#include <opencv2/opencv.hpp>
#include <opencv2/xfeatures2d.hpp>
#include <iostream>
#include <fstream>
#include <vector>
#include <filesystem>

using namespace cv;
using namespace cv::xfeatures2d;
using namespace std;
using namespace std::filesystem;

const auto detector = SIFT::create();
/// <summary>
/// 提取图片特征描述符
/// </summary>
/// <param name="image">待提取图片路径</param>
/// <param name="output">保存描述符路径</param>
void process_image(const path& image, const path& output) {
	ofstream fs(output.string().c_str());
	if (!fs.is_open()) {
		cout << "create file error!";
	}
	fs.close();

	Mat input_image = imread(image.string());

	vector<KeyPoint> keypoints_cat;

	Mat descriptor_cat, descriptor_smallCat;
	detector->detectAndCompute(input_image, Mat(), keypoints_cat, descriptor_cat);

	Mat convert;

	if (descriptor_cat.type() != CV_32F)
	{
		descriptor_cat.convertTo(convert, CV_32F, 1.0 / 255, 0);
	}
	else
	{
		convert = descriptor_cat;
	}

	imwrite(output.string(), convert);
}

void deep_copy(const path& src, const path& des) {
	if (is_regular_file(src)) {
		auto d = des.string().substr(0, des.string().size() - 3) + "png\0";

		process_image(src, path(d));
		return;
	}

	if (!exists(des)) {
		create_directories(des);
	}

	for (auto& it : directory_iterator(src)) {
		string current = it.path().lexically_relative(it.path().parent_path()).string();
		path des_next(des);
		deep_copy(it.path(), des_next /= current);
	}
}

int main(int argc, char** argv) {
	string input_dir = "D:\\Work\\Cards";
	//string output_dir = "D:\\Work\\Outputs";
	string output_dir = "D:\\Work\\SIFT";

	path input_dir_path(input_dir.c_str());
	path output_dir_path(output_dir.c_str());

	if (!exists(input_dir_path)) {
		cout << "请设置正确的卡片存放路径" << endl;
	}

	if (exists(output_dir_path)) {
		remove_all(output_dir_path);
	}
	else {
		create_directories(output_dir_path);
	}

	directory_entry input_entry(input_dir_path);

	assert(input_entry.status().type() == file_type::directory);

	copy(input_dir_path, output_dir_path);

	deep_copy(input_dir_path, output_dir_path);

	return 0;
}