/**
* This file is part of ORB-SLAM3
*
* Copyright (C) 2017-2021 Carlos Campos, Richard Elvira, Juan J. Gómez Rodríguez, José M.M. Montiel and Juan D. Tardós, University of Zaragoza.
* Copyright (C) 2014-2016 Raúl Mur-Artal, José M.M. Montiel and Juan D. Tardós, University of Zaragoza.
*
* ORB-SLAM3 is free software: you can redistribute it and/or modify it under the terms of the GNU General Public
* License as published by the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* ORB-SLAM3 is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even
* the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along with ORB-SLAM3.
* If not, see <http://www.gnu.org/licenses/>.
*/

#ifndef G2OTYPES_H
#define G2OTYPES_H

#include "Thirdparty/g2o/g2o/core/base_vertex.h"
#include "Thirdparty/g2o/g2o/core/base_binary_edge.h"
#include "Thirdparty/g2o/g2o/types/types_sba.h"
#include "Thirdparty/g2o/g2o/core/base_multi_edge.h"
#include "Thirdparty/g2o/g2o/core/base_unary_edge.h"

#include<opencv2/core/core.hpp>

#include <Eigen/Core>
#include <Eigen/Geometry>
#include <Eigen/Dense>

#include <Frame.h>
#include <KeyFrame.h>

#include"Converter.h"
#include <math.h>

namespace ORB_SLAM3
{

class KeyFrame;
class Frame;
class GeometricCamera;

typedef Eigen::Matrix<double, 6, 1> Vector6d;
typedef Eigen::Matrix<double, 9, 1> Vector9d;
typedef Eigen::Matrix<double, 12, 1> Vector12d;
typedef Eigen::Matrix<double, 15, 1> Vector15d;
typedef Eigen::Matrix<double, 12, 12> Matrix12d;
typedef Eigen::Matrix<double, 15, 15> Matrix15d;
typedef Eigen::Matrix<double, 9, 9> Matrix9d;

Eigen::Matrix3d ExpSO3(const double x, const double y, const double z);
Eigen::Matrix3d ExpSO3(const Eigen::Vector3d &w);

Eigen::Vector3d LogSO3(const Eigen::Matrix3d &R);

Eigen::Matrix3d InverseRightJacobianSO3(const Eigen::Vector3d &v);
Eigen::Matrix3d RightJacobianSO3(const Eigen::Vector3d &v);
Eigen::Matrix3d RightJacobianSO3(const double x, const double y, const double z);

Eigen::Matrix3d Skew(const Eigen::Vector3d &w);
Eigen::Matrix3d InverseRightJacobianSO3(const double x, const double y, const double z);

template<typename T = double>
Eigen::Matrix<T,3,3> NormalizeRotation(const Eigen::Matrix<T,3,3> &R) {
    Eigen::JacobiSVD<Eigen::Matrix<T,3,3>> svd(R,Eigen::ComputeFullU | Eigen::ComputeFullV);
    return svd.matrixU() * svd.matrixV().transpose();
}


class ImuCamPose
{
public:
    EIGEN_MAKE_ALIGNED_OPERATOR_NEW
    ImuCamPose(){}
    ImuCamPose(KeyFrame* pKF);
    ImuCamPose(Frame* pF);
    ImuCamPose(Eigen::Matrix3d &_Rwc, Eigen::Vector3d &_twc, KeyFrame* pKF);

    void SetParam(const std::vector<Eigen::Matrix3d> &_Rcw, const std::vector<Eigen::Vector3d> &_tcw, const std::vector<Eigen::Matrix3d> &_Rbc,
                  const std::vector<Eigen::Vector3d> &_tbc, const double &_bf);

    void Update(const double *pu); // update in the imu reference
    void UpdateW(const double *pu); // update in the world reference
    Eigen::Vector2d Project(const Eigen::Vector3d &Xw, int cam_idx=0) const; // Mono
    Eigen::Vector3d ProjectStereo(const Eigen::Vector3d &Xw, int cam_idx=0) const; // Stereo
    bool isDepthPositive(const Eigen::Vector3d &Xw, int cam_idx=0) const;

public:
    // For IMU
    Eigen::Matrix3d Rwb;
    Eigen::Vector3d twb;

