#pragma once

#include <type_traits>

#include "ComponentManager.h"

namespace crepe {

template <class T, typename... Args>
void ComponentManager::add_component(uint32_t id, Args &&... args) {
	using namespace std;

	static_assert(is_base_of<Component, T>::value,
				  "add_component must recieve a derivative class of Component");

	// Determine the type of T (this is used as the key of the unordered_map<>)
	type_index type = typeid(T);

	// Check if this component type is already in the unordered_map<>
	if (components.find(type) == components.end()) {
		//If not, create a new (empty) vector<> of vector<unique_ptr<Component>>
		components[type] = vector<vector<unique_ptr<Component>>>();
	}

	// Resize the vector<> if the id is greater than the current size
	if (id >= components[type].size()) {
		// Initialize new slots to nullptr (resize does automatically init to nullptr)
		components[type].resize(id + 1);
	}

	// Create a new component of type T (arguments directly forwarded). The
	// constructor must be called by ComponentManager.
	T * instance = new T(id,forward<Args>(args)...);
	// store its unique_ptr in the vector<>
	components[type][id].push_back(unique_ptr<T>(instance));
}

template <typename T>
void ComponentManager::delete_components_by_id(uint32_t id) {
	using namespace std;

	// Determine the type of T (this is used as the key of the unordered_map<>)
	type_index type = typeid(T);

	// Find the type (in the unordered_map<>)
	if (components.find(type) != components.end()) {
		// Get the correct vector<>
		vector<vector<unique_ptr<Component>>> & component_array
			= components[type];

		// Make sure that the id (that we are looking for) is within the boundaries of the vector<>
		if (id < component_array.size()) {
			// Clear the whole vector<> of this specific type and id
			component_array[id].clear();
		}
	}
}

template <typename T>
void ComponentManager::delete_components() {
	// Determine the type of T (this is used as the key of the unordered_map<>)
	std::type_index type = typeid(T);

	// Find the type (in the unordered_map<>)
	if (components.find(type) != components.end()) {
		// Clear the whole vector<> of this specific type
		components[type].clear();
	}
}

template <typename T>
std::vector<std::reference_wrapper<T>>
ComponentManager::get_components_by_id(uint32_t id) const {
	using namespace std;

	// Determine the type of T (this is used as the key of the unordered_map<>)
	type_index type = typeid(T);

	// Create an empty vector<>
	vector<reference_wrapper<T>> component_vector;

	// Find the type (in the unordered_map<>)
	if (components.find(type) != components.end()) {
		// Get the correct vector<>
		const vector<vector<unique_ptr<Component>>> & component_array
			= components.at(type);

		// Make sure that the id (that we are looking for) is within the boundaries of the vector<>
		if (id < component_array.size()) {
			// Loop trough the whole vector<>
			for (const unique_ptr<Component> & component_ptr :
				 component_array[id]) {
				// Cast the unique_ptr to a raw pointer
				T * casted_component = static_cast<T *>(component_ptr.get());

				// Ensure that the cast was successful
				if (casted_component) {
					// Add the dereferenced raw pointer to the vector<>
					component_vector.push_back(*casted_component);
				}
			}
		}
	}

	// Return the vector<>
	return component_vector;
}

template <typename T>
std::vector<std::reference_wrapper<T>>
ComponentManager::get_components_by_type() const {
	using namespace std;

	// Determine the type of T (this is used as the key of the unordered_map<>)
	type_index type = typeid(T);

	// Create an empty vector<>
	vector<reference_wrapper<T>> component_vector;
	// Set the id to 0 (the id will also be stored in the returned vector<>)
	// uint32_t id = 0;

	// Find the type (in the unordered_map<>)
	if (components.find(type) != components.end()) {

		// Get the correct vector<>
		const vector<vector<unique_ptr<Component>>> & component_array
			= components.at(type);

		// Loop through the whole vector<>
		for (const vector<unique_ptr<Component>> & component :
			 component_array) {
			// Loop trough the whole vector<>
			for (const unique_ptr<Component> & component_ptr : component) {
				// Cast the unique_ptr to a raw pointer
				T * casted_component = static_cast<T *>(component_ptr.get());

				// Ensure that the cast was successful
				if (casted_component) {
					// Pair the dereferenced raw pointer and the id and add it to the vector<>
					component_vector.emplace_back(ref(*casted_component));
				}
			}

			// Increase the id (the id will also be stored in the returned vector<>)
			//++id;
		}
	}

	// Return the vector<>
	return component_vector;
}

} // namespace crepe