#include <cmath>
#include <algorithm>
#include <cstddef>
#include <variant>

#include "CollisionSystem.h"

#include "../ComponentManager.h"
#include "../api/BoxCollider.h"
#include "../api/CircleCollider.h"
#include "../api/Vector2.h"
#include "../api/Rigidbody.h"
#include "../api/Transform.h"

#include "Collider.h"
#include "iostream"

using namespace crepe;

CollisionSystem::CollisionSystem() {}

void CollisionSystem::update() {
	ComponentManager & mgr = ComponentManager::get_instance();
	std::vector<std::reference_wrapper<BoxCollider>> boxcolliders	= mgr.get_components_by_type<BoxCollider>();
	std::vector<std::reference_wrapper<CircleCollider>> circlecolliders	= mgr.get_components_by_type<CircleCollider>();
	std::vector<std::pair<CollisionSystem::collider_stor, CollisionSystem::collider_stor>> collided = check_collisions(boxcolliders,circlecolliders);
	std::cout << "DEBUG INFO" << std::endl;
	for (const std::pair<CollisionSystem::collider_stor, CollisionSystem::collider_stor>& collision : collided) {
		
		if (const BoxCollider* box_collider1 = std::get_if<BoxCollider>(&collision.first)) {
			std::cout << "Processing a BoxCollider\n";
			if (const BoxCollider* box_collider2 = std::get_if<BoxCollider>(&collision.second)) {
			std::cout << "Processing a BoxCollider\n";
			} else if (const CircleCollider* circle_collider2 = std::get_if<CircleCollider>(&collision.first)) {
				std::cout << "Processing a CircleCollider\n";
			}
		} else if (const CircleCollider* circle_collider1 = std::get_if<CircleCollider>(&collision.first)) {
			std::cout << "Processing a CircleCollider\n";
			if (const BoxCollider* box_collider2 = std::get_if<BoxCollider>(&collision.first)) {
				std::cout << "Processing a BoxCollider\n";
			} else if (const CircleCollider* circle_collider2 = std::get_if<CircleCollider>(&collision.first)) {
				std::cout << "Processing a CircleCollider\n";
			}
		}

	}
	if(collided.empty()) {
		std::cout << "No objects collided" << std::endl;
	}
}

void CollisionSystem::call_collision_handler(const Rigidbody& rigidbody1,const Rigidbody& rigidbody2){

}

std::vector<std::pair<CollisionSystem::collider_stor, CollisionSystem::collider_stor>> CollisionSystem::check_collisions(const std::vector<std::reference_wrapper<BoxCollider>>& boxcolliders, const std::vector<std::reference_wrapper<CircleCollider>>& circlecolliders) {
	ComponentManager & mgr = ComponentManager::get_instance();
	std::vector<std::pair<collider_stor, collider_stor>> collisions_ret;
	//if no colliders skip
	//check if colliders has rigibocdy if not skip

	//if amount is higer than lets say 16 for now use quadtree otwerwise skip
	//quadtree code
	//quadtree is placed over the input vector

	// Check collisions
	for (size_t i = 0; i < boxcolliders.size(); ++i) {
		// Fetch components for the first box collider
		if(!boxcolliders[i].get().active) continue;
		int game_object_id_1 = boxcolliders[i].get().game_object_id;
		Transform& transform1 = mgr.get_components_by_id<Transform>(game_object_id_1).front().get();
		Rigidbody& rigidbody1 = mgr.get_components_by_id<Rigidbody>(game_object_id_1).front().get();

		// Check CircleCollider vs CircleCollider
		for (size_t j = i + 1; j < boxcolliders.size(); ++j) {
			if(!boxcolliders[j].get().active) continue;
			// Skip self collision
			int game_object_id_2 = boxcolliders[j].get().game_object_id;
			if (game_object_id_1 == game_object_id_2) continue;

			// Fetch components for the second box collider
			Transform & transform2 = mgr.get_components_by_id<Transform>(boxcolliders[j].get().game_object_id).front().get();
			Rigidbody & rigidbody2 = mgr.get_components_by_id<Rigidbody>(boxcolliders[j].get().game_object_id).front().get();

