/*
    * Copyright (C) 2018 Alberto Irurueta Carro (alberto@irurueta.com)
    *
    * Licensed under the Apache License, Version 2.0 (the "License");
    * you may not use this file except in compliance with the License.
    * You may obtain a copy of the License at
    *
    *         http://www.apache.org/licenses/LICENSE-2.0
    *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  package com.irurueta.navigation.indoor.radiosource;
  
  import com.irurueta.geometry.Point2D;
  import com.irurueta.navigation.indoor.Beacon;
  import com.irurueta.navigation.indoor.BeaconWithPowerAndLocated2D;
  import com.irurueta.navigation.indoor.RadioSource;
  import com.irurueta.navigation.indoor.RadioSourceLocated;
  import com.irurueta.navigation.indoor.RangingAndRssiReadingLocated;
  import com.irurueta.navigation.indoor.WifiAccessPoint;
  import com.irurueta.navigation.indoor.WifiAccessPointWithPowerAndLocated2D;
  
  import java.util.List;
  
  /**
   * Estimates 2D position, transmitted power and path loss exponent of a
   * radio source (e.g. Wi-Fi access point or bluetooth beacon) assuming
   * that the ranging data is available to obtain position with greater
   * accuracy and that the radio source emits isotropically following the
   * expression below:
   * Pr = Pt*Gt*Gr*lambda^2 / (4*pi*d)^2,
   * where Pr is the received power (expressed in mW),
   * Gt is the Gain of the transmission antenna
   * Gr is the Gain of the receiver antenna
   * d is the distance between emitter and receiver
   * and lambda is the wavelength and is equal to: lambda = c / f,
   * where c is the speed of light
   * and f is the carrier frequency of the radio signal.
   * Because usually information about the antenna of the radio source cannot be
   * retrieved (because many measurements are made on unknown devices where
   * physical access is not possible), this implementation will estimate the
   * equivalent transmitted power as: Pte = Pt * Gt * Gr.
   * If Readings contain RSSI standard deviations, those values will be used,
   * otherwise it will be assumed an RSSI standard deviation of 1 dB.
   * <p>
   * Although RssiRadioSourceEstimator can estimate the same parameters of a radio
   * source, when ranging measures are available along with RSSI measurements,
   * implementations of this class should be preferred instead as they can provide
   * greater accuracy.
   *
   * @param <S> a {@link RadioSource} type.
   */
  @SuppressWarnings("Duplicates")
  public class RangingAndRssiRadioSourceEstimator2D<S extends RadioSource> extends
          RangingAndRssiRadioSourceEstimator<S, Point2D> {
  
      /**
       * Constructor.
       */
      public RangingAndRssiRadioSourceEstimator2D() {
          super();
      }
  
      /**
       * Constructor.
       * Sets radio signal readings belonging to the same radio source.
       *
       * @param readings radio signal readings belonging to the same
       *                 radio sources.
       * @throws IllegalArgumentException if readings are not valid.
       */
      public RangingAndRssiRadioSourceEstimator2D(
              final List<? extends RangingAndRssiReadingLocated<S, Point2D>> readings) {
          super(readings);
      }
  
      /**
       * Constructor.
       *
       * @param listener listener in charge of attending events raised by this instance.
       */
      public RangingAndRssiRadioSourceEstimator2D(final RangingAndRssiRadioSourceEstimatorListener<S, Point2D> listener) {
          super(listener);
      }
  
      /**
       * Constructor.
       * Sets radio signal readings belonging to the same radio source.
       *
       * @param readings radio signal readings belonging to the same radio source.
       * @param listener listener in charge of attending events raised by this instance.
       * @throws IllegalArgumentException if readings are not valid.
       */
      public RangingAndRssiRadioSourceEstimator2D(final List<? extends RangingAndRssiReadingLocated<S, Point2D>> readings,
                                                  final RangingAndRssiRadioSourceEstimatorListener<S, Point2D> listener) {
         super(readings, listener);
     }
 
     /**
      * Constructor.
      *
      * @param initialPosition initial position to start the estimation of radio
      *                        source position.
      */
     public RangingAndRssiRadioSourceEstimator2D(final Point2D initialPosition) {
         super(initialPosition);
     }
 
