#ifndef PARTICLE_H
#define PARTICLE_H

#include <pthread.h>
#include <stdlib.h>
#include <unistd.h>
#include <stdatomic.h>

#define G_CONSTANT 0.207f

typedef struct {
	float x, y, z;
} Vec3;

typedef struct {
	float r, g, b, a;
} Color;

typedef struct {
	Vec3 position;
	Vec3 velocity;
	Color color;

	float dampening;
	float life;
	float size;
} Particle;

typedef struct {
	Particle *particle;
	unsigned long long thread_id;
	unsigned long long interval_start;
	unsigned long long interval_end;
	int alive_count;
	float time;

	pthread_mutex_t *mutex;
	pthread_cond_t *cond;
	int *barrier;
	atomic_int exit;
} Physics_params;

// INFO: This adds adder to out, basicaly out + adder
void vec_add(Vec3 &out, Vec3 adder) {
	out.x += adder.x;
	out.y += adder.y;
	out.z += adder.z;
}

Particle particle_init(Vec3 position, Color color) {
	Particle p;
	p.position = position;
	p.color = color;
	p.velocity = {0.0f, 0.0f, 0.0f};

	p.life = 10;
	p.dampening = 0.97f;
	return p;
}

int particle_update(Particle *particles, unsigned long long size, float time) {
	int alive_count = 0;
	for (unsigned long long i = 0; i < size; i++) {
		Particle p = particles[i];
		if (p.life == 0) {
			continue;
		}

		// p.velocity.y -= (G_CONSTANT * time);

		p.position.x += p.velocity.x * time;
		p.position.y += p.velocity.y * time;
		p.position.z += p.velocity.z * time;

		if (p.position.y <= 0) {
			p.position.y = 0;
			p.velocity.y *= (-1 * p.dampening);
		}

		if (p.life > 0)
			p.life -= time;
		if (p.life < 0 && p.life >= -1.0f)
			p.life = 0;

		particles[i] = p;
		alive_count++;
	}

	return alive_count;
}

void *t_update(void *args) {
	Physics_params *params = (Physics_params *)args;
	while (params->exit != 1) {
        pthread_mutex_lock(params->mutex);
		if (params->(missing) == 0) {
			sleep(100);
		}
        pthread_mutex_unlock(params->mutex);

        params->alive_count = 0;
		for (unsigned long long i = params->interval_start; i < params->interval_end; i++) {
			Particle p = params->particle[i];

			if (p.life == 0) {
				continue;
			}

			p.velocity.y -= (G_CONSTANT * params->time);

			p.position.x += p.velocity.x * params->time;
			p.position.y += p.velocity.y * params->time;
			p.position.z += p.velocity.z * params->time;

			if (p.position.y <= 0) {
				p.position.y = 0;
				p.velocity.y *= (-1 * p.dampening);
			}

			if (p.life > 0)
				p.life -= params->time;
			if (p.life < 0 && p.life >= -1.0f)
				p.life = 0;

			// DEBUG
			if (params->thread_id == 0) {
				p.color = {1.0f, 1.0f, 1.0f, 1.0f};
			} else if (params->thread_id == 1) {
				p.color = {1.0f, 0.0f, 0.0f, 1.0f};
			} else if (params->thread_id == 2) {
				p.color = {0.0f, 1.0f, 0.0f, 1.0f};
			} else if (params->thread_id == 3) {
				p.color = {0.0f, 0.0f, 1.0f, 1.0f};
			} else {
				p.color = {0.7f, 0.7f, 0.7f, 1.0f};
				;
			}

			params->particle[i] = p;
			params->alive_count++;
		}
	}

	return NULL;
}

#endif // PARTICLE_H