iOS round 6: Live Activities, Sign in with Apple, in-app purchase, Siri and Handoff

apps/mobile/app.config.ts

@@ -5,6 +5,9 @@ import path from 'node:path';
 import type { ConfigContext, ExpoConfig } from 'expo/config';
 import { type ConfigPlugin, withEntitlementsPlist } from 'expo/config-plugins';
 
+// CommonJS, because Node loads what app.config.ts imports as it is.
+import { withAppIntents } from './plugins/with-app-intents';
+
 
 // One config for Expo Go, the web export and the development build.
 // DEBATELAB_BUILD=dev (set by the `development` profile in eas.json) adds the
@@ -22,9 +25,21 @@ type PermissionStrings = { speechRecognition: string; microphone: string };
 
 const build = process.env.DEBATELAB_BUILD;
 const appGroup = process.env.DEBATELAB_APP_GROUP;
+// DEBATELAB_APPLE_ACCOUNT=1: the build is signed by DebateOwl's own Apple
+// Developer team, whose App IDs carry the capabilities in docs/apple-platform.md
+// (Sign in with Apple, Push, Time Sensitive Notifications, Associated Domains,
+// In-App Purchase). Without it a development build keeps to what the borrowed
+// signing profile allows.
+const appleAccount = process.env.DEBATELAB_APPLE_ACCOUNT;
 if (build !== undefined && build !== '' && build !== 'dev') {
   throw new Error(`DEBATELAB_BUILD must be "dev" or unset, not "${build}".`);
 }
+if (appleAccount !== undefined && appleAccount !== '' && appleAccount !== '1') {
+  throw new Error(`DEBATELAB_APPLE_ACCOUNT must be "1" or unset, not "${appleAccount}".`);
+}
+if (appleAccount === '1' && build !== 'dev') {
+  throw new Error('DEBATELAB_APPLE_ACCOUNT only applies to a development build (DEBATELAB_BUILD=dev).');
+}
 if (appGroup && build !== 'dev') {
   throw new Error('DEBATELAB_APP_GROUP only applies to a development build (DEBATELAB_BUILD=dev).');
 }
@@ -54,11 +69,14 @@ function iosLocale(strings: PermissionStrings) {
 
 // expo-widgets adds the push entitlement even with its push option off, and
 // prebuild applies expo-notifications' plugin on its own once the package is
-// installed, which adds it too. The signing profile has no push, so every
-// development build drops it until a profile with push exists.
-const withoutPushEntitlement: ConfigPlugin = (config) =>
+// installed, which adds it too; expo-apple-authentication's plugin, also
+// applied on its own, adds Sign in with Apple. The borrowed signing profile
+// has neither, so a development build drops both unless it is signed by
+// DebateOwl's own account (DEBATELAB_APPLE_ACCOUNT).
+const withoutAccountEntitlements: ConfigPlugin = (config) =>
   withEntitlementsPlist(config, (mod) => {
     delete mod.modResults['aps-environment'];
+    delete mod.modResults['com.apple.developer.applesignin'];
     return mod;
   });
 
@@ -163,6 +181,40 @@ export function withRound4(config: ExpoConfig, opts: { appGroup?: string; projec
   return config;
 }
 
+// Round 6 (docs/apple-platform.md): Sign in with Apple and Google, the
+// time-sensitive timer alert, Handoff and push, for development builds only,
+// so the Expo Go config never changes. What needs DebateOwl's own Apple
+// account waits for DEBATELAB_APPLE_ACCOUNT.
+export function withApplePlatform(config: ExpoConfig, opts: { appleAccount: boolean }): ExpoConfig {
+  // Handoff (src/lib/handoff.ts), next to Expo Router's own activity type.
+  config.ios = {
+    ...config.ios,
+    infoPlist: {
+      ...config.ios?.infoPlist,
+      NSUserActivityTypes: [...((config.ios?.infoPlist?.NSUserActivityTypes as string[] | undefined) ?? []), 'com.pistack.debateowl.browsing'],
+    },
+  };
+  config.extra = {
+    ...config.extra,
+    // Google sign-in runs in any development build: the redirect comes back on the app's own scheme.
+    googleSignIn: true,
+    signInWithApple: opts.appleAccount,
+  };
+  if (!opts.appleAccount) return config;
+  config.ios = { ...config.ios, usesAppleSignIn: true };
+  config.ios.associatedDomains = [
+    ...(config.ios.associatedDomains ?? []),
+    // Handoff from debateowl.com in Safari to the app.
+    'activitycontinuation:debateowl.com',
+  ];
+  config.ios.entitlements = {
+    ...config.ios.entitlements,
+    // The timer's time-up alert breaks through a Focus (src/lib/timer-alerts.ts).
+    'com.apple.developer.usernotifications.time-sensitive': true,
+  };
+  return config;
+}
+
 export default ({ projectRoot }: ConfigContext): ExpoConfig => {
   const config: ExpoConfig = {
     name: 'DebateOwl',
@@ -278,7 +330,12 @@ export default ({ projectRoot }: ConfigContext): ExpoConfig => {
   }
   // The Current Debate widget (with the App Group), quick actions and Spotlight; see withRound4 above.
   withRound4(config, { appGroup, projectRoot });
+  withApplePlatform(config, { appleAccount: appleAccount === '1' });
+  // Siri and Shortcuts: the intents compile into the app target (plugins/with-app-intents.js).
+  const withIntents = withAppIntents(config);
+  // DebateOwl's own account has Push and Sign in with Apple on its App ID, so its builds keep both.
+  if (appleAccount === '1') return withIntents;
   // Registered before Expo applies the plugins list. Mods registered later act
   // first, so this one runs after the plugins have written their entitlements.
-  return withoutPushEntitlement(config);
+  return withoutAccountEntitlements(withIntents);
 };