    // For set of cameras
    std::vector<Eigen::Matrix3d> Rcw;
    std::vector<Eigen::Vector3d> tcw;
    std::vector<Eigen::Matrix3d> Rcb, Rbc;
    std::vector<Eigen::Vector3d> tcb, tbc;
    double bf;
    std::vector<GeometricCamera*> pCamera;

    // For posegraph 4DoF
    Eigen::Matrix3d Rwb0;
    Eigen::Matrix3d DR;

    int its;
};

class InvDepthPoint
{
public:
    EIGEN_MAKE_ALIGNED_OPERATOR_NEW
    InvDepthPoint(){}
    InvDepthPoint(double _rho, double _u, double _v, KeyFrame* pHostKF);

    void Update(const double *pu);

    double rho;
    double u, v; // they are not variables, observation in the host frame

    double fx, fy, cx, cy, bf; // from host frame

    int its;
};

// Optimizable parameters are IMU pose
class VertexPose : public g2o::BaseVertex<6,ImuCamPose>
{
public:
    EIGEN_MAKE_ALIGNED_OPERATOR_NEW
    VertexPose(){}
    VertexPose(KeyFrame* pKF){
        setEstimate(ImuCamPose(pKF));
    }
    VertexPose(Frame* pF){
        setEstimate(ImuCamPose(pF));
    }


    virtual bool read(std::istream& is);
    virtual bool write(std::ostream& os) const;

    virtual void setToOriginImpl() {
        }

    virtual void oplusImpl(const double* update_){
        _estimate.Update(update_);
        updateCache();
    }
};

class VertexPose4DoF : public g2o::BaseVertex<4,ImuCamPose>
{
    // Translation and yaw are the only optimizable variables
public:
    EIGEN_MAKE_ALIGNED_OPERATOR_NEW
    VertexPose4DoF(){}
    VertexPose4DoF(KeyFrame* pKF){
        setEstimate(ImuCamPose(pKF));
    }
    VertexPose4DoF(Frame* pF){
        setEstimate(ImuCamPose(pF));
    }
    VertexPose4DoF(Eigen::Matrix3d &_Rwc, Eigen::Vector3d &_twc, KeyFrame* pKF){

        setEstimate(ImuCamPose(_Rwc, _twc, pKF));
    }

    virtual bool read(std::istream& is){return false;}
    virtual bool write(std::ostream& os) const{return false;}

    virtual void setToOriginImpl() {
        }

    virtual void oplusImpl(const double* update_){
        double update6DoF[6];
        update6DoF[0] = 0;
        update6DoF[1] = 0;
        update6DoF[2] = update_[0];
        update6DoF[3] = update_[1];
        update6DoF[4] = update_[2];
        update6DoF[5] = update_[3];
        _estimate.UpdateW(update6DoF);
        updateCache();
    }
};

class VertexVelocity : public g2o::BaseVertex<3,Eigen::Vector3d>
{
public:
    EIGEN_MAKE_ALIGNED_OPERATOR_NEW
    VertexVelocity(){}
    VertexVelocity(KeyFrame* pKF);
    VertexVelocity(Frame* pF);

    virtual bool read(std::istream& is){return false;}
    virtual bool write(std::ostream& os) const{return false;}

    virtual void setToOriginImpl() {
        }

    virtual void oplusImpl(const double* update_){
        Eigen::Vector3d uv;
        uv << update_[0], update_[1], update_[2];
        setEstimate(estimate()+uv);
    }
};

