NemAn/gRPCServer/Services/AuthService.cs

//using IdentityProvider.Protos.AuthService;
using Blazored.LocalStorage;
using Grpc.Core;
using Grpc.Net.Client;
using GrpcShared;
using GrpcShared.DTO;
using GrpcShared.DTO.Auth;
using GrpcShared.DTO.Db;
using GrpcShared.DTO.User;
using GrpcShared.Interfaces;
using Microsoft.Extensions.Options;
using Microsoft.Net.Http.Headers;
using Newtonsoft.Json;
using System.Diagnostics;
using System.IO;
using System.Net;
using System.Net.Http.Headers;
using System.Text;
using System.Text.Json;

namespace SpotifyService.Services
{
    public class AuthService : IAuthService
    {
        private readonly ILogger<AuthService> _logger;
        private readonly CodeRequest _params;
        private readonly IHttpClientFactory _httpClientFactory;
        //private ISessionStorageService _sessionStorageService;
        public AuthService(ILogger<AuthService> logger, IOptions<CodeRequest> options, IHttpClientFactory httpClientFactory)
        {
            _logger = logger;
            _params = options.Value;
            _httpClientFactory = httpClientFactory;
        }

        public async Task<TokenResponse> GetAccessToken(TokenRequest tokenRequest)
        {
            var http = _httpClientFactory.CreateClient("HttpClient");

            string url = "https://accounts.spotify.com/api/token";
            http.BaseAddress = new Uri(url);

            //get client id and secret, and redirect uri from appsettings, convert to base64 and set as header
            var secrets = await GetAuthParams();
            byte[] contentType = Encoding.UTF8.GetBytes($"{secrets.ClientId}:{secrets.ClientSecret}");
            tokenRequest.RedirectUri = secrets.RedirectURI;

            //AUTHORIZATION HEADER
            http.DefaultRequestHeaders.Add(HeaderNames.Authorization, "Basic " + Convert.ToBase64String(contentType));

            //BODY PARAMS
            var requestBody = new Dictionary<string, string>();
            requestBody["grant_type"] = tokenRequest.GrantType;
            requestBody["code"] = tokenRequest.Code!;
            requestBody["redirect_uri"] = tokenRequest.RedirectUri!;

            try
            {
                //REQUEST
                var response = await http.PostAsync(url, new FormUrlEncodedContent(requestBody));

                var contents = JsonConvert.DeserializeObject<TokenResponse>(await response.Content.ReadAsStringAsync())!;
                return contents;
            }
            catch (RpcException e)
            {
                if (e.StatusCode == StatusCode.Cancelled)
                {
                    return new TokenResponse();
                }
                throw;
            }


        }

        public async Task<CodeRequest> GetAuthParams()
        {
            var authParams = new CodeRequest
            {
                ClientId = _params.ClientId,
                RedirectURI = _params.RedirectURI,
                Scope = _params.Scope,
                ClientSecret = _params.ClientSecret
            };
            return await Task.FromResult(authParams);
        }

        public async Task<UserInfoResponse> GetUserInfo(UserResponse tokenM)
        {
            // expired token example "BQBMgFm6jnFNWWeZEMGIRP_f-ENPid7Kw8JubAyuWAe4JK0S1DPFGlaAdZ_Fey6ePkCnz8-cqC0oyRmrciWUy5ISUTQKDe8PTQn4iBRMYCgM0n4GnS1xAErHJcm4Vpu2TAngk-4vQUOfTQRcedNTfCaHKP4uFJgTlTI7JHGrtB-_EZLnFcZ2OQe31oFQIJ1wM3ZtvwnN"

            var http = _httpClientFactory.CreateClient("HttpClient");

            http.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Bearer", tokenM.Token!);
            var response = await http.GetAsync("me");

            //make this a method in http utils
            if (response.StatusCode == HttpStatusCode.Unauthorized)
            {

                //refresh the token
                var refreshResponse = await RefreshAccessToken(tokenM);

                //if response is invalid redirect to login
                http.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Bearer", refreshResponse.AccessToken);
                response = await http.GetAsync("me");

            }
            //var headerError = response.Headers.WwwAuthenticate.;
            var userInfo = JsonConvert.DeserializeObject<UserInfoResponse>(await response.Content.ReadAsStringAsync())!;
            userInfo.ResponseMsg = response.StatusCode;

            return userInfo;

        }

        public async Task<RefreshTokenResponse> RefreshAccessToken(UserResponse tokenM)
        {
            var client = _httpClientFactory.CreateClient("HttpClient");
            client.BaseAddress = new Uri("https://accounts.spotify.com/api/token");

            //BODY PARAMS
            var requestBody = new Dictionary<string, string>();
            requestBody["refresh_token"] = tokenM.RefreshToken!;
            requestBody["grant_type"] = "refresh_token";

            var secrets = await GetAuthParams();
            byte[] contentType = Encoding.UTF8.GetBytes($"{secrets.ClientId}:{secrets.ClientSecret}");

            //AUTHORIZATION HEADER
            client.DefaultRequestHeaders.Add(HeaderNames.Authorization, "Basic " + Convert.ToBase64String(contentType));

            //REQUEST
            var response = await client.PostAsync("https://accounts.spotify.com/api/token", new FormUrlEncodedContent(requestBody));
         
            var contents = JsonConvert.DeserializeObject<RefreshTokenResponse>(await response.Content.ReadAsStringAsync())!;
            return contents;
        }
    }
}