/*
 * =====================================================================================
 *
 *       Filename:  state.cpp
 *
 *    Description:  A Class for managing body and features.
 *
 *        Version:  1.0
 *        Created:  03/17/2017 07:55:56 PM
 *       Revision:  none
 *       Compiler:  gcc
 *
 *         Author:  Martin Miller (MHM), miller7@illinois.edu
 *   Organization:  Aerospace Robotics and Controls Lab (ARC)
 *
 * =====================================================================================
 */
#include "state.h"

State::State ( )
{
    body = new Body;
    P = Matrix<double,Dynamic,Dynamic>::Zero(9,9);
    P.block(6,6,3,3) = 1e-6*Matrix3d::Identity();
    return ;
}		/* -----  end of method State::State  ----- */

void
State::vel ( const Matrix<double,3,1> &v )
{
    body->vel(v);
    return ;
}		/* -----  end of method State::vel  ----- */

void
State::enu ( const UTM &utm )
{
    utm_c = utm.zone_c;
    utm_i = utm.zone_i;
    body->enu(utm);
    return ;
}		/* -----  end of method State::enu  ----- */

void 
State::update ( const Matrix<double,1,1> &z )
{
    Matrix<double,1,9> H;
    H=body->H();
    Matrix<double,1,1> S;
    S=body->S(P);
    Matrix<double,9,1> K;
    K = P*H.transpose()*S.inverse();
    P = (Matrix<double,9,9>::Identity()-K*H)*P;
    P = 0.5*(P+P.transpose());
    Matrix<double,9,1> dx;
    Matrix<double,1,1> h;
    h = body->h();
    dx = K*(z-h);
    body->update(dx);
}

void
State::feature_update ( const std::vector<measurement_t> &z, const Quaterniond &q)
{
    std::vector<measurement_t> featuresToAdd;
    for (auto i=z.begin(); i!=z.end(); ++i) {
        if (exists(i->id)) {
            ;
        } else {
            featuresToAdd.push_back(*i);
        }
    }
    addFeatures( featuresToAdd, q);

    return ;
}		/* -----  end of method State::feature_update  ----- */

void
State::addFeatures ( std::vector<measurement_t> &F, const Quaterniond &q)
{
    // Expand P matrix all at once
    expandP(F.size());
    //
    // Add new features
    for (auto i=F.begin(); i!=F.end(); ++i) {
        // Estimate initial depth
        Vector3d xib;

        // Create feature
        Feature *f = new Feature(i->id, i->source, i->reflection, body->ned(), q, -0.44);
        features.push_back(f);
        
        // Initialize P values
        int j=features.size();
        Matrix<double,3,3> Pi;
        Pi = f->P0();
        initializePi(j,Pi);
    }
    return ;
}		/* -----  end of method State::addFeatures  ----- */

/*
 *--------------------------------------------------------------------------------------
 *       Class:  State
 *      Method:  State :: initializePi
 * Description:  Zeros out the off-diagonal blocks and sets the Pii block to Pi.
 *--------------------------------------------------------------------------------------
 */
    void
State::initializePi ( int i, const Matrix<double,3,3> &Pi )
{
    int pt=9+3*(i-1);
    std::cout << pt << std::endl;
    std::cout << P.cols() << std::endl;
    P.block(pt,0,3,P.cols()) = MatrixXd::Zero(3,P.cols());
    P.block(0,pt,P.rows(),3) = MatrixXd::Zero(P.rows(),3);
    P.block<3,3>(pt,pt) = Pi;

    return ;
}		/* -----  end of method State::initializePi  ----- */

/*
 *--------------------------------------------------------------------------------------
 *       Class:  State
 *      Method:  State :: Q
 * Description:  Compose full Q from body and features.
 *--------------------------------------------------------------------------------------
 */
MatrixXd
State::Q ( double dt )
{
    MatrixXd q;
    int rows = 9 + 3*features.size();
    q = MatrixXd::Zero(rows,rows);
    q.topLeftCorner<9,9>() = body->Q(dt);
    { // limit i's scope
        auto i = features.begin();
        for (int row=9; row<rows; row+=3, ++i) {
            q.block<3,3>(row,row) = (*i)->Q(dt);
        }
    }
    return q;
}		/* -----  end of method State::q  ----- */