apps/mobile/modules/handoff/expo-module.config.json

@@ -0,0 +1,7 @@
+{
+  "platforms": ["apple"],
+  "apple": {
+    "modules": ["HandoffModule"],
+    "appDelegateSubscribers": ["HandoffAppDelegateSubscriber"]
+  }
+}

apps/mobile/modules/handoff/ios/Handoff.podspec

@@ -0,0 +1,19 @@
+Pod::Spec.new do |s|
+  s.name           = 'Handoff'
+  s.version        = '1.0.0'
+  s.summary        = "DebateOwl's Handoff activity"
+  s.description    = 'Advertises the screen open in DebateOwl (NSUserActivity) so a Mac continues on debateowl.com and an iPad in the app.'
+  s.author         = ''
+  s.homepage       = 'https://debateowl.com'
+  s.platforms      = { :ios => '16.4' }
+  s.source         = { git: '' }
+  s.static_framework = true
+
+  s.dependency 'ExpoModulesCore'
+
+  s.pod_target_xcconfig = {
+    'DEFINES_MODULE' => 'YES',
+  }
+
+  s.source_files = "**/*.{h,m,mm,swift}"
+end

apps/mobile/modules/handoff/ios/HandoffModule.swift

@@ -0,0 +1,161 @@
+import ExpoModulesCore
+import UIKit
+
+// Handoff for src/lib/handoff.ts. JavaScript says which screen is open (a title,
+// the debateowl.com page that matches it and the app route); this advertises it
+// as the current NSUserActivity, so a Mac signed in to the same Apple Account
+// offers to continue in Safari, and an iPad with DebateOwl continues in the app.
+//
+// App to web needs no entitlement: the activity carries webpageURL. App to app
+// needs the activity type in Info.plist's NSUserActivityTypes. Web to app (Safari
+// on a Mac handing debateowl.com to the phone) would need the Associated Domains
+// entitlement `activitycontinuation:debateowl.com`; it is not set up.
+//
+// The activity is made current with becomeCurrent() and kept here, not attached
+// to a view controller's userActivity: UIKit empties a responder-managed
+// activity's userInfo before it asks the responder to refill it, which would
+// drop the route.
+
+public class HandoffModule: Module {
+  public func definition() -> ModuleDefinition {
+    Name("DebateOwlHandoff")
+
+    // Another device handed a screen over; JavaScript takes it with takeContinuedPath.
+    Events("onContinue")
+
+    OnCreate {
+      HandoffCenter.shared.onContinue = { [weak self] in
+        self?.sendEvent("onContinue", [:])
+      }
+    }
+
+    OnDestroy {
+      HandoffCenter.shared.onContinue = nil
+    }
+
+    Function("setActivity") { (activity: [String: Any]) in
+      DispatchQueue.main.async { HandoffCenter.shared.set(activity) }
+    }
+
+    Function("clearActivity") {
+      DispatchQueue.main.async { HandoffCenter.shared.clear() }
+    }
+
+    // The route (or, failing that, the web address) another device handed over,
+    // once. Kept until asked, so a handover that launched the app is not lost
+    // while JavaScript starts.
+    Function("takeContinuedPath") { () -> String? in
+      HandoffCenter.shared.takePending()
+    }
+  }
+}
+
+/// Receives activities handed over from another device. Expo's linking
+/// subscriber only takes web-browsing activities, so ours would otherwise
+/// open the app on its first screen.
+public class HandoffAppDelegateSubscriber: ExpoAppDelegateSubscriber {
+  public func application(
+    _ application: UIApplication,
+    continue userActivity: NSUserActivity,
+    restorationHandler: @escaping ([any UIUserActivityRestoring]?) -> Void
+  ) -> Bool {
+    return HandoffCenter.shared.receive(userActivity)
+  }
+}
+
+// Unchecked: the activity is touched on the main thread only, `pending` behind
+// the lock, and `onContinue` is set once when the module is created.
+final class HandoffCenter: @unchecked Sendable {
+  static let shared = HandoffCenter()
+  /// Also listed in Info.plist's NSUserActivityTypes (app.config.ts).
+  static let activityType = "com.pistack.debateowl.browsing"
