using System;
using System.Collections.Generic;
using System.Net.Http;
using System.Threading.Tasks;
using Newtonsoft.Json;

namespace ConsoleResourceOwnerFlowRefreshToken
{
    public class Program
    {
        public static void Main(string[] args) => MainAsync().GetAwaiter().GetResult();

        private static async Task MainAsync()
        {
            string tokenEndpoint = null;
            while (tokenEndpoint == null)
            {
                Console.Clear();
                Console.WriteLine("Get TokenEndpoint");
                try
                {
                    tokenEndpoint = await GetTokenEndpointUri("https://localhost:5000/.well-known/openid-configuration");
                }
                catch (Exception e)
                {
                    Console.WriteLine();
                    Console.WriteLine($"Error: {e}");
                    Console.WriteLine();
                    Console.WriteLine("Press q to quit or any other key to retry");
                    if (char.ToLower(Console.ReadKey().KeyChar) == 'q')
                        return;
                    tokenEndpoint = null;
                }
            }
            var tokenRequest = new TokenRequest
            {
                TokenEndppointUri = tokenEndpoint,
                Scopes = new[] { "openid", "c1s_api", "roles" },
                ClientIdentifier = "anyClient",
                ClientSecret = "anySecret",
                Username = "someUserName",
                Password = "someUserPassword"
            };
            do
            {
                Console.Clear();
                try
                {
                    Console.WriteLine($"Token-Endpoint: {tokenEndpoint}");
                    Console.WriteLine();
                    var token = await GetToken(tokenRequest);
                    Console.WriteLine(token ?? "null");
                }
                catch (Exception e)
                {
                    Console.WriteLine($"Error: {e}");
                }
                Console.WriteLine();
                Console.WriteLine("Press q to quit or any other key to renew token");
            } while (char.ToLower(Console.ReadKey().KeyChar) != 'q');
        }

        private static async Task<string> GetToken(TokenRequest tokenRequest)
        {
            using (var httpClient = new HttpClient())
            {
                //Use Client-Identifier / Client-Secret for Basic-Authentication
                httpClient.DefaultRequestHeaders.Authorization = new BasicAuthenticationHeaderValue(tokenRequest.ClientIdentifier, tokenRequest.ClientSecret);
				
                //Create a POST request to the token-endpoint with data in FormUrlEncoded format
                var tokenResponse = await httpClient.PostAsync(tokenRequest.TokenEndppointUri, new FormUrlEncodedContent(new Dictionary<string, string>
                {
                    {"grant_type" , "password"},
                    {"username", tokenRequest.Username },
                    {"password", tokenRequest.Password },
                    {"scope",  string.Join(" ", tokenRequest.Scopes)}
                }));
                //return the property access_token from POST-Response
                var tokenResponseDoc = await tokenResponse.Content.ReadAsStringAsync();
                var tokenElement = (dynamic)JsonConvert.DeserializeObject(tokenResponseDoc);
                return (string)tokenElement.access_token;
            }
        }

        private static async Task<string> GetTokenEndpointUri(string discoUri)
        {
            using (var httpClient = new HttpClient())
            {
                //Create a simple GET-Request to the Discovery-Uri
                var discoDoc = await httpClient.GetStringAsync(discoUri);
                //return the property token_endpoint from GET-Response
                var discoElement = (dynamic)JsonConvert.DeserializeObject(discoDoc);
                return (string)discoElement.token_endpoint;
            }
        }
    }
	
	public class TokenRequest
    {
        public string TokenEndppointUri { get; set; }
        public string ClientIdentifier { get; set; }
        public string ClientSecret { get; set; }
        public string Username { get; set; }
        public string Password { get; set; }
        public string[] Scopes { get; set; }
    }
}