#include "path_sprite.h"
#include <cmath>	  // Para abs
#include <stdlib.h>	  // Para abs
#include <functional> // Para function
#include <utility>	  // Para move

// Devuelve un vector con los puntos que conforman la ruta
std::vector<SDL_Point> createPath(int start, int end, PathType type, int fixed_pos, int steps, const std::function<double(double)> &easingFunction)
{
	std::vector<SDL_Point> v;
	v.reserve(steps);

	for (int i = 0; i < steps; ++i)
	{
		double t = static_cast<double>(i) / (steps - 1);
		double value = start + (end - start) * easingFunction(t);

		if (start > 0 && end < 0)
		{
			value = start - std::abs(end - start) * easingFunction(t);
		}
		else if (start < 0 && end > 0)
		{
			value = start + std::abs(end - start) * easingFunction(t);
		}

		switch (type)
		{
		case PathType::HORIZONTAL:
			v.emplace_back(SDL_Point{static_cast<int>(value), fixed_pos});
			break;
		case PathType::VERTICAL:
			v.emplace_back(SDL_Point{fixed_pos, static_cast<int>(value)});
			break;
		default:
			break;
		}
	}

	return v;
}

// Actualiza la posición y comprueba si ha llegado a su destino
void PathSprite::update()
{
	if (enabled_)
	{
		moveThroughCurrentPath();
		goToNextPathOrDie();
	}
}

// Añade un recorrido
void PathSprite::addPath(Path path, bool centered)
{
	PathCentered path_centered = PathCentered::NONE;
	if (centered)
		path_centered = (path.spots.back().x == path.spots.front().x) ? PathCentered::ON_X : PathCentered::ON_Y;

	switch (path_centered)
	{
	case PathCentered::ON_X:
	{
		const int x = path.spots.back().x - pos_.w / 2;
		for (auto &spot : path.spots)
			spot.x = x;
		paths_.emplace_back(path);
		break;
	}
	case PathCentered::ON_Y:
	{
		const int y = path.spots.back().y - pos_.h / 2;
		for (auto &spot : path.spots)
			spot.y = y;
		paths_.emplace_back(path);
		break;
	}
	default:
		paths_.emplace_back(path);
		break;
	}
}

// Añade un recorrido
void PathSprite::addPath(int start, int end, PathType type, int fixed_pos, int steps, const std::function<double(double)> &easingFunction, int waiting_counter)
{
	paths_.emplace_back(createPath(start, end, type, fixed_pos, steps, easingFunction), waiting_counter);
}

// Añade un recorrido
void PathSprite::addPath(std::vector<SDL_Point> spots, int waiting_counter)
{
	paths_.emplace_back(std::move(spots), waiting_counter);
}

// Habilita el objeto
void PathSprite::enable()
{
	enabled_ = true;
}

// Coloca el sprite en los diferentes puntos del recorrido
void PathSprite::moveThroughCurrentPath()
{
	auto &path = paths_.at(current_path_);

	// Establece la posición
	const auto &p = path.spots.at(path.counter);
	setPosition(p);

	// Comprobar si ha terminado el recorrido
	if (!path.on_destination)
	{
		++path.counter;
		if (path.counter >= static_cast<int>(path.spots.size()))
		{
			path.on_destination = true;
			path.counter = static_cast<int>(path.spots.size()) - 1;
		}
	}

	// Comprobar si ha terminado la espera
	if (path.on_destination)
	{
		if (path.waiting_counter == 0)
			path.finished = true;
		else
			--path.waiting_counter;
	}
}

// Cambia de recorrido o finaliza
void PathSprite::goToNextPathOrDie()
{
	// Comprueba si ha terminado el recorrdo actual
	if (paths_.at(current_path_).finished)
		++current_path_;

	// Comprueba si quedan mas recorridos
	if (current_path_ >= static_cast<int>(paths_.size()))
		enabled_ = false;
}

// Indica si ha terminado todos los recorridos
bool PathSprite::hasFinished()
{
	return !enabled_;
}