using System;
using System.Collections.Generic;
using System.Globalization;
using System.Linq;
using System.Net;

using System.Text;
using System.Threading.Tasks;
using gehGassi.Core.Interfaces;
using gehGassi.Domain.Common;
using Microsoft.Extensions.Options;
using PayPalCheckoutSdk.Core;
using PayPalCheckoutSdk.Orders;
using PayPalHttp;


namespace gehGassi.External.Services
{
    /// <summary>
    /// Service der alle PayPal-Funktionen zur Verfügung stellt
    /// </summary>
    public class PayPalService : IPayPalService
    {
        private HttpClient _httpClient;
        private readonly IOptions<ShopOptions> _shopOptions;
        private readonly IOrderService _orderService;
        private readonly ICustomerService _customerService;

        /// <summary>
        /// Erstellt eine Instanz
        /// </summary>
        /// <param name="shopOptions">Instanz von PaymentOptions</param>
        /// <param name="orderService">Instanz eines IOrderService</param>
        /// <param name="customerService">Instanz eines ICustomerService</param>
        public PayPalService(IOptions<ShopOptions> shopOptions, IOrderService orderService, ICustomerService customerService)
        {
            _shopOptions = shopOptions;
            _orderService = orderService;
            _customerService = customerService;
        }

        /// <summary>
        /// Gibt einen HTTP-Client für die Kommunikation mit PayPal zurück
        /// </summary>
        /// <param name="environment">PayPalEnvironment</param>
        /// <returns>HttpClient</returns>
        internal HttpClient GetHttpClient(PayPalEnvironment environment)
        {
            return _httpClient ??= new PayPalHttpClient(environment);
        }

        /// <summary>
        /// Gibt das PayPal Environment basierend auf den Einstellungen zurück
        /// </summary>
        /// <param name="clientId">PayPal ClientId</param>
        /// <param name="secret">PayPal Secret</param>
        /// <returns>PayPal Environment</returns>
        internal PayPalEnvironment GetEnvironment(string clientId, string secret)
        {
            PayPalEnvironment environment;
            if (_shopOptions.Value.PayPalUseSandbox)
                environment = new SandboxEnvironment(clientId, secret);
            else
                environment = new LiveEnvironment(clientId, secret);
            return environment;
        }


        /// <summary>
        /// Prüft ob die PayPal Credentials korrekt sind und eine Verbindung zur Api aufgenommen werden kann
        /// </summary>
        /// <param name="clientId">PayPal ClientId</param>
        /// <param name="secret">PayPal Secret</param>
        /// <returns>true wenn erfolgreich, false sonst</returns>
        public async Task<bool> TestCredentialsAsync(string clientId, string secret)
        {
            var environment = GetEnvironment(clientId, secret);
            var client = GetHttpClient(environment);
            var request = new AccessTokenRequest(GetEnvironment(clientId, secret));
            try
            {
                var result = await client.Execute(request);
                return result.StatusCode == HttpStatusCode.OK;
            }
            catch (Exception ex)
            {
                return false;
            }
        }

        /// <summary>
        /// Erstellen einer PayPal-Order
        /// </summary>
        /// <param name="orderId">Id der Bestellung</param>
        /// <param name="clientId">PayPal ClientId</param>
        /// <param name="secret">PayPal Secret</param>
        /// <param name="successUrl">Redirect-Url für ERFOLG</param>
        /// <param name="cancelUrl">Redirect-URL für Fehler oder Abbrechen</param>
        /// <returns>REdirect-Url zu PayPal oder leer wenn Fehler</returns>
        public async Task<string> CreateOrderAsync(long orderId, string clientId, string secret, string successUrl, string cancelUrl)
        {
            var environment = GetEnvironment(clientId, secret);
            var client = GetHttpClient(environment);

            var order = await _orderService.GetAsync(orderId);
            if (order == null)
                return string.Empty;

            var orderItems = await _orderService.GetItemsAsync(orderId);
            if (!orderItems.Any())
                return string.Empty;

            var customer = await _customerService.GetAsync(order.CustomerId.Value);
            if (customer == null)
                return string.Empty;

