using System;
using System.Globalization;
using System.Linq;
using System.Text;
using System.Text.Encodings.Web;
using System.Text.RegularExpressions;
using System.Threading.Tasks;
using BTCPayServer.Abstractions.Constants;
using BTCPayServer.Abstractions.Extensions;
using BTCPayServer.Models.AppViewModels;
using BTCPayServer.Services.Apps;
using Microsoft.AspNetCore.Mvc;

namespace BTCPayServer.Controllers
{
    public partial class UIAppsController
    {
        [HttpGet("{appId}/settings/pos")]
        public async Task<IActionResult> UpdatePointOfSale(string appId)
        {
            var app = GetCurrentApp();
            if (app == null)
                return NotFound();

            var settings = app.GetSettings<PointOfSaleSettings>();
            settings.DefaultView = settings.EnableShoppingCart ? PosViewType.Cart : settings.DefaultView;
            settings.EnableShoppingCart = false;
            
            var vm = new UpdatePointOfSaleViewModel
            {
                Id = appId,
                StoreId = app.StoreDataId,
                StoreName = app.StoreData?.StoreName,
                StoreDefaultCurrency = await GetStoreDefaultCurrentIfEmpty(app.StoreDataId, settings.Currency),
                AppName = app.Name,
                Title = settings.Title,
                DefaultView = settings.DefaultView,
                ShowCustomAmount = settings.ShowCustomAmount,
                ShowDiscount = settings.ShowDiscount,
                EnableTips = settings.EnableTips,
                Currency = settings.Currency,
                Template = settings.Template,
                ButtonText = settings.ButtonText ?? PointOfSaleSettings.BUTTON_TEXT_DEF,
                CustomButtonText = settings.CustomButtonText ?? PointOfSaleSettings.CUSTOM_BUTTON_TEXT_DEF,
                CustomTipText = settings.CustomTipText ?? PointOfSaleSettings.CUSTOM_TIP_TEXT_DEF,
                CustomTipPercentages = settings.CustomTipPercentages != null ? string.Join(",", settings.CustomTipPercentages) : string.Join(",", PointOfSaleSettings.CUSTOM_TIP_PERCENTAGES_DEF),
                CustomCSSLink = settings.CustomCSSLink,
                EmbeddedCSS = settings.EmbeddedCSS,
                Description = settings.Description,
                NotificationUrl = settings.NotificationUrl,
                RedirectUrl = settings.RedirectUrl,
                SearchTerm = app.TagAllInvoices ? $"storeid:{app.StoreDataId}" : $"orderid:{AppService.GetAppOrderId(app)}",
                RedirectAutomatically = settings.RedirectAutomatically.HasValue ? settings.RedirectAutomatically.Value ? "true" : "false" : "",
                RequiresRefundEmail = settings.RequiresRefundEmail
            };
            if (HttpContext?.Request != null)
            {
                var appUrl = HttpContext.Request.GetAbsoluteUri($"/apps/{appId}/pos");
                var encoder = HtmlEncoder.Default;
                if (settings.ShowCustomAmount)
                {
                    StringBuilder builder = new StringBuilder();
                    builder.AppendLine(CultureInfo.InvariantCulture, $"<form method=\"POST\" action=\"{encoder.Encode(appUrl)}\">");
                    builder.AppendLine($"  <input type=\"hidden\" name=\"amount\" value=\"100\" />");
                    builder.AppendLine($"  <input type=\"hidden\" name=\"email\" value=\"customer@example.com\" />");
                    builder.AppendLine($"  <input type=\"hidden\" name=\"orderId\" value=\"CustomOrderId\" />");
                    builder.AppendLine($"  <input type=\"hidden\" name=\"notificationUrl\" value=\"https://example.com/callbacks\" />");
                    builder.AppendLine($"  <input type=\"hidden\" name=\"redirectUrl\" value=\"https://example.com/thanksyou\" />");
                    builder.AppendLine($"  <button type=\"submit\">Buy now</button>");
                    builder.AppendLine($"</form>");
                    vm.Example1 = builder.ToString();
                }
                try
                {
                    var items = _appService.Parse(settings.Template, settings.Currency);
                    var builder = new StringBuilder();
                    builder.AppendLine(CultureInfo.InvariantCulture, $"<form method=\"POST\" action=\"{encoder.Encode(appUrl)}\">");
                    builder.AppendLine($"  <input type=\"hidden\" name=\"email\" value=\"customer@example.com\" />");
                    builder.AppendLine($"  <input type=\"hidden\" name=\"orderId\" value=\"CustomOrderId\" />");
                    builder.AppendLine($"  <input type=\"hidden\" name=\"notificationUrl\" value=\"https://example.com/callbacks\" />");
                    builder.AppendLine($"  <input type=\"hidden\" name=\"redirectUrl\" value=\"https://example.com/thanksyou\" />");
                    builder.AppendLine(CultureInfo.InvariantCulture, $"  <button type=\"submit\" name=\"choiceKey\" value=\"{items[0].Id}\">Buy now</button>");
                    builder.AppendLine($"</form>");
                    vm.Example2 = builder.ToString();
                }
                catch { }
                vm.InvoiceUrl = appUrl + "invoices/SkdsDghkdP3D3qkj7bLq3";
            }

