/*
    * Copyright (C) 2017 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.ar.sfm;
  
  import com.irurueta.ar.slam.BaseCalibrationData;
  import com.irurueta.ar.slam.BaseSlamEstimator;
  import com.irurueta.geometry.InhomogeneousPoint3D;
  import com.irurueta.geometry.MetricTransformation3D;
  import com.irurueta.geometry.PinholeCamera;
  import com.irurueta.geometry.PinholeCameraIntrinsicParameters;
  import com.irurueta.geometry.Point3D;
  import com.irurueta.geometry.Quaternion;
  
  import java.util.ArrayList;
  
  /**
   * Base class in charge of estimating cameras and 3D reconstructed points from
   * sparse image point correspondences in two views and also in charge of
   * estimating overall scene scale by means of SLAM (Simultaneous Location And
   * Mapping) using data obtained from sensors like accelerometers or gyroscopes.
   *
   * @param <D> type of calibration data.
   * @param <C> type of configuration.
   * @param <R> type of re-constructor.
   * @param <L> type of listener.
   * @param <S> type of SLAM estimator.
   */
  @SuppressWarnings("DuplicatedCode")
  public abstract class BaseSlamTwoViewsSparseReconstructor<
          D extends BaseCalibrationData,
          C extends BaseSlamTwoViewsSparseReconstructorConfiguration<D, C>,
          R extends BaseSlamTwoViewsSparseReconstructor<D, C, R, L, S>,
          L extends BaseSlamTwoViewsSparseReconstructorListener<R>,
          S extends BaseSlamEstimator<D>> extends BaseTwoViewsSparseReconstructor<C, R, L> {
  
      /**
       * Slam estimator to estimate position, speed, orientation using
       * accelerometer and gyroscope data.
       */
      protected S slamEstimator;
  
      /**
       * Position estimated by means of SLAM. It is reused each time it is notified.
       */
      private final InhomogeneousPoint3D slamPosition = new InhomogeneousPoint3D();
  
      /**
       * Camera estimated by means of SLAM. It is reused each time it is notified.
       */
      private final PinholeCamera slamCamera = new PinholeCamera();
  
      /**
       * Camera rotation estimated by means of SLAM. It is reused each time it is notified.
       */
      private final Quaternion slamRotation = new Quaternion();
  
      /**
       * Constructor.
       *
       * @param configuration configuration for this re-constructor.
       * @param listener      listener in charge of handling events.
       * @throws NullPointerException if listener or configuration is not
       *                              provided.
       */
      protected BaseSlamTwoViewsSparseReconstructor(final C configuration, final L listener) {
          super(configuration, listener);
      }
  
      /**
       * Provides a new accelerometer sample to update SLAM estimation.
       * This method must be called whenever the accelerometer sensor receives new
       * data.
       * If re-constructor is not running, calling this method has no effect.
       *
       * @param timestamp     timestamp of accelerometer sample since epoch time and
       *                      expressed in nanoseconds.
       * @param accelerationX linear acceleration along x-axis expressed in meters
       *                      per squared second (m/s^2).
       * @param accelerationY linear acceleration along y-axis expressed in meters
       *                      per squared second (m/s^2).
       * @param accelerationZ linear acceleration along z-axis expressed in meters
       *                      per squared second (m/s^2).
       */
      public void updateAccelerometerSample(
              final long timestamp, final float accelerationX, final float accelerationY, final float accelerationZ) {
          if (slamEstimator != null) {
             slamEstimator.updateAccelerometerSample(timestamp, accelerationX, accelerationY, accelerationZ);
         }
     }
 
     /**
      * Provides a new accelerometer sample to update SLAM estimation.
      * This method must be called whenever the accelerometer sensor receives new
      * data.
      * If re-constructor is not running, calling this method has no effect.
      *
      * @param timestamp timestamp of accelerometer sample since epoch time and
      *                  expressed in nanoseconds.
      * @param data      array containing x,y,z components of linear acceleration
      *                  expressed in meters per squared second (m/s^2).
      * @throws IllegalArgumentException if provided array does not have length
      *                                  3.
      */
     public void updateAccelerometerSample(final long timestamp, final float[] data) {
         if (slamEstimator != null) {
             slamEstimator.updateAccelerometerSample(timestamp, data);
         }
     }
 
