Apple Pay

import SwiftUI
import PayablMerchant
import Combine
import PassKit

class DemoCartViewModel: ObservableObject {
    var pblApplePay: PBLApplePay?
    @Published var pblApplePayLoaded: Bool = false
    var configuration: PBLConfiguration?

    // In your server, this endpoint should call the /mobile/init API
    let backendCheckoutUrl = URL(string: "backend_endpoint/payment_page")!

    func prepareOrder() async -> PBLConfiguration? {
        var request = URLRequest(url: backendCheckoutUrl)
        request.httpMethod = "POST"

        await withCheckedContinuation { continuation in
            let task = URLSession.shared.dataTask(with: request) { [weak self] data, response, error in
                guard let data = data,
                      let json = try? JSONSerialization.jsonObject(with: data) as? [String: Any]
                else { return }

                let sessionId = json["sessionId"] as! String
                let ephemeralKey = json["empheralKey"] as! String
                let transactionId = json["transactionId"] as! Int

                self?.configuration = PBLConfiguration(
                    sessionId: sessionId,
                    ephemeralKey: ephemeralKey,
                    customerId: "", // not used for Apple Pay
                    environment: .sandbox, // use .production when going live
                    transactionId: transactionId,
                    appleMerchantId: "merchant.payabl.isdk" // your Apple Merchant ID
                )
                continuation.resume()
            }
            task.resume()
        }
        return configuration
    }
}

extension DemoCartViewModel: PBLApplePayTapDelegate {
    // Called when the user taps the button — load the session, then hand the config back to the SDK
    func applePayTapped(onLoadSessionCompleted: @escaping (PBLConfiguration) -> Void) {
        Task {
            guard let config = await prepareOrder() else { return }
            onLoadSessionCompleted(config)
        }
    }

    // Called with the final result of the payment
    func applePayCompleted(result: PBLPaymentResult) {
        handlePaymentResult(result)
    }
}

extension DemoCartViewModel: PBLErrorDelegate {
    func errorOccured(error: any Error) {
        // Handle SDK errors (e.g., configuration or session issues)
        print("error from sdk: ", error)
    }
}

struct ContentView: View {
    let cartVM = DemoCartViewModel()

    var body: some View {
        VStack {
            if cartVM.pblApplePayLoaded {
                cartVM.pblApplePay?.button
                    .frame(maxWidth: .infinity)
            }
        }
        .padding()
        .onAppear {
            cartVM.pblApplePay = PBLApplePay(style: .whiteOutline, delegate: cartVM, errorDelegate: cartVM)
            cartVM.pblApplePayLoaded = true
        }
    }
}

func handlePaymentResult(result: PBLPaymentResult) {
    switch result {
    case .completed:
        // Payment successful — update order status
        break
    case .canceled:
        // User dismissed the Apple Pay sheet
        break
    case .failed:
        // Payment failed — inspect the result for the error code
        break
    }
}