class VertexGyroBias : public g2o::BaseVertex<3,Eigen::Vector3d>
{
public:
    EIGEN_MAKE_ALIGNED_OPERATOR_NEW
    VertexGyroBias(){}
    VertexGyroBias(KeyFrame* pKF);
    VertexGyroBias(Frame* pF);

    virtual bool read(std::istream& is){return false;}
    virtual bool write(std::ostream& os) const{return false;}

    virtual void setToOriginImpl() {
        }

    virtual void oplusImpl(const double* update_){
        Eigen::Vector3d ubg;
        ubg << update_[0], update_[1], update_[2];
        setEstimate(estimate()+ubg);
    }
};


class VertexAccBias : public g2o::BaseVertex<3,Eigen::Vector3d>
{
public:
    EIGEN_MAKE_ALIGNED_OPERATOR_NEW
    VertexAccBias(){}
    VertexAccBias(KeyFrame* pKF);
    VertexAccBias(Frame* pF);

    virtual bool read(std::istream& is){return false;}
    virtual bool write(std::ostream& os) const{return false;}

    virtual void setToOriginImpl() {
        }

    virtual void oplusImpl(const double* update_){
        Eigen::Vector3d uba;
        uba << update_[0], update_[1], update_[2];
        setEstimate(estimate()+uba);
    }
};


// Gravity direction vertex
class GDirection
{
public:
    EIGEN_MAKE_ALIGNED_OPERATOR_NEW
    GDirection(){}
    GDirection(Eigen::Matrix3d pRwg): Rwg(pRwg){}

    void Update(const double *pu)
    {
        Rwg=Rwg*ExpSO3(pu[0],pu[1],0.0);
    }

    Eigen::Matrix3d Rwg, Rgw;

    int its;
};

class VertexGDir : public g2o::BaseVertex<2,GDirection>
{
public:
    EIGEN_MAKE_ALIGNED_OPERATOR_NEW
    VertexGDir(){}
    VertexGDir(Eigen::Matrix3d pRwg){
        setEstimate(GDirection(pRwg));
    }

    virtual bool read(std::istream& is){return false;}
    virtual bool write(std::ostream& os) const{return false;}

    virtual void setToOriginImpl() {
        }

    virtual void oplusImpl(const double* update_){
        _estimate.Update(update_);
        updateCache();
    }
};

// scale vertex
class VertexScale : public g2o::BaseVertex<1,double>
{
public:
    EIGEN_MAKE_ALIGNED_OPERATOR_NEW
    VertexScale(){
        setEstimate(1.0);
    }
    VertexScale(double ps){
        setEstimate(ps);
    }

    virtual bool read(std::istream& is){return false;}
    virtual bool write(std::ostream& os) const{return false;}

    virtual void setToOriginImpl(){
        setEstimate(1.0);
    }

    virtual void oplusImpl(const double *update_){
        setEstimate(estimate()*exp(*update_));
    }
};


// Inverse depth point (just one parameter, inverse depth at the host frame)
class VertexInvDepth : public g2o::BaseVertex<1,InvDepthPoint>
{
public:
    EIGEN_MAKE_ALIGNED_OPERATOR_NEW
    VertexInvDepth(){}
    VertexInvDepth(double invDepth, double u, double v, KeyFrame* pHostKF){
        setEstimate(InvDepthPoint(invDepth, u, v, pHostKF));
    }

    virtual bool read(std::istream& is){return false;}
    virtual bool write(std::ostream& os) const{return false;}

    virtual void setToOriginImpl() {
        }

    virtual void oplusImpl(const double* update_){
        _estimate.Update(update_);
        updateCache();
    }
};

class EdgeMono : public g2o::BaseBinaryEdge<2,Eigen::Vector2d,g2o::VertexSBAPointXYZ,VertexPose>
{
public:
    EIGEN_MAKE_ALIGNED_OPERATOR_NEW

