7 files changed, 103 insertions, 41 deletions

diff --git a/src/crepe/Component.cpp b/src/crepe/Component.cpp
index acfd35c..141e1a8 100644
--- a/src/crepe/Component.cpp
+++ b/src/crepe/Component.cpp
@@ -3,3 +3,8 @@
 using namespace crepe;
 
 Component::Component(game_object_id_t id) : game_object_id(id) {}
+
+Component & Component::operator=(const Component &) {
+	return *this;
+}
+
diff --git a/src/crepe/Component.h b/src/crepe/Component.h
index eff5a58..47c5c34 100644
--- a/src/crepe/Component.h
+++ b/src/crepe/Component.h
@@ -32,9 +32,13 @@ protected:
 	//! Only ComponentManager can create components
 	friend class ComponentManager;
 
-	Component(const Component &) = delete;
+	// create snapshot
+	Component(const Component &) = default;
+	// restore snapshot
+	virtual Component & operator=(const Component &);
+
+	// components are never moved
 	Component(Component &&) = delete;
-	virtual Component & operator=(const Component &) = delete;
 	virtual Component & operator=(Component &&) = delete;
 
 public:
diff --git a/src/crepe/api/LoopManager.cpp b/src/crepe/api/LoopManager.cpp
index 637fbe1..ff428fd 100644
--- a/src/crepe/api/LoopManager.cpp
+++ b/src/crepe/api/LoopManager.cpp
@@ -13,18 +13,17 @@
 using namespace crepe;
 using namespace std;
 
-LoopManager::LoopManager()
-	: systems({
-		ScriptSystem{this->mediator},
-		PhysicsSystem{this->mediator},
-		CollisionSystem{this->mediator},
-		AnimatorSystem{this->mediator},
-		ParticleSystem{this->mediator},
-		RenderSystem{this->mediator},
-		InputSystem{this->mediator},
-		EventSystem{this->mediator},
-		AudioSystem{this->mediator},
-	}) { }
+LoopManager::LoopManager() {
+	this->load_system<ScriptSystem>();
+	this->load_system<PhysicsSystem>();
+	this->load_system<CollisionSystem>();
+	this->load_system<AnimatorSystem>();
+	this->load_system<ParticleSystem>();
+	this->load_system<RenderSystem>();
+	this->load_system<InputSystem>();
+	this->load_system<EventSystem>();
+	this->load_system<AudioSystem>();
+}
 
 void LoopManager::start() {
 	this->setup();
@@ -32,16 +31,16 @@ void LoopManager::start() {
 }
 
 void LoopManager::fixed_update() {
-	for (System & system : this->systems) {
-		if (!system.active) continue;
-		system.fixed_update();
+	for (auto & [type, system] : this->systems) {
+		if (!system->active) continue;
+		system->fixed_update();
 	}
 }
 
 void LoopManager::frame_update() {
-	for (System & system : this->systems) {
-		if (!system.active) continue;
-		system.frame_update();
+	for (auto & [type, system] : this->systems) {
+		if (!system->active) continue;
+		system->frame_update();
 	}
 }
 
diff --git a/src/crepe/api/LoopManager.h b/src/crepe/api/LoopManager.h
index 1183a4d..4b1fc1e 100644
--- a/src/crepe/api/LoopManager.h
+++ b/src/crepe/api/LoopManager.h
@@ -73,15 +73,32 @@ private:
 	SaveManager save_manager{mediator};
 
 	//! SDL context \todo no more singletons!
-	SDLContext & sdl_context = SDLContext::get_instance();
+	SDLContext & sdl_context = mediator.sdl_context;
 	//! Loop timer \todo no more singletons!
 	LoopTimer & loop_timer = LoopTimer::get_instance();
 
 private:
 	/**
 	 * \brief Collection of System instances
+	 *
+	 * This map holds System instances indexed by the system's class typeid. It is filled in the
+	 * constructor of \c LoopManager using LoopManager::load_system.
+	 */
+	std::unordered_map<std::type_index, std::unique_ptr<System>> systems;
+	/**
+	 * \brief Initialize a system
+	 * \tparam T System type (must be derivative of \c System)
+	 */
+	template <class T>
+	void load_system();
+	/**
+	 * \brief Retrieve a reference to ECS system
+	 * \tparam T System type
+	 * \returns Reference to system instance
+	 * \throws std::runtime_error if the System is not initialized
 	 */
-	std::vector<System> systems;
+	template <class T>
+	T & get_system();
 };
 
