/*
This file is part of Minitrem.

Minitrem is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 2 of the License, or
(at your option) any later version.

Minitrem is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with Minitrem.  If not, see <http://www.gnu.org/licenses/>.
*/

#include "common.hpp"
#include <chrono>
#ifdef CONFIG_SHOW_RSS
#include <sys/types.h>
#include <unistd.h>
#include <fstream>
#endif

bool debug_draw_cmodels = false;
bool debug_draw_paths = false;
bool debug_draw_tile_coords = false;
bool debug_AI = false;
render::state_t *debug_render;

static ntime_t nclock_ref;

// always > 0
ntime_t nclock(void)
{
	return std::chrono::high_resolution_clock::now().time_since_epoch() /
	       std::chrono::nanoseconds(1) - nclock_ref;
}

freq_counter_t::freq_counter_t(size_t num_samples_)
{
	num_samples = num_samples_;
	samples = (ntime_t*)malloc(sizeof(ntime_t) * num_samples);
}

freq_counter_t::~freq_counter_t(void)
{
	free(samples);
}

void freq_counter_t::push(ntime_t sample)
{
	collected++;
	samples[collected % num_samples] = sample;
}

void freq_counter_t::tick(void)
{
	ntime_t now = nclock();

	if (last_tick)
		push(now - last_tick);

	last_tick = now;
}

float freq_counter_t::freq_ma(void)
{
	ntime_t now;
	float res = 0.0f;
	size_t to_count;

	now = nclock();

	if (last_ma_time && now - last_ma_time < 500000000)
		return last_ma;

	to_count = std::min(collected, num_samples);

	for (size_t i = 0; i < to_count; i++)
		res += samples[i] * 1.0e-9f;
	res = 1.0f / (res / to_count);

	last_ma_time = now;
	last_ma = res;
	return res;
}

freq_counter_t fc_render = freq_counter_t(20);
freq_counter_t fc_game = freq_counter_t(10);

#ifdef CONFIG_SHOW_RSS
size_t sys_get_rss(void)
{
	std::ifstream file;
	pid_t pid;
	std::string line;
	size_t res = 0;

	pid = getpid();

	file.open("/proc/" + std::to_string(pid) + "/status");
	while (file >> line) {
		if (line == "VmRSS:") {
			file >> res;
			break;
		}
	}

	return res * 1024;
}
#endif

int main()
{
	nclock_ref = nclock() - 1;

	sf::RenderWindow window(sf::VideoMode(800, 600), "Minitrem");
	render::state_t render(&window);
	game::state_t game;
	interface::state_t interface(&window, &game);

	game.interface = &interface;
	debug_render = &render;
	window.setVerticalSyncEnabled(true);

	game::load_assets();
	game.start();

	while (1) {
		static ntime_t before = 0;
		ntime_t now = nclock();
		double dt;

		if (before)
			dt = (now - before) * 1.0e-9;
		else
			dt = 0.1;
		before = now;

		game.tick(now);
		interface.tick(dt);
		if (!window.isOpen())
			break;

		sys_get_rss();

		window.clear();
		render.begin_frame(now, dt);
		render.render(&game);
		game.compute_ambience(&render);
		interface.render_to(&render);
		audio::update(interface.camera_3d, game.paused);
		render.end_frame();
	}

	game.stop();
	return 0;
}