// This file is part of OpenCV project.
// It is subject to the license terms in the LICENSE file found in the top-level directory
// of this distribution and at http://opencv.org/license.html.
//
// Copyright (C) 2020 Intel Corporation

#ifndef OPENCV_GAPI_VIDEO_TESTS_COMMON_HPP
#define OPENCV_GAPI_VIDEO_TESTS_COMMON_HPP

#include "gapi_tests_common.hpp"
#include "../../include/opencv2/gapi/video.hpp"

#ifdef HAVE_OPENCV_VIDEO
#include <opencv2/video.hpp>
#endif // HAVE_OPENCV_VIDEO



namespace opencv_test
{
namespace
{
inline void initTrackingPointsArray(std::vector<cv::Point2f>& points, int width, int height,
                                    int nPointsX, int nPointsY)
{
    if (nPointsX > width || nPointsY > height)
    {
        FAIL() << "Specified points number is too big";
    }

    int stepX = width  / nPointsX;
    int stepY = height / nPointsY;


    points.clear();
    GAPI_Assert((nPointsX >= 0) && (nPointsY) >= 0);
    points.reserve(static_cast<size_t>(nPointsX * nPointsY));

    for (int x = stepX / 2; x < width; x += stepX)
    {
        for (int y = stepY / 2; y < height; y += stepY)
        {
            Point2f pt(static_cast<float>(x), static_cast<float>(y));
            points.push_back(pt);
        }
    }
}

template<typename Type>
struct OptFlowLKTestInput
{
    Type& prevData;
    Type& nextData;
    std::vector<cv::Point2f>& prevPoints;
};

struct OptFlowLKTestOutput
{
    std::vector<cv::Point2f> &nextPoints;
    std::vector<uchar>       &statuses;
    std::vector<float>       &errors;
};

struct OptFlowLKTestParams
{
    OptFlowLKTestParams(): fileNamePattern(""), format(1), channels(0), pointsNum{0, 0},
                           winSize(0), maxLevel(3), minEigThreshold(1e-4), flags(0) { }

    OptFlowLKTestParams(const std::string& namePat, int chans,
                        const std::tuple<int,int>& ptsNum, int winSz,
                        const cv::TermCriteria& crit, const cv::GCompileArgs& compArgs,
                        int flgs = 0, int fmt = 1, int maxLvl = 3, double minEigThresh = 1e-4):

                        fileNamePattern(namePat), format(fmt), channels(chans),
                        pointsNum(ptsNum), winSize(winSz), maxLevel(maxLvl),
                        criteria(crit), minEigThreshold(minEigThresh), compileArgs(compArgs),
                        flags(flgs) { }

    std::string fileNamePattern   = "";
    int format                    = 1;
    int channels                  = 0;
    std::tuple<int,int> pointsNum = std::make_tuple(0, 0);
    int winSize                   = 0;
    int maxLevel                  = 3;
    cv::TermCriteria criteria;
    double minEigThreshold        = 1e-4;
    cv::GCompileArgs compileArgs;
    int flags                     = 0;
};

#ifdef HAVE_OPENCV_VIDEO

template<typename GType, typename Type>
cv::GComputation runOCVnGAPIOptFlowLK(OptFlowLKTestInput<Type>& in,
                                      int width, int height,
                                      const OptFlowLKTestParams& params,
                                      OptFlowLKTestOutput& ocvOut,
                                      OptFlowLKTestOutput& gapiOut)
{

    int nPointsX = 0, nPointsY = 0;
    std::tie(nPointsX, nPointsY) = params.pointsNum;

    initTrackingPointsArray(in.prevPoints, width, height, nPointsX, nPointsY);

    cv::Size winSize(params.winSize, params.winSize);

    // OpenCV code /////////////////////////////////////////////////////////////
    {
        cv::calcOpticalFlowPyrLK(in.prevData, in.nextData, in.prevPoints,
                                 ocvOut.nextPoints, ocvOut.statuses, ocvOut.errors,
                                 winSize, params.maxLevel, params.criteria,
                                 params.flags, params.minEigThreshold);
    }

