#include "rgb.hpp"
#include "math.hpp"

#include <image_io.hpp>
#include <av/sws.hpp>

#include <algorithm>
#include <iostream>

namespace fingerprints {

static raw_rgb_image downscale_step(av::frame const & frame, int factor) {
	raw_rgb_image image(frame->width / factor, frame->height / factor);

	auto context = sws::create_context(frame, image.frame);
	sws::scale(context, frame, image.frame);

	return image;
}

static raw_rgb_image downscale_to(av::frame const & frame, int w, int h){
	// ffmpeg doesnt let us downscale all the way to 5 at once :(, so we do a loop
	raw_rgb_image image;
	auto* new_frame = &frame;
	while((*new_frame)->width > 8*w && (*new_frame)->height > 8*h){
		image = downscale_step(*new_frame, 4);
		new_frame = &image.frame;
	}
	return to_raw_rgb_image(image.frame, w, h);
}

rgb rgb::pre_calculate(av::frame const & frame){
	auto const image = downscale_to(crop_to_square(frame), 5, 5);

	rgb ret;
	ret.data.assign(image.data.size(), 0);

	std::copy(image.data.begin(), image.data.end(), ret.data.begin());

	return ret;
}

rgb rgb::calculate(const av::frame& frame){
	return pre_calculate(frame);
}

double rgb::distance_to(const rgb& fingerprint) const {
	assert(data.size() == fingerprint.data.size());

	double distance = 0;
	for(size_t i = 0; i < data.size(); ++i){
		distance += square(data[i] - fingerprint.data[i]);
	}

	return distance;
}

} // namespace fingerprints