay = delay,
         factor = 1.0
     )
 
     class Exponential(
         maxRetries: Int,
-        initialDelay: Long,
-        minDelay: Long = initialDelay,
+        seedDelay: Long,
+        minDelay: Long = seedDelay,
         maxDelay: Long,
         factor: Double
     ) : PORetryStrategy(
         maxRetries = maxRetries,
-        initialDelay = initialDelay,
+        seedDelay = seedDelay,
         minDelay = minDelay,
         maxDelay = maxDelay,
         factor = factor
     )
 
-    class Iterator(
-        private val iterator: kotlin.collections.Iterator<Double>,
+    class BackoffIterator(
+        private val iterator: Iterator<Double>,
         private val minDelay: Long,
         private val maxDelay: Long
-    ) : kotlin.collections.Iterator<Long> {
+    ) : Iterator<Long> {
 
         override fun hasNext(): Boolean = iterator.hasNext()
 
@@ -53,12 +53,11 @@ sealed class PORetryStrategy(
         }
     }
 
-    val iterator: Iterator
-        get() = Iterator(
-            iterator = generateSequence(initialDelay.toDouble()) { previous ->
-                previous * factor
-            }.iterator(),
-            minDelay = minDelay,
-            maxDelay = maxDelay
-        )
+    fun newBackoffIterator() = BackoffIterator(
+        iterator = generateSequence(seed = seedDelay.toDouble()) { previous ->
+            previous * factor
+        }.iterator(),
+        minDelay = minDelay,
+        maxDelay = maxDelay
+    )
 }

sdk/src/main/kotlin/com/processout/sdk/ui/nativeapm/NativeAlternativePaymentMethodViewModel.kt

@@ -3,6 +3,7 @@ package com.processout.sdk.ui.nativeapm
 import android.app.Application
 import android.os.Handler
 import android.os.Looper
+import android.os.SystemClock
 import android.util.Patterns
 import android.view.View
 import android.view.inputmethod.EditorInfo
@@ -79,7 +80,7 @@ internal class NativeAlternativePaymentMethodViewModel private constructor(
                     eventDispatcher = PODefaultEventDispatchers.defaultNativeAlternativePaymentMethod,
                     captureRetryStrategy = Exponential(
                         maxRetries = Int.MAX_VALUE,
-                        initialDelay = 150,
+                        seedDelay = 150,
                         minDelay = 3 * 1000,
                         maxDelay = 90 * 1000,
                         factor = 1.45
@@ -104,8 +105,8 @@ internal class NativeAlternativePaymentMethodViewModel private constructor(
 
     var animateViewTransition = true
 
-    private var captureStartTimestamp = 0L
-    private var capturePassedTimestamp = 0L
+    private var captureStartTime = 0L
+    private var captureElapsedTime = 0L
 
     private val handler by lazy { Handler(Looper.getMainLooper()) }
 
@@ -521,26 +522,26 @@ internal class NativeAlternativePaymentMethodViewModel private constructor(
     }
 
     private fun capture() {
-        if (captureStartTimestamp != 0L) {
+        if (captureStartTime != 0L) {
             return
         }
-        captureStartTimestamp = System.currentTimeMillis()
+        captureStartTime = SystemClock.elapsedRealtime()
         options.showPaymentConfirmationProgressIndicatorAfterSeconds?.let { afterSeconds ->
             showPaymentConfirmationProgressIndicator(
                 afterMillis = TimeUnit.SECONDS.toMillis(afterSeconds.toLong())
             )
         }
         viewModelScope.launch {
-            val iterator = captureRetryStrategy.iterator
-            while (capturePassedTimestamp <= options.paymentConfirmationTimeoutSeconds * 1000) {
+            val backoffIterator = captureRetryStrategy.newBackoffIterator()
+            while (captureElapsedTime <= options.paymentConfirmationTimeoutSeconds * 1000L) {
                 val result = invoicesService.captureNativeAlternativePayment(invoiceId, gatewayConfigurationId)
                 POLogger.debug("Attempted to capture invoice.")
                 if (isCaptureRetryable(result)) {
-                    delay(iterator.next())
-                    capturePassedTimestamp = System.currentTimeMillis() - captureStartTimestamp
+                    delay(timeMillis = backoffIterator.next())
+                    captureElapsedTime = SystemClock.elapsedRealtime() - captureStartTime
                 } else {
-                    captureStartTimestamp = 0L
-                    capturePassedTimestamp = 0L
+                    captureStartTime = 0L
+                    captureElapsedTime = 0L
                     when (result) {
                         is ProcessOutResult.Success ->
                             _uiState.value.doWhenCapture { uiModel ->
@@ -552,8 +553,8 @@ internal class NativeAlternativePaymentMethodViewModel private constructor(
                     return@launch
                 }
             }
-            captureStartTimestamp = 0L
-            capturePassedTimestamp = 0L
+            captureStartTime = 0L
+            captureElapsedTime = 0L
             _uiState.value = Failure(
                 ProcessOutResult.Failure(
                     Timeout(), "Payment confirmation timed out."

ui-core/src/main/kotlin/com/processout/sdk/ui/core/component/POCountdownTimerText.kt

