3 files changed, 140 insertions, 25 deletions

diff --git a/src/crepe/manager/ComponentManager.cpp b/src/crepe/manager/ComponentManager.cpp
index 80cf8b4..df30d27 100644
--- a/src/crepe/manager/ComponentManager.cpp
+++ b/src/crepe/manager/ComponentManager.cpp
@@ -1,4 +1,5 @@
 #include "../api/GameObject.h"
+#include "../api/Metadata.h"
 #include "../types.h"
 #include "../util/Log.h"
 
@@ -61,3 +62,13 @@ GameObject ComponentManager::new_object(const string & name, const string & tag,
 void ComponentManager::set_persistent(game_object_id_t id, bool persistent) {
 	this->persistent[id] = persistent;
 }
+
+set<game_object_id_t> ComponentManager::get_objects_by_name(const string & name) const {
+	return this->get_objects_by_predicate<Metadata>(
+		[name](const Metadata & data) { return data.name == name; });
+}
+
+set<game_object_id_t> ComponentManager::get_objects_by_tag(const string & tag) const {
+	return this->get_objects_by_predicate<Metadata>(
+		[tag](const Metadata & data) { return data.tag == tag; });
+}
diff --git a/src/crepe/manager/ComponentManager.h b/src/crepe/manager/ComponentManager.h
index 44429d9..19a8e81 100644
--- a/src/crepe/manager/ComponentManager.h
+++ b/src/crepe/manager/ComponentManager.h
@@ -1,6 +1,7 @@
 #pragma once
 
 #include <memory>
+#include <set>
 #include <typeindex>
 #include <unordered_map>
 #include <vector>
@@ -134,8 +135,77 @@ public:
 	 */
 	template <typename T>
 	RefVector<T> get_components_by_type() const;
+	/**
+	 * \brief Get all components of a specific type on a GameObject with name \c name
+	 * 
+	 * \tparam T The type of the component
+	 * \param name Metadata::name for the same game_object_id as the returned components
+	 * \return Components matching criteria
+	 */
+	template <typename T>
+	RefVector<T> get_components_by_name(const std::string & name) const;
+	/**
+	 * \brief Get all components of a specific type on a GameObject with tag \c tag
+	 * 
+	 * \tparam T The type of the component
+	 * \param name Metadata::tag for the same game_object_id as the returned components
+	 * \return Components matching criteria
+	 */
+	template <typename T>
+	RefVector<T> get_components_by_tag(const std::string & tag) const;
+
+private:
+	/**
+	 * \brief Get object IDs by predicate function
+	 *
+	 * This function calls the predicate function \c pred for all components matching type \c T,
+	 * and adds their parent game_object_id to a \c std::set if the predicate returns true.
+	 *
+	 * \tparam T The type of the component to check the predicate against
+	 * \param pred Predicate function
+	 *
+	 * \note The predicate function may be called for multiple components with the same \c
+	 * game_object_id. In this case, the ID is added if *any* call returns \c true.
+	 *
+	 * \returns game_object_id for all components where the predicate returned true
+	 */
+	template <typename T>
+	std::set<game_object_id_t>
+	get_objects_by_predicate(const std::function<bool(const T &)> & pred) const;
+
+	/**
+	 * \brief Get components of type \c T for multiple game object IDs
+	 *
+	 * \tparam T The type of the components to return
+	 * \param ids The object IDs
+	 *
+	 * \return All components matching type \c T and one of the IDs in \c ids
+	 */
+	template <typename T>
+	RefVector<T> get_components_by_ids(const std::set<game_object_id_t> & ids) const;
+
+	/**
+	 * \brief Get object IDs for objects with name \c name
+	 *
+	 * \param name Object name to match
+	 * \returns Object IDs where Metadata::name is equal to \c name
+	 */
+	std::set<game_object_id_t> get_objects_by_name(const std::string & name) const;
+	/**
+	 * \brief Get object IDs for objects with tag \c tag
+	 *
+	 * \param tag Object tag to match
+	 * \returns Object IDs where Metadata::tag is equal to \c tag
+	 */
+	std::set<game_object_id_t> get_objects_by_tag(const std::string & tag) const;
 
 private:
+	//! By Component \c std::type_index (readability helper type)
+	template <typename T>
+	using by_type = std::unordered_map<std::type_index, T>;
+	//! By \c game_object_id index (readability helper type)
+	template <typename T>
+	using by_id_index = std::vector<T>;
 	/**
 	 * \brief The components
 	 *
@@ -146,8 +216,7 @@ private:
 	 * The first vector is for the ids of the GameObjects and the second vector is for the
 	 * components (because a GameObject might have multiple components).
 	 */
-	std::unordered_map<std::type_index, std::vector<std::vector<std::unique_ptr<Component>>>>
-		components;
+	by_type<by_id_index<std::vector<std::unique_ptr<Component>>>> components;
 
 	//! Persistent flag for each GameObject
 	std::unordered_map<game_object_id_t, bool> persistent;
diff --git a/src/crepe/manager/ComponentManager.hpp b/src/crepe/manager/ComponentManager.hpp
index ffb38ec..9e70865 100644
--- a/src/crepe/manager/ComponentManager.hpp
+++ b/src/crepe/manager/ComponentManager.hpp
@@ -95,32 +95,25 @@ template <typename T>
 RefVector<T> ComponentManager::get_components_by_id(game_object_id_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<>
-	RefVector<T> component_vector;
-
-	if (this->components.find(type) == this->components.end()) return component_vector;
-
-	// Get the correct vector<>
-	const vector<vector<