 } // namespace crepe
diff --git a/src/crepe/api/LoopManager.hpp b/src/crepe/api/LoopManager.hpp
index 51afa70..627b281 100644
--- a/src/crepe/api/LoopManager.hpp
+++ b/src/crepe/api/LoopManager.hpp
@@ -1,5 +1,10 @@
 #pragma once
 
+#include <memory>
+#include <cassert>
+#include <format>
+
+#include "../system/System.h"
 #include "LoopManager.h"
 
 namespace crepe {
@@ -9,4 +14,33 @@ void LoopManager::add_scene() {
 	this->scene_manager.add_scene<T>();
 }
 
+template <class T>
+T & LoopManager::get_system() {
+	using namespace std;
+	static_assert(is_base_of<System, T>::value, "get_system must recieve a derivative class of System");
+
+	const type_info & type = typeid(T);
+	if (!this->systems.contains(type))
+		throw runtime_error(format("LoopManager: {} is not initialized", type.name()));
+
+	System * system = this->systems.at(type).get();
+	T * concrete_system = dynamic_cast<T *>(system);
+	assert(concrete_system != nullptr);
+
+	return *concrete_system;
+}
+
+template <class T>
+void LoopManager::load_system() {
+	using namespace std;
+	static_assert(is_base_of<System, T>::value,
+			"load_system must recieve a derivative class of System");
+
+	const type_info & type = typeid(T);
+	if (this->systems.contains(type))
+		throw runtime_error(format("LoopManager: {} is already initialized", type.name()));
+	System * system = new T(this->mediator);
+	this->systems[type] = unique_ptr<System>(system);
+}
+
 } // namespace crepe
diff --git a/src/crepe/manager/ComponentManager.h b/src/crepe/manager/ComponentManager.h
index 19a8e81..94fd94f 100644
--- a/src/crepe/manager/ComponentManager.h
+++ b/src/crepe/manager/ComponentManager.h
@@ -21,13 +21,6 @@ class GameObject;
  * This class manages all components. It provides methods to add, delete and get components.
  */
 class ComponentManager : public Manager {
-	// TODO: This relation should be removed! I (loek) believe that the scene manager should
-	// create/destroy components because the GameObject's are stored in concrete Scene classes,
-	// which will in turn call GameObject's destructor, which will in turn call
-	// ComponentManager::delete_components_by_id or something. This is a pretty major change, so
-	// here is a comment and temporary fix instead :tada:
-	friend class SceneManager;
-
 public:
 	ComponentManager(Mediator & mediator);
 	~ComponentManager(); // dbg_trace
@@ -49,12 +42,7 @@ public:
 						  const vec2 & position = {0, 0}, double rotation = 0,
 						  double scale = 1);
 
-protected:
-	/**
-	 * GameObject is used as an interface to add/remove components, and the game programmer is
-	 * supposed to use it instead of interfacing with the component manager directly.
-	 */
-	friend class GameObject;
+public:
 	/**
 	 * \brief Add a component to the ComponentManager
 	 *
@@ -154,6 +142,16 @@ public:
 	template <typename T>
 	RefVector<T> get_components_by_tag(const std::string & tag) const;
 
+	struct SnapshotComponent {
+		by_type<by_id_index<std::vector<std::unique_ptr<Component>>>> components;
+		Component component;
+	};
+	struct Snapshot {
+		
+	};
+	Snapshot save();
+	void restore(const Snapshot &);
+
 private:
 	/**
 	 * \brief Get object IDs by predicate function
diff --git a/src/crepe/manager/ReplayManager.h b/src/crepe/manager/ReplayManager.h
index 242eae4..c50196c 100644
--- a/src/crepe/manager/ReplayManager.h
+++ b/src/crepe/manager/ReplayManager.h
@@ -1,6 +1,8 @@
 #pragma once
 
 #include "Manager.h"
+#include "ComponentManager.h"
+#include <unordered_map>
 
 namespace crepe {
 
@@ -18,15 +20,18 @@ protected:
 	void record_frame();
 
 private:
-	bool recording;
-	struct Recording {
-		recording_t id;
-		std::vector<Memento> frames;
-	};
+	typedef std::vector<ComponentManager::Snapshot> Recording;
+
+	bool recording = false;
+	recording_t current_recording = -1;
+
+
+	std::unordered_map<recording_t, std::unique_ptr<Recording>> memory;
 public:
 	void record_start();
 	recording_t record_end();
-	
+	void play(recording_t handle);
+	void release(recording_t handle);
 };
 
 } // namespace crepe