+  private static let hosts: Set<String> = ["debateowl.com", "www.debateowl.com"]
+
+  var onContinue: (() -> Void)?
+
+  // Main thread only.
+  private var current: NSUserActivity?
+  private var activation: NSObjectProtocol?
+
+  // Written on the main thread, read from JavaScript's.
+  private let lock = NSLock()
+  private var pending: String?
+
+  /// Makes `entry` the current activity. Anything but our type with an https
+  /// debateowl.com address clears it instead.
+  func set(_ entry: [String: Any]) {
+    guard entry["type"] as? String == Self.activityType,
+          let address = entry["webpageURL"] as? String,
+          let url = URL(string: address),
+          url.scheme == "https",
+          let host = url.host?.lowercased(),
+          Self.hosts.contains(host)
+    else {
+      clear()
+      return
+    }
+    let title = entry["title"] as? String
+    let path = entry["appPath"] as? String
+
+    // The same screen again (a re-render, a language change): keep the activity.
+    if let current, current.webpageURL == url, current.userInfo?["path"] as? String == path {
+      current.title = title
+      current.becomeCurrent()
+      return
+    }
+
+    let activity = NSUserActivity(activityType: Self.activityType)
+    activity.title = title
+    activity.webpageURL = url
+    if let path {
+      activity.addUserInfoEntries(from: ["path": path])
+    }
+    activity.isEligibleForHandoff = true
+    // Spotlight and Siri suggestions belong to their own work.
+    activity.isEligibleForSearch = false
+    activity.isEligibleForPublicIndexing = false
+    activity.isEligibleForPrediction = false
+
+    current?.invalidate()
+    current = activity
+    activity.becomeCurrent()
+    observeActivation()
+  }
+
+  func clear() {
+    current?.invalidate()
+    current = nil
+  }
+
+  /// Advertises the activity again when the app returns to the foreground.
+  private func observeActivation() {
+    guard activation == nil else { return }
+    activation = NotificationCenter.default.addObserver(
+      forName: UIApplication.didBecomeActiveNotification,
+      object: nil,
+      queue: .main
+    ) { [weak self] _ in
+      self?.current?.becomeCurrent()
+    }
+  }
+
+  /// Keeps a handed-over screen for JavaScript; false for activities that are not ours.
+  func receive(_ activity: NSUserActivity) -> Bool {
+    guard activity.activityType == Self.activityType else { return false }
+    let value = (activity.userInfo?["path"] as? String) ?? activity.webpageURL?.absoluteString
+    guard let value else { return true }
+    lock.lock()
+    pending = value
+    lock.unlock()
+    onContinue?()
+    return true
+  }
+
+  func takePending() -> String? {
+    lock.lock()
+    defer { lock.unlock() }
+    let value = pending
+    pending = nil
+    return value
+  }
+}

apps/mobile/modules/store-kit/expo-module.config.json

@@ -0,0 +1,6 @@
+{
+  "platforms": ["apple"],
+  "apple": {
+    "modules": ["StoreKitModule"]
+  }
+}

apps/mobile/modules/store-kit/ios/StoreKitBridge.podspec

@@ -0,0 +1,22 @@
+Pod::Spec.new do |s|
+  s.name           = 'StoreKitBridge'
+  s.version        = '1.0.0'
+  s.summary        = "DebateOwl's in-app subscriptions"
+  s.description    = 'StoreKit 2 products, purchases, transactions and Apple subscription sheets for the DebateOwl app, called from JavaScript.'
+  s.author         = ''
+  s.homepage       = 'https://debateowl.com'
+  s.platforms      = { :ios => '16.4' }
+  s.source         = { git: '' }
+  s.static_framework = true
+  # Swift 5 mode, as expo-store-review, so StoreKit's non-Sendable types cross the async functions without strict checks.
+  s.swift_version  = '5.9'
+
+  s.dependency 'ExpoModulesCore'
+  s.frameworks = 'StoreKit'
+
+  s.pod_target_xcconfig = {
+    'DEFINES_MODULE' => 'YES',
+  }
+
+  s.source_files = "**/*.{h,m,mm,swift}"
+end