     /**
      * Provides a new gyroscope sample to update SLAM estimation.
      * If re-constructor is not running, calling this method has no effect.
      *
      * @param timestamp     timestamp of gyroscope sample since epoch time and
      *                      expressed in nanoseconds.
      * @param angularSpeedX angular speed of rotation along x-axis expressed in
      *                      radians per second (rad/s).
      * @param angularSpeedY angular speed of rotation along y-axis expressed in
      *                      radians per second (rad/s).
      * @param angularSpeedZ angular speed of rotation along z-axis expressed in
      *                      radians per second (rad/s).
      */
     public void updateGyroscopeSample(
             final long timestamp, final float angularSpeedX, final float angularSpeedY, final float angularSpeedZ) {
         if (slamEstimator != null) {
             slamEstimator.updateGyroscopeSample(timestamp, angularSpeedX, angularSpeedY, angularSpeedZ);
         }
     }
 
     /**
      * Provides a new gyroscope sample to update SLAM estimation.
      * If re-constructor is not running, calling this method has no effect.
      *
      * @param timestamp timestamp of gyroscope sample since epoch time and
      *                  expressed in nanoseconds.
      * @param data      angular speed of rotation along x,y,z axes expressed in
      *                  radians per second (rad/s).
      * @throws IllegalArgumentException if provided array does not have length
      *                                  3.
      */
     public void updateGyroscopeSample(final long timestamp, final float[] data) {
         if (slamEstimator != null) {
             slamEstimator.updateGyroscopeSample(timestamp, data);
         }
     }
 
     /**
      * Set ups calibration data on SLAM estimator if available.
      */
     protected void setUpCalibrationData() {
         D calibrationData = configuration.getCalibrationData();
         if (calibrationData != null) {
             slamEstimator.setCalibrationData(calibrationData);
         }
     }
 
     /**
      * Configures listener of SLAM estimator
      */
     protected void setUpSlamEstimatorListener() {
         slamEstimator.setListener(new BaseSlamEstimator.BaseSlamEstimatorListener<>() {
             @Override
             public void onFullSampleReceived(final BaseSlamEstimator<D> estimator) {
                 // not used
             }
 
             @Override
             public void onFullSampleProcessed(final BaseSlamEstimator<D> estimator) {
                 notifySlamStateAndCamera();
             }
 
             @Override
             public void onCorrectWithPositionMeasure(final BaseSlamEstimator<D> estimator) {
                 // not used
             }
 
             @Override
             public void onCorrectedWithPositionMeasure(final BaseSlamEstimator<D> estimator) {
                 notifySlamStateAndCamera();
             }
 
             private void notifySlamStateAndCamera() {
                 notifySlamStateIfNeeded();
                 notifySlamCameraIfNeeded();
             }
         });
     }
 
     /**
      * Update scene scale using SLAM data.
      *
      * @return true if scale was successfully updated, false otherwise.
      */
     protected boolean updateScale() {
         // obtain baseline (camera separation from slam estimator data
         final var posX = slamEstimator.getStatePositionX();
         final var posY = slamEstimator.getStatePositionY();
         final var posZ = slamEstimator.getStatePositionZ();
 
         // to estimate baseline, we assume that first camera is placed at
         // world origin
         final var baseline = Math.sqrt(posX * posX + posY * posY + posZ * posZ);
 
         try {
             final var camera1 = estimatedCamera1.getCamera();
             final var camera2 = estimatedCamera2.getCamera();
 
             camera1.decompose();
             camera2.decompose();
 
             final var center1 = camera1.getCameraCenter();
             final var center2 = camera2.getCameraCenter();
 
             final var estimatedBaseline = center1.distanceTo(center2);
 
             final var scale = baseline / estimatedBaseline;
 
             final var scaleTransformation = new MetricTransformation3D(scale);
 
             // update scale of cameras
             scaleTransformation.transform(camera1);
             scaleTransformation.transform(camera2);
 
             estimatedCamera1.setCamera(camera1);
             estimatedCamera2.setCamera(camera2);
 
