Add Apple Sign-In to Your App

"use client"

import { useState } from 'react'

export default function LoginPage() {
  const [isLoading, setIsLoading] = useState(false)

  const handleAppleSignIn = async () => {
    setIsLoading(true)

    // Call OAuth42's social auth init endpoint
    const response = await fetch('/api/auth/social/apple', {
      method: 'POST',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify({
        provider: 'apple',
        client_id: process.env.NEXT_PUBLIC_OAUTH42_CLIENT_ID,
        is_signup: false,
      }),
    })

    const data = await response.json()

    if (data.authorization_url) {
      // Redirect to Apple
      window.location.href = data.authorization_url
    }
  }

  return (
    <div className="min-h-screen flex items-center justify-center bg-gray-100">
      <div className="max-w-md w-full space-y-6 p-8 bg-white rounded-lg shadow">
        <h1 className="text-2xl font-bold text-center">Sign In</h1>

        {/* Apple Sign-In Button - Following Apple's UI Guidelines */}
        <button
          onClick={handleAppleSignIn}
          disabled={isLoading}
          className="w-full flex items-center justify-center gap-3 py-3 px-4 bg-black text-white rounded-lg hover:bg-gray-800 transition-colors"
        >
          <svg className="w-5 h-5" viewBox="0 0 24 24" fill="currentColor">
            <path d="M17.05 20.28c-.98.95-2.05.8-3.08.35-1.09-.46-2.09-.48-3.24 0-1.44.62-2.2.44-3.06-.35C2.79 15.25 3.51 7.59 9.05 7.31c1.35.07 2.29.74 3.08.8 1.18-.24 2.31-.93 3.57-.84 1.51.12 2.65.72 3.4 1.8-3.12 1.87-2.38 5.98.48 7.13-.57 1.5-1.31 2.99-2.54 4.09l.01-.01zM12.03 7.25c-.15-2.23 1.66-4.07 3.74-4.25.29 2.58-2.34 4.5-3.74 4.25z"/>
          </svg>
          {isLoading ? 'Redirecting...' : 'Sign in with Apple'}
        </button>

        <div className="relative">
          <div className="absolute inset-0 flex items-center">
            <div className="w-full border-t border-gray-300" />
          </div>
          <div className="relative flex justify-center text-sm">
            <span className="px-2 bg-white text-gray-500">or</span>
          </div>
        </div>

        {/* Your regular email/password login form */}
        <form className="space-y-4">
          <input
            type="email"
            placeholder="Email"
            className="w-full px-4 py-3 border border-gray-300 rounded-lg"
          />
          <input
            type="password"
            placeholder="Password"
            className="w-full px-4 py-3 border border-gray-300 rounded-lg"
          />
          <button
            type="submit"
            className="w-full py-3 px-4 bg-indigo-600 text-white rounded-lg hover:bg-indigo-700"
          >
            Sign In
          </button>
        </form>
      </div>
    </div>
  )
}

mkdir -p app/api/auth/social/apple
touch app/api/auth/social/apple/route.ts

import { NextRequest, NextResponse } from 'next/server'

const API_BASE_URL = process.env.OAUTH42_ISSUER || 'https://api.oauth42.com'

export async function POST(request: NextRequest) {
  try {
    const body = await request.json()

    const response = await fetch(`${API_BASE_URL}/api/social-auth/init`, {
      method: 'POST',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify({
        provider: 'apple',
        client_id: body.client_id,
        is_signup: body.is_signup || false,
        state: body.state,
      }),
    })

    const data = await response.json()

    if (!response.ok) {
      return NextResponse.json(data, { status: response.status })
    }

    return NextResponse.json(data)
  } catch (error) {
    console.error('[Apple Social Auth] Error:', error)
    return NextResponse.json(
      { error: 'Failed to initiate Apple auth' },
      { status: 500 }
    )
  }
}

import AuthenticationServices
import SwiftUI

struct AppleSignInButton: View {
    @Environment(\.colorScheme) var colorScheme

    var body: some View {
        SignInWithAppleButton(
            onRequest: { request in
                request.requestedScopes = [.email, .fullName]
            },
            onCompletion: { result in
                switch result {
                case .success(let authorization):
                    handleAppleSignIn(authorization: authorization)
                case .failure(let error):
                    print("Sign in with Apple failed: \(error)")
                }
            }
        )
        .signInWithAppleButtonStyle(colorScheme == .dark ? .white : .black)
        .frame(height: 50)
    }

    func handleAppleSignIn(authorization: ASAuthorization) {
        guard let appleIDCredential = authorization.credential as? ASAuthorizationAppleIDCredential,
              let identityToken = appleIDCredential.identityToken,
              let tokenString = String(data: identityToken, encoding: .utf8) else {
            return
        }

        // Exchange Apple identity token with OAuth42
        Task {
            await exchangeAppleToken(
                identityToken: tokenString,
                authorizationCode: String(data: appleIDCredential.authorizationCode ?? Data(), encoding: .utf8) ?? ""
            )
        }
    }

    func exchangeAppleToken(identityToken: String, authorizationCode: String) async {
        // Call your backend API which will forward to OAuth42
        // Your backend should call: POST /api/social-auth/apple/native
        let url = URL(string: "https://your-api.com/auth/apple/native")!
        var request = URLRequest(url: url)
        request.httpMethod = "POST"
        request.setValue("application/json", forHTTPHeaderField: "Content-Type")

        let body: [String: Any] = [
            "identity_token": identityToken,
            "authorization_code": authorizationCode,
            "client_id": "your-oauth42-client-id"
        ]
        request.httpBody = try? JSONSerialization.data(withJSONObject: body)

        do {
            let (data, _) = try await URLSession.shared.data(for: request)
            // Handle OAuth42 tokens response
            let tokens = try JSONDecoder().decode(TokenResponse.self, from: data)
            // Store tokens and navigate to main app
        } catch {
            print("Token exchange failed: \(error)")
        }
    }
}

import AuthenticationServices

class AuthManager: NSObject, ASWebAuthenticationPresentationContextProviding {

    func signInWithApple() {
        let authURL = URL(string: "https://your-oauth42-app.com/hosted-auth/login?provider=apple")!
        let callbackScheme = "yourapp" // Your app's URL scheme

        let session = ASWebAuthenticationSession(
            url: authURL,
            callbackURLScheme: callbackScheme
        ) { callbackURL, error in
            if let error = error {
                print("Auth error: \(error)")
                return
            }

            guard let callbackURL = callbackURL,
                  let components = URLComponents(url: callbackURL, resolvingAgainstBaseURL: false),
                  let code = components.queryItems?.first(where: { $0.name == "code" })?.value else {
                return
            }

            // Exchange code for tokens
            self.exchangeCodeForTokens(code: code)
        }

        session.presentationContextProvider = self
        session.prefersEphemeralWebBrowserSession = true
        session.start()
    }

    func presentationAnchor(for session: ASWebAuthenticationSession) -> ASPresentationAnchor {
        return UIApplication.shared.windows.first { $0.isKeyWindow }!
    }
}