/**
* This file is part of ORB-SLAM3
*
* Copyright (C) 2017-2020 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 OPTIMIZER_H
#define OPTIMIZER_H

#include "Frame.h"
#include "KeyFrame.h"
#include "LoopClosing.h"
#include "Map.h"
#include "MapPoint.h"

#include <math.h>

#include "Thirdparty/g2o/g2o/core/block_solver.h"
#include "Thirdparty/g2o/g2o/core/optimization_algorithm_gauss_newton.h"
#include "Thirdparty/g2o/g2o/core/optimization_algorithm_levenberg.h"
#include "Thirdparty/g2o/g2o/core/robust_kernel_impl.h"
#include "Thirdparty/g2o/g2o/core/sparse_block_matrix.h"
#include "Thirdparty/g2o/g2o/solvers/linear_solver_dense.h"
#include "Thirdparty/g2o/g2o/solvers/linear_solver_eigen.h"
#include "Thirdparty/g2o/g2o/types/types_seven_dof_expmap.h"
#include "Thirdparty/g2o/g2o/types/types_six_dof_expmap.h"

namespace ORB_SLAM3 {

class LoopClosing;

class Optimizer {
public:
    void static BundleAdjustment(const std::vector<KeyFrame*>& vpKF, const std::vector<MapPoint*>& vpMP,
        int nIterations = 5, bool* pbStopFlag = NULL, const unsigned long nLoopKF = 0,
        const bool bRobust = true);
    void static GlobalBundleAdjustemnt(Map* pMap, int nIterations = 5, bool* pbStopFlag = NULL,
        const unsigned long nLoopKF = 0, const bool bRobust = true);
    void static FullInertialBA(Map* pMap, int its, const bool bFixLocal = false, const unsigned long nLoopKF = 0, bool* pbStopFlag = NULL, bool bInit = false, float priorG = 1e2, float priorA = 1e6, Eigen::VectorXd* vSingVal = NULL, bool* bHess = NULL);

    void static LocalBundleAdjustment(KeyFrame* pKF, bool* pbStopFlag, vector<KeyFrame*>& vpNonEnoughOptKFs);
    void static LocalBundleAdjustment(KeyFrame* pKF, bool* pbStopFlag, Map* pMap, int& num_fixedKF);

    void static MergeBundleAdjustmentVisual(KeyFrame* pCurrentKF, vector<KeyFrame*> vpWeldingKFs, vector<KeyFrame*> vpFixedKFs, bool* pbStopFlag);

    int static PoseOptimization(Frame* pFrame);

    // TODO Semantic
    int static PoseOptimization(KeyFrame* pFrame, bool bUpdateMap);
    //myx :特征点匹配
    Eigen::Vector2d static matchFeaturePoints(KeyFrame& CurrentKeyFrame, KeyFrame& LastKeyFrame, const cv::KeyPoint& CF_kp,MapPoint* pMP);
    //myx :计算极线误差
    Eigen::Vector2d static computeEpipolarErrorAsVector(const Eigen::Vector2d &p2, const cv::Mat &F, const Eigen::Vector2d &p1);
    //myx :因子图优化
    int static PoseGraphOptimizer(KeyFrame*pLastFrame,KeyFrame* pFrame, bool bUpdateMap);

    // void static SemanticBundleAdjustment(KeyFrame* pKF, bool* pbStopFlag);
    // void static SemanticBundleAdjustment(KeyFrame* pKF);
    void static SemanticBundleAdjustment(KeyFrame* pKF, bool* pbStopFlag, Map* pMap, int& num_fixedKF);


    int static PoseInertialOptimizationLastKeyFrame(Frame* pFrame, bool bRecInit = false);
    int static PoseInertialOptimizationLastFrame(Frame* pFrame, bool bRecInit = false);