    EdgeMono(int cam_idx_=0): cam_idx(cam_idx_){
    }

    virtual bool read(std::istream& is){return false;}
    virtual bool write(std::ostream& os) const{return false;}

    void computeError(){
        const g2o::VertexSBAPointXYZ* VPoint = static_cast<const g2o::VertexSBAPointXYZ*>(_vertices[0]);
        const VertexPose* VPose = static_cast<const VertexPose*>(_vertices[1]);
        const Eigen::Vector2d obs(_measurement);
        _error = obs - VPose->estimate().Project(VPoint->estimate(),cam_idx);
    }


    virtual void linearizeOplus();

    bool isDepthPositive()
    {
        const g2o::VertexSBAPointXYZ* VPoint = static_cast<const g2o::VertexSBAPointXYZ*>(_vertices[0]);
        const VertexPose* VPose = static_cast<const VertexPose*>(_vertices[1]);
        return VPose->estimate().isDepthPositive(VPoint->estimate(),cam_idx);
    }

    Eigen::Matrix<double,2,9> GetJacobian(){
        linearizeOplus();
        Eigen::Matrix<double,2,9> J;
        J.block<2,3>(0,0) = _jacobianOplusXi;
        J.block<2,6>(0,3) = _jacobianOplusXj;
        return J;
    }

    Eigen::Matrix<double,9,9> GetHessian(){
        linearizeOplus();
        Eigen::Matrix<double,2,9> J;
        J.block<2,3>(0,0) = _jacobianOplusXi;
        J.block<2,6>(0,3) = _jacobianOplusXj;
        return J.transpose()*information()*J;
    }

public:
    const int cam_idx;
};

class EdgeMonoOnlyPose : public g2o::BaseUnaryEdge<2,Eigen::Vector2d,VertexPose>
{
public:
    EIGEN_MAKE_ALIGNED_OPERATOR_NEW

    EdgeMonoOnlyPose(const Eigen::Vector3f &Xw_, int cam_idx_=0):Xw(Xw_.cast<double>()),
        cam_idx(cam_idx_){}

    virtual bool read(std::istream& is){return false;}
    virtual bool write(std::ostream& os) const{return false;}

    void computeError(){
        const VertexPose* VPose = static_cast<const VertexPose*>(_vertices[0]);
        const Eigen::Vector2d obs(_measurement);
        _error = obs - VPose->estimate().Project(Xw,cam_idx);
    }

    virtual void linearizeOplus();

    bool isDepthPositive()
    {
        const VertexPose* VPose = static_cast<const VertexPose*>(_vertices[0]);
        return VPose->estimate().isDepthPositive(Xw,cam_idx);
    }

    Eigen::Matrix<double,6,6> GetHessian(){
        linearizeOplus();
        return _jacobianOplusXi.transpose()*information()*_jacobianOplusXi;
    }

public:
    const Eigen::Vector3d Xw;
    const int cam_idx;
};

class EdgeStereo : public g2o::BaseBinaryEdge<3,Eigen::Vector3d,g2o::VertexSBAPointXYZ,VertexPose>
{
public:
    EIGEN_MAKE_ALIGNED_OPERATOR_NEW

    EdgeStereo(int cam_idx_=0): cam_idx(cam_idx_){}

    virtual bool read(std::istream& is){return false;}
    virtual bool write(std::ostream& os) const{return false;}

    void computeError(){
        const g2o::VertexSBAPointXYZ* VPoint = static_cast<const g2o::VertexSBAPointXYZ*>(_vertices[0]);
        const VertexPose* VPose = static_cast<const VertexPose*>(_vertices[1]);
        const Eigen::Vector3d obs(_measurement);
        _error = obs - VPose->estimate().ProjectStereo(VPoint->estimate(),cam_idx);
    }


    virtual void linearizeOplus();

    Eigen::Matrix<double,3,9> GetJacobian(){
        linearizeOplus();
        Eigen::Matrix<double,3,9> J;
        J.block<3,3>(0,0) = _jacobianOplusXi;
        J.block<3,6>(0,3) = _jacobianOplusXj;
        return J;
    }

