Manage compatible app updates and historical versions

assets/Localizable.xcstrings

@@ -129,6 +129,22 @@
         }
       }
     },
+    "All Apps Are Up to Date": {
+      "localizations": {
+        "en": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "All Apps Are Up to Date"
+          }
+        },
+        "zh-Hans": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "全部应用已是最新"
+          }
+        }
+      }
+    },
     "App Repository": {
       "localizations": {
         "en": {
@@ -369,6 +385,22 @@
         }
       }
     },
+    "Change Installed Version?": {
+      "localizations": {
+        "en": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "Change Installed Version?"
+          }
+        },
+        "zh-Hans": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "更改已安装版本？"
+          }
+        }
+      }
+    },
     "Check Again": {
       "localizations": {
         "en": {
@@ -689,6 +721,22 @@
         }
       }
     },
+    "Downgrade": {
+      "localizations": {
+        "en": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "Downgrade"
+          }
+        },
+        "zh-Hans": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "降级"
+          }
+        }
+      }
+    },
     "Download Size": {
       "localizations": {
         "en": {
@@ -753,6 +801,38 @@
         }
       }
     },
+    "Install %@ on %@? The installed version could not be compared.": {
+      "localizations": {
+        "en": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "Install %1$@ on %2$@? The installed version could not be compared."
+          }
+        },
+        "zh-Hans": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "在 %2$@ 上安装 %1$@？无法比较已安装版本。"
+          }
+        }
+      }
+    },
+    "Install %@ on %@? This is an older version and may not work with existing app data.": {
+      "localizations": {
+        "en": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "Install %1$@ on %2$@? This is an older version and may not work with existing app data."
+          }
+        },
+        "zh-Hans": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "在 %2$@ 上安装 %1$@？这是较旧的版本，可能无法使用现有应用数据。"
+          }
+        }
+      }
+    },
     "Install Xcode to add iPhone and iPad simulators.": {
       "localizations": {
         "en": {
@@ -913,6 +993,38 @@
         }
       }
     },
+    "Newer compatible versions of your installed apps will appear here.": {
+      "localizations": {
+        "en": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "Newer compatible versions of your installed apps will appear here."
+          }
+        },
+        "zh-Hans": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "已安装应用有兼容的新版本时，会显示在这里。"
+          }
+        }
+      }
+    },
+    "Newer versions for your simulator.": {
+      "localizations": {
+        "en": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "Newer versions for your simulator."
+          }
+        },
+        "zh-Hans": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "适用于此模拟器的新版本。"
+          }
+        }
+      }
+    },
     "No Apps Available": {
       "localizations": {
         "en": {
@@ -1889,6 +2001,22 @@
         }
       }
     },
+    "Update": {
+      "localizations": {
+        "en": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "Update"
+          }
+        },
+        "zh-Hans": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "更新"
+          }
+        }
+      }
+    },
     "Update SimStore to read this app catalog.": {
       "localizations": {
         "en": {

src/AppCatalog.swift

@@ -34,7 +34,18 @@ struct CatalogApp: Identifiable, Hashable, Sendable {
   }
 
   func recommendedVersion(for runtime: String) -> CatalogVersion {
-    versions.first { $0.isCompatible(with: runtime) } ?? latestVersion
+    latestCompatibleVersion(for: runtime) ?? latestVersion
+  }
+
+  func latestCompatibleVersion(for runtime: String) -> CatalogVersion? {
+    versions.first { $0.isCompatible(with: runtime) }
+  }
+
+  func availableUpdate(from installedVersion: String?, runtime: String) -> CatalogVersion? {
+    guard let version = latestCompatibleVersion(for: runtime),
+      version.comparison(with: installedVersion) == .orderedDescending
+    else { return nil }
+    return version
   }
 }
 
@@ -55,6 +66,14 @@ struct CatalogVersion: Identifiable, Hashable, Sendable {
     else { return false }
     return installed >= minimum
   }
+
+  func comparison(with installedVersion: String?) -> ComparisonResult? {
+    guard let installedVersion, let installed = CatalogVersionNumber(installedVersion),
+      let candidate = CatalogVersionNumber(version)
+    else { return nil }
+    if candidate == installed { return .orderedSame }
+    return candidate > installed ? .orderedDescending : .orderedAscending
+  }
 }
 
 enum AppCatalogError: LocalizedError, Equatable {

src/AppInstallButton.swift

@@ -5,65 +5,101 @@ struct AppInstallButton: View {
   let version: CatalogVersion
   let device: SimulatorDevice
   let store: AppInstallationStore
-  let isInstalled: Bool?
+  let installedApps: InstalledAppsStore
   var allowsIncompatible = false
+  var allowsVersionChanges = false
   var isDefaultAction = false
 
-  private enum Action: CaseIterable {
-    case install, open, cancel, installing, canceling, opening, uninstalling
+  @State private var showsConfirmation = false
+  @State private var pendingVersionChange: VersionChange?
 
