Messenger - restore from backup

XXMessengerClient

• Add MessengerRestoreBackup function wrapper
  • Restore CMix and UserDiscovery from backup
  • Return restored params and contacts
• Add MessengerIsListeningForMessages function

xx-messenger example

• Restore backup from file
• Refactor app startup

Sources/XXMessengerClient/Messenger/Functions/MessengerRestoreBackup.swift

+import Foundation
+import XXClient
+import XCTestDynamicOverlay
+
+public struct MessengerRestoreBackup {
+  public var run: (Data, String) throws -> BackupParams
+
+  public func callAsFunction(
+    backupData: Data,
+    backupPassphrase: String
+  ) throws -> BackupParams {
+    try run(backupData, backupPassphrase)
+  }
+}
+
+extension MessengerRestoreBackup {
+  public static func live(_ env: MessengerEnvironment) -> MessengerRestoreBackup {
+    MessengerRestoreBackup { backupData, backupPassphrase in
+      let storageDir = env.storageDir
+      do {
+        let ndfData = try env.downloadNDF(env.ndfEnvironment)
+        let password = env.generateSecret()
+        try env.passwordStorage.save(password)
+        try env.fileManager.removeDirectory(storageDir)
+        try env.fileManager.createDirectory(storageDir)
+        let report = try env.newCMixFromBackup(
+          ndfJSON: String(data: ndfData, encoding: .utf8)!,
+          storageDir: storageDir,
+          backupPassphrase: backupPassphrase,
+          sessionPassword: password,
+          backupFileContents: backupData
+        )
+        let cMix = try env.loadCMix(
+          storageDir: storageDir,
+          password: password,
+          cMixParamsJSON: env.getCMixParams()
+        )
+        let e2e = try env.login(
+          cMixId: cMix.getId(),
+          authCallbacks: env.authCallbacks.registered(),
+          identity: try cMix.makeReceptionIdentity(legacy: true),
+          e2eParamsJSON: env.getE2EParams()
+        )
+        let decoder = JSONDecoder()
+        let paramsData = report.params.data(using: .utf8)!
+        let params = try decoder.decode(BackupParams.self, from: paramsData)
+        let ud = try env.newUdManagerFromBackup(
+          params: NewUdManagerFromBackup.Params(
+            e2eId: e2e.getId(),
+            username: Fact(type: .username, value: params.username),
+            email: params.email.map { Fact(type: .email, value: $0) },
+            phone: params.phone.map { Fact(type: .phone, value: $0) },
+            cert: env.udCert ?? e2e.getUdCertFromNdf(),
+            contact: env.udContact ?? (try e2e.getUdContactFromNdf()),
+            address: env.udAddress ?? e2e.getUdAddressFromNdf()
+          ),
+          follower: UdNetworkStatus { cMix.networkFollowerStatus() }
+        )
+        env.cMix.set(cMix)
+        env.e2e.set(e2e)
+        env.ud.set(ud)
+        return params
+      } catch {
+        try? env.fileManager.removeDirectory(storageDir)
+        throw error
+      }
+    }
+  }
+}
+
+extension MessengerRestoreBackup {
+  public static let unimplemented = MessengerRestoreBackup(
+    run: XCTUnimplemented("\(Self.self)")
+  )
+}