using System;
using System.Diagnostics;
using System.Text;
using System.Threading;
using SpotifyAPI.Web.Enums;
using SpotifyAPI.Web.Models;

namespace SpotifyAPI.Web.Auth
{
    public class ImplicitGrantAuth
    {
        public delegate void OnResponseReceived(Token token, String state);

        private SimpleHttpServer _httpServer;
        private Thread _httpThread;
        public String ClientId { get; set; }
        public String RedirectUri { get; set; }
        public String State { get; set; }
        public Scope Scope { get; set; }
        public Boolean ShowDialog { get; set; }
        public event OnResponseReceived OnResponseReceivedEvent;

        /// <summary>
        ///     Start the auth process (Make sure the internal HTTP-Server ist started)
        /// </summary>
        public void DoAuth()
        {
            String uri = GetUri();
            Process.Start(uri);
        }

        private String GetUri()
        {
            StringBuilder builder = new StringBuilder("https://accounts.spotify.com/authorize/?");
            builder.Append("client_id=" + ClientId);
            builder.Append("&response_type=token");
            builder.Append("&redirect_uri=" + RedirectUri);
            builder.Append("&state=" + State);
            builder.Append("&scope=" + Scope.GetStringAttribute(" "));
            builder.Append("&show_dialog=" + ShowDialog);
            return builder.ToString();
        }

        /// <summary>
        ///     Start the internal HTTP-Server
        /// </summary>
        public void StartHttpServer(int port = 80)
        {
            _httpServer = new SimpleHttpServer(port, AuthType.Implicit);
            _httpServer.OnAuth += HttpServerOnOnAuth;

            _httpThread = new Thread(_httpServer.Listen);
            _httpThread.Start();
        }

        private void HttpServerOnOnAuth(AuthEventArgs e)
        {
            if (OnResponseReceivedEvent != null)
                OnResponseReceivedEvent(new Token
                {
                    AccessToken = e.Code,
                    TokenType = e.TokenType,
                    ExpiresIn = e.ExpiresIn,
                    Error = e.Error
                }, e.State);
        }

        /// <summary>
        ///     This will stop the internal HTTP-Server (Should be called after you got the Token)
        /// </summary>
        public void StopHttpServer()
        {
            _httpServer.Dispose();
            _httpServer = null;
        }
    }
}