#include "backlight.h"

#include <iostream>
#include <fstream>
#include <algorithm>

#include "power_console.h"

int
getBacklightPercent( const std::filesystem::path &backlightPath )
{
	std::ifstream i_max{ backlightPath / "max_brightness" };

	int max;
	i_max >> max;


	std::ifstream inf{ backlightPath / "brightness" };
	int in;
	inf >> in;

	return 100 * in / max;
}

std::filesystem::path getBacklightPath();


namespace
{
	void
	changeBrightness( int pct )
	{
		std::ifstream i_max{ getBacklightPath() / "max_brightness" };

		int max;
		i_max >> max;

		// Clamp to never hit 0 backlight or pass max.
		int adj= std::clamp( max * pct / 100, 1, max );
		std::cerr << "Adjustment computed: " << adj << std::endl;

		std::ofstream out{ getBacklightPath() / "brightness" };
		out << adj;
	}

	void
	increaseBrightness( int pct )
	{
		changeBrightness( pct );
	}

	void
	decreaseBrightness( int pct )
	{
		changeBrightness( -pct );
	}
}

void
adjustBrightness( MouseWheelSlider *, void * )
{
	const int amount= brightness->value();
	std::cerr << "Adjusting brightness by " << amount << std::endl;
	changeBrightness( amount );
}