using IdentityModel.Client;
using System;
using System.Net.Http;
using System.Threading.Tasks;

public class KeycloakService
{
    private readonly HttpClient _httpClient;
    private static readonly string KeycloakAuthUrl = "http://localhost:8080/realms/master/protocol/openid-connect/token";
    private static readonly string ClientId = "GoodBooks";
    private static readonly string ClientSecret = "cGZTwahvvm7EnuABvy1bTepzoFrP0Orx";

    public KeycloakService()
    {
        _httpClient = new HttpClient();
    }

    public async Task<string> GetAccessTokenAsync(string username, string password)
    {
        try
        {
            var tokenRequest = new PasswordTokenRequest
            {
                Address = KeycloakAuthUrl,
                ClientId = ClientId, 
                ClientSecret = ClientSecret,
                UserName = username,
                Password = password,
                Scope = "openid", 
                GrantType = "password"
            };

            var tokenResponse = await _httpClient.RequestPasswordTokenAsync(tokenRequest);

            if (tokenResponse.IsError)
            {
                throw new Exception($"Keycloak Authentication failed: {tokenResponse.Error}");
            }

            return tokenResponse.AccessToken;
        }
        catch(Exception ex)
        {
            throw new Exception($"Keycloak Authentication failed: {ex.Message}");
        }
    }
}