Update in app expiry notifications over time

4 files changed, 87 insertions, 6 deletions

diff --git a/android/service/src/main/kotlin/net/mullvad/mullvadvpn/service/notifications/accountexpiry/AccountExpiryAndroidNotification.kt b/android/service/src/main/kotlin/net/mullvad/mullvadvpn/service/notifications/accountexpiry/AccountExpiryAndroidNotification.kt
index 0e8a1a528f..d6d18fd58a 100644
--- a/android/service/src/main/kotlin/net/mullvad/mullvadvpn/service/notifications/accountexpiry/AccountExpiryAndroidNotification.kt
+++ b/android/service/src/main/kotlin/net/mullvad/mullvadvpn/service/notifications/accountexpiry/AccountExpiryAndroidNotification.kt
@@ -39,7 +39,7 @@ private fun Notification.AccountExpiry.contentIntent(context: Context): PendingI
 
 private fun Resources.contentTitle(remainingTime: Duration): String =
     when {
-        remainingTime.isShorterThan(Duration.ZERO) -> {
+        remainingTime.isShorterThan(Duration.ZERO) || remainingTime == Duration.ZERO -> {
             getString(R.string.account_credit_has_expired)
         }
         remainingTime.standardDays >= 1 -> {
diff --git a/android/service/src/main/kotlin/net/mullvad/mullvadvpn/service/notifications/accountexpiry/AccountExpiryConstant.kt b/android/service/src/main/kotlin/net/mullvad/mullvadvpn/service/notifications/accountexpiry/AccountExpiryConstant.kt
index 7ca2b33a22..49b891d55c 100644
--- a/android/service/src/main/kotlin/net/mullvad/mullvadvpn/service/notifications/accountexpiry/AccountExpiryConstant.kt
+++ b/android/service/src/main/kotlin/net/mullvad/mullvadvpn/service/notifications/accountexpiry/AccountExpiryConstant.kt
@@ -1,4 +1,15 @@
+@file:Suppress("MagicNumber")
+
 package net.mullvad.mullvadvpn.service.notifications.accountexpiry
 
-const val ACCOUNT_EXPIRY_POLL_INTERVAL: Long = 15 /* s */ * 1000 /* ms */
-const val ACCOUNT_EXPIRY_CLOSE_TO_EXPIRY_THRESHOLD_DAYS = 3
+import kotlin.time.Duration.Companion.seconds
+import org.joda.time.Duration
+
+val ACCOUNT_EXPIRY_POLL_INTERVAL = 15.seconds
+val ACCOUNT_EXPIRY_IN_APP_NOTIFICATION_UPDATE_INTERVAL: Duration = Duration.standardDays(1)
+val ACCOUNT_EXPIRY_CLOSE_TO_EXPIRY_THRESHOLD: Duration = Duration.standardDays(3)
+
+val ACCOUNT_EXPIRY_ANDROID_NOTIFICATION_UPDATE_INTERVAL_LONG: Duration = Duration.standardDays(1)
+val ACCOUNT_EXPIRY_ANDROID_NOTIFICATION_UPDATE_INTERVAL_SHORT: Duration = Duration.standardHours(1)
+val ACCOUNT_EXPIRY_ANDROID_NOTIFICATION_UPDATE_INTERVAL_SHORT_THRESHOLD: Duration =
+    Duration.standardDays(1)
diff --git a/android/service/src/main/kotlin/net/mullvad/mullvadvpn/service/notifications/accountexpiry/AccountExpiryNotificationProvider.kt b/android/service/src/main/kotlin/net/mullvad/mullvadvpn/service/notifications/accountexpiry/AccountExpiryNotificationProvider.kt
index 3250054459..a6a2f80d06 100644
--- a/android/service/src/main/kotlin/net/mullvad/mullvadvpn/service/notifications/accountexpiry/AccountExpiryNotificationProvider.kt
+++ b/android/service/src/main/kotlin/net/mullvad/mullvadvpn/service/notifications/accountexpiry/AccountExpiryNotificationProvider.kt
@@ -55,8 +55,6 @@ class AccountExpiryNotificationProvider(
     }
 