/*
 *--------------------------------------------------------------------------------------
 *       Class:  State
 *      Method:  State :: F
 * Description:  Compose full F from body and features
 *--------------------------------------------------------------------------------------
 */
MatrixXd
State::F ( const Quaterniond &q, const Vector3d &w, double dt )
{
    Vector3d v;
    v = body->vel();
    // Allocate matrix F
    MatrixXd f;
    int rows = 9 + 3*features.size();
    f = MatrixXd::Zero(rows,rows);

    // Set body F
    f.topLeftCorner<9,9>() = body->F(w,q,dt);
    // Set Fxi Fyi
    { // limit i's scope
        auto i = features.begin();
        for (int row=9; row<rows; row+=3,++i) {
            f.block<3,9>(row,0) = (*i)->Fx(dt);
            f.block<3,3>(row,row) = (*i)->Fy(v,w,dt);
        }
    }

    return f ;
}		/* -----  end of method State::F  ----- */

/*
 *--------------------------------------------------------------------------------------
 *       Class:  State
 *      Method:  State :: Pkk1
 * Description:  Updates P_k|k-1
 *--------------------------------------------------------------------------------------
 */
void
State::Pkk1 ( const Vector3d &ang, const Quaterniond &q, const double dt)
{
    MatrixXd f,fullQ;
    fullQ = Q(dt);
    f = F ( q, ang, dt );
    P = f*P*f.transpose()+fullQ;
    // Enforce symmetry
    P = 0.5*(P+P.transpose());
    return ;
}		/* -----  end of method State::Pkk1  ----- */

void
State::motionModel ( const Vector3d &acc, const Vector3d &ang,
    const Quaterniond &q, const double dt)
{
    Pkk1(ang,q,dt);
    body->motionModel(acc,ang,q,dt);
    return ;
}		/* -----  end of method State::motionModel  ----- */

void
State::position_covariance ( const Matrix<double,3,3> &p )
{
    P.block(0,0,3,3) = p;
    return ;
}		/* -----  end of method State::position_covariance  ----- */

void
State::velocity_covariance ( const Matrix<double,3,3> &p )
{
    P.block(3,3,3,3) = p;
    return ;
}		/* -----  end of method State::velocity_covariance  ----- */

void
State::unicsv ( )
{
    body->unicsv();
    return ;
}		/* -----  end of method State::unicsv  ----- */

void
State::accelerometer_bias ( const Vector3d &b)
{
    body->accelerometer_bias(b);
    return ;
}		/* -----  end of method State::accelerometer_bias  ----- */

/*
 *--------------------------------------------------------------------------------------
 *       Class:  State
 *      Method:  State :: exists
 * Description:  Tests if the id is a current feature.
 *--------------------------------------------------------------------------------------
 */
bool
State::exists ( int id )
{
    for (auto i=features.begin(); i!=features.end(); ++i) {
        if ((*i)->id()==id) return true;
    }
    return false;
}		/* -----  end of method State::exists  ----- */

/*
 *--------------------------------------------------------------------------------------
 *       Class:  State
 *      Method:  State :: expandP
 * Description:  Grows P so that Nnew new features can be added. This could mean
 * explicitly resizing the P matrix or P being a block of a preallocated matrix.
 *--------------------------------------------------------------------------------------
 */
void
State::expandP ( int Nnew )
{
    int curRows, newRows;
    curRows = P.rows();
    newRows = curRows + 3*Nnew;
    P.conservativeResize(newRows,newRows);
    return ;
}		/* -----  end of method State::expandP  ----- */