-    var title: String {
-      switch self {
-      case .install: String(localized: "Install")
-      case .open: String(localized: "Open")
-      case .cancel: String(localized: "Cancel")
-      case .installing: AppInstallationPhase.installing.title
-      case .canceling: AppInstallationPhase.canceling.title
-      case .opening: AppInstallationPhase.opening.title
-      case .uninstalling: AppInstallationPhase.uninstalling.title
-      }
-    }
+  private struct VersionChange {
+    let app: CatalogApp
+    let version: CatalogVersion
+    let device: SimulatorDevice
+    let action: AppInstallationAction
+  }
+
+  private var isInstalled: Bool? {
+    installedApps.isInstalled(bundleID: app.bundleID, deviceID: device.id)
+  }
+
+  private var idleAction: AppInstallationAction {
+    .forVersion(
+      version, installed: installedApps.application(bundleID: app.bundleID, deviceID: device.id),
+      allowsChanges: allowsVersionChanges)
   }
 
   private var phase: AppInstallationPhase? {
     store.phase(appID: app.id, deviceID: device.id)
   }
 
-  private var action: Action {
+  private var action: AppInstallationAction {
     switch phase {
     case .downloading, .verifying, .extracting: .cancel
     case .installing: .installing
     case .canceling: .canceling
     case .opening: .opening
     case .uninstalling: .uninstalling
-    case nil: isInstalled == true ? .open : .install
+    case nil: idleAction
     }
   }
 
   private var enabled: Bool {
     if let phase { return phase.canCancel }
     guard device.state == "Booted", let isInstalled else { return false }
-    return isInstalled || allowsIncompatible || version.isCompatible(with: device.runtime)
+    if idleAction == .open { return isInstalled }
+    return allowsIncompatible || version.isCompatible(with: device.runtime)
   }
 
   var body: some View {
-    if phase == nil {
-      button.buttonStyle(.borderedProminent)
-    } else {
-      button.buttonStyle(.bordered)
+    Group {
+      if phase == nil {
+        button.buttonStyle(.borderedProminent)
+      } else {
+        button.buttonStyle(.bordered)
+      }
+    }
+    .alert(
+      "Change Installed Version?", isPresented: $showsConfirmation, presenting: pendingVersionChange
+    ) { request in
+      Button("Cancel", role: .cancel) {}
+      Button(role: .destructive) {
+        store.replace(app: request.app, version: request.version, on: request.device)
+      } label: {
+        Text(verbatim: request.action.title)
+      }
+    } message: { request in
+      if request.action == .downgrade {
+        Text(
+          "Install \(request.version.version) on \(request.device.name)? This is an older version and may not work with existing app data."
+        )
+      } else {
+        Text(
+          "Install \(request.version.version) on \(request.device.name)? The installed version could not be compared."
+        )
+      }
     }
   }
 
   private var button: some View {
     Button {
       switch action {
       case .install: store.install(app: app, version: version, on: device)
+      case .update, .downgrade, .replace:
+        if action.needsConfirmation {
+          pendingVersionChange = VersionChange(
+            app: app, version: version, device: device, action: action)
+          showsConfirmation = true
+        } else {
+          store.replace(app: app, version: version, on: device)
+        }
       case .open: store.open(app: app, on: device)
       case .cancel: store.cancel(appID: app.id, deviceID: device.id)
       case .installing, .canceling, .opening, .uninstalling: break
       }
     } label: {
-      StableSizeView(action, states: Action.allCases) { value in
+      StableSizeView(action, states: AppInstallationAction.allCases) { value in
         Text(verbatim: value.title)
       }
       .lineLimit(1)

src/AppInstallationAction.swift

@@ -0,0 +1,40 @@
+import Foundation
+
+enum AppInstallationAction: CaseIterable {
+  case install, open, update, downgrade, replace
+  case cancel, installing, canceling, opening, uninstalling
+
+  var title: String {
+    switch self {
+    case .install: String(localized: "Install")
+    case .open: String(localized: "Open")
+    case .update: String(localized: "Update")
+    case .downgrade: String(localized: "Downgrade")
+    case .replace: Self.install.title
+    case .cancel: String(localized: "Cancel")
+    case .installing: AppInstallationPhase.installing.title
+    case .canceling: AppInstallationPhase.canceling.title
+    case .opening: AppInstallationPhase.opening.title
+    case .uninstalling: AppInstallationPhase.uninstalling.title
+    }
+  }
+
+  var isVersionChange: Bool {
+    self == .update || self == .downgrade || self == .replace
+  }
+
+  var needsConfirmation: Bool { self == .downgrade || self == .replace }
+
+  static func forVersion(
+    _ version: CatalogVersion, installed: SimulatorApplication?, allowsChanges: Bool
+  ) -> Self {
+    guard let installed else { return .install }
+    guard allowsChanges, installed.isUserApplication else { return .open }
+    switch version.comparison(with: installed.version) {
+    case .orderedSame: return .open
+    case .orderedDescending: return .update
+    case .orderedAscending: return .downgrade
+    case nil: return .replace
+    }
+  }
+}