     /**
      * Constructor.
      * Sets radio signal readings belonging to the same radio source.
      *
      * @param readings        radio signal readings belonging to the same radio source.
      * @param initialPosition initial position to start the estimation of radio
      *                        source position.
      * @throws IllegalArgumentException if readings are not valid.
      */
     public RangingAndRssiRadioSourceEstimator2D(
             final List<? extends RangingAndRssiReadingLocated<S, Point2D>> readings, final Point2D initialPosition) {
         super(readings, initialPosition);
     }
 
     /**
      * Constructor.
      *
      * @param initialPosition initial position to start the estimation of radio
      *                        source position.
      * @param listener        listener in charge of attending events raised by this instance.
      */
     public RangingAndRssiRadioSourceEstimator2D(
             final Point2D initialPosition, final RangingAndRssiRadioSourceEstimatorListener<S, Point2D> listener) {
         super(initialPosition, listener);
     }
 
     /**
      * Constructor.
      * Sets radio signal readings belonging to the same radio source.
      *
      * @param readings        radio signal readings belonging to the same radio source.
      * @param initialPosition initial position to start the estimation of radio
      *                        source position.
      * @param listener        listener in charge of attending events raised by this instance.
      * @throws IllegalArgumentException if readings are not valid.
      */
     public RangingAndRssiRadioSourceEstimator2D(
             final List<? extends RangingAndRssiReadingLocated<S, Point2D>> readings, final Point2D initialPosition,
             final RangingAndRssiRadioSourceEstimatorListener<S, Point2D> listener) {
         super(readings, initialPosition, listener);
     }
 
     /**
      * Constructor.
      *
      * @param initialTransmittedPowerDbm initial transmitted power to start the
      *                                   estimation of radio source transmitted power
      *                                   (expressed in dBm's).
      */
     public RangingAndRssiRadioSourceEstimator2D(final Double initialTransmittedPowerDbm) {
         super(initialTransmittedPowerDbm);
     }
 
     /**
      * Constructor.
      * Sets radio signal readings belonging to the same radio source.
      *
      * @param readings                   radio signal readings belonging to the same radio source.
      * @param initialTransmittedPowerdBm initial transmitted power to start the
      *                                   estimation of radio source transmitted power
      *                                   (expressed in dBm's).
      * @throws IllegalArgumentException if readings are not valid.
      */
     public RangingAndRssiRadioSourceEstimator2D(
             final List<? extends RangingAndRssiReadingLocated<S, Point2D>> readings,
             final Double initialTransmittedPowerdBm) {
         super(readings, initialTransmittedPowerdBm);
     }
 
     /**
      * Constructor.
      *
      * @param initialTransmittedPowerdBm initial transmitted power to start the
      *                                   estimation of radio source transmitted power
      *                                   (expressed in dBm's).
      * @param listener                   listener in charge of attending events raised by this instance.
      */
     public RangingAndRssiRadioSourceEstimator2D(
             final Double initialTransmittedPowerdBm,
             final RangingAndRssiRadioSourceEstimatorListener<S, Point2D> listener) {
         super(initialTransmittedPowerdBm, listener);
     }
 
     /**
      * Constructor.
      * Sets radio signal readings belonging to the same radio source.
      *
      * @param readings                   radio signal readings belonging to the same radio source.
      * @param initialTransmittedPowerdBm initial transmitted power to start the
      *                                   estimation of radio source transmitted power
      *                                   (expressed in dBm's).
      * @param listener                   listener in charge of attending events raised by this instance.
      * @throws IllegalArgumentException if readings are not valid.
      */
     public RangingAndRssiRadioSourceEstimator2D(
             final List<? extends RangingAndRssiReadingLocated<S, Point2D>> readings,
             final Double initialTransmittedPowerdBm,
             final RangingAndRssiRadioSourceEstimatorListener<S, Point2D> listener) {
         super(readings, initialTransmittedPowerdBm, listener);
     }
 
     /**
      * Constructor.
      * Sets radio signal readings belonging to the same radio source.
      *
      * @param readings                   radio signal readings belonging to the same radio source.
      * @param initialPosition            initial position to start the estimation of radio
      *                                   source position.
      * @param initialTransmittedPowerdBm initial transmitted power to start the
      *                                   estimation of radio source transmitted power
      *                                   (expressed in dBm's).
      * @throws IllegalArgumentException if readings are not valid.
      */
     public RangingAndRssiRadioSourceEstimator2D(
             final List<? extends RangingAndRssiReadingLocated<S, Point2D>> readings, final Point2D initialPosition,
             final Double initialTransmittedPowerdBm) {
         super(readings, initialPosition, initialTransmittedPowerdBm);
     }
 
