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

#include "cvtools.h"

#ifndef M_PI
    #define M_PI 3.14159265358979323846
#endif

static unsigned int nStepsPrimary = 32; // number of shifts/steps in primary
static unsigned int nStepsSecondary = 16; // number of shifts/steps in secondary
static unsigned int nStepsTertiary = 16; // number of shifts/steps in tertiary
static float nPeriodPrimary = 256; // number of primary periods
static float nPeriodSecondary = 16; // number of secondary periods

// Algorithm
static cv::Mat computePhaseVector(unsigned int length, float phase, float pitch){

    cv::Mat phaseVector(length, 1, CV_8UC3);
    //phaseVector.setTo(0);

    const float pi = M_PI;

    // Loop through vector
    for(int i=0; i<phaseVector.rows; i++){
        // Amplitude of channels
        float amp = 0.5*(1+cos(2*pi*i/pitch - phase));
        phaseVector.at<cv::Vec3b>(i, 0) = cv::Vec3b(255.0*amp, 255.0*amp, 255.0*amp);
    }

    return phaseVector;
}

AlgorithmPhaseShiftThreeFreq::AlgorithmPhaseShiftThreeFreq(unsigned int _screenCols, unsigned int _screenRows) : Algorithm(_screenCols, _screenRows){

    // Set N
    N = 2+nStepsPrimary+nStepsSecondary+nStepsTertiary;

    // all on pattern
    cv::Mat allOn(1, screenCols, CV_8UC3, cv::Scalar::all(255));
    patterns.push_back(allOn);

    // all off pattern
    cv::Mat allOff(1, screenCols, CV_8UC3, cv::Scalar::all(0));
    patterns.push_back(allOff);

    // Precompute encoded patterns
    const float pi = M_PI;

    // Primary encoding patterns
    for(unsigned int i=0; i<nStepsPrimary; i++){
        float phase = 2.0*pi/nStepsPrimary * i;
        float pitch = screenCols/nPeriodPrimary;
        cv::Mat patternI(1,1,CV_8U);
        patternI = computePhaseVector(screenCols, phase, pitch);
        patterns.push_back(patternI.t());
    }

    // Secondary encoding patterns
    for(unsigned int i=0; i<nStepsSecondary; i++){
        float phase = 2.0*pi/nStepsSecondary * i;
        float pitch = screenCols/nPeriodSecondary;
        cv::Mat patternI(1,1,CV_8U);
        patternI = computePhaseVector(screenCols, phase, pitch);
        patterns.push_back(patternI.t());
    }
    // Tertiary encoding patterns
    for(unsigned int i=0; i<nStepsTertiary; i++){
        float phase = 2.0*pi/nStepsTertiary * i;
        float pitch = screenCols;
        cv::Mat patternI(1,1,CV_8U);
        patternI = computePhaseVector(screenCols, phase, pitch);
        patterns.push_back(patternI.t());
    }

}

cv::Mat AlgorithmPhaseShiftThreeFreq::getEncodingPattern(unsigned int depth){
    return patterns[depth];
}


//// Absolute phase from 3 frames
//static cv::Mat getPhase(const cv::Mat I1, const cv::Mat I2, const cv::Mat I3){

//    cv::Mat_<float> I1_(I1);
//    cv::Mat_<float> I2_(I2);
//    cv::Mat_<float> I3_(I3);

//    cv::Mat phase;

//    // One call approach
//    cv::phase(2.0*I1_-I3_-I2_, sqrt(3.0)*(I2_-I3_), phase);
//    return phase;

//}

// Phase unwrapping by means of a phase cue
static cv::Mat unwrapWithCue(const cv::Mat up, const cv::Mat upCue, float nPhases){

    const float pi = M_PI;

    // Determine number of jumps
    cv::Mat P = (upCue*nPhases-up)/(2.0*pi);

    // Round to integers
    P.convertTo(P, CV_8U);
    P.convertTo(P, CV_32F);

    // Add to phase
    cv::Mat upUnwrapped = up + P*2*pi;

    // Scale to range [0; 2pi]
    upUnwrapped *= 1.0/nPhases;

    return upUnwrapped;
}

// Absolute phase and magnitude from N frames
static std::vector<cv::Mat> getDFTComponents(const std::vector<cv::Mat> frames){

    unsigned int N = frames.size();

//    std::vector<cv::Mat> framesReverse = frames;
//    std::reverse(framesReverse.begin(), framesReverse.end());

    // DFT approach
    cv::Mat I;
    cv::merge(frames, I);
    unsigned int w = I.cols;
    unsigned int h = I.rows;
    I = I.reshape(1, h*w);
    I.convertTo(I, CV_32F);
    cv::Mat fI;
    cv::dft(I, fI, cv::DFT_ROWS + cv::DFT_COMPLEX_OUTPUT);
    fI = fI.reshape(N*2, h);

    std::vector<cv::Mat> fIcomp;
    cv::split(fI, fIcomp);

    return fIcomp;

