/**
 * 作者： 葉應是葉
 * 時間： 2017/8/22 18:25
 * 描述：
 */
public class WifiStateView extends AppCompatImageView {

  private WifiManager wifiManager;

  private WifiHandler wifiHandler;

  //沒有開啟Wifi或開啟了Wifi但沒有連接
  private static final int LEVEL_NONE = 0;

  //Wifi信號等級（最弱）
  private static final int LEVEL_1 = 1;

  //Wifi信號等級
  private static final int LEVEL_2 = 2;

  //Wifi信號等級
  private static final int LEVEL_3 = 3;

  //Wifi信號等級（最強）
  private static final int LEVEL_4 = 4;

  private final String TAG = "WifiStateView";

  private static class WifiHandler extends Handler {

    //虛引用
    private WeakReference<WifiStateView> stateViewWeakReference;

    WifiHandler(WifiStateView wifiStateView) {
      stateViewWeakReference = new WeakReference<>(wifiStateView);
    }

    @Override
    public void handleMessage(Message msg) {
      WifiStateView wifiStateView = stateViewWeakReference.get();
      if (wifiStateView == null) {
        return;
      }
      switch (msg.what) {
        case LEVEL_1:
          wifiStateView.setImageResource(R.drawable.wifi_1);
          break;
        case LEVEL_2:
          wifiStateView.setImageResource(R.drawable.wifi_2);
          break;
        case LEVEL_3:
          wifiStateView.setImageResource(R.drawable.wifi_3);
          break;
        case LEVEL_4:
          wifiStateView.setImageResource(R.drawable.wifi_4);
          break;
        case LEVEL_NONE:
        default:
          wifiStateView.setImageResource(R.drawable.wifi_none);
          break;
      }
    }
  }

  private BroadcastReceiver wifiStateReceiver = new BroadcastReceiver() {
    @Override
    public void onReceive(Context context, Intent intent) {
      Log.e(TAG, "action " + intent.getAction());
      switch (intent.getAction()) {
        case WifiManager.WIFI_STATE_CHANGED_ACTION:
          if (wifiManager.getWifiState() == WifiManager.WIFI_STATE_DISABLING) {
            wifiHandler.sendEmptyMessage(LEVEL_NONE);
          }
          break;
        case WifiManager.RSSI_CHANGED_ACTION:
          if (wifiManager.getWifiState() == WifiManager.WIFI_STATE_DISABLED) {
            wifiHandler.sendEmptyMessage(LEVEL_NONE);
            return;
          }
          WifiInfo wifiInfo = wifiManager.getConnectionInfo();
          int level = WifiManager.calculateSignalLevel(wifiInfo.getRssi(), 5);
          Log.e(TAG, "level:" + level);
          wifiHandler.sendEmptyMessage(level);
          break;
      }
    }
  };


  public WifiStateView(Context context) {
    this(context, null);
  }

  public WifiStateView(Context context, @Nullable AttributeSet attrs) {
    this(context, attrs, 0);
  }

  public WifiStateView(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
    super(context, attrs, defStyleAttr);
    wifiManager = (WifiManager) context.getApplicationContext().getSystemService(Context.WIFI_SERVICE);
    wifiHandler = new WifiHandler(this);
  }

  @Override
  protected void onAttachedToWindow() {
    super.onAttachedToWindow();
    IntentFilter intentFilter = new IntentFilter();
    //Wifi連接狀態(tài)變化
    intentFilter.addAction(WifiManager.WIFI_STATE_CHANGED_ACTION);
    //Wifi信號強度變化
    intentFilter.addAction(WifiManager.RSSI_CHANGED_ACTION);
    getContext().registerReceiver(wifiStateReceiver, intentFilter);
  }

  @Override
  protected void onDetachedFromWindow() {
    super.onDetachedFromWindow();
    wifiHandler.removeCallbacksAndMessages(null);
    getContext().unregisterReceiver(wifiStateReceiver);
  }

}