            vm.ExampleCallback = "{\n  \"id\":\"SkdsDghkdP3D3qkj7bLq3\",\n  \"url\":\"https://btcpay.example.com/invoice?id=SkdsDghkdP3D3qkj7bLq3\",\n  \"status\":\"paid\",\n  \"price\":10,\n  \"currency\":\"EUR\",\n  \"invoiceTime\":1520373130312,\n  \"expirationTime\":1520374030312,\n  \"currentTime\":1520373179327,\n  \"exceptionStatus\":false,\n  \"buyerFields\":{\n    \"buyerEmail\":\"customer@example.com\",\n    \"buyerNotify\":false\n  },\n  \"paymentSubtotals\": {\n    \"BTC\":114700\n  },\n  \"paymentTotals\": {\n    \"BTC\":118400\n  },\n  \"transactionCurrency\": \"BTC\",\n  \"amountPaid\": \"1025900\",\n  \"exchangeRates\": {\n    \"BTC\": {\n      \"EUR\": 8721.690715789999,\n      \"USD\": 10817.99\n    }\n  }\n}";
            return View(vm);
        }

        [HttpPost("{appId}/settings/pos")]
        public async Task<IActionResult> UpdatePointOfSale(string appId, UpdatePointOfSaleViewModel vm)
        {
            var app = GetCurrentApp();
            if (app == null)
                return NotFound();

            if (!ModelState.IsValid)
                return View(vm);

            vm.Currency = await GetStoreDefaultCurrentIfEmpty(app.StoreDataId, vm.Currency);
            if (_currencies.GetCurrencyData(vm.Currency, false) == null)
                ModelState.AddModelError(nameof(vm.Currency), "Invalid currency");
            try
            {
                vm.Template = _appService.SerializeTemplate(_appService.Parse(vm.Template, vm.Currency));
            }
            catch
            {
                ModelState.AddModelError(nameof(vm.Template), "Invalid template");
            }
            if (!ModelState.IsValid)
            {
                return View(vm);
            }

            app.Name = vm.AppName;
            app.SetSettings(new PointOfSaleSettings
            {
                Title = vm.Title,
                DefaultView = vm.DefaultView,
                ShowCustomAmount = vm.ShowCustomAmount,
                ShowDiscount = vm.ShowDiscount,
                EnableTips = vm.EnableTips,
                Currency = vm.Currency,
                Template = vm.Template,
                ButtonText = vm.ButtonText,
                CustomButtonText = vm.CustomButtonText,
                CustomTipText = vm.CustomTipText,
                CustomTipPercentages = ListSplit(vm.CustomTipPercentages),
                CustomCSSLink = vm.CustomCSSLink,
                NotificationUrl = vm.NotificationUrl,
                RedirectUrl = vm.RedirectUrl,
                Description = vm.Description,
                EmbeddedCSS = vm.EmbeddedCSS,
                RedirectAutomatically = string.IsNullOrEmpty(vm.RedirectAutomatically) ? (bool?)null : bool.Parse(vm.RedirectAutomatically),
                RequiresRefundEmail = vm.RequiresRefundEmail,
            });
            await _appService.UpdateOrCreateApp(app);
            TempData[WellKnownTempData.SuccessMessage] = "App updated";
            return RedirectToAction(nameof(UpdatePointOfSale), new { appId });
        }

        private int[] ListSplit(string list, string separator = ",")
        {
            if (string.IsNullOrEmpty(list))
            {
                return Array.Empty<int>();
            }

            // Remove all characters except numeric and comma
            Regex charsToDestroy = new Regex(@"[^\d|\" + separator + "]");
            list = charsToDestroy.Replace(list, "");

            return list.Split(separator, StringSplitOptions.RemoveEmptyEntries).Select(int.Parse).ToArray();
        }
    }
}