     /**
      * Constructor.
      *
      * @param initialPosition            initial position to start the estimation of radio
      *                                   source position.
      * @param initialTransmittedPowerdBm initial transmitted power to start the
      *                                   estimation of radio source transmitted power
      *                                   (expressed in dBm's).
      */
     public RangingAndRssiRadioSourceEstimator2D(
             final Point2D initialPosition, final Double initialTransmittedPowerdBm) {
         super(initialPosition, initialTransmittedPowerdBm);
     }
 
     /**
      * Constructor.
      *
      * @param initialPosition            initial position to start the estimation of radio
      *                                   source position.
      * @param initialTransmittedPowerdBm initial transmitted power to start the
      *                                   estimation of radio source transmitted power
      *                                   (expressed in dBm's).
      * @param listener                   listener in charge of attending events raised by this instance.
      */
     public RangingAndRssiRadioSourceEstimator2D(
             final Point2D initialPosition, final Double initialTransmittedPowerdBm,
             final RangingAndRssiRadioSourceEstimatorListener<S, Point2D> listener) {
         super(initialPosition, initialTransmittedPowerdBm, listener);
     }
 
     /**
      * Constructor.
      * Sets radio signal readings belonging to the same radio source.
      *
      * @param readings                   radio signal readings belonging to the same radio source.
      * @param initialPosition            initial position to start the estimation of radio
      *                                   source position.
      * @param initialTransmittedPowerdBm initial transmitted power to start the
      *                                   estimation of radio source transmitted power
      *                                   (expressed in dBm's).
      * @param listener                   listener in charge of attending events raised by this instance.
      * @throws IllegalArgumentException if readings are not valid.
      */
     public RangingAndRssiRadioSourceEstimator2D(
             final List<? extends RangingAndRssiReadingLocated<S, Point2D>> readings, final Point2D initialPosition,
             final Double initialTransmittedPowerdBm,
             final RangingAndRssiRadioSourceEstimatorListener<S, Point2D> listener) {
         super(readings, initialPosition, initialTransmittedPowerdBm, listener);
     }
 
     /**
      * Constructor.
      * Sets radio signal readings belonging to the same radio source.
      *
      * @param readings                   radio signal readings belonging to the same radio source.
      * @param initialPosition            initial position to start the estimation of radio
      *                                   source position.
      * @param initialTransmittedPowerdBm initial transmitted power to start the
      *                                   estimation of radio source transmitted power
      *                                   (expressed in dBm's).
      * @param initialPathLossExponent    initial path loss exponent. A typical value is 2.0.
      * @throws IllegalArgumentException if readings are not valid.
      */
     public RangingAndRssiRadioSourceEstimator2D(
             final List<? extends RangingAndRssiReadingLocated<S, Point2D>> readings, final Point2D initialPosition,
             final Double initialTransmittedPowerdBm, final double initialPathLossExponent) {
         super(readings, initialPosition, initialTransmittedPowerdBm, initialPathLossExponent);
     }
 
     /**
      * Constructor.
      *
      * @param initialPosition            initial position to start the estimation of radio
      *                                   source position.
      * @param initialTransmittedPowerdBm initial transmitted power to start the
      *                                   estimation of radio source transmitted power
      *                                   (expressed in dBm's).
      * @param initialPathLossExponent    initial path loss exponent. A typical value is 2.0.
      */
     public RangingAndRssiRadioSourceEstimator2D(
             final Point2D initialPosition, final Double initialTransmittedPowerdBm,
             final double initialPathLossExponent) {
         super(initialPosition, initialTransmittedPowerdBm, initialPathLossExponent);
     }
 
     /**
      * Constructor.
      *
      * @param initialPosition            initial position to start the estimation of radio
      *                                   source position.
      * @param initialTransmittedPowerdBm initial transmitted power to start the
      *                                   estimation of radio source transmitted power
      *                                   (expressed in dBm's).
      * @param initialPathLossExponent    initial path loss exponent. A typical value is 2.0.
      * @param listener                   listener in charge of attending events raised by this instance.
      */
     public RangingAndRssiRadioSourceEstimator2D(
             final Point2D initialPosition, final Double initialTransmittedPowerdBm,
             final double initialPathLossExponent,
             final RangingAndRssiRadioSourceEstimatorListener<S, Point2D> listener) {
         super(initialPosition, initialTransmittedPowerdBm, initialPathLossExponent, listener);
     }
 