			// Check collision
			if (check_box_box_collision(boxcolliders[i], boxcolliders[j], transform1, transform2, rigidbody1, rigidbody2)) {
				collisions_ret.emplace_back(boxcolliders[i], boxcolliders[j]);
			}
		}

		// Check BoxCollider vs CircleCollider
		for (size_t j = 0; j < circlecolliders.size(); ++j) {
			if(!circlecolliders[j].get().active) continue;
			// Skip self collision
			int game_object_id_2 = circlecolliders[j].get().game_object_id;
			if (game_object_id_1 == game_object_id_2) continue;

			// Fetch components for the second collider (circle)
			Transform & transform2 = mgr.get_components_by_id<Transform>(circlecolliders[j].get().game_object_id).front().get();
			Rigidbody & rigidbody2 = mgr.get_components_by_id<Rigidbody>(circlecolliders[j].get().game_object_id).front().get();

			// Check collision
			if (check_box_circle_collision(boxcolliders[i], circlecolliders[j], transform1, transform2, rigidbody1, rigidbody2)) {
				collisions_ret.emplace_back(boxcolliders[i], circlecolliders[j]);
			}
		}
	}
	// Check CircleCollider vs CircleCollider
	for (size_t i = 0; i < circlecolliders.size(); ++i) {
		if(!circlecolliders[i].get().active) continue;
		// Fetch components for the first circle collider
		int game_object_id_1 = circlecolliders[i].get().game_object_id;
		Transform & transform1 = mgr.get_components_by_id<Transform>(circlecolliders[i].get().game_object_id).front().get();
		Rigidbody & rigidbody1 = mgr.get_components_by_id<Rigidbody>(circlecolliders[i].get().game_object_id).front().get();
		for (size_t j = i + 1; j < circlecolliders.size(); ++j) {
			if(!circlecolliders[j].get().active) continue;
			// Skip self collision
			int game_object_id_2 = circlecolliders[j].get().game_object_id;
			if (game_object_id_1 == game_object_id_2) continue;

			// Fetch components for the second circle collider
			Transform & transform2 = mgr.get_components_by_id<Transform>(circlecolliders[j].get().game_object_id).front().get();
			Rigidbody & rigidbody2 = mgr.get_components_by_id<Rigidbody>(circlecolliders[j].get().game_object_id).front().get();

			// Check collision
			if (check_circle_circle_collision(circlecolliders[i], circlecolliders[j], transform1, transform2, rigidbody1, rigidbody2)) {
				collisions_ret.emplace_back(circlecolliders[i], circlecolliders[j]);
			}
		}
	}
	return collisions_ret;
}

bool CollisionSystem::check_box_box_collision(const BoxCollider& box1, const BoxCollider& box2, const Transform& transform1, const Transform& transform2, const Rigidbody& rigidbody1, const Rigidbody& rigidbody2)
{
	// Get current positions of colliders
	Vector2 final_position1 = current_position(box1,transform1,rigidbody1);
	Vector2 final_position2 = current_position(box2,transform2,rigidbody2);

	 // Log final positions for debugging purposes
	std::cout << "Final Position of Box 1: (" << final_position1.x << ", " << final_position1.y << ")" << std::endl;
	std::cout << "Final Position of Box 2: (" << final_position2.x << ", " << final_position2.y << ")" << std::endl;

	// Log rotation values for debugging
	std::cout << "Rotation of Box 1: " << transform1.rotation << " degrees" << std::endl;
	std::cout << "Rotation of Box 2: " << transform2.rotation << " degrees" << std::endl;


	// Calculate half-extents (half width and half height)
	double half_width1 = box1.width / 2.0;
	double half_height1 = box1.height / 2.0;
	double half_width2 = box2.width / 2.0;
	double half_height2 = box2.height / 2.0;

