Add BackupSubscriptionCheckJob.

core-util/src/main/java/org/signal/core/util/billing/BillingApi.kt

@@ -27,7 +27,7 @@ interface BillingApi {
    * Queries the user's current purchases. This enqueues a check and will
    * propagate it to the normal callbacks in the api.
    */
-  suspend fun queryPurchases() = Unit
+  suspend fun queryPurchases(): BillingPurchaseResult = BillingPurchaseResult.None
 
   suspend fun launchBillingFlow(activity: Activity) = Unit
 

core-util/src/main/java/org/signal/core/util/billing/BillingPurchaseResult.kt

@@ -5,6 +5,9 @@
 
 package org.signal.core.util.billing
 
+import kotlin.time.Duration.Companion.days
+import kotlin.time.Duration.Companion.milliseconds
+
 /**
  * Sealed class hierarchy representing the different success
  * and error states of google play billing purchases.
@@ -13,8 +16,21 @@ sealed interface BillingPurchaseResult {
   data class Success(
     val purchaseToken: String,
     val isAcknowledged: Boolean,
-    val purchaseTime: Long
-  ) : BillingPurchaseResult
+    val purchaseTime: Long,
+    val isAutoRenewing: Boolean
+  ) : BillingPurchaseResult {
+
+    /**
+     * @return true if purchaseTime is within the last month.
+     */
+    fun isWithinTheLastMonth(): Boolean {
+      val now = System.currentTimeMillis().milliseconds
+      val oneMonthAgo = now - 31.days
+      val purchaseTime = this.purchaseTime.milliseconds
+
+      return oneMonthAgo >= purchaseTime
+    }
+  }
   data object UserCancelled : BillingPurchaseResult
   data object None : BillingPurchaseResult
   data object TryAgainLater : BillingPurchaseResult