    Eigen::Matrix<double,9,9> GetHessian(){
        linearizeOplus();
        Eigen::Matrix<double,3,9> J;
        J.block<3,3>(0,0) = _jacobianOplusXi;
        J.block<3,6>(0,3) = _jacobianOplusXj;
        return J.transpose()*information()*J;
    }

public:
    const int cam_idx;
};


class EdgeStereoOnlyPose : public g2o::BaseUnaryEdge<3,Eigen::Vector3d,VertexPose>
{
public:
    EIGEN_MAKE_ALIGNED_OPERATOR_NEW

    EdgeStereoOnlyPose(const Eigen::Vector3f &Xw_, int cam_idx_=0):
        Xw(Xw_.cast<double>()), cam_idx(cam_idx_){}

    virtual bool read(std::istream& is){return false;}
    virtual bool write(std::ostream& os) const{return false;}

    void computeError(){
        const VertexPose* VPose = static_cast<const VertexPose*>(_vertices[0]);
        const Eigen::Vector3d obs(_measurement);
        _error = obs - VPose->estimate().ProjectStereo(Xw, cam_idx);
    }

    virtual void linearizeOplus();

    Eigen::Matrix<double,6,6> GetHessian(){
        linearizeOplus();
        return _jacobianOplusXi.transpose()*information()*_jacobianOplusXi;
    }

public:
    const Eigen::Vector3d Xw; // 3D point coordinates
    const int cam_idx;
};

class EdgeInertial : public g2o::BaseMultiEdge<9,Vector9d>
{
public:
    EIGEN_MAKE_ALIGNED_OPERATOR_NEW

    EdgeInertial(IMU::Preintegrated* pInt);

    virtual bool read(std::istream& is){return false;}
    virtual bool write(std::ostream& os) const{return false;}

    void computeError();
    virtual void linearizeOplus();

    Eigen::Matrix<double,24,24> GetHessian(){
        linearizeOplus();
        Eigen::Matrix<double,9,24> J;
        J.block<9,6>(0,0) = _jacobianOplus[0];
        J.block<9,3>(0,6) = _jacobianOplus[1];
        J.block<9,3>(0,9) = _jacobianOplus[2];
        J.block<9,3>(0,12) = _jacobianOplus[3];
        J.block<9,6>(0,15) = _jacobianOplus[4];
        J.block<9,3>(0,21) = _jacobianOplus[5];
        return J.transpose()*information()*J;
    }

    Eigen::Matrix<double,18,18> GetHessianNoPose1(){
        linearizeOplus();
        Eigen::Matrix<double,9,18> J;
        J.block<9,3>(0,0) = _jacobianOplus[1];
        J.block<9,3>(0,3) = _jacobianOplus[2];
        J.block<9,3>(0,6) = _jacobianOplus[3];
        J.block<9,6>(0,9) = _jacobianOplus[4];
        J.block<9,3>(0,15) = _jacobianOplus[5];
        return J.transpose()*information()*J;
    }

    Eigen::Matrix<double,9,9> GetHessian2(){
        linearizeOplus();
        Eigen::Matrix<double,9,9> J;
        J.block<9,6>(0,0) = _jacobianOplus[4];
        J.block<9,3>(0,6) = _jacobianOplus[5];
        return J.transpose()*information()*J;
    }

    const Eigen::Matrix3d JRg, JVg, JPg;
    const Eigen::Matrix3d JVa, JPa;
    IMU::Preintegrated* mpInt;
    const double dt;
    Eigen::Vector3d g;
};


// Edge inertial whre gravity is included as optimizable variable and it is not supposed to be pointing in -z axis, as well as scale
class EdgeInertialGS : public g2o::BaseMultiEdge<9,Vector9d>
{
public:
    EIGEN_MAKE_ALIGNED_OPERATOR_NEW