            var payPalOrder = new OrderRequest
            {
                CheckoutPaymentIntent = "CAPTURE",
                ApplicationContext = new ApplicationContext()
                {
                    BrandName = $"gehGassi GmbH",
                    LandingPage = "NO_PREFERENCE",
                    UserAction = "CONTINUE",
                    ShippingPreference = "SET_PROVIDED_ADDRESS",
                    ReturnUrl = successUrl,
                    CancelUrl = cancelUrl
                },
                PurchaseUnits = new List<PurchaseUnitRequest>()
                {
                    new PurchaseUnitRequest()
                    {
                        CustomId = order.UniqueId.ToString(),
                        InvoiceId = order.Number,
                        SoftDescriptor = $"gehGassi GmbH",
                        AmountWithBreakdown = new AmountWithBreakdown()
                        {
                            AmountBreakdown = new AmountBreakdown()
                            {
                                ItemTotal = new Money(){CurrencyCode = "EUR", Value = order.Subtotal.ToString(CultureInfo.InvariantCulture)},
                                Shipping = new Money(){CurrencyCode = "EUR", Value = order.Shipment.ToString(CultureInfo.InvariantCulture)},
                                TaxTotal = new Money(){CurrencyCode = "EUR", Value = (order.TotalGross - order.Total).ToString(CultureInfo.InvariantCulture)},
                            },
                            CurrencyCode = "EUR",
                            Value = order.TotalGross.ToString(CultureInfo.InvariantCulture)
                        },
                        ShippingDetail = new ShippingDetail()
                        {
                            Name = new Name()
                            {
                                FullName = $"{order.DeliveryAddress.GetNameForPayPal()}"
                            },
                            AddressPortable = new AddressPortable()
                            {
                                AddressLine1 = order.DeliveryAddress.AddressLine1,
                                AddressLine2 = order.DeliveryAddress.AddressLine2,
                                AdminArea2 = order.DeliveryAddress.City,
                                AdminArea1 = order.DeliveryAddress.State,
                                PostalCode = order.DeliveryAddress.Zip,
                                CountryCode = order.DeliveryAddress.CountryCode
                            }
                        }
                    }
                }
            };
            var items = new List<Item>();
            foreach (var orderItem in orderItems)
            {
                var price = orderItem.Price + orderItem.Price2;
                price = decimal.Round(price, 2, MidpointRounding.AwayFromZero);
                var item = new Item()
                {
                    Name = orderItem.Name,
                    Quantity = orderItem.Quantity.ToString(CultureInfo.InvariantCulture),
                    UnitAmount = new Money() { CurrencyCode = "EUR", Value = price.ToString(CultureInfo.InvariantCulture) },
                    //Tax = new Money() { CurrencyCode = "EUR", Value = (orderItem.PriceGross - orderItem.Price).ToString(CultureInfo.InvariantCulture) },
                    //Category = "PHYSICAL_GOODS"
                };
                switch (orderItem.ProductType)
                {
                    case ProductType.Physical:
                        item.Category = "PHYSICAL_GOODS";
                        break;
                    case ProductType.Download:
                        item.Category = "DIGITAL_GOODS";
                        break;
                    case ProductType.Listing:
                        item.Category = "DIGITAL_GOODS";
                        break;
                    case ProductType.Advertisement:
                        item.Category = "DIGITAL_GOODS";
                        break;
                    case ProductType.Pin:
                        item.Category = "DIGITAL_GOODS";
                        break;
                    case ProductType.Banner:
                        item.Category = "DIGITAL_GOODS";
                        break;
                    default:
                        item.Category = "PHYSICAL_GOODS";
                        break;
                }

                items.Add(item);
            }
            payPalOrder.PurchaseUnits.First().Items = items;

            try
            {
                
                var payPalOrderCreateRequest = new OrdersCreateRequest();
                payPalOrderCreateRequest.Prefer("return=representation");
                payPalOrderCreateRequest.RequestBody(payPalOrder);
                var orderResponse = await _httpClient.Execute(payPalOrderCreateRequest);
                var statusCode = orderResponse.StatusCode;
                if (statusCode == HttpStatusCode.Created)
                {
                    var result = orderResponse.Result<Order>();

                    var approveLink = string.Empty;
                    if (result.Links.Any())
                    {
                        var link = result.Links.FirstOrDefault(c => c.Rel == "approve");
                        if (link != null)
                            approveLink = link.Href;
                    }

                    order.PayPalOrderId = result.Id;
                    order.PaymentStatus = PaymentStatus.Pending;
                    order.PaymentInfo = $"{DateTime.UtcNow}: PayPal order created. OrderId: {result.Id}" + System.Environment.NewLine + order.PaymentInfo;
                    await _orderService.CommitAsync("paypal");

                    return approveLink;
                }
            }
            catch (Exception ex)
            {
                var msg = ex.Message;
            }
            return string.Empty;
        }

        /// <summary>
        /// Authorisieren der PayPal Order - Bezahlung durchführen
        /// </summary>
        /// <param name="payPalOrder">PayPal-Order-Id</param>
        /// <param name="clientId">PayPal ClientId</param>
        /// <param name="secret">PayPal Secret</param>
        /// <returns>true wenn erfolgreich, false sonst</returns>
        public async Task<bool> AuthorizeOrderAsync(string payPalOrder, string clientId, string secret)
        {
            var environment = GetEnvironment(clientId, secret);
            var client = GetHttpClient(environment);

            var request = new OrdersCaptureRequest(payPalOrder);
            request.Prefer("return=representation");
            request.RequestBody(new OrderActionRequest());
            var response = await client.Execute(request);
            var result = response.Result<Order>();
            return result.Status.ToUpper() == "COMPLETED";
        }
    }
}