#include "ImageApplyColorCastCorrect.h"
#include <fstream>
#include <iostream>

#define max(a, b) ((a) > (b) ? (a) : (b))
constexpr auto SIZE_OF_TABLE = 256;


CImageApplyColorCastCorrect::CImageApplyColorCastCorrect(const std::vector<double>& points_x, const std::vector<double>& points_y)
	: m_table(new uchar[SIZE_OF_TABLE])
{
    createTable(points_x, points_y);
}

CImageApplyColorCastCorrect::CImageApplyColorCastCorrect(const std::string& fileName)
    : m_table(new uchar[SIZE_OF_TABLE])
{
    std::fstream file(fileName, std::ios::in | std::ios::binary);
    if (file)
        file.read(reinterpret_cast<char*>(m_table), SIZE_OF_TABLE);
    file.close();
}

CImageApplyColorCastCorrect::CImageApplyColorCastCorrect(const uchar* table_h)
    : m_table(new uchar[SIZE_OF_TABLE])
{
    memcpy(m_table, table_h, SIZE_OF_TABLE);
}

CImageApplyColorCastCorrect::CImageApplyColorCastCorrect(const int type)
    : m_table(new uchar[SIZE_OF_TABLE])
{
    if(type == 1) 
        memcpy(m_table,CIS_DN_PATCH1,SIZE_OF_TABLE);
    else 
        memcpy(m_table,CIS_DN_PATCH2,SIZE_OF_TABLE);
}

CImageApplyColorCastCorrect::~CImageApplyColorCastCorrect(void)
{
	delete[] m_table;
}

void CImageApplyColorCastCorrect::setlutdata(const int type)
{
    if(type == 1) memcpy(m_table,CIS_DN_PATCH1,SIZE_OF_TABLE);
    else memcpy(m_table,CIS_DN_PATCH2,SIZE_OF_TABLE);
}

void CImageApplyColorCastCorrect::apply(cv::Mat& pDib, int side)
{
    if (pDib.channels() != 3)
        return;

    cv::Mat hsv;
    cv::cvtColor(pDib, hsv, cv::COLOR_BGR2HSV_FULL);

    cv::Mat hsv_mv[3];
    cv::split(hsv, hsv_mv);

    cv::Mat lut(256, 1, CV_8UC1, m_table);
    cv::LUT(hsv_mv[0], lut, hsv_mv[0]);
    cv::merge(hsv_mv, 3, pDib);

    cv::cvtColor(pDib, pDib, cv::COLOR_HSV2BGR_FULL);
}

void CImageApplyColorCastCorrect::apply(std::vector<cv::Mat>& mats, bool isTwoSide)
{
    (void)isTwoSide;
    int i = 0;
    for (cv::Mat& var : mats) {
        if (i != 0 && isTwoSide == false)
            break;
        if (!var.empty())
            apply(var, 0);
        i++;
    }
}

void CImageApplyColorCastCorrect::exportTableData(const std::string& fileName)
{
    std::fstream file(fileName, std::ios::out | std::ios::binary);
    if (file)
        file.write(reinterpret_cast<char*>(m_table), SIZE_OF_TABLE);
    file.close();
}

void CImageApplyColorCastCorrect::createTable(const std::vector<double>& points_x, const std::vector<double>& points_y)
{
    int table_temp[256]{};

    for (size_t i = 0; i < points_x.size(); i++)
    {
        int current_index = static_cast<int>(points_x[i]);
        if (current_index == 255)
            current_index = 0;
        int next_index = static_cast<int>(points_x[(i + 1) % points_x.size()]);

        double low = points_y[i];
        double up = points_y[(i + 1) % points_y.size()];
        if (low == 255)
            low = 0;
        if (up < low)
            up += 255;

        if (next_index < current_index)
            next_index += 256;

        int length = next_index - current_index + 1;
        double step = (up - low) / length;

        for (int j = 0; j < length; j++)
        {
            int temp = (j + current_index) % 256;
            table_temp[temp] = step * j + low;
        }

        for (size_t j = 0; j < 256; j++)
            if (table_temp[j] > 255)
                m_table[j] = table_temp[j] - 255;
            else
                m_table[j] = table_temp[j];
    }
}