using System;
using System.Collections.Generic;
using ln.http.resources.session;
using ln.logging;
using ln.types.threads;
using ln.types;
using ln.http.listener;
using ln.http.connections;
using ln.types.net;
using ln.http.cert;
using System.Globalization;
using System.Net.Sockets;


namespace ln.http
{
    public class HTTPServer
    {
        public static int backlog = 5;
        public static int defaultPort = 8080;
        public static bool exclusivePortListener = false;

        public HttpApplication DefaultApplication { get; set; }
        public SessionCache SessionCache { get; set; }

        public bool IsRunning => !shutdown && (threadPool.CurrentPoolSize > 0);
        public Func<HTTPServer,HTTPServerConnection> CreateServerConnection { get; set; }

        public Logger Logger { get; set; }
        bool shutdown = false;

        List<Listener> listeners = new List<Listener>();
        public Listener[] Listeners => listeners.ToArray();

        Dictionary<URI, HttpApplication> applications = new Dictionary<URI, HttpApplication>();

        DynamicPool threadPool;
        public DynamicPool ThreadPool => threadPool;

        public HTTPServer()
        {
            Logger = Logger.Default;

            SessionCache = new SessionCache();
            threadPool = new DynamicPool(1024);
        }

        public void AddListener(Listener listener)
        {
            listeners.Add(listener);
            if (IsRunning)
                StartListener(listener);
        }

        public void StartListener(Listener listener)
        {
            listener.Open();

            threadPool.Enqueue(
                () => listener.AcceptMany(
                    (connection) => threadPool.Enqueue(
                        () => this.HandleConnection(connection)
                    )
                )
            );
        }

        public void StopListener(Listener listener)
        {
            listener.Close();
        }


        public void AddEndpoint(Endpoint endpoint)
        {
            AddListener(new HttpListener(endpoint));
        }

        public void AddApplication(URI BaseURI, HttpApplication application)
        {
            applications[BaseURI] = application;
        }

        public HttpApplication GetHttpApplication(URI baseURI)
        {
            HttpApplication application = DefaultApplication;

            if (applications.ContainsKey(baseURI))
                application = applications[baseURI];

            return application;
        }


        public void Start()
        {
            threadPool.Start();

            foreach (Listener listener in listeners)
                StartListener(listener);
        }

        public void Stop()
        {
            lock (this)
            {
                this.shutdown = true;
            }
            foreach (Listener listener in listeners)
                StopListener(listener);

            threadPool.Stop(true);
        }

        private void HandleConnection(Connection connection)
        {
            HttpRequest httpRequest = null;
            bool keepAlive = true;
            try
            {
                do
                {
                    httpRequest = connection.ReadRequest(this);
                    if (httpRequest == null)
                        break;

                    httpRequest.ApplySession(SessionCache);

                    HttpApplication application = GetHttpApplication(new URI(httpRequest.BaseURI.ToString()));

                    application.Authenticate(httpRequest);
                    application.Authorize(httpRequest);

                    HttpResponse response = application.GetResponse(httpRequest);

                    keepAlive = httpRequest.GetRequestHeader("connection","keep-alive").Equals("keep-alive") && response.GetHeader("connection", "keep-alive").Equals("keep-alive");
                    response.SetHeader("connection", keepAlive ? "keep-alive" : "close");

                    connection.SendResponse(response);

                } while (keepAlive);
            }
            catch (Exception e)
            {
                Logging.Log(e);
                if (httpRequest != null)
                {
                    HttpResponse httpResponse = new HttpResponse(httpRequest);
                    httpResponse.StatusCode = 500;
                    httpResponse.ContentWriter.WriteLine("500 Internal Server Error");

                    connection.SendResponse(httpResponse);
                }
            }

            connection.GetStream().Close();
        }

        public void Log(DateTime startTime,double duration,HttpRequest httpRequest,HttpResponse httpResponse)
        {
            Logger.Log(LogLevel.INFO, "{0} {1} {2} {3}",startTime.ToString("yyyyMMdd-HH:mm:ss"),duration.ToString(CultureInfo.InvariantCulture),httpRequest.Hostname,httpRequest.RequestURL);
        }

    }
}