TechHelper/TechHelper.Client/AuthProviders/AuthStateProvider.cs

using Microsoft.AspNetCore.Components.Authorization;
using System.Security.Claims;
using System.Net.Http.Headers;
using TechHelper.Features;
using Microsoft.JSInterop;

namespace TechHelper.Client.AuthProviders
{
	public class AuthStateProvider : AuthenticationStateProvider
	{
		private readonly HttpClient _httpClient;
		private readonly AuthenticationState _anonymous;
		private readonly ILocalStorageService _localStorageService;

		public AuthStateProvider(ILocalStorageService localStorageService, HttpClient httpClient)
		{
			_localStorageService = localStorageService;
			_httpClient = httpClient;
			_anonymous = new AuthenticationState(
				new ClaimsPrincipal(new ClaimsIdentity()));
		}


		public override async Task<AuthenticationState> GetAuthenticationStateAsync()
		{
			string? token = null;

			try
			{
				token =  _localStorageService.GetItem<string>("authToken");
			}
			catch (Exception ex)
			{
				Console.WriteLine($"Error accessing LocalStorage or parsing token: {ex.Message}"); 
				return _anonymous; 
			}
			if (string.IsNullOrEmpty(token))
				return _anonymous;

			_httpClient.DefaultRequestHeaders.Authorization = 
				new AuthenticationHeaderValue("bearer", token);

			return new AuthenticationState(new ClaimsPrincipal(
				new ClaimsIdentity(JWTParser.ParseClaimsFromJwt(token), "jwtAuthType")));
		}

		public void NotifyUserAuthentication(string token)
		{
			var authenticatedUser = new ClaimsPrincipal(new ClaimsIdentity(
				JWTParser.ParseClaimsFromJwt(token), "jwtAuthType"));

			var authState = Task.FromResult(new AuthenticationState(authenticatedUser));	

			NotifyAuthenticationStateChanged(authState);
		}

		public void NotifyUserLogout()
		{
			var authState = Task.FromResult(_anonymous);

			NotifyAuthenticationStateChanged(authState);
		}
	}
}