annotations/Azaion.CommonSecurity/Services/AzaionApiClient.cs

using System.IdentityModel.Tokens.Jwt;
using System.Net;
using System.Net.Http.Headers;
using System.Security;
using System.Text;
using Azaion.CommonSecurity.DTO;
using Newtonsoft.Json;

namespace Azaion.CommonSecurity.Services;

public class AzaionApiClient(HttpClient httpClient) : IDisposable
{
    const string JSON_MEDIA = "application/json";

    private static ApiConfig _apiConfig = null!;

    private string Email { get; set; } = null!;
    private SecureString Password { get; set; } = new();
    private string JwtToken { get; set; } = null!;
    public User User { get; set; } = null!;

    public static AzaionApiClient Create(ApiCredentials credentials, ApiConfig apiConfig)
    {
        _apiConfig = apiConfig;
        var api = new AzaionApiClient(new HttpClient
        {
            BaseAddress = new Uri(_apiConfig.Url),
            Timeout = TimeSpan.FromSeconds(_apiConfig.TimeoutSeconds)
        });

        api.EnterCredentials(credentials);
        return api;
    }

    public void EnterCredentials(ApiCredentials credentials)
    {
        if (string.IsNullOrWhiteSpace(credentials.Email) || string.IsNullOrWhiteSpace(credentials.Password))
            throw new Exception("Email or password is empty!");

        Email = credentials.Email;
        Password = credentials.Password.ToSecureString();
    }

    public async Task<Stream> GetResource(string fileName, string password, HardwareInfo hardware, CancellationToken cancellationToken = default)
    {
        var response = await Send(httpClient, new HttpRequestMessage(HttpMethod.Post, $"/resources/get/{_apiConfig.ResourcesFolder}")
        {
            Content = new StringContent(JsonConvert.SerializeObject(new { fileName, password, hardware }), Encoding.UTF8, JSON_MEDIA)
        }, cancellationToken);
        return await response.Content.ReadAsStreamAsync(cancellationToken);
    }

    private async Task Authorize()
    {
        if (string.IsNullOrEmpty(Email) || Password.Length == 0)
            throw new Exception("Email or password is empty! Please do EnterCredentials first!");

        var payload = new
        {
            email = Email,
            password = Password.ToRealString()
        };
        var response = await httpClient.PostAsync(
            "login",
            new StringContent(JsonConvert.SerializeObject(payload), Encoding.UTF8, JSON_MEDIA));

        if (!response.IsSuccessStatusCode)
            throw new Exception($"EnterCredentials failed: {response.StatusCode}");

        var responseData = await response.Content.ReadAsStringAsync();

        var result = JsonConvert.DeserializeObject<LoginResponse>(responseData);

        if (string.IsNullOrEmpty(result?.Token))
            throw new Exception("JWT Token not found in response");

        var handler = new JwtSecurityTokenHandler();
        var token = handler.ReadJwtToken(result.Token);

        User = new User(token.Claims);
        JwtToken = result.Token;
    }

    private async Task<HttpResponseMessage> Send(HttpClient client, HttpRequestMessage request, CancellationToken cancellationToken = default)
    {
        if (string.IsNullOrEmpty(JwtToken))
             await Authorize();
        request.Headers.Authorization = new AuthenticationHeaderValue("Bearer", JwtToken);
        var response = await client.SendAsync(request, cancellationToken);

        if (response.StatusCode == HttpStatusCode.Unauthorized)
        {
            await Authorize();
            request.Headers.Authorization = new AuthenticationHeaderValue("Bearer", JwtToken);
            response = await client.SendAsync(request, cancellationToken);
        }

        if (response.IsSuccessStatusCode)
            return response;

        var result = await response.Content.ReadAsStringAsync(cancellationToken);
        throw new Exception($"Failed: {response.StatusCode}! Result: {result}");
    }

    public void Dispose()
    {
        httpClient.Dispose();
        Password.Dispose();
    }
}