Kitty_Fall_Mytel/Kitty_Fall/Kitty_Fall/Kitty_Fall.Website/Helpers/LoginRequiredMiddleware.cs

using Common.Extension;

namespace Kitty_Fall.Website.Helpers;

public class LoginRequiredMiddleware
{
    private readonly RequestDelegate _next;

    public LoginRequiredMiddleware(RequestDelegate next)
    {
        _next = next;
    }

    public async Task InvokeAsync(HttpContext context)
    {
        if (ShouldSkip(context))
        {
            await _next(context);
            return;
        }

        var msisdn = context.Session.GetComplexData<string>("msisdn");
        if (!string.IsNullOrWhiteSpace(msisdn))
        {
            await _next(context);
            return;
        }

        context.Response.Headers.CacheControl = "no-store";
        if (IsAjaxRequest(context.Request))
        {
            // Ajax: quay lại trang đang đứng (Referer) sau khi đăng nhập trên trình duyệt.
            var redirectUrl = AccessChannelHelper.GetLoginRedirectUrl(context, GetLocalReferer(context.Request));
            context.Response.StatusCode = StatusCodes.Status401Unauthorized;
            context.Response.Headers["X-Login-Required"] = "true";
            context.Response.Headers["X-Login-Redirect"] = redirectUrl;
            await context.Response.WriteAsJsonAsync(new
            {
                success = false,
                errorCode = Common.CommonErrorCode.LoginRequired,
                redirectUrl
            });
            return;
        }

        var returnUrl = context.Request.Method == HttpMethods.Get
            ? $"{context.Request.PathBase}{context.Request.Path}{context.Request.QueryString}"
            : null;
        context.Response.Redirect(AccessChannelHelper.GetLoginRedirectUrl(context, returnUrl));
    }

    private static bool ShouldSkip(HttpContext context)
    {
        var path = context.Request.Path;

        if (path.StartsWithSegments("/Login")) return true;
        if (path.StartsWithSegments("/Home/ChangeLanguage")) return true;
        if (path.StartsWithSegments("/favicon.ico")) return true;
        if (path.StartsWithSegments("/kitty")) return true;
        if (path.StartsWithSegments("/css")) return true;
        if (path.StartsWithSegments("/js")) return true;
        if (path.StartsWithSegments("/lib")) return true;
        if (path.StartsWithSegments("/assets")) return true;

        return false;
    }

    private static string? GetLocalReferer(HttpRequest request)
    {
        var referer = request.Headers.Referer.ToString();
        if (string.IsNullOrWhiteSpace(referer)
            || !Uri.TryCreate(referer, UriKind.Absolute, out var uri)
            || !string.Equals(uri.Host, request.Host.Host, StringComparison.OrdinalIgnoreCase))
        {
            return null;
        }

        return uri.PathAndQuery;
    }

    private static bool IsAjaxRequest(HttpRequest request)
    {
        return string.Equals(request.Headers["X-Requested-With"], "XMLHttpRequest", StringComparison.OrdinalIgnoreCase)
            || string.Equals(request.Headers["Sec-Fetch-Dest"], "empty", StringComparison.OrdinalIgnoreCase)
            || request.Headers.Accept.Any(x => x?.Contains("application/json", StringComparison.OrdinalIgnoreCase) == true);
    }

}