Authentication

import SwiftUI
import AuthenticationServices

struct LoginView: View {
    var body: some View {
        SignInWithAppleButton(.signIn) { request in
            request.requestedScopes = [.fullName, .email]
        } onCompletion: { result in
            switch result {
            case .success(let authorization):
                if let appleIDCredential = authorization.credential as? ASAuthorizationAppleIDCredential {
                    let userIdentifier = appleIDCredential.user
                    let identityToken = appleIDCredential.identityToken
                    // Forward identityToken to backend for JWT validation
                }
            case .failure(let error):
                // Handle authorization error
                break
            }
        }
        .signInWithAppleButtonStyle(.black)
        .frame(height: 50)
    }
}

let provider = ASAuthorizationPlatformPublicKeyCredentialProvider(relyingPartyIdentifier: "example.com")
let request = provider.createCredentialAssertionRequest(challenge: serverChallenge)

let controller = ASAuthorizationController(authorizationRequests: [request])
controller.delegate = self
controller.presentationContextProvider = self
controller.performRequests()

let session = ASWebAuthenticationSession(
    url: authURL,
    callbackURLScheme: "myapp"
) { callbackURL, error in
    guard let callbackURL, error == nil else { return }
    // Extract authorization code from callbackURL
}
session.presentationContextProvider = self
session.prefersEphemeralWebBrowserSession = false // true prevents shared cookie login
session.start()

let passwordRequest = ASAuthorizationPasswordProvider().createCredentialRequest()
let controller = ASAuthorizationController(authorizationRequests: [passkeyRequest, passwordRequest])

import LocalAuthentication

func authenticateUser() async throws {
    let context = LAContext()
    var error: NSError?

    guard context.canEvaluatePolicy(.deviceOwnerAuthenticationWithBiometrics, error: &error) else {
        throw AuthError.biometricsUnavailable
    }

    let success = try await context.evaluatePolicy(
        .deviceOwnerAuthenticationWithBiometrics,
        localizedReason: "Unlock your account"
    )
    guard success else { throw AuthError.failed }
}