From f06e6c4fe8a323f7a6074669dc7ca1e17b673eb4 Mon Sep 17 00:00:00 2001
From: Evan Hahn <69474926+EvanHahn-Signal@users.noreply.github.com>
Date: Wed, 19 Apr 2023 09:42:20 -0500
Subject: [PATCH] `AppExpiry` should read app build time from `AppVersion`

---
 SignalServiceKit/src/Util/AppExpiry.swift  | 34 +++++-----------------
 SignalServiceKit/src/Util/AppVersion.swift | 14 +++++++++
 2 files changed, 22 insertions(+), 26 deletions(-)

diff --git a/SignalServiceKit/src/Util/AppExpiry.swift b/SignalServiceKit/src/Util/AppExpiry.swift
index 769fe816fd..263ffbe819 100644
--- a/SignalServiceKit/src/Util/AppExpiry.swift
+++ b/SignalServiceKit/src/Util/AppExpiry.swift
@@ -136,8 +136,7 @@ public class AppExpiry: NSObject {
 
         if let newExpirationDate = newExpirationDate {
             // Ignore any expiration date that is later than when the app expires by default.
-            guard newExpirationDate < Self.defaultExpirationDate else { return }
-
+            guard newExpirationDate < AppVersion.shared.defaultExpirationDate else { return }
             updateExpirationState(ExpirationState(mode: .atDate, expirationDate: newExpirationDate))
         } else {
             updateExpirationState(ExpirationState(mode: .default))
@@ -151,7 +150,7 @@ public class AppExpiry: NSObject {
         let state = expirationState.get()
         switch state.mode {
         case .default:
-            return Self.defaultExpirationDate
+            return AppVersion.shared.defaultExpirationDate
         case .atDate:
             guard let expirationDate = state.expirationDate else {
                 owsFailDebug("Missing expiration date, expiring immediately")
@@ -167,27 +166,10 @@ public class AppExpiry: NSObject {
     public var isExpired: Bool {
         return expirationDate < Date()
     }
-
-    // MARK: - Build Time
-
-    private static let defaultExpirationDate: Date = {
-        guard let buildTime = loadBuildTime() else {
-            owsAssert(OWSIsTestableBuild(), "Production builds should always expire.")
-            Logger.debug("No build timestamp, assuming app never expires.")
-            return .distantFuture
-        }
-        // By default, we expire 90 days after the app was compiled.
-        return buildTime.addingTimeInterval(90 * kDayInterval)
-    }()
-
-    private static func loadBuildTime() -> Date? {
-        guard
-            let buildDetails = Bundle.main.app.object(forInfoDictionaryKey: "BuildDetails") as? [String: Any],
-            let buildTimestamp = buildDetails["Timestamp"] as? TimeInterval
-        else {
-            return nil
-        }
-        return Date(timeIntervalSince1970: buildTimestamp)
-    }
-
+}
+
+// MARK: - Build time
+
+fileprivate extension AppVersion {
+    var defaultExpirationDate: Date { buildDate.addingTimeInterval(90 * kDayInterval) }
 }
diff --git a/SignalServiceKit/src/Util/AppVersion.swift b/SignalServiceKit/src/Util/AppVersion.swift
index 2bc4365724..dd605e18e8 100644
--- a/SignalServiceKit/src/Util/AppVersion.swift
+++ b/SignalServiceKit/src/Util/AppVersion.swift
@@ -95,6 +95,8 @@ public class AppVersion {
         }
     }
 
+    public let buildDate: Date
+
     // MARK: - Setup
 
     private init(bundle: Bundle, userDefaults: UserDefaults) {
@@ -102,6 +104,18 @@ public class AppVersion {
         self.currentAppBuildVersion = bundle.string(forInfoDictionaryKey: "CFBundleVersion")
         self.currentAppVersion4 = bundle.string(forInfoDictionaryKey: "OWSBundleVersion4")
 
+        if
+            let rawBuildDetails = bundle.app.object(forInfoDictionaryKey: "BuildDetails"),
+            let buildDetails = rawBuildDetails as? [String: Any],
+            let buildTimestamp = buildDetails["Timestamp"] as? TimeInterval {
+            self.buildDate = Date(timeIntervalSince1970: buildTimestamp)
+        } else {
+            #if !TESTABLE_BUILD
+            owsFailBeta("Expected a build date to be defined. Assuming build date is right now")
+            #endif
+            self.buildDate = Date()
+        }
+
         self.userDefaults = userDefaults
     }