Fix critical app extension link handling bugs

Shared/SharedExtension/ExtensionsAddLinkRequestsManager.swift

@@ -8,101 +8,38 @@
 
 import Foundation
 
-final class ExtensionsAddLinkRequestsManager: NSObject, Logging {
+final class ExtensionsAddLinkRequestsManager: Logging {
 
-    private static var filePathUrl: URL = {
-        URL.storeURL(for: "group.com.mattrighetti.Ulry", filename: "external_links.plist")
-    }()
+    private static let suite = "group.com.mattrighetti.Ulry"
+    private static let key = "pendingLinks"
 
-    var canSaveMoreLinks: Bool {
-        externalCache.count < 15
-    }
-
-    override init() {
-        super.init()
-        NotificationCenter.default.addObserver(self, selector: #selector(remove(_:)), name: NSNotification.Name("UserDidAddLink"), object: nil)
-    }
-
-    @objc func remove(_ notification: Notification) {
-        guard let url = notification.userInfo?["toRemoveFromCache"] as? String else { return }
-        externalCache.removeValue(forKey: url)
-    }
-
-    lazy var externalCache: [String:ExtensionsAddLinkRequests] = {
-        getCache()
-    }()
-
-    func getCache() -> [String:ExtensionsAddLinkRequests] {
-        let decoder = PropertyListDecoder()
-        var cache = [String:ExtensionsAddLinkRequests]()
-        if let data = try? Data(contentsOf: Self.filePathUrl),
-           let requests = try? decoder.decode([ExtensionsAddLinkRequests].self, from: data) {
-            for req in requests {
-                cache[req.url] = req
-            }
-        }
-        return cache
-    }
-
-    func dropCache() {
-        externalCache = [String:ExtensionsAddLinkRequests]()
+    private var defaults: UserDefaults? {
+        UserDefaults(suiteName: Self.suite)
     }
 
-    func persistCache() {
-        let encoder = PropertyListEncoder()
-        encoder.outputFormat = .binary
-
-        coordinateFileWrite { url in
-            do {
-                let data = try encoder.encode(externalCache)
-                try data.write(to: url)
-            } catch {
-                logger.error("Save to disk failed: \(error.localizedDescription, privacy: .public)")
-            }
-        }
+    var canSaveMoreLinks: Bool {
+        pendingLinks.count < 15
     }
 
-    /// Coordinates file access
-    private func coordinateFileWrite(run accessor: (URL) throws -> Void) {
-        let errorPointer: NSErrorPointer = nil
-        let fileCoordinator = NSFileCoordinator()
-        let fileUrl = ExtensionsAddLinkRequestsManager.filePathUrl
-
-        fileCoordinator.coordinate(writingItemAt: fileUrl, options: [.forMerging], error: errorPointer, byAccessor: { url in
-            do {
-                try accessor(url)
-            } catch {
-                logger.error("Save to disk failed: \(error.localizedDescription, privacy: .public)")
-            }
-        })
-
-        if let error = errorPointer?.pointee {
-            logger.error("Save to disk coordination failed: \(error.localizedDescription, privacy: .public)")
-        }
+    var pendingLinks: [ExtensionsAddLinkRequests] {
+        guard
+            let data = defaults?.data(forKey: Self.key),
+            let links = try? JSONDecoder().decode([ExtensionsAddLinkRequests].self, from: data)
+        else { return [] }
+        return links
     }
 
-    /// Stores given `urlString` and `note` to external file
+    /// Stores given `urlString` and `note` to UserDefaults
     func add(_ urlString: String, note: String?) {
         logger.info("saving \(urlString) with note \(note ?? "")")
-        let decoder = PropertyListDecoder()
-        let encoder = PropertyListEncoder()
-        encoder.outputFormat = .binary
-
-        coordinateFileWrite { url in
-            var requests: [ExtensionsAddLinkRequests]
-            if
-                let fileData = try? Data(contentsOf: url),
-                let decodedRequests = try? decoder.decode([ExtensionsAddLinkRequests].self, from: fileData)
-            {
-                requests = decodedRequests
-            } else {
-                requests = [ExtensionsAddLinkRequests]()
-            }
-
-            requests.append(ExtensionsAddLinkRequests(url: urlString, note: note))
-
-            let data = try encoder.encode(requests)
-            try data.write(to: url)
+        var links = pendingLinks
+        links.append(ExtensionsAddLinkRequests(url: urlString, note: note))
+        if let data = try? JSONEncoder().encode(links) {
+            defaults?.set(data, forKey: Self.key)
         }
     }
+
+    func clearAll() {
+        defaults?.removeObject(forKey: Self.key)
+    }
 }

Shared/Utils/+URL.swift

@@ -18,7 +18,7 @@ public extension URL {
         var path: URL = fileContainer
         if let folders = folders {
             for folder in folders {
-                path = path.appendingPathExtension(folder)
+                path = path.appendingPathComponent(folder)
             }
         }
         return path.appendingPathComponent(filename)

Ulry/AddToUlryAction/AddToUlryActionViewController.swift

@@ -40,13 +40,19 @@ class ActionViewController: UIViewController {
 
         navigationItem.title = "Action"
 
-        let extensionItem = extensionContext?.inputItems.first as! NSExtensionItem
-        let itemProvider = (extensionItem.attachments?.first)! as NSItemProvider
-
+        guard
+            let extensionItem = extensionContext?.inputItems.first as? NSExtensionItem,
+            let itemProvider = extensionItem.attachments?.first
+        else {
+            os_log(.error, "Encountered error while trying to insert link from action: missing extension item")
+            extensionContext?.completeRequest(returningItems: [], completionHandler: nil)
+            return
+        }
+
         let propertyList = String(describing: UTType.propertyList)
         if itemProvider.hasItemConformingToTypeIdentifier(propertyList) {
             itemProvider.loadItem(forTypeIdentifier: propertyList, options: nil) { item, error in
-                let dictionary = item as! NSDictionary
+                guard let dictionary = item as? NSDictionary else { return }
                 OperationQueue.main.addOperation { [weak self] in
                     if let results = dictionary[NSExtensionJavaScriptPreprocessingResultsKey] as? NSDictionary {
                         self?.handleData(dict: results)

Ulry/SceneDelegate.swift

@@ -44,6 +44,8 @@ class SceneDelegate: UIResponder, UIWindowSceneDelegate {
         NotificationCenter.default.addObserver(self, selector: #selector(processExternalLinks), name: UIApplication.willEnterForegroundNotification, object: nil)
 
         self.window = window
+
+        processExternalLinks()
     }
 
     func sceneDidDisconnect(_ scene: UIScene) {
@@ -77,13 +79,14 @@ class SceneDelegate: UIResponder, UIWindowSceneDelegate {
     }
 
     @objc private func processExternalLinks() {
-        guard addLinkRequestManger.getCache().count > 0 else { return }
-        os_log(.info, "moving \(self.addLinkRequestManger.externalCache.count) links from external file")
-        let links = addLinkRequestManger.externalCache.values.map { Link(url: $0.url, note: $0.note) }
-
+        let pending = addLinkRequestManger.pendingLinks
+        guard !pending.isEmpty else { return }
+        os_log(.info, "moving \(pending.count) links from external file")
+        let links = pending.map { Link(url: $0.url, note: $0.note) }
+
         Task {
             await account.insertBatch(links: links)
-            addLinkRequestManger.persistCache()
+            addLinkRequestManger.clearAll()
         }
     }
 }