             // update scale of reconstructed points
             final var numPoints = reconstructedPoints.size();
             final var reconstructedPoints3D = new ArrayList<Point3D>();
             for (final var reconstructedPoint : reconstructedPoints) {
                 reconstructedPoints3D.add(reconstructedPoint.getPoint());
             }
 
             scaleTransformation.transformAndOverwritePoints(reconstructedPoints3D);
 
             // set scaled points into result
             for (var i = 0; i < numPoints; i++) {
                 reconstructedPoints.get(i).setPoint(reconstructedPoints3D.get(i));
             }
 
             return true;
         } catch (final Exception e) {
             failed = true;
             //noinspection unchecked
             listener.onFail((R) this);
 
             return false;
         }
     }
 
     /**
      * Notifies SLAM state if notification is enabled at configuration time.
      */
     private void notifySlamStateIfNeeded() {
         if (!configuration.isNotifyAvailableSlamDataEnabled()) {
             return;
         }
 
         final var positionX = slamEstimator.getStatePositionX();
         final var positionY = slamEstimator.getStatePositionY();
         final var positionZ = slamEstimator.getStatePositionZ();
 
         final var velocityX = slamEstimator.getStateVelocityX();
         final var velocityY = slamEstimator.getStateVelocityY();
         final var velocityZ = slamEstimator.getStateVelocityZ();
 
         final var accelerationX = slamEstimator.getStateAccelerationX();
         final var accelerationY = slamEstimator.getStateAccelerationY();
         final var accelerationZ = slamEstimator.getStateAccelerationZ();
 
         final var quaternionA = slamEstimator.getStateQuaternionA();
         final var quaternionB = slamEstimator.getStateQuaternionB();
         final var quaternionC = slamEstimator.getStateQuaternionC();
         final var quaternionD = slamEstimator.getStateQuaternionD();
 
         final var angularSpeedX = slamEstimator.getStateAngularSpeedX();
         final var angularSpeedY = slamEstimator.getStateAngularSpeedY();
         final var angularSpeedZ = slamEstimator.getStateAngularSpeedZ();
 
         //noinspection unchecked
         listener.onSlamDataAvailable((R) this, positionX, positionY, positionZ,
                 velocityX, velocityY, velocityZ, accelerationX, accelerationY, accelerationZ,
                 quaternionA, quaternionB, quaternionC, quaternionD, angularSpeedX, angularSpeedY, angularSpeedZ,
                 slamEstimator.getStateCovariance());
     }
 
     /**
      * Notifies estimated camera by means of SLAM if notification is enabled at
      * configuration time and intrinsics are already available.
      */
     private void notifySlamCameraIfNeeded() {
         if (!configuration.isNotifyEstimatedSlamCameraEnabled()) {
             return;
         }
 
         PinholeCameraIntrinsicParameters intrinsicParameters = null;
         if (configuration.getInitialIntrinsic1() != null) {
             intrinsicParameters = configuration.getInitialIntrinsic1();
         } else if (configuration.getInitialIntrinsic2() != null) {
             intrinsicParameters = configuration.getInitialIntrinsic2();
         }
 
         if (intrinsicParameters == null) {
             return;
         }
 
         final var positionX = slamEstimator.getStatePositionX();
         final var positionY = slamEstimator.getStatePositionY();
         final var positionZ = slamEstimator.getStatePositionZ();
         slamPosition.setInhomogeneousCoordinates(positionX, positionY, positionZ);
 
         final var quaternionA = slamEstimator.getStateQuaternionA();
         final var quaternionB = slamEstimator.getStateQuaternionB();
         final var quaternionC = slamEstimator.getStateQuaternionC();
         final var quaternionD = slamEstimator.getStateQuaternionD();
         slamRotation.setA(quaternionA);
         slamRotation.setB(quaternionB);
         slamRotation.setC(quaternionC);
         slamRotation.setD(quaternionD);
 
         slamCamera.setIntrinsicAndExtrinsicParameters(intrinsicParameters, slamRotation, slamPosition);
 
         //noinspection unchecked
         listener.onSlamCameraEstimated((R) this, slamCamera);
     }
 }