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

namespace FarmmapsApi.Services
{
    public class OpenIdConnectService
    {
        private readonly IDiscoveryCache _discoveryCache;
        private readonly Configuration _configuration;
        private readonly HttpClient _httpClient;

        public OpenIdConnectService(IDiscoveryCache discoveryCache, 
            IHttpClientFactory httpFactory, Configuration configuration)
        {
            _discoveryCache = discoveryCache;
            _configuration = configuration;
            _httpClient = httpFactory.CreateClient();
        }

        public async Task<DiscoveryDocumentResponse> GetDiscoveryDocumentAsync()
        {
            var disco = await _discoveryCache.GetAsync();
            if (disco.IsError)
                throw new Exception(disco.Error);

            return disco;
        }

        public async Task<TokenResponse> GetTokenClientCredentialsAsync(string tokenEndpointUrl, string clientId, string clientSecret)
        {
            return await _httpClient.RequestClientCredentialsTokenAsync(new ClientCredentialsTokenRequest()
            {
                Address = tokenEndpointUrl,
                ClientId = clientId,
                ClientSecret = clientSecret,
                Scope = string.Join(" ", _configuration.Scopes)
            });
        }

        public async Task<TokenResponse> GetTokenUsernamePasswordAsync(string tokenEndpointUrl, string grantClientId, string username, string password)
        {
            return await _httpClient.RequestPasswordTokenAsync(new PasswordTokenRequest()
            {
                Address = tokenEndpointUrl,
                UserName = username,
                Password = password,
                ClientId = grantClientId,
                GrantType = OidcConstants.GrantTypes.Password,
                Scope = string.Join(" ", _configuration.Scopes)
            });
        }
        
        public async Task<TokenResponse> RefreshTokensAsync(string tokenEndpointUrl, string refreshToken)
        {
            return await _httpClient.RequestRefreshTokenAsync(new RefreshTokenRequest()
            {
                Address = tokenEndpointUrl,
                ClientId = _configuration.ClientId,
                ClientSecret = _configuration.ClientSecret,
                RefreshToken = refreshToken
            });
        }
    }
}