feat(DRAFT): implement update checker and alert for new versions

Platform/macOS/UTMApp.swift

@@ -32,6 +32,7 @@ struct UTMApp: App {
                     data.showErrorAlert(message: message)
                 }
             }
+            .modifier(UpdateAlertModifier())
     }
 
     @SceneBuilder
@@ -72,3 +73,12 @@ struct UTMApp: App {
         }
     }
 }
+
+private struct UpdateAlertModifier: ViewModifier {
+    func body(content: Content) -> some View {
+        ZStack {
+            content
+            UTMUpdateAlert()
+        }
+    }
+}

Platform/macOS/UTMUpdateAlert.swift

@@ -0,0 +1,43 @@
+//
+// Copyright © 2025 osy. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+
+import SwiftUI
+
+struct UTMUpdateAlert: View {
+    @StateObject private var updateChecker = UTMUpdateChecker()
+
+    var body: some View {
+        EmptyView()
+            .onAppear {
+                Task {
+                    await updateChecker.checkForUpdates()
+                }
+            }
+            .alert(isPresented: $updateChecker.isUpdateAvailable) {
+                Alert(
+                    title: Text("Update Available"),
+                    message: Text("Version \(updateChecker.latestVersion ?? "") is now available"),
+                    primaryButton: .default(Text("Download")) {
+                        if let url = updateChecker.updateURL {
+                            NSWorkspace.shared.open(url)
+                        }
+                    },
+                    secondaryButton: .cancel(Text("Later"))
+                )
+            }
+    }
+}

Platform/macOS/UTMUpdateChecker.swift

@@ -0,0 +1,104 @@
+import Foundation
+
+class UTMUpdateChecker: ObservableObject {
+    @Published var isUpdateAvailable = false
+    @Published var latestVersion: String?
+    @Published var updateURL: URL?
+
+    private let currentVersion: String
+    private static let githubAPI = "https://api.github.com/repos/utmapp/UTM/releases/latest"
+
+    init() {
+        // Get current version from bundle
+        self.currentVersion = Bundle.main.infoDictionary?["CFBundleShortVersionString"] as? String ?? "0.0.0"
+    }
+
+    @MainActor
+    func checkForUpdates() async {
+        do {
+            // Configure the API request
+            let configuration = URLSessionConfiguration.ephemeral
+            configuration.allowsCellularAccess = true
+            configuration.allowsExpensiveNetworkAccess = false
+            configuration.allowsConstrainedNetworkAccess = false
+            configuration.waitsForConnectivity = false
+            configuration.httpAdditionalHeaders = [
+                "Accept": "application/vnd.github+json",
+                "X-GitHub-Api-Version": "2022-11-28"
+            ]
+
+            let session = URLSession(configuration: configuration)
+            let url = URL(string: Self.githubAPI)!
+            let (data, response) = try await session.data(from: url)
+
+            guard let httpResponse = response as? HTTPURLResponse,
+                  httpResponse.statusCode == 200 else {
+                throw URLError(.badServerResponse)
+            }
+
+            let release = try JSONDecoder().decode(GitHubRelease.self, from: data)
+            let latestVersion = release.tagName.trimmingCharacters(in: CharacterSet(charactersIn: "v"))
+
+            self.latestVersion = latestVersion
+
+            // Compare versions
+            if compareVersions(currentVersion, latestVersion) {
+                self.isUpdateAvailable = true
+                // Get macOS dmg asset URL
+                if let dmgAsset = release.assets.first(where: { asset in
+                    asset.name.hasSuffix(".dmg") && !asset.name.contains("unsigned")
+                }) {
+                    self.updateURL = URL(string: dmgAsset.browserDownloadUrl)
+                }
+            }
+
+        } catch {
+            print("Failed to check for updates: \(error.localizedDescription)")
+        }
+    }
+
+    private func compareVersions(_ current: String, _ latest: String) -> Bool {
+        let currentComponents = current.split(separator: ".")
+        let latestComponents = latest.split(separator: ".")
+
+        let currentMajor = Int(currentComponents[0]) ?? 0
+        let currentMinor = Int(currentComponents[1]) ?? 0
+        let currentPatch = Int(currentComponents[2]) ?? 0
+
+        let latestMajor = Int(latestComponents[0]) ?? 0
+        let latestMinor = Int(latestComponents[1]) ?? 0
+        let latestPatch = Int(latestComponents[2]) ?? 0
+
+        if latestMajor > currentMajor {
+            return true
+        }
+        if latestMajor == currentMajor && latestMinor > currentMinor {
+            return true
+        }
+        if latestMajor == currentMajor && latestMinor == currentMinor && latestPatch > currentPatch {
+            return true
+        }
+        return false
+    }
+}
+
+// GitHub API response models
+private struct GitHubRelease: Codable {
+    let tagName: String
+    let assets: [Asset]
+
+    enum CodingKeys: String, CodingKey {
+        case tagName = "tag_name"
+        case assets
+    }
+}
+
+private struct Asset: Codable {
+    let name: String
+    let browserDownloadUrl: String
+
+    enum CodingKeys: String, CodingKey {
+        case name
+        case browserDownloadUrl = "browser_download_url"
+    }
+}