From 1bf81a9c5eeb85dddfdde9c58e0f1f1596e630be Mon Sep 17 00:00:00 2001
From: Max Radermacher <max@signal.org>
Date: Fri, 21 Nov 2025 14:48:55 -0600
Subject: [PATCH] Use Cron for periodic remote megaphone updates

---
 Signal/AppLaunch/AppDelegate.swift            | 19 +++---
 .../Megaphones/RemoteMegaphoneFetcher.swift   | 58 ++-----------------
 SignalServiceKit/Jobs/Cron.swift              |  1 +
 3 files changed, 16 insertions(+), 62 deletions(-)

diff --git a/Signal/AppLaunch/AppDelegate.swift b/Signal/AppLaunch/AppDelegate.swift
index a8a8f75ee3..98201f2840 100644
--- a/Signal/AppLaunch/AppDelegate.swift
+++ b/Signal/AppLaunch/AppDelegate.swift
@@ -697,14 +697,17 @@ final class AppDelegate: UIResponder, UIApplicationDelegate {
             }
         }
 
-        appReadiness.runNowOrWhenAppDidBecomeReadyAsync {
-            Task {
-                try? await RemoteMegaphoneFetcher(
-                    databaseStorage: SSKEnvironment.shared.databaseStorageRef,
-                    signalService: SSKEnvironment.shared.signalServiceRef
-                ).syncRemoteMegaphonesIfNecessary()
-            }
-        }
+        let remoteMegaphoneFetcher = RemoteMegaphoneFetcher(
+            databaseStorage: SSKEnvironment.shared.databaseStorageRef,
+            signalService: SSKEnvironment.shared.signalServiceRef,
+        )
+        cron.schedulePeriodically(
+            uniqueKey: .fetchMegaphones,
+            approximateInterval: 3 * .day,
+            mustBeRegistered: false,
+            mustBeConnected: true,
+            operation: { try await remoteMegaphoneFetcher.syncRemoteMegaphones() },
+        )
 
         appReadiness.runNowOrWhenAppDidBecomeReadyAsync {
             DependenciesBridge.shared.orphanedAttachmentCleaner.beginObserving()
diff --git a/Signal/Megaphones/RemoteMegaphoneFetcher.swift b/Signal/Megaphones/RemoteMegaphoneFetcher.swift
index 68d9df27d8..2a853524ce 100644
--- a/Signal/Megaphones/RemoteMegaphoneFetcher.swift
+++ b/Signal/Megaphones/RemoteMegaphoneFetcher.swift
@@ -4,14 +4,14 @@
 //
 
 import Foundation
-public import SignalServiceKit
+import SignalServiceKit
 
 /// Handles fetching and parsing remote megaphones.
-public class RemoteMegaphoneFetcher {
+class RemoteMegaphoneFetcher {
     private let databaseStorage: SDSDatabaseStorage
     private let signalService: any OWSSignalServiceProtocol
 
-    public init(
+    init(
         databaseStorage: SDSDatabaseStorage,
         signalService: any OWSSignalServiceProtocol
     ) {
@@ -22,12 +22,7 @@ public class RemoteMegaphoneFetcher {
     /// Fetch all remote megaphones currently on the service and persist them
     /// locally. Removes any locally-persisted remote megaphones that are no
     /// longer available remotely.
-    public func syncRemoteMegaphonesIfNecessary() async throws {
-        let shouldSync = databaseStorage.read { self.shouldSync(transaction: $0) }
-        guard shouldSync else {
-            return
-        }
-
+    func syncRemoteMegaphones() async throws {
         Logger.info("Beginning remote megaphone fetch.")
 
         let megaphones: [RemoteMegaphoneModel]
@@ -45,55 +40,10 @@ public class RemoteMegaphoneFetcher {
                 withFetchedMegaphones: megaphones,
                 transaction: transaction
             )
-
-            self.recordCompletedSync(transaction: transaction)
         }
     }
 }
 
-// MARK: - Sync conditions
-
-private extension String {
-    static let fetcherStoreCollection = "RemoteMegaphoneFetcher"
-    static let appVersionAtLastFetchKey = "appVersionAtLastFetch"
-    static let lastFetchDateKey = "lastFetchDate"
-}
-
-private extension RemoteMegaphoneFetcher {
-    private static let fetcherStore = KeyValueStore(collection: .fetcherStoreCollection)
-
-    private static let delayBetweenSyncs: TimeInterval = 3 * .day
-
-    func shouldSync(transaction: DBReadTransaction) -> Bool {
-        guard
-            let appVersionAtLastFetch = Self.fetcherStore.getString(.appVersionAtLastFetchKey, transaction: transaction),
-            let lastFetchDate = Self.fetcherStore.getDate(.lastFetchDateKey, transaction: transaction)
-        else {
-            // If we have never recorded last-fetch data, we should sync.
-            return true
-        }
-
-        let hasChangedAppVersion = appVersionAtLastFetch != AppVersionImpl.shared.currentAppVersion
-        let hasWaitedEnoughSinceLastSync = Date().timeIntervalSince(lastFetchDate) > Self.delayBetweenSyncs
-
-        return hasChangedAppVersion || hasWaitedEnoughSinceLastSync
-    }
-
-    func recordCompletedSync(transaction: DBWriteTransaction) {
-        Self.fetcherStore.setString(
-            AppVersionImpl.shared.currentAppVersion,
-            key: .appVersionAtLastFetchKey,
-            transaction: transaction
-        )
-
-        Self.fetcherStore.setDate(
-            Date(),
-            key: .lastFetchDateKey,
-            transaction: transaction
-        )
-    }
-}
-
 // MARK: - Persisted megaphones
 
 private extension RemoteMegaphoneFetcher {
diff --git a/SignalServiceKit/Jobs/Cron.swift b/SignalServiceKit/Jobs/Cron.swift
index 8c86f4b700..c1185d788e 100644
--- a/SignalServiceKit/Jobs/Cron.swift
+++ b/SignalServiceKit/Jobs/Cron.swift
@@ -68,6 +68,7 @@ public class Cron {
         case fetchDevices
         case fetchEmojiSearch
         case fetchLocalProfile
+        case fetchMegaphones
         case fetchSenderCertificates
         case fetchStaleGroup
         case fetchStaleProfiles