PaymentViewModel

class PaymentViewModel : ObservableObject{
    @Published var isLoadingRetrieveProducts = false
    @Published var yearlySubscriptionPrice = ""
    @Published var monthlySubscriptionPrice = ""
    @Published var lifetimeSubscriptionPrice = ""
    
    @Published var isLoadingPayment = false

    @Published var showAlert = false
    @Published var title: String = ""
    @Published var payments : [PaymentView] = []
    
    init(){
        payments.append(PaymentView.init(paymentId: PaymentId.monthly, title: "_monthly".localized, index: 0,price: "",extraInfo: "Free for 3 days".localized))
        payments.append(PaymentView.init(paymentId: PaymentId.yearly, title: "_annual".localized, index: 1,price: "",extraInfo: "Free for 3 days".localized))
        payments.append(PaymentView.init(paymentId: PaymentId.lifetime, title: "_lifetime".localized, index: 2,price : "",extraInfo: ""))
    }
    
    func retrieveProducts(){
        isLoadingRetrieveProducts = true
        SwiftyStoreKit.retrieveProductsInfo([PaymentId.monthly,PaymentId.yearly,PaymentId.lifetime]) { result in
            self.isLoadingRetrieveProducts = false
            result.retrievedProducts.forEach { skProduct in

                switch(skProduct.productIdentifier){
                case PaymentId.monthly:
                    self.payments[0].price = skProduct.localizedPrice ?? "\(skProduct.price)"
                    break;
                    
                case PaymentId.yearly:
                    self.payments[1].price = skProduct.localizedPrice ?? "\(skProduct.price)"
                    let monthlyPrice = String(format: "%.1f",Float(skProduct.price) / 12)
                    let currency = skProduct.priceLocale.currencySymbol ?? ""
                    self.payments[1].discount = "\(currency)\(monthlyPrice) / \("_mo".localized) "

                    break;
                case PaymentId.lifetime:
                    self.payments[2].price = skProduct.localizedPrice ?? "\(skProduct.price)"
                    break;
                default:
                    debugPrint("PaymentViewModel default")
                    break;
                }
            }
        }
        
    }


func startPayment(with paymentId: String, completion: @escaping (PaymentResult) -> Void){
    isLoadingPayment = true
    SwiftyStoreKit.purchaseProduct(paymentId, quantity: 1, atomically: true) { result in
        debugPrint("PaymentManager startPayment => \(paymentId)")
        switch result {
        case .success(let purchase):
            debugPrint("PaymentManager success => \(purchase.productId)")
            completion(PaymentResult(success: true,error: nil))
        case .error(let error):
            if let _error = PaymentErrorHandler.map(from: error){
                debugPrint("PaymentManager error => \(_error)")
                completion(PaymentResult(success: false,error: _error))
            }else {
                completion(PaymentResult(success: false,error: nil))
            }
        case .deferred(purchase: let purchase):
            debugPrint("PaymentManager deferred => \(purchase.productId)")
            completion(PaymentResult(success: false,error: nil))
        }
        self.isLoadingPayment = false

    }
}
    
    private func showAlert(title : String){
        self.title = title
        self.showAlert = true
    }

func restorePurchases(completion: @escaping (PaymentResult) -> Void){
    debugPrint("PaymentManager restorePurchases")
    isLoadingPayment = true
    
    SwiftyStoreKit.restorePurchases(atomically: true) { results in
        debugPrint("PaymentManager restorePurchases results => \(results)")
        if results.restoreFailedPurchases.count > 0 {
            self.showAlert(title: "No restored purchase")
            completion(PaymentResult(success: false,error: nil))
        }
        else if results.restoredPurchases.count > 0 {
            if let purchase =  results.restoredPurchases.first{
                self.startPayment(with: purchase.productId, completion: completion)
            }
        }
        else {
            self.showAlert(title: "No restored purchase")
            completion(PaymentResult(success: false,error: nil))
        }
        self.isLoadingPayment = false
    }
}

}
struct PaymentResult {
    var success: Bool
    var error : String?
}

struct PaymentErrorHandler{
    static func map(from error: SKError) -> String? {
        var errorDescription : String? = nil
        switch error.code {
        case .unknown:
            errorDescription = "Unknown error. Please contact support"
        case .clientInvalid:
            errorDescription = "Not allowed to make the payment"
        case .paymentCancelled:
            errorDescription = "Payment cancelled"
        case .paymentInvalid:
            errorDescription = "The purchase identifier was invalid"
        case .paymentNotAllowed:
            errorDescription = "The device is not allowed to make the payment"
        case .storeProductNotAvailable:
            errorDescription = "The product is not available in the current storefront"
        case .cloudServicePermissionDenied:
            errorDescription = "Access to cloud service information is not allowed"
        case .cloudServiceNetworkConnectionFailed:
            errorDescription = "Could not connect to the network"
        case .cloudServiceRevoked:
            errorDescription = "User has revoked permission to use this cloud service"
        default:
            errorDescription = (error as NSError).localizedDescription
        }
        return errorDescription
    }
}

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