}

void AlgorithmPhaseShiftThreeFreq::get3DPoints(SMCalibrationParameters calibration, const std::vector<cv::Mat>& frames0, const std::vector<cv::Mat>& frames1, std::vector<cv::Point3f>& Q, std::vector<cv::Vec3b>& color){

    const float pi = M_PI;

    assert(frames0.size() == N);
    assert(frames1.size() == N);

    int frameRows = frames0[0].rows;
    int frameCols = frames0[0].cols;

    // Rectifying homographies (rotation+projections)
    cv::Size frameSize(frameCols, frameRows);
    cv::Mat R, T;
    // stereoRectify segfaults unless R is double precision
    cv::Mat(calibration.R1).convertTo(R, CV_64F);
    cv::Mat(calibration.T1).convertTo(T, CV_64F);
    cv::Mat R0, R1, P0, P1, QRect;
    cv::stereoRectify(calibration.K0, calibration.k0, calibration.K1, calibration.k1, frameSize, R, T, R0, R1, P0, P1, QRect, 0);

    // Interpolation maps (lens distortion and rectification)
    cv::Mat map0X, map0Y, map1X, map1Y;
    cv::initUndistortRectifyMap(calibration.K0, calibration.k0, R0, P0, frameSize, CV_32F, map0X, map0Y);
    cv::initUndistortRectifyMap(calibration.K1, calibration.k1, R1, P1, frameSize, CV_32F, map1X, map1Y);


    // Gray-scale and remap
    std::vector<cv::Mat> frames0Rect(N);
    std::vector<cv::Mat> frames1Rect(N);
    for(unsigned int i=0; i<N; i++){
        cv::Mat temp;
        cv::cvtColor(frames0[i], temp, CV_BayerBG2GRAY);
        cv::remap(temp, frames0Rect[i], map0X, map0Y, CV_INTER_LINEAR);
        cv::cvtColor(frames1[i], temp, CV_BayerBG2GRAY);
        cv::remap(temp, frames1Rect[i], map1X, map1Y, CV_INTER_LINEAR);
    }

    // Decode camera0
    std::vector<cv::Mat> frames0Primary(frames0Rect.begin()+2, frames0Rect.begin()+2+nStepsPrimary);
    std::vector<cv::Mat> frames0Secondary(frames0Rect.begin()+2+nStepsPrimary, frames0Rect.end()-nStepsTertiary);
    std::vector<cv::Mat> frames0Tertiary(frames0Rect.end()-nStepsTertiary, frames0Rect.end());

    std::vector<cv::Mat> F0Primary = getDFTComponents(frames0Primary);
    cv::Mat up0Primary;
    cv::phase(F0Primary[2], -F0Primary[3], up0Primary);
    std::vector<cv::Mat> F0Secondary = getDFTComponents(frames0Secondary);
    cv::Mat up0Secondary;
    cv::phase(F0Secondary[2], -F0Secondary[3], up0Secondary);
    std::vector<cv::Mat> F0Tertiary = getDFTComponents(frames0Tertiary);
    cv::Mat up0Tertiary;
    cv::phase(F0Tertiary[2], -F0Tertiary[3], up0Tertiary);

    cv::Mat up0Unwrap = unwrapWithCue(up0Secondary, up0Tertiary, nPeriodSecondary);
    cv::Mat up0 = unwrapWithCue(up0Primary, up0Unwrap, nPeriodPrimary);
    up0 *= screenCols/(2.0*pi);
    cv::Mat amplitude0;
    cv::magnitude(F0Primary[2], -F0Primary[3], amplitude0);

    // Decode camera1
    std::vector<cv::Mat> frames1Primary(frames1Rect.begin()+2, frames1Rect.begin()+2+nStepsPrimary);
    std::vector<cv::Mat> frames1Secondary(frames1Rect.begin()+2+nStepsPrimary, frames1Rect.end()-nStepsTertiary);
    std::vector<cv::Mat> frames1Tertiary(frames1Rect.end()-nStepsTertiary, frames1Rect.end());

    std::vector<cv::Mat> F1Primary = getDFTComponents(frames1Primary);
    cv::Mat up1Primary;
    cv::phase(F1Primary[2], -F1Primary[3], up1Primary);
    std::vector<cv::Mat> F1Secondary = getDFTComponents(frames1Secondary);
    cv::Mat up1Secondary;
    cv::phase(F1Secondary[2], -F1Secondary[3], up1Secondary);
    std::vector<cv::Mat> F1Tertiary = getDFTComponents(frames1Tertiary);
    cv::Mat up1Tertiary;
    cv::phase(F1Tertiary[2], -F1Tertiary[3], up1Tertiary);

    cv::Mat up1Unwrap = unwrapWithCue(up1Secondary, up1Tertiary, nPeriodSecondary);
    cv::Mat up1 = unwrapWithCue(up1Primary, up1Unwrap, nPeriodPrimary);
    up1 *= screenCols/(2.0*pi);
    cv::Mat amplitude1;
    cv::magnitude(F1Primary[2], -F1Primary[3], amplitude1);