    // G-API code //////////////////////////////////////////////////////////////
    {
        GType               inPrev,  inNext;
        GArray<cv::Point2f> prevPts, predPts, nextPts;
        GArray<uchar>       statuses;
        GArray<float>       errors;
        std::tie(nextPts, statuses, errors) = cv::gapi::calcOpticalFlowPyrLK(
                                                    inPrev, inNext,
                                                    prevPts, predPts, winSize,
                                                    params.maxLevel, params.criteria,
                                                    params.flags, params.minEigThreshold);

        cv::GComputation c(cv::GIn(inPrev, inNext, prevPts, predPts),
                           cv::GOut(nextPts, statuses, errors));

        c.apply(cv::gin(in.prevData, in.nextData, in.prevPoints, std::vector<cv::Point2f>{ }),
                cv::gout(gapiOut.nextPoints, gapiOut.statuses, gapiOut.errors),
                std::move(const_cast<cv::GCompileArgs&>(params.compileArgs)));

        return c;
    }
}

inline cv::GComputation runOCVnGAPIOptFlowLK(TestFunctional& testInst,
                                             std::vector<cv::Point2f>& inPts,
                                             const OptFlowLKTestParams& params,
                                             OptFlowLKTestOutput& ocvOut,
                                             OptFlowLKTestOutput& gapiOut)
{
    testInst.initMatsFromImages(params.channels,
                                params.fileNamePattern,
                                params.format);

    OptFlowLKTestInput<cv::Mat> in{ testInst.in_mat1, testInst.in_mat2, inPts };

    return runOCVnGAPIOptFlowLK<cv::GMat>(in,
                                          testInst.in_mat1.cols,
                                          testInst.in_mat1.rows,
                                          params,
                                          ocvOut,
                                          gapiOut);
}

inline cv::GComputation runOCVnGAPIOptFlowLKForPyr(TestFunctional& testInst,
                                                   OptFlowLKTestInput<std::vector<cv::Mat>>& in,
                                                   const OptFlowLKTestParams& params,
                                                   bool withDeriv,
                                                   OptFlowLKTestOutput& ocvOut,
                                                   OptFlowLKTestOutput& gapiOut)
{
    testInst.initMatsFromImages(params.channels,
                                params.fileNamePattern,
                                params.format);

    cv::Size winSize(params.winSize, params.winSize);

    OptFlowLKTestParams updatedParams(params);
    updatedParams.maxLevel = cv::buildOpticalFlowPyramid(testInst.in_mat1, in.prevData,
                                                         winSize, params.maxLevel, withDeriv);
    updatedParams.maxLevel = cv::buildOpticalFlowPyramid(testInst.in_mat2, in.nextData,
                                                         winSize, params.maxLevel, withDeriv);


    return runOCVnGAPIOptFlowLK<cv::GArray<cv::GMat>>(in,
                                                      testInst.in_mat1.cols,
                                                      testInst.in_mat1.rows,
                                                      updatedParams,
                                                      ocvOut,
                                                      gapiOut);
}

#else // !HAVE_OPENCV_VIDEO

inline cv::GComputation runOCVnGAPIOptFlowLK(TestFunctional&,
                                             std::vector<cv::Point2f>&,
                                             const OptFlowLKTestParams&,
                                             OptFlowLKTestOutput&,
                                             OptFlowLKTestOutput&)
{
    GAPI_Assert(0 && "This function shouldn't be called without opencv_video");
}

inline cv::GComputation runOCVnGAPIOptFlowLKForPyr(TestFunctional&,
                                                   OptFlowLKTestInput<std::vector<cv::Mat>>&,
                                                   const OptFlowLKTestParams&,
                                                   bool,
                                                   OptFlowLKTestOutput&,
                                                   OptFlowLKTestOutput&)
{
    GAPI_Assert(0 && "This function shouldn't be called without opencv_video");
}

#endif // HAVE_OPENCV_VIDEO

template <typename Elem>
inline bool compareVectorsAbsExactForOptFlow(std::vector<Elem> outOCV, std::vector<Elem> outGAPI)
{
    return AbsExactVector<Elem>().to_compare_f()(outOCV, outGAPI);
}

inline void compareOutputsOptFlow(const OptFlowLKTestOutput& outOCV,
                                  const OptFlowLKTestOutput& outGAPI)
{
    EXPECT_TRUE(compareVectorsAbsExactForOptFlow(outGAPI.nextPoints, outOCV.nextPoints));
    EXPECT_TRUE(compareVectorsAbsExactForOptFlow(outGAPI.statuses,   outOCV.statuses));
    EXPECT_TRUE(compareVectorsAbsExactForOptFlow(outGAPI.errors,     outOCV.errors));
}


inline std::ostream& operator<<(std::ostream& os, const cv::TermCriteria& criteria)
{
    os << "{";
    switch (criteria.type) {
    case cv::TermCriteria::COUNT:
        os << "COUNT; ";
        break;
    case cv::TermCriteria::EPS:
        os << "EPS; ";
        break;
    case cv::TermCriteria::COUNT | cv::TermCriteria::EPS:
        os << "COUNT | EPS; ";
        break;
    default:
        os << "TypeUndifined; ";
        break;
    };

    return os << criteria.maxCount << "; " << criteria.epsilon <<"}";
}
} // namespace
} // namespace opencv_test


#endif // OPENCV_GAPI_VIDEO_TESTS_COMMON_HPP