    // EdgeInertialGS(IMU::Preintegrated* pInt);
    EdgeInertialGS(IMU::Preintegrated* pInt);

    virtual bool read(std::istream& is){return false;}
    virtual bool write(std::ostream& os) const{return false;}

    void computeError();
    virtual void linearizeOplus();

    const Eigen::Matrix3d JRg, JVg, JPg;
    const Eigen::Matrix3d JVa, JPa;
    IMU::Preintegrated* mpInt;
    const double dt;
    Eigen::Vector3d g, gI;

    Eigen::Matrix<double,27,27> GetHessian(){
        linearizeOplus();
        Eigen::Matrix<double,9,27> J;
        J.block<9,6>(0,0) = _jacobianOplus[0];
        J.block<9,3>(0,6) = _jacobianOplus[1];
        J.block<9,3>(0,9) = _jacobianOplus[2];
        J.block<9,3>(0,12) = _jacobianOplus[3];
        J.block<9,6>(0,15) = _jacobianOplus[4];
        J.block<9,3>(0,21) = _jacobianOplus[5];
        J.block<9,2>(0,24) = _jacobianOplus[6];
        J.block<9,1>(0,26) = _jacobianOplus[7];
        return J.transpose()*information()*J;
    }

    Eigen::Matrix<double,27,27> GetHessian2(){
        linearizeOplus();
        Eigen::Matrix<double,9,27> J;
        J.block<9,3>(0,0) = _jacobianOplus[2];
        J.block<9,3>(0,3) = _jacobianOplus[3];
        J.block<9,2>(0,6) = _jacobianOplus[6];
        J.block<9,1>(0,8) = _jacobianOplus[7];
        J.block<9,3>(0,9) = _jacobianOplus[1];
        J.block<9,3>(0,12) = _jacobianOplus[5];
        J.block<9,6>(0,15) = _jacobianOplus[0];
        J.block<9,6>(0,21) = _jacobianOplus[4];
        return J.transpose()*information()*J;
    }

    Eigen::Matrix<double,9,9> GetHessian3(){
        linearizeOplus();
        Eigen::Matrix<double,9,9> J;
        J.block<9,3>(0,0) = _jacobianOplus[2];
        J.block<9,3>(0,3) = _jacobianOplus[3];
        J.block<9,2>(0,6) = _jacobianOplus[6];
        J.block<9,1>(0,8) = _jacobianOplus[7];
        return J.transpose()*information()*J;
    }



    Eigen::Matrix<double,1,1> GetHessianScale(){
        linearizeOplus();
        Eigen::Matrix<double,9,1> J = _jacobianOplus[7];
        return J.transpose()*information()*J;
    }

    Eigen::Matrix<double,3,3> GetHessianBiasGyro(){
        linearizeOplus();
        Eigen::Matrix<double,9,3> J = _jacobianOplus[2];
        return J.transpose()*information()*J;
    }

    Eigen::Matrix<double,3,3> GetHessianBiasAcc(){
        linearizeOplus();
        Eigen::Matrix<double,9,3> J = _jacobianOplus[3];
        return J.transpose()*information()*J;
    }

    Eigen::Matrix<double,2,2> GetHessianGDir(){
        linearizeOplus();
        Eigen::Matrix<double,9,2> J = _jacobianOplus[6];
        return J.transpose()*information()*J;
    }
};



class EdgeGyroRW : public g2o::BaseBinaryEdge<3,Eigen::Vector3d,VertexGyroBias,VertexGyroBias>
{
public:
    EIGEN_MAKE_ALIGNED_OPERATOR_NEW

    EdgeGyroRW(){}

    virtual bool read(std::istream& is){return false;}
    virtual bool write(std::ostream& os) const{return false;}

    void computeError(){
        const VertexGyroBias* VG1= static_cast<const VertexGyroBias*>(_vertices[0]);
        const VertexGyroBias* VG2= static_cast<const VertexGyroBias*>(_vertices[1]);
        _error = VG2->estimate()-VG1->estimate();
    }

    virtual void linearizeOplus(){
        _jacobianOplusXi = -Eigen::Matrix3d::Identity();
        _jacobianOplusXj.setIdentity();
    }

