using System;
using System.Collections;
using System.Collections.Generic;
using System.Net;
using System.Security.Cryptography.X509Certificates;
using MediaBrowser.Model.Cryptography;
using MediaBrowser.Model.IO;
using MediaBrowser.Model.Net;
using MediaBrowser.Model.System;
using Microsoft.Extensions.Logging;

namespace SocketHttpListener.Net
{
    public sealed class HttpListener : IDisposable
    {
        internal ICryptoProvider CryptoProvider { get; private set; }
        internal ISocketFactory SocketFactory { get; private set; }
        internal IFileSystem FileSystem { get; private set; }
        internal IStreamHelper StreamHelper { get; private set; }
        internal IEnvironmentInfo EnvironmentInfo { get; private set; }

        public bool EnableDualMode { get; set; }

        private AuthenticationSchemes auth_schemes;
        private HttpListenerPrefixCollection prefixes;
        private AuthenticationSchemeSelector auth_selector;
        private string realm;
        private bool unsafe_ntlm_auth;
        private bool listening;
        private bool disposed;

        private Dictionary<HttpListenerContext, HttpListenerContext> registry;
        private Dictionary<HttpConnection, HttpConnection> connections;
        private ILogger _logger;
        private X509Certificate _certificate;

        public Action<HttpListenerContext> OnContext { get; set; }

        public HttpListener(
            ILogger logger,
            ICryptoProvider cryptoProvider,
            ISocketFactory socketFactory,
            IStreamHelper streamHelper,
            IFileSystem fileSystem,
            IEnvironmentInfo environmentInfo)
        {
            _logger = logger;
            CryptoProvider = cryptoProvider;
            SocketFactory = socketFactory;
            StreamHelper = streamHelper;
            FileSystem = fileSystem;
            EnvironmentInfo = environmentInfo;

            prefixes = new HttpListenerPrefixCollection(logger, this);
            registry = new Dictionary<HttpListenerContext, HttpListenerContext>();
            connections = new Dictionary<HttpConnection, HttpConnection>();
            auth_schemes = AuthenticationSchemes.Anonymous;
        }

        public HttpListener(
            ILogger logger,
            X509Certificate certificate,
            ICryptoProvider cryptoProvider,
            ISocketFactory socketFactory,
            IStreamHelper streamHelper,
            IFileSystem fileSystem,
            IEnvironmentInfo environmentInfo)
            : this(logger, cryptoProvider, socketFactory, streamHelper, fileSystem, environmentInfo)
        {
            _certificate = certificate;
        }

        public void LoadCert(X509Certificate cert)
        {
            _certificate = cert;
        }

        // TODO: Digest, NTLM and Negotiate require ControlPrincipal
        public AuthenticationSchemes AuthenticationSchemes
        {
            get => auth_schemes;
            set
            {
                CheckDisposed();
                auth_schemes = value;
            }
        }

        public AuthenticationSchemeSelector AuthenticationSchemeSelectorDelegate
        {
            get => auth_selector;
            set
            {
                CheckDisposed();
                auth_selector = value;
            }
        }

        public bool IsListening => listening;

        public static bool IsSupported => true;

        public HttpListenerPrefixCollection Prefixes
        {
            get
            {
                CheckDisposed();
                return prefixes;
            }
        }

        // TODO: use this
        public string Realm
        {
            get => realm;
            set
            {
                CheckDisposed();
                realm = value;
            }
        }

        public bool UnsafeConnectionNtlmAuthentication
        {
            get => unsafe_ntlm_auth;
            set
            {
                CheckDisposed();
                unsafe_ntlm_auth = value;
            }
        }

        //internal IMonoSslStream CreateSslStream(Stream innerStream, bool ownsStream, MSI.MonoRemoteCertificateValidationCallback callback)
        //{
        //    lock (registry)
        //    {
        //        if (tlsProvider == null)
        //            tlsProvider = MonoTlsProviderFactory.GetProviderInternal();
        //        if (tlsSettings == null)
        //            tlsSettings = MSI.MonoTlsSettings.CopyDefaultSettings();
        //        if (tlsSettings.RemoteCertificateValidationCallback == null)
        //            tlsSettings.RemoteCertificateValidationCallback = callback;
        //        return tlsProvider.CreateSslStream(innerStream, ownsStream, tlsSettings);
        //    }
        //}

        internal X509Certificate Certificate => _certificate;

        public void Abort()
        {
            if (disposed)
                return;

            if (!listening)
            {
                return;
            }

            Close(true);
        }

        public void Close()
        {
            if (disposed)
                return;

            if (!listening)
            {
                disposed = true;
                return;
            }

            Close(true);
            disposed = true;
        }

        void Close(bool force)
        {
            CheckDisposed();
            HttpEndPointManager.RemoveListener(_logger, this);
            Cleanup(force);
        }

        void Cleanup(bool close_existing)
        {
            lock (registry)
            {
                if (close_existing)
                {
                    // Need to copy this since closing will call UnregisterContext
                    ICollection keys = registry.Keys;
                    var all = new HttpListenerContext[keys.Count];
                    keys.CopyTo(all, 0);
                    registry.Clear();
                    for (int i = all.Length - 1; i >= 0; i--)
                        all[i].Connection.Close(true);
                }

                lock (connections)
                {
                    ICollection keys = connections.Keys;
                    var conns = new HttpConnection[keys.Count];
                    keys.CopyTo(conns, 0);
                    connections.Clear();
                    for (int i = conns.Length - 1; i >= 0; i--)
                        conns[i].Close(true);
                }
            }
        }

        internal AuthenticationSchemes SelectAuthenticationScheme(HttpListenerContext context)
        {
            if (AuthenticationSchemeSelectorDelegate != null)
                return AuthenticationSchemeSelectorDelegate(context.Request);
            else
                return auth_schemes;
        }

        public void Start()
        {
            CheckDisposed();
            if (listening)
                return;

            HttpEndPointManager.AddListener(_logger, this);
            listening = true;
        }

        public void Stop()
        {
            CheckDisposed();
            listening = false;
            Close(false);
        }

        void IDisposable.Dispose()
        {
            if (disposed)
                return;

            Close(true); //TODO: Should we force here or not?
            disposed = true;
        }

        internal void CheckDisposed()
        {
            if (disposed)
                throw new ObjectDisposedException(GetType().Name);
        }

        internal void RegisterContext(HttpListenerContext context)
        {
            if (OnContext != null && IsListening)
            {
                OnContext(context);
            }

            lock (registry)
                registry[context] = context;
        }

        internal void UnregisterContext(HttpListenerContext context)
        {
            lock (registry)
                registry.Remove(context);
        }

        internal void AddConnection(HttpConnection cnc)
        {
            lock (connections)
            {
                connections[cnc] = cnc;
            }
        }

        internal void RemoveConnection(HttpConnection cnc)
        {
            lock (connections)
            {
                connections.Remove(cnc);
            }
        }
    }
}