using System;
using System.Collections.Generic;
using System.Linq;
using Vinno.FIS.Sonopost.Wireless.Win32;
using Vinno.FIS.Sonopost.Wireless.Win32.Interop;
using NotifCodeACM = Vinno.FIS.Sonopost.Wireless.Win32.Interop.WlanNotificationCodeAcm;
using NotifCodeMSM = Vinno.FIS.Sonopost.Wireless.Win32.Interop.WlanNotificationCodeMsm;

namespace Vinno.FIS.Sonopost.Wireless
{
    public class Wifi
    {
        public event EventHandler<WifiStatusEventArgs> ConnectionStatusChanged;

        private WlanClient _client;
        private WifiStatus _connectionStatus;
        private bool _isConnectionStatusSet = false;
        public bool NoWifiAvailable = false;

        public Wifi()
        {
            _client = new WlanClient();
            NoWifiAvailable = _client.NoWifiAvailable;
            if (_client.NoWifiAvailable)
                return;

            foreach (var inte in _client.Interfaces)
                inte.WlanNotification += inte_WlanNotification;
        }

        /// <summary>
        /// Returns a list over all available access points
        /// </summary>
        public List<AccessPoint> GetAccessPoints(string id, bool wifiScan)
        {
            List<AccessPoint> accessPoints = new List<AccessPoint>();
            if (_client.NoWifiAvailable)
                return accessPoints;

            var wlanInterface = _client.Interfaces.FirstOrDefault(c => c.NetworkInterface.Id == id);
            if (wlanInterface == null)
            {
                return accessPoints;
            }
            if (wifiScan)
            {
                wlanInterface.Scan();//会影响网络
            }
            WlanAvailableNetwork[] rawNetworks = wlanInterface.GetAvailableNetworkList(WlanGetAvailableNetworkFlags.IncludeAllAdhocProfiles);
            List<WlanAvailableNetwork> networks = new List<WlanAvailableNetwork>();

            // Remove network entries without profile name if one exist with a profile name.
            foreach (WlanAvailableNetwork network in rawNetworks)
            {
                //屏蔽特殊wifi
                if (CheckAvailableSSID(network.dot11Ssid) == false)
                {
                    continue;
                }

                bool hasProfileName = !string.IsNullOrEmpty(network.profileName);
                bool anotherInstanceWithProfileExists = rawNetworks.Where(n => n.Equals(network) && !string.IsNullOrEmpty(n.profileName)).Any();

                if (!anotherInstanceWithProfileExists || hasProfileName)
                    networks.Add(network);
            }

            foreach (WlanAvailableNetwork network in networks)
            {
                accessPoints.Add(new AccessPoint(wlanInterface, network));
            }

            return accessPoints;
        }

        /// <summary>
        /// Disconnect all wifi interfaces
        /// </summary>
        public void Disconnect()
        {
            if (_client.NoWifiAvailable)
                return;

            foreach (WlanInterface wlanIface in _client.Interfaces)
            {
                wlanIface.Disconnect();
            }
        }

        public WifiStatus ConnectionStatus
        {
            get
            {
                if (!_isConnectionStatusSet)
                    ConnectionStatus = GetForcedConnectionStatus();

                return _connectionStatus;
            }
            private set
            {
                _isConnectionStatusSet = true;
                _connectionStatus = value;
            }
        }

        private void inte_WlanNotification(WlanNotificationData notifyData)
        {
            if (notifyData.notificationSource == WlanNotificationSource.ACM && (NotifCodeACM)notifyData.NotificationCode == NotifCodeACM.Disconnected)
                OnConnectionStatusChanged(WifiStatus.Disconnected);
            else if (notifyData.notificationSource == WlanNotificationSource.MSM && (NotifCodeMSM)notifyData.NotificationCode == NotifCodeMSM.Connected)
                OnConnectionStatusChanged(WifiStatus.Connected);
        }

        private void OnConnectionStatusChanged(WifiStatus newStatus)
        {
            ConnectionStatus = newStatus;

            if (ConnectionStatusChanged != null)
                ConnectionStatusChanged(this, new WifiStatusEventArgs(newStatus));
        }

        // I don't like this method, it's slow, ugly and should be refactored ASAP.
        private WifiStatus GetForcedConnectionStatus()
        {
            if (NoWifiAvailable)
                return WifiStatus.Disconnected;

            bool connected = false;

            foreach (var i in _client.Interfaces)
            {
                try
                {
                    var a = i.CurrentConnection; // Current connection throws an exception if disconnected.
                    connected = true;
                }
                catch { }
            }

            if (connected)
                return WifiStatus.Connected;
            else
                return WifiStatus.Disconnected;
        }

        private bool CheckAvailableSSID(Dot11Ssid ssid)
        {
            var len = ssid.SSIDLength;
            var bytes = ssid.SSID;

            for (int i = 0; i < len; i++)
            {
                if (bytes[i] != 0)
                {
                    return true;
                }
            }
            return false;
        }
    }

    public class WifiStatusEventArgs : EventArgs
    {
        public WifiStatus NewStatus { get; private set; }

        internal WifiStatusEventArgs(WifiStatus status) : base()
        {
            this.NewStatus = status;
        }
    }

    public enum WifiStatus
    {
        Disconnected,
        Connected
    }
}