	// Check if the boxes overlap along the X and Y axes
	return !(final_position1.x + half_width1 < final_position2.x - half_width2 ||  // box1 is left of box2
						final_position1.x - half_width1 > final_position2.x + half_width2 ||  // box1 is right of box2
						final_position1.y + half_height1 < final_position2.y - half_height2 || // box1 is above box2
						final_position1.y - half_height1 > final_position2.y + half_height2);  // box1 is below box2
}

bool CollisionSystem::check_box_circle_collision(const BoxCollider& box1, const CircleCollider& circle2, const Transform& transform1, const Transform& transform2, const Rigidbody& rigidbody1, const Rigidbody& rigidbody2) {
	// Get current positions of colliders
	Vector2 final_position1 = current_position(box1, transform1, rigidbody1);
	Vector2 final_position2 = current_position(circle2, transform2, rigidbody2);

	// Log final positions for debugging purposes
	std::cout << "Final Position of Box: (" << final_position1.x << ", " << final_position1.y << ")" << std::endl;
	std::cout << "Final Position of Circle: (" << final_position2.x << ", " << final_position2.y << ")" << std::endl;

	// Calculate box half-extents
	double half_width = box1.width / 2.0;
	double half_height = box1.height / 2.0;

	// Find the closest point on the box to the circle's center
	double closest_x = std::max(final_position1.x - half_width, std::min(final_position2.x, final_position1.x + half_width));
	double closest_y = std::max(final_position1.y - half_height, std::min(final_position2.y, final_position1.y + half_height));


	// Calculate the distance squared between the circle's center and the closest point on the box
	double distance_x = final_position2.x - closest_x;
	double distance_y = final_position2.y - closest_y;
	double distance_squared = distance_x * distance_x + distance_y * distance_y;

	// Compare distance squared with the square of the circle's radius
	return distance_squared <= circle2.radius * circle2.radius;
}

bool CollisionSystem::check_circle_circle_collision(const CircleCollider& circle1, const CircleCollider& circle2, const Transform& transform1, const Transform& transform2, const Rigidbody& rigidbody1, const Rigidbody& rigidbody2) {
	// Get current positions of colliders
	Vector2 final_position1 = current_position(circle1,transform1,rigidbody1);
	Vector2 final_position2 = current_position(circle2,transform2,rigidbody2);

	// Log final positions for debugging purposes
	std::cout << "Final Position of Circle 1: (" << final_position1.x << ", " << final_position1.y << ")" << std::endl;
	std::cout << "Final Position of Circle 2: (" << final_position2.x << ", " << final_position2.y << ")" << std::endl;

	// Log rotation values for debugging (circles do not rotate, so this might not be needed for circles)
	std::cout << "Rotation of Circle 1: " << transform1.rotation << " degrees" << std::endl;
	std::cout << "Rotation of Circle 2: " << transform2.rotation << " degrees" << std::endl;

	double distance_x = final_position1.x - final_position2.x;
	double distance_y = final_position1.y - final_position2.y;
	double distance_squared = distance_x * distance_x + distance_y * distance_y;

	// Calculate the sum of the radii
	double radius_sum = circle1.radius + circle2.radius;

	// Check if the distance between the centers is less than or equal to the sum of the radii
	return distance_squared <= radius_sum * radius_sum;
}

Vector2 CollisionSystem::current_position(const Collider& collider, const Transform& transform, const Rigidbody& rigidbody) {
	// Function to convert degrees to radians
	auto degrees_to_radians = [](double degrees) {
			return degrees * (M_PI / 180.0);
	};

	// Get the rotation in radians
	double radians1 = degrees_to_radians(transform.rotation);

	// Calculate total offset with scale
	Vector2 total_offset = (rigidbody.data.offset + collider.offset) * transform.scale;

	// Rotate
	double rotated_total_offset_x1 = total_offset.x * cos(radians1) - total_offset.y * sin(radians1);
	double rotated_total_offset_y1 = total_offset.x * sin(radians1) + total_offset.y * cos(radians1);

	// Final positions considering scaling and rotation
	return(transform.position + Vector2(rotated_total_offset_x1, rotated_total_offset_y1));

}