    // if bFixScale is true, 6DoF optimization (stereo,rgbd), 7DoF otherwise (mono)
    void static OptimizeEssentialGraph(Map* pMap, KeyFrame* pLoopKF, KeyFrame* pCurKF,
        const LoopClosing::KeyFrameAndPose& NonCorrectedSim3,
        const LoopClosing::KeyFrameAndPose& CorrectedSim3,
        const map<KeyFrame*, set<KeyFrame*> >& LoopConnections,
        const bool& bFixScale);
    void static OptimizeEssentialGraph6DoF(KeyFrame* pCurKF, vector<KeyFrame*>& vpFixedKFs, vector<KeyFrame*>& vpFixedCorrectedKFs,
        vector<KeyFrame*>& vpNonFixedKFs, vector<MapPoint*>& vpNonCorrectedMPs, double scale);
    void static OptimizeEssentialGraph(KeyFrame* pCurKF, vector<KeyFrame*>& vpFixedKFs, vector<KeyFrame*>& vpFixedCorrectedKFs,
        vector<KeyFrame*>& vpNonFixedKFs, vector<MapPoint*>& vpNonCorrectedMPs);
    void static OptimizeEssentialGraph(KeyFrame* pCurKF,
        const LoopClosing::KeyFrameAndPose& NonCorrectedSim3,
        const LoopClosing::KeyFrameAndPose& CorrectedSim3);
    // For inetial loopclosing
    void static OptimizeEssentialGraph4DoF(Map* pMap, KeyFrame* pLoopKF, KeyFrame* pCurKF,
        const LoopClosing::KeyFrameAndPose& NonCorrectedSim3,
        const LoopClosing::KeyFrameAndPose& CorrectedSim3,
        const map<KeyFrame*, set<KeyFrame*> >& LoopConnections);

    // if bFixScale is true, optimize SE3 (stereo,rgbd), Sim3 otherwise (mono) (OLD)
    static int OptimizeSim3(KeyFrame* pKF1, KeyFrame* pKF2, std::vector<MapPoint*>& vpMatches1,
        g2o::Sim3& g2oS12, const float th2, const bool bFixScale);
    // if bFixScale is true, optimize SE3 (stereo,rgbd), Sim3 otherwise (mono) (NEW)
    static int OptimizeSim3(KeyFrame* pKF1, KeyFrame* pKF2, std::vector<MapPoint*>& vpMatches1,
        g2o::Sim3& g2oS12, const float th2, const bool bFixScale,
        Eigen::Matrix<double, 7, 7>& mAcumHessian, const bool bAllPoints = false);
    static int OptimizeSim3(KeyFrame* pKF1, KeyFrame* pKF2, vector<MapPoint*>& vpMatches1, vector<KeyFrame*>& vpMatches1KF,
        g2o::Sim3& g2oS12, const float th2, const bool bFixScale, Eigen::Matrix<double, 7, 7>& mAcumHessian,
        const bool bAllPoints = false);

    // For inertial systems

    void static LocalInertialBA(KeyFrame* pKF, bool* pbStopFlag, Map* pMap, bool bLarge = false, bool bRecInit = false);

    void static MergeInertialBA(KeyFrame* pCurrKF, KeyFrame* pMergeKF, bool* pbStopFlag, Map* pMap, LoopClosing::KeyFrameAndPose& corrPoses);

    // Local BA in welding area when two maps are merged
    void static LocalBundleAdjustment(KeyFrame* pMainKF, vector<KeyFrame*> vpAdjustKF, vector<KeyFrame*> vpFixedKF, bool* pbStopFlag);

    // Marginalize block element (start:end,start:end). Perform Schur complement.
    // Marginalized elements are filled with zeros.
    static Eigen::MatrixXd Marginalize(const Eigen::MatrixXd& H, const int& start, const int& end);
    // Condition block element (start:end,start:end). Fill with zeros.
    static Eigen::MatrixXd Condition(const Eigen::MatrixXd& H, const int& start, const int& end);
    // Remove link between element 1 and 2. Given elements 1,2 and 3 must define the whole matrix.
    static Eigen::MatrixXd Sparsify(const Eigen::MatrixXd& H, const int& start1, const int& end1, const int& start2, const int& end2);

    // Inertial pose-graph
    void static InertialOptimization(Map* pMap, Eigen::Matrix3d& Rwg, double& scale, Eigen::Vector3d& bg, Eigen::Vector3d& ba, bool bMono, Eigen::MatrixXd& covInertial, bool bFixedVel = false, bool bGauss = false, float priorG = 1e2, float priorA = 1e6);
    void static InertialOptimization(Map* pMap, Eigen::Vector3d& bg, Eigen::Vector3d& ba, float priorG = 1e2, float priorA = 1e6);
    void static InertialOptimization(vector<KeyFrame*> vpKFs, Eigen::Vector3d& bg, Eigen::Vector3d& ba, float priorG = 1e2, float priorA = 1e6);
    void static InertialOptimization(Map* pMap, Eigen::Matrix3d& Rwg, double& scale);
};

} //namespace ORB_SLAM3

#endif // OPTIMIZER_H