using System.Globalization;
using Microsoft.AspNetCore.Localization;
using Microsoft.Extensions.Options;

services.Configure<RequestLocalizationOptions>(options =>
{
   var supportedCultures = new[]
    {
        new CultureInfo("en"),
        new CultureInfo("de"),
        new CultureInfo("fr"),
        new CultureInfo("es"),
        new CultureInfo("ru"),
        new CultureInfo("ja"),
        new CultureInfo("ar"),
        new CultureInfo("zh"),
        new CultureInfo("en-GB")
    };
    options.DefaultRequestCulture = new RequestCulture("en-GB");
    options.SupportedCultures = supportedCultures;
    options.SupportedUICultures = supportedCultures;
});

app.UseHttpsRedirection();
app.UseStaticFiles();
app.UseRouting();
var localizationOptions = app.ApplicationServices.GetService<IOptions<RequestLocalizationOptions>>().Value;
app.UseRequestLocalization(localizationOptions);

using System.Collections.Generic;
using System.Globalization;
namespace Localisation.Models
{
    public class CultureSwitcherModel
    {
        public CultureInfo CurrentUICulture { get; set; }
        public List<CultureInfo> SupportedCultures { get; set; }
    }
}

using Localisation.Models;
using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Localization;
using Microsoft.AspNetCore.Mvc;
using Microsoft.Extensions.Options;
using System.Linq;
namespace Localisation.ViewComponents
{
    public class CultureSwitcherViewComponent : ViewComponent
    {
        private readonly IOptions<RequestLocalizationOptions> localizationOptions;
        public CultureSwitcherViewComponent(IOptions<RequestLocalizationOptions> localizationOptions) =>
            this.localizationOptions = localizationOptions;
        public IViewComponentResult Invoke()
        {
            var cultureFeature = HttpContext.Features.Get<IRequestCultureFeature>();
            var model = new CultureSwitcherModel
            {
                SupportedCultures = localizationOptions.Value.SupportedUICultures.ToList(),
                CurrentUICulture = cultureFeature.RequestCulture.UICulture
            };
            return View(model);
        }
    }
}

@model CultureSwitcherModel
<div>
    <form id="culture-switcher">
        <select name="culture" id="culture-options">
            <option></option>
            @foreach (var culture in Model.SupportedCultures)
            {
                <option value="@culture.Name" selected="@(Model.CurrentUICulture.Name == culture.Name)">@culture.DisplayName</option>
            }
        </select>
    </form>
</div>
<script>
    document.getElementById("culture-options").addEventListener("change", () => {
        document.getElementById("culture-switcher").submit();
    });
</script>

@using Localisation
@using Localisation.Models
@using System.Globalization
@namespace Localisation.Pages
@addTagHelper *, Microsoft.AspNetCore.Mvc.TagHelpers
@addTagHelper *, Localisation

<div class="navbar-collapse collapse d-sm-inline-flex flex-sm-row-reverse">
    <ul class="navbar-nav flex-grow-1">
        <li class="nav-item">
            <a class="nav-link text-dark" asp-area="" asp-page="/Index">Home</a>
        </li>
        <li class="nav-item">
            <a class="nav-link text-dark" asp-area="" asp-page="/Privacy">Privacy</a>
        </li>
    </ul>
</div>
<vc:culture-switcher/>

@page
@using Microsoft.AspNetCore.Localization
@model IndexModel
@{
    ViewData["Title"] = "Home page";
    var requestCultureFeature = HttpContext.Features.Get<IRequestCultureFeature>();
    var requestCulture = requestCultureFeature.RequestCulture;
}
<div class="text-center">
    <h1 class="display-4">Welcome</h1>
    <p>Learn about <a href="https://docs.microsoft.com/aspnet/core">building Web apps with ASP.NET Core</a>.</p>
    <table class="table culture-table">
        <tr>
            <td style="width:50%;">Culture</td>
            <td>@requestCulture.Culture.DisplayName {@requestCulture.Culture.Name}</td>
        </tr>
        <tr>
            <td>UI Culture</td>
            <td>@requestCulture.UICulture.Name</td>
        </tr>
        <tr>
            <td>UICulture Parent</td>
            <td>@requestCulture.UICulture.Parent</td>
        </tr>
        <tr>
            <td>Date</td>
            <td>@DateTime.Now.ToLongDateString()</td>
        </tr>
        <tr>
            <td>Currency</td>
            <td>
                @(12345.00.ToString("c"))
            </td>
        </tr>
        <tr>
            <td>Number</td>
            <td>
                @(123.45m.ToString("F2"))
            </td>
        </tr>
    </table>
</div>