     /**
      * Constructor.
      * Sets radio signal readings belonging to the same radio source.
      *
      * @param readings                   radio signal readings belonging to the same radio source.
      * @param initialPosition            initial position to start the estimation of radio
      *                                   source position.
      * @param initialTransmittedPowerdBm initial transmitted power to start the
      *                                   estimation of radio source transmitted power
      *                                   (expressed in dBm's).
      * @param initialPathLossExponent    initial path loss exponent. A typical value is 2.0.
      * @param listener                   listener in charge of attending events raised by this instance.
      * @throws IllegalArgumentException if readings are not valid.
      */
     public RangingAndRssiRadioSourceEstimator2D(
             final List<? extends RangingAndRssiReadingLocated<S, Point2D>> readings, final Point2D initialPosition,
             final Double initialTransmittedPowerdBm, final double initialPathLossExponent,
             final RangingAndRssiRadioSourceEstimatorListener<S, Point2D> listener) {
         super(readings, initialPosition, initialTransmittedPowerdBm, initialPathLossExponent, listener);
     }
 
     /**
      * Gets number of dimensions of position points.
      * This is always 2.
      *
      * @return number of dimensions of position points.
      */
     @Override
     public int getNumberOfDimensions() {
         return Point2D.POINT2D_INHOMOGENEOUS_COORDINATES_LENGTH;
     }
 
     /**
      * Gets estimated located radio source.
      *
      * @return estimated located radio source or null.
      */
     @Override
     @SuppressWarnings("unchecked")
     public RadioSourceLocated<Point2D> getEstimatedRadioSource() {
         final var readings = getReadings();
         if (readings == null || readings.isEmpty()) {
             return null;
         }
         final var source = readings.get(0).getSource();
 
         final var estimatedPosition = getEstimatedPosition();
         if (estimatedPosition == null) {
             return null;
         }
 
         final var estimatedPositionCovariance = getEstimatedPositionCovariance();
 
         final var transmittedPowerdBm = getEstimatedTransmittedPowerdBm();
 
         final var transmittedPowerVariance = getEstimatedTransmittedPowerVariance();
         final var transmittedPowerStandardDeviation = transmittedPowerVariance != null
                 ? Math.sqrt(transmittedPowerVariance) : null;
 
         final var pathLossExponent = getEstimatedPathLossExponent();
 
         final var pathLossExponentVariance = getEstimatedPathLossExponentVariance();
         final var pathLossExponentStandardDeviation = pathLossExponentVariance != null
                 ? Math.sqrt(pathLossExponentVariance) : null;
 
         if (source instanceof WifiAccessPoint accessPoint) {
             return new WifiAccessPointWithPowerAndLocated2D(accessPoint.getBssid(), accessPoint.getFrequency(),
                     accessPoint.getSsid(), transmittedPowerdBm, transmittedPowerStandardDeviation, pathLossExponent,
                     pathLossExponentStandardDeviation, estimatedPosition, estimatedPositionCovariance);
         } else if (source instanceof Beacon beacon) {
             return new BeaconWithPowerAndLocated2D(beacon.getIdentifiers(), beacon.getTransmittedPower(),
                     beacon.getFrequency(), beacon.getBluetoothAddress(), beacon.getBeaconTypeCode(),
                     beacon.getManufacturer(), beacon.getServiceUuid(), beacon.getBluetoothName(), pathLossExponent,
                     transmittedPowerStandardDeviation, pathLossExponentStandardDeviation, estimatedPosition,
                     estimatedPositionCovariance);
         } else {
             return null;
         }
     }
 
     /**
      * Creates inner estimators if needed.
      */
     @Override
     protected void createInnerEstimatorsIfNeeded() {
         if (rangingInnerEstimator == null) {
             rangingInnerEstimator = new RangingRadioSourceEstimator2D<>();
         }
 
         if (rssiInnerEstimator == null && (transmittedPowerEstimationEnabled || pathLossEstimationEnabled)) {
             rssiInnerEstimator = new RssiRadioSourceEstimator2D<>();
         }
     }
 }