     private fun Duration.isCloseToExpiry(): Boolean {
-        return isShorterThan(
-            Duration.standardDays(ACCOUNT_EXPIRY_CLOSE_TO_EXPIRY_THRESHOLD_DAYS.toLong())
-        )
+        return isShorterThan(ACCOUNT_EXPIRY_CLOSE_TO_EXPIRY_THRESHOLD)
     }
 }
diff --git a/android/service/src/main/kotlin/net/mullvad/mullvadvpn/service/notifications/accountexpiry/AccountExpiryTickerFlow.kt b/android/service/src/main/kotlin/net/mullvad/mullvadvpn/service/notifications/accountexpiry/AccountExpiryTickerFlow.kt
new file mode 100644
index 0000000000..67c954a3ce
--- /dev/null
+++ b/android/service/src/main/kotlin/net/mullvad/mullvadvpn/service/notifications/accountexpiry/AccountExpiryTickerFlow.kt
@@ -0,0 +1,72 @@
+package net.mullvad.mullvadvpn.service.notifications.accountexpiry
+
+import kotlinx.coroutines.delay
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.flow
+import org.joda.time.DateTime
+import org.joda.time.Duration
+import org.joda.time.Period
+
+fun expiryTickerFlow(
+    expiry: DateTime,
+    tickStart: Duration,
+    updateInterval: (expiry: DateTime) -> Duration,
+): Flow<Period> = flow {
+    var currentUpdateInterval = updateInterval(expiry).millis
+
+    expiry.millisFromNow().let { expiryMillis ->
+        if (expiryMillis <= 0) {
+            // Has expired.
+            emit(Period.ZERO)
+            return@flow
+        } else if (expiryMillis <= currentUpdateInterval) {
+            emit(Period(DateTime.now(), expiry))
+            delay(expiry.millisFromNow())
+            emit(Period.ZERO)
+            return@flow
+        } else if (expiryMillis > tickStart.millis) {
+            // Delay until the time we should start emitting.
+            delay(expiryMillis - tickStart.millis + 1)
+        }
+    }
+
+    // Always emit at start of flow.
+    emit(Period(DateTime.now(), expiry))
+
+    // Delay until the next update interval.
+    delay(expiry.millisFromNow() % currentUpdateInterval)
+
+    var delayCount = calculateDelaysNeeded(expiry.millisFromNow(), currentUpdateInterval)
+
+    while (delayCount > 0) {
+        emit(Period(DateTime.now(), expiry))
+        delay(currentUpdateInterval)
+
+        val newUpdateInterval = updateInterval(expiry).millis
+        if (newUpdateInterval != currentUpdateInterval) {
+            delayCount = calculateDelaysNeeded(expiry.millisFromNow(), newUpdateInterval)
+            currentUpdateInterval = newUpdateInterval
+        } else {
+            delayCount -= 1
+        }
+    }
+
+    // We may have remaining time if the update interval wasn't a multiple of the remaining time.
+    delay(expiry.millisFromNow())
+
+    // We have now expired.
+    emit(Period.ZERO)
+}
+
+// Calculate how many times we need to delay and and emit until the expiry time is reached.
+// Note that the returned delays may add upp to less than the remaining time, for example
+// if we have 100ms remaining and currentUpdateIntervalMillis is 40ms this function will return 2.
+private fun calculateDelaysNeeded(millisUntilExpiry: Long, currentUpdateIntervalMillis: Long): Int {
+    return if (millisUntilExpiry <= 0) {
+        0
+    } else {
+        (millisUntilExpiry / currentUpdateIntervalMillis).toInt()
+    }
+}
+
+private fun DateTime.millisFromNow(): Long = Duration(DateTime.now(), this).millis