using System;
using Android.Content;
using Android.Net.Wifi;

namespace Shared.Net
{
    public class WifiUtil
    {
        /*
        * 切换到指定wifi
        * @param wifiName  指定的wifi名字
        * @param wifiPwd   wifi密码，如果已经保存过密码，可以传入null
        * @return
        */
        public void ConnectToWifi (Action<bool> action, string wifiName, string wifiPwd = null)
        {
            bool result = false;
            try {
                string tempWifiName = "\"" + wifiName + "\"";
                // 如果wifi权限没打开（1、先打开wifi，2，使用指定的wifi
                if (!mWifiManager.IsWifiEnabled) {
                    if (!mWifiManager.SetWifiEnabled (true)) {
                        return;
                    }
                }
                var wifiList = mWifiManager.ConfiguredNetworks;
                var bFindInList = false;
                for (int i = 0; i < wifiList.Count; i++) {
                    var wifiInfo0 = wifiList [i];
                    // 先找到对应的wifi
                    if (tempWifiName == (wifiInfo0.Ssid) || wifiName == (wifiInfo0.Ssid)) {
                        bFindInList = true;
                        // 1、 先启动，可能已经输入过密码，可以直接启动
                        result = doChange2Wifi (wifiInfo0.NetworkId);
                    }
                }
                // 2、如果wifi还没有输入过密码，尝试输入密码，启动wifi
                if (!bFindInList) {
                    var wifiNewConfiguration = createWifiInfo (wifiName, wifiPwd);//使用wpa2的wifi加密方式
                    int newNetworkId = mWifiManager.AddNetwork (wifiNewConfiguration);
                    if (newNetworkId == -1) {
                        //Log.e (TAG, "操作失败,需要您到手机wifi列表中取消对设备连接的保存");
                    } else {
                        result = doChange2Wifi (newNetworkId);
                    }
                }
            } catch { } finally {
                if (action != null)
                    action (result);
            }
        }

        bool doChange2Wifi (int newNetworkId)
        {
            var enableNetwork = mWifiManager.EnableNetwork (newNetworkId, true);
            if (!enableNetwork) {
                //"切换到指定wifi失败";
                return false;
            } else {
                // "切换到指定wifi成功";
                return true;
            }
        }

         /*
         * 创建 WifiConfiguration，这里创建的是wpa2加密方式的wifi
         * @param ssid     wifi账号
         * @param password wifi密码
         * @return
         */
        WifiConfiguration createWifiInfo (string ssid, string password)
        {
            var config = new WifiConfiguration ();
            config.AllowedAuthAlgorithms.Clear ();
            config.AllowedGroupCiphers.Clear ();
            config.AllowedKeyManagement.Clear ();
            config.AllowedPairwiseCiphers.Clear ();
            config.AllowedProtocols.Clear ();
            config.Ssid = "\"" + ssid + "\"";
            config.PreSharedKey = "\"" + password + "\"";
            config.AllowedAuthAlgorithms.Set ((int)WifiConfiguration.AuthAlgorithm.Open);
            config.AllowedGroupCiphers.Set ((int)WifiConfiguration.GroupCipher.Tkip);
            config.AllowedGroupCiphers.Set ((int)WifiConfiguration.GroupCipher.Ccmp);
            config.AllowedKeyManagement.Set ((int)WifiConfiguration.KeyMgmt.WpaPsk);
            config.AllowedPairwiseCiphers.Set ((int)WifiConfiguration.PairwiseCipher.Tkip);
            config.AllowedPairwiseCiphers.Set ((int)WifiConfiguration.PairwiseCipher.Ccmp);
            config.AllowedProtocols.Set ((int)WifiConfiguration.Protocol.Rsn);
            config.AllowedProtocols.Set ((int)WifiConfiguration.Protocol.Wpa);
            config.StatusField = WifiStatus.Enabled;
            return config;
        }

        WifiManager mWifiManager;

        // 单例
        static WifiUtil ourInstance = new WifiUtil ();

        public static WifiUtil Instance {
            get {
                if (ourInstance.mWifiManager == null) {
                    ourInstance.mWifiManager = (WifiManager)Shared.Application.Activity.GetSystemService (Context.WifiService);
                }
                return ourInstance;
            }
        }
    }
}