06/22 Add Check for Update button in Settings

2026-06-22 10:36:07 -04:00
parent a57d6f02ba
commit 6c48a38743
3 changed files with 174 additions and 0 deletions
@@ -0,0 +1,125 @@
+// Utils/UpdateChecker.swift
+// --------------------------
+// Checks the App Store for a newer published version of this app and
+// surfaces an "Update Available" prompt when one exists.
+//
+// The app is distributed via App Store *unlisted* distribution — it is a
+// real App Store listing (just excluded from public search/browse), so the
+// standard public iTunes Lookup API works correctly here:
+//   https://itunes.apple.com/lookup?bundleId=<bundle id>
+// No private server endpoint or App Store Connect API key is required.
+//
+// Usage:
+//   - Automatic: ContentView calls `await UpdateChecker.shared.checkForUpdate()`
+//     once per app launch (see .task in ContentView.swift). If a newer version
+//     is found, `updateAvailable` flips true and the root view presents an alert.
+//   - Manual: Settings → "Check for Updates" button calls checkForUpdate(force: true).
+//
+// Throttling: automatic launch checks are skipped if the last check was less
+// than 24 hours ago, to avoid hitting Apple's endpoint on every cold start.
+// The manual button always bypasses the throttle (force: true).
+
+import Foundation
+import Combine
+
+@MainActor
+final class UpdateChecker: ObservableObject {
+    static let shared = UpdateChecker()
+
+    /// True once a newer version has been confirmed on the App Store.
+    /// The root view observes this to present the update alert.
+    @Published var updateAvailable = false
+    /// The newer version string, for display in the alert ("Version 1.3 is available").
+    @Published var latestVersion: String?
+    /// The App Store page URL to open when the user taps "Update".
+    @Published var appStoreURL: URL?
+    /// True while a check is in flight — lets the Settings button show a spinner.
+    @Published var isChecking = false
+
+    private static let lastCheckKey = "jqc.updateChecker.lastCheckedAt"
+    private static let throttleInterval: TimeInterval = 24 * 60 * 60   // 24 hours
+
+    /// Must match PRODUCT_BUNDLE_IDENTIFIER in project.pbxproj.
+    private let bundleId = "com.ltservicesinc.JanitorialQC"
+
+    private init() {}
+
+    /// Compares the running app's version against the App Store's published
+    /// version. Sets `updateAvailable`/`latestVersion`/`appStoreURL` when a
+    /// newer version exists. Silent no-op on any network/parse failure —
+    /// an update check failing must never block or interrupt app usage.
+    ///
+    /// - Parameter force: bypass the 24-hour throttle (used by the manual
+    ///   "Check for Updates" button in Settings).
+    func checkForUpdate(force: Bool = false) async {
+        guard force || shouldCheck() else { return }
+
+        isChecking = true
+        defer { isChecking = false }
+
+        guard let currentVersion = Bundle.main.infoDictionary?["CFBundleShortVersionString"] as? String,
+              let url = URL(string: "https://itunes.apple.com/lookup?bundleId=\(bundleId)")
+        else { return }
+
+        do {
+            let (data, _) = try await URLSession.shared.data(from: url)
+            let lookup = try JSONDecoder().decode(LookupResponse.self, from: data)
+
+            UserDefaults.standard.set(Date(), forKey: Self.lastCheckKey)
+
+            guard let result = lookup.results.first else { return }
+
+            if isVersion(result.version, newerThan: currentVersion) {
+                latestVersion   = result.version
+                appStoreURL     = URL(string: result.trackViewUrl)
+                updateAvailable = true
+            } else {
+                updateAvailable = false
+            }
+        } catch {
+            // Network failure, offline, or unexpected response shape —
+            // fail silently. The next launch (or manual check) will retry.
+        }
+    }
+
+    /// Dismisses the current prompt without disabling future checks.
+    /// Called when the user taps "Later" on the update alert.
+    func dismissForNow() {
+        updateAvailable = false
+    }
+
+    // ── Throttle ─────────────────────────────────────────────────────────
+
+    private func shouldCheck() -> Bool {
+        guard let last = UserDefaults.standard.object(forKey: Self.lastCheckKey) as? Date
+        else { return true }
+        return Date().timeIntervalSince(last) >= Self.throttleInterval
+    }
+
+    // ── Version comparison ──────────────────────────────────────────────
+    // Compares dotted version strings ("1.10" > "1.9") component-by-component
+    // as integers, rather than lexicographically (which would incorrectly
+    // rank "1.10" before "1.9"). Missing trailing components are treated as 0.
+
+    private func isVersion(_ a: String, newerThan b: String) -> Bool {
+        let aParts = a.split(separator: ".").compactMap { Int($0) }
+        let bParts = b.split(separator: ".").compactMap { Int($0) }
+        let count = max(aParts.count, bParts.count)
+        for i in 0..<count {
+            let av = i < aParts.count ? aParts[i] : 0
+            let bv = i < bParts.count ? bParts[i] : 0
+            if av != bv { return av > bv }
+        }
+        return false
+    }
+
+    // ── iTunes Lookup response shape ────────────────────────────────────
+
+    private struct LookupResponse: Decodable {
+        let results: [LookupResult]
+    }
+    private struct LookupResult: Decodable {
+        let version: String
+        let trackViewUrl: String
+    }
+}