Messenger example - auth requests handling

Examples/xx-messenger/Sources/AppCore/AuthCallbackHandler/AuthCallbackHandler.swift

+import Foundation
+import XCTestDynamicOverlay
+import XXClient
+import XXMessengerClient
+import XXModels
+
+public struct AuthCallbackHandler {
+  public typealias OnError = (Error) -> Void
+
+  public var run: (@escaping OnError) -> Cancellable
+
+  public func callAsFunction(onError: @escaping OnError) -> Cancellable {
+    run(onError)
+  }
+}
+
+extension AuthCallbackHandler {
+  public static func live(
+    messenger: Messenger,
+    handleRequest: AuthCallbackHandlerRequest,
+    handleConfirm: AuthCallbackHandlerConfirm,
+    handleReset: AuthCallbackHandlerReset
+  ) -> AuthCallbackHandler {
+    AuthCallbackHandler { onError in
+      messenger.registerAuthCallbacks(.init { callback in
+        do {
+          switch callback {
+          case .request(let contact, _, _, _):
+            try handleRequest(contact)
+
+          case .confirm(let contact, _, _, _):
+            try handleConfirm(contact)
+
+          case .reset(let contact, _, _, _):
+            try handleReset(contact)
+          }
+        } catch {
+          onError(error)
+        }
+      })
+    }
+  }
+}
+
+extension AuthCallbackHandler {
+  public static let unimplemented = AuthCallbackHandler(
+    run: XCTUnimplemented("\(Self.self)", placeholder: Cancellable {})
+  )
+}