Express Checkout: shipping in the Apple Pay and Google Pay sheets

val settings = PrimerSettings(
    paymentMethodOptions = PrimerPaymentMethodOptions(
        googlePayOptions = PrimerGooglePayOptions(
            merchantName = "Example Store",
            // Optional: ask for the phone number too. The SDK asks for the address itself.
            shippingAddressParameters = PrimerGoogleShippingAddressParameters(
                phoneNumberRequired = true,
            ),
        ),
    ),
)

val checkout = rememberPrimerCheckoutController(clientToken, settings)

let settings = PrimerSettings(
  paymentMethodOptions: PrimerPaymentMethodOptions(
    applePayOptions: PrimerApplePayOptions(
      merchantIdentifier: "merchant.com.example",
      merchantName: "Example Store",
      // Optional: other shipping contact fields. The SDK adds the postal address itself.
      shippingOptions: PrimerApplePayOptions.ShippingOptions(
        shippingContactFields: [.name, .emailAddress],
        // Required by the initializer. The handlers decide whether the sheet shows options.
        requireShippingMethod: false
      )
    )
  )
)

let session = PrimerCheckoutSession(clientToken: clientToken, settings: settings)

LaunchedEffect(checkout) {
    checkout.onShippingAddressChange { change ->
        myBackend.shippingRates(change.shippingAddress).map { rate ->
            PrimerShippingOption(
                id = rate.id,
                name = rate.name,
                description = rate.eta,
                amount = rate.amountInMinorUnits,
            )
        }
    }
}

data class PrimerShippingAddressChange(
    val paymentMethodType: String,
    val shippingAddress: PrimerAddress,
)

data class PrimerShippingOption(
    val id: String,          // Echoed back on selection. Must match order.shipping.methodId.
    val name: String,        // Display label, for example "Standard"
    val description: String, // Display detail, for example "5-7 business days"
    val amount: Int,         // Shipping cost in MINOR UNITS, for example 500 = £5.00
)

session.onShippingAddressChange = { change in
  let rates = try await myBackend.shippingRates(for: change.shippingAddress)
  return rates.map {
    PrimerShippingOption(
      id: $0.id,
      name: $0.name,
      description: $0.eta,
      amount: $0.amountInMinorUnits
    )
  }
}

public struct PrimerShippingAddressChange: Sendable {
  public let paymentMethodType: String
  public let shippingAddress: PrimerAddress
}

public struct PrimerShippingOption: Equatable, Sendable {
  public let id: String          // Echoed back on selection. Must match order.shipping.methodId.
  public let name: String        // Display label, for example "Standard"
  public let description: String // Display detail, for example "5-7 business days"
  public let amount: Int         // Shipping cost in MINOR UNITS, for example 500 = £5.00
}

LaunchedEffect(checkout) {
    checkout.onShippingOptionChange { change ->
        // Send the id only. Your backend resolves the price.
        myBackend.updateShipping(orderId, change.selectedShippingOption.id)
    }
}

data class PrimerShippingOptionChange(
    val paymentMethodType: String,
    val selectedShippingOption: PrimerShippingOption,
)

session.onShippingOptionChange = { change in
  // Send the id only. Your backend resolves the price.
  try await myBackend.commitShipping(optionId: change.selectedShippingOption.id)
}

public struct PrimerShippingOptionChange: Sendable {
  public let paymentMethodType: String
  public let selectedShippingOption: PrimerShippingOption
}

PrimerCheckout(
  clientToken: clientToken,
  primerSettings: settings,
  onShippingAddressChange: { change in try await myBackend.rates(for: change.shippingAddress) },
  onShippingOptionChange: { change in
    try await myBackend.commitShipping(optionId: change.selectedShippingOption.id)
  }
)