using System;
using System.Collections.Generic;
using System.Linq;

using Microsoft.Extensions.Configuration;
using Newtonsoft.Json;
using RestSharp;

using Icarus.Models;

namespace Icarus.Controllers.Managers
{
    public class TokenManager : BaseManager
    {
        #region Fields
        private string _clientId;
        private string _clientSecret;
        private string _audience;
        private string _grantType;
        private string _url;
        #endregion


        #region Properties
        #endregion


        #region Constructors
        public TokenManager(IConfiguration config)
        {
            _config = config;
            InitializeValues();
        }
        #endregion


        #region Methods
        public LoginResult RetrieveLoginResult(User user)
        {
            _logger.Info("Preparing Auth0 API request");

            var client = new RestClient(_url);
            var request = new RestRequest("oauth/token", Method.POST);
            var tokenRequest = RetrieveTokenRequest();

            _logger.Info("Serializing token object into JSON");
            var tokenObject = JsonConvert.SerializeObject(tokenRequest);

            request.AddParameter("application/json; charset=utf-8", 
                tokenObject, ParameterType.RequestBody);

            request.RequestFormat = DataFormat.Json;

            _logger.Info("Sending request");
            IRestResponse response = client.Execute(request);
            _logger.Info("Response received");


            _logger.Info("Deserializing response");
            var tokenResult = JsonConvert
                .DeserializeObject<Token>(response.Content);
            _logger.Info("Response deserialized");

            return new LoginResult
            {
                UserID = user.UserID, Username = user.Username, Token = tokenResult.AccessToken,
                TokenType = tokenResult.TokenType, Expiration = tokenResult.Expiration,
                Message = "Successfully retrieved token"
            };
        }
        
        private TokenRequest RetrieveTokenRequest()
        {
            _logger.Info("Retrieving token object");

            return new TokenRequest
            {
                ClientId = _clientId, ClientSecret = _clientSecret,
                Audience = _audience, GrantType = _grantType
            };
        }

        private void InitializeValues()
        {
            _logger.Info("Analyzing Auth0 information");

            _clientId = _config["Auth0:ClientId"];
            _clientSecret = _config["Auth0:ClientSecret"];
            _audience = _config["Auth0:ApiIdentifier"];
            _grantType = "client_credentials";
            _url = $"https://{_config["Auth0:Domain"]}";

            PrintCredentials();
        }

        #region Testing Methods
        // For testing purposes
        private void PrintCredentials()
        {
            Console.WriteLine("Auth0 credentials:");
            Console.WriteLine($"Client Id: {_clientId}");
            Console.WriteLine($"Client Secret: {_clientSecret}");
            Console.WriteLine($"Audience: {_audience}");
            Console.WriteLine($"Url: {_url}");
        }
        #endregion
        #endregion


        #region Classes
        private class TokenRequest
        {
            [JsonProperty("client_id")]
            public string ClientId { get; set; }
            [JsonProperty("client_secret")]
            public string ClientSecret { get; set; }
            [JsonProperty("audience")]
            public string Audience { get; set; }
            [JsonProperty("grant_type")]
            public string GrantType { get; set; }
        }
        private class Token
        {
            [JsonProperty("access_token")]
            public string AccessToken { get; set; }
            [JsonProperty("expires_in")]
            public int Expiration { get; set; }
            [JsonProperty("token_type")]
            public string TokenType { get; set; }
        }
        #endregion
    }
}