@@ -2,6 +2,7 @@
 
 package com.processout.sdk.ui.core.component
 
+import android.os.SystemClock
 import androidx.compose.runtime.*
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.text.font.FontWeight
@@ -16,23 +17,25 @@ import kotlinx.coroutines.delay
 fun POCountdownTimerText(
     textFormat: String,
     timeoutSeconds: Int,
+    initialElapsedRealtime: Long,
     modifier: Modifier = Modifier,
     style: POText.Style = POText.Style(
         color = colors.text.primary,
         textStyle = typography.s15(FontWeight.Medium)
     )
 ) {
-    var secondsLeft by remember { mutableIntStateOf(timeoutSeconds) }
-    val formattedText = remember(secondsLeft) {
-        val minutes = secondsLeft / 60
-        val seconds = secondsLeft % 60
+    var remainingSeconds by remember { mutableIntStateOf(timeoutSeconds) }
+    val formattedText = remember(remainingSeconds) {
+        val minutes = remainingSeconds / 60
+        val seconds = remainingSeconds % 60
         val formattedTime = String.format("%02d:%02d", minutes, seconds)
         String.format(textFormat, formattedTime)
     }
-    LaunchedEffect(secondsLeft) {
-        if (secondsLeft > 0) {
+    LaunchedEffect(Unit) {
+        while (remainingSeconds > 0) {
+            val elapsedSeconds = ((SystemClock.elapsedRealtime() - initialElapsedRealtime) / 1000L).toInt()
+            remainingSeconds = (timeoutSeconds - elapsedSeconds).coerceAtLeast(minimumValue = 0)
             delay(timeMillis = 1000)
-            secondsLeft -= 1
         }
     }
     POText(

ui-core/src/main/kotlin/com/processout/sdk/ui/core/component/stepper/POStepper.kt

@@ -1,5 +1,6 @@
 package com.processout.sdk.ui.core.component.stepper
 
+import android.os.SystemClock
 import androidx.compose.runtime.Composable
 import androidx.compose.ui.text.font.FontWeight
 import androidx.compose.ui.unit.dp
@@ -22,7 +23,8 @@ object POStepper {
 
         data class CountdownTimerText(
             val textFormat: String,
-            val timeoutSeconds: Int
+            val timeoutSeconds: Int,
+            val initialElapsedRealtime: Long = SystemClock.elapsedRealtime()
         )
     }
 

ui-core/src/main/kotlin/com/processout/sdk/ui/core/component/stepper/POVerticalStepper.kt

@@ -104,6 +104,7 @@ fun POVerticalStepper(
                         POCountdownTimerText(
                             textFormat = description.textFormat,
                             timeoutSeconds = description.timeoutSeconds,
+                            initialElapsedRealtime = description.initialElapsedRealtime,
                             modifier = Modifier
                                 .fillMaxWidth()
                                 .padding(vertical = spacing.space4),

ui/build.gradle

@@ -92,6 +92,7 @@ dependencies {
 
     api "androidx.activity:activity-compose:$androidxActivityVersion"
     api "androidx.lifecycle:lifecycle-viewmodel-compose:$androidxLifecycleVersion"
+    implementation "androidx.lifecycle:lifecycle-process:$androidxLifecycleVersion"
 
     implementation "androidx.camera:camera-camera2:$androidxCameraVersion"
     implementation "androidx.camera:camera-lifecycle:$androidxCameraVersion"

ui/src/main/kotlin/com/processout/sdk/ui/card/scanner/recognition/CardRecognitionSession.kt

@@ -2,6 +2,7 @@ package com.processout.sdk.ui.card.scanner.recognition
 
 import android.app.Application
 import android.graphics.Bitmap
+import android.os.SystemClock
 import androidx.camera.core.ImageProxy
 import com.google.android.gms.common.moduleinstall.InstallStatusListener
 import com.google.android.gms.common.moduleinstall.ModuleInstall
@@ -50,7 +51,7 @@ internal class CardRecognitionSession(
     private val moduleInstallClient = ModuleInstall.getClient(app)
     private val textRecognizer = TextRecognition.getClient(TextRecognizerOptions.DEFAULT_OPTIONS)
 
-    private var startTimestamp = 0L
+    private var startTime = 0L
     private val recognizedCards = mutableListOf<POScannedCard>()
 
     init {
@@ -163,8 +164,8 @@ internal class CardRecognitionSession(
             val candidates = text.candidates(MIN_CONFIDENCE)
             val number = numberDetector.firstMatch(candidates)
             if (number != null) {
-                if (startTimestamp == 0L) {
-                    startTimestamp = System.currentTimeMillis()
+                if (startTime == 0L) {
+                    startTime = SystemClock.elapsedRealtime()
                 }
                 val card = POScannedCard(
                     number = number,
@@ -178,12 +179,12 @@ internal class CardRecognitionSession(
                     _currentCard.send(card)
                 }
             }
-            if (System.currentTimeMillis() - startTimestamp > RECOGNITION_DURATION_MS) {
+            if (SystemClock.elapsedRealtime() - startTime > RECOGNITION_DURATION_MS) {
                 if (recognizedCards.isNotEmpty()) {
                     sendMostFrequentCard()
                     recognizedCards.clear()
                 }
-                startTimestamp = 0L
+                startTime = 0L
             }
             imageProxy.close()
         }