    Eigen::Matrix<double,6,6> GetHessian(){
        linearizeOplus();
        Eigen::Matrix<double,3,6> J;
        J.block<3,3>(0,0) = _jacobianOplusXi;
        J.block<3,3>(0,3) = _jacobianOplusXj;
        return J.transpose()*information()*J;
    }

    Eigen::Matrix3d GetHessian2(){
        linearizeOplus();
        return _jacobianOplusXj.transpose()*information()*_jacobianOplusXj;
    }
};


class EdgeAccRW : public g2o::BaseBinaryEdge<3,Eigen::Vector3d,VertexAccBias,VertexAccBias>
{
public:
    EIGEN_MAKE_ALIGNED_OPERATOR_NEW

    EdgeAccRW(){}

    virtual bool read(std::istream& is){return false;}
    virtual bool write(std::ostream& os) const{return false;}

    void computeError(){
        const VertexAccBias* VA1= static_cast<const VertexAccBias*>(_vertices[0]);
        const VertexAccBias* VA2= static_cast<const VertexAccBias*>(_vertices[1]);
        _error = VA2->estimate()-VA1->estimate();
    }

    virtual void linearizeOplus(){
        _jacobianOplusXi = -Eigen::Matrix3d::Identity();
        _jacobianOplusXj.setIdentity();
    }

    Eigen::Matrix<double,6,6> GetHessian(){
        linearizeOplus();
        Eigen::Matrix<double,3,6> J;
        J.block<3,3>(0,0) = _jacobianOplusXi;
        J.block<3,3>(0,3) = _jacobianOplusXj;
        return J.transpose()*information()*J;
    }

    Eigen::Matrix3d GetHessian2(){
        linearizeOplus();
        return _jacobianOplusXj.transpose()*information()*_jacobianOplusXj;
    }
};

class ConstraintPoseImu
{
public:
    EIGEN_MAKE_ALIGNED_OPERATOR_NEW

    ConstraintPoseImu(const Eigen::Matrix3d &Rwb_, const Eigen::Vector3d &twb_, const Eigen::Vector3d &vwb_,
                       const Eigen::Vector3d &bg_, const Eigen::Vector3d &ba_, const Matrix15d &H_):
                       Rwb(Rwb_), twb(twb_), vwb(vwb_), bg(bg_), ba(ba_), H(H_)
    {
        H = (H+H)/2;
        Eigen::SelfAdjointEigenSolver<Eigen::Matrix<double,15,15> > es(H);
        Eigen::Matrix<double,15,1> eigs = es.eigenvalues();
        for(int i=0;i<15;i++)
            if(eigs[i]<1e-12)
                eigs[i]=0;
        H = es.eigenvectors()*eigs.asDiagonal()*es.eigenvectors().transpose();
    }

    Eigen::Matrix3d Rwb;
    Eigen::Vector3d twb;
    Eigen::Vector3d vwb;
    Eigen::Vector3d bg;
    Eigen::Vector3d ba;
    Matrix15d H;
};

class EdgePriorPoseImu : public g2o::BaseMultiEdge<15,Vector15d>
{
public:
        EIGEN_MAKE_ALIGNED_OPERATOR_NEW
        EdgePriorPoseImu(ConstraintPoseImu* c);

        virtual bool read(std::istream& is){return false;}
        virtual bool write(std::ostream& os) const{return false;}

        void computeError();
        virtual void linearizeOplus();

        Eigen::Matrix<double,15,15> GetHessian(){
            linearizeOplus();
            Eigen::Matrix<double,15,15> J;
            J.block<15,6>(0,0) = _jacobianOplus[0];
            J.block<15,3>(0,6) = _jacobianOplus[1];
            J.block<15,3>(0,9) = _jacobianOplus[2];
            J.block<15,3>(0,12) = _jacobianOplus[3];
            return J.transpose()*information()*J;
        }