//cvtools::writeMat(up0Primary, "up0Primary.mat", "up0Primary");
//cvtools::writeMat(up0Secondary, "up0Secondary.mat", "up0Secondary");
//cvtools::writeMat(up0Tertiary, "up0Tertiary.mat", "up0Tertiary");
//cvtools::writeMat(up0Unwrap, "up0Unwrap.mat", "up0Unwrap");
//cvtools::writeMat(up0, "up0.mat", "up0");
//cvtools::writeMat(up1, "up1.mat", "up1");
//cvtools::writeMat(amplitude0, "amplitude0.mat", "amplitude0");

//cvtools::writeMat(amplitude0, "amplitude0.mat", "amplitude0");
//cvtools::writeMat(amplitude1, "amplitude1.mat", "amplitude1");

    // Color debayer and remap
    cv::Mat color0, color1;
    cv::cvtColor(frames0[0], color0, CV_BayerBG2RGB);
    cv::cvtColor(frames1[0], color1, CV_BayerBG2RGB);

//cvtools::writeMat(color0, "color0.mat", "color0");
//cvtools::writeMat(color1, "color1.mat", "color1");

    // Occlusion masks
    cv::Mat occlusion0, occlusion1;
    cv::subtract(frames0Rect[0], frames0Rect[1], occlusion0);
    occlusion0 = (occlusion0 > 5) & (occlusion0 < 250);
    cv::subtract(frames1Rect[0], frames1Rect[1], occlusion1);
    occlusion1 = (occlusion1 > 5) & (occlusion1 < 250);

//    // Threshold on energy at primary frequency
//    occlusion0 = occlusion0 & (amplitude0 > 5.0*nStepsPrimary);
//    occlusion1 = occlusion1 & (amplitude1 > 5.0*nStepsPrimary);

//cvtools::writeMat(occlusion0, "occlusion0.mat", "occlusion0");
//cvtools::writeMat(occlusion1, "occlusion1.mat", "occlusion1");

//    // Erode occlusion masks
//    cv::Mat strel = cv::getStructuringElement(cv::MORPH_ELLIPSE, cv::Size(5,5));
//    cv::erode(occlusion0, occlusion0, strel);
//    cv::erode(occlusion1, occlusion1, strel);

    // Threshold on gradient of phase
    cv::Mat edges0;
    cv::Sobel(up0, edges0, -1, 1, 1, 5);
    occlusion0 = occlusion0 & (abs(edges0) < 150);
    cv::Mat edges1;
    cv::Sobel(up1, edges1, -1, 1, 1, 5);
    occlusion1 = occlusion1 & (abs(edges1) < 150);

//cvtools::writeMat(edges0, "edges0.mat", "edges0");
//cvtools::writeMat(edges1, "edges1.mat", "edges1");

    // Match phase maps
    int frameRectRows = map0X.rows;
    int frameRectCols = map0X.cols;

    // camera0 against camera1
    std::vector<cv::Vec2f> q0, q1;
    for(int row=0; row<frameRectRows; row++){
        for(int col=0; col<frameRectCols; col++){

            if(!occlusion0.at<char>(row,col))
                continue;

            float up0i = up0.at<float>(row,col);
            for(int col1=0; col1<up1.cols-1; col1++){

                if(!occlusion1.at<char>(row,col1) || !occlusion1.at<char>(row,col1+1))
                    continue;

                float up1Left = up1.at<float>(row,col1);
                float up1Right = up1.at<float>(row,col1+1);

                if((up1Left <= up0i) && (up0i <= up1Right) && (up0i-up1Left < 1.0) && (up1Right-up0i < 1.0)){

                    float col1i = col1 + (up0i-up1Left)/(up1Right-up1Left);

                    q0.push_back(cv::Point2f(col, row));
                    q1.push_back(cv::Point2f(col1i, row));

                    break;
                }
            }
        }
    }

    int nMatches = q0.size();

    if(nMatches < 1){
        Q.resize(0);
        color.resize(0);

        return;
    }

    // Retrieve color information
    color.resize(nMatches);
    for(int i=0; i<nMatches; i++){

        cv::Vec3b c0 = color0.at<cv::Vec3b>(q0[i][1], q0[i][0]);
        cv::Vec3b c1 = color1.at<cv::Vec3b>(q1[i][1], q1[i][0]);

        color[i] = 0.5*c0 + 0.5*c1;
    }

    // Triangulate points
    cv::Mat QMatHomogenous, QMat;
    cv::triangulatePoints(P0, P1, q0, q1, QMatHomogenous);
    cvtools::convertMatFromHomogeneous(QMatHomogenous, QMat);

    // Undo rectification
    cv::Mat R0Inv;
    cv::Mat(R0.t()).convertTo(R0Inv, CV_32F);
    QMat = R0Inv*QMat;

    cvtools::matToPoints3f(QMat, Q);

}