FrontOffice/src/FrontOffice.Main/App.razor.cs

using System;
using System.Threading.Tasks;
using Blazored.LocalStorage;
using FrontOffice.Main.Utilities;
using Microsoft.AspNetCore.Components;
using Microsoft.AspNetCore.Components.Routing;

namespace FrontOffice.Main;

public partial class App
{
    private const string TokenStorageKey = "auth:token";

    [Inject] private ILocalStorageService LocalStorage { get; set; } = default!;

    private async Task HandleNavigationAsync(NavigationContext context)
    {
        var relativePath = Navigation.ToBaseRelativePath(context.Path);
        if (IsAuthPath(relativePath))
        {
            return;
        }

        var token = await LocalStorage.GetItemAsync<string>(TokenStorageKey);
        if (string.IsNullOrWhiteSpace(token))
        {
            var normalized = NormalizePath(relativePath);
            var redirectQuery = string.IsNullOrEmpty(normalized) || normalized == "/"
                ? string.Empty
                : $"?redirect={Uri.EscapeDataString(normalized)}";

            Navigation.NavigateTo(RouteConstants.Auth.Phone + redirectQuery, forceLoad: true);
        }
    }

    private static bool IsAuthPath(string? path)
    {
        if (string.IsNullOrWhiteSpace(path))
        {
            return false;
        }

        path = path.TrimStart('/');
        return path.StartsWith("auth", StringComparison.OrdinalIgnoreCase);
    }

    private static string NormalizePath(string? path)
    {
        if (string.IsNullOrWhiteSpace(path))
        {
            return string.Empty;
        }

        var normalized = path.StartsWith('/') ? path : "/" + path;
        return normalized;
    }
}