        Eigen::Matrix<double,9,9> GetHessianNoPose(){
            linearizeOplus();
            Eigen::Matrix<double,15,9> J;
            J.block<15,3>(0,0) = _jacobianOplus[1];
            J.block<15,3>(0,3) = _jacobianOplus[2];
            J.block<15,3>(0,6) = _jacobianOplus[3];
            return J.transpose()*information()*J;
        }
        Eigen::Matrix3d Rwb;
        Eigen::Vector3d twb, vwb;
        Eigen::Vector3d bg, ba;
};

// Priors for biases
class EdgePriorAcc : public g2o::BaseUnaryEdge<3,Eigen::Vector3d,VertexAccBias>
{
public:
    EIGEN_MAKE_ALIGNED_OPERATOR_NEW

    EdgePriorAcc(const Eigen::Vector3f &bprior_):bprior(bprior_.cast<double>()){}

    virtual bool read(std::istream& is){return false;}
    virtual bool write(std::ostream& os) const{return false;}

    void computeError(){
        const VertexAccBias* VA = static_cast<const VertexAccBias*>(_vertices[0]);
        _error = bprior - VA->estimate();
    }
    virtual void linearizeOplus();

    Eigen::Matrix<double,3,3> GetHessian(){
        linearizeOplus();
        return _jacobianOplusXi.transpose()*information()*_jacobianOplusXi;
    }

    const Eigen::Vector3d bprior;
};

class EdgePriorGyro : public g2o::BaseUnaryEdge<3,Eigen::Vector3d,VertexGyroBias>
{
public:
    EIGEN_MAKE_ALIGNED_OPERATOR_NEW

    EdgePriorGyro(const Eigen::Vector3f &bprior_):bprior(bprior_.cast<double>()){}

    virtual bool read(std::istream& is){return false;}
    virtual bool write(std::ostream& os) const{return false;}

    void computeError(){
        const VertexGyroBias* VG = static_cast<const VertexGyroBias*>(_vertices[0]);
        _error = bprior - VG->estimate();
    }
    virtual void linearizeOplus();

    Eigen::Matrix<double,3,3> GetHessian(){
        linearizeOplus();
        return _jacobianOplusXi.transpose()*information()*_jacobianOplusXi;
    }

    const Eigen::Vector3d bprior;
};


class Edge4DoF : public g2o::BaseBinaryEdge<6,Vector6d,VertexPose4DoF,VertexPose4DoF>
{
public:
    EIGEN_MAKE_ALIGNED_OPERATOR_NEW

    Edge4DoF(const Eigen::Matrix4d &deltaT){
        dTij = deltaT;
        dRij = deltaT.block<3,3>(0,0);
        dtij = deltaT.block<3,1>(0,3);
    }

    virtual bool read(std::istream& is){return false;}
    virtual bool write(std::ostream& os) const{return false;}

    void computeError(){
        const VertexPose4DoF* VPi = static_cast<const VertexPose4DoF*>(_vertices[0]);
        const VertexPose4DoF* VPj = static_cast<const VertexPose4DoF*>(_vertices[1]);
        _error << LogSO3(VPi->estimate().Rcw[0]*VPj->estimate().Rcw[0].transpose()*dRij.transpose()),
                 VPi->estimate().Rcw[0]*(-VPj->estimate().Rcw[0].transpose()*VPj->estimate().tcw[0])+VPi->estimate().tcw[0] - dtij;
    }

    // virtual void linearizeOplus(); // numerical implementation

    Eigen::Matrix4d dTij;
    Eigen::Matrix3d dRij;
    Eigen::Vector3d dtij;
};

} //namespace ORB_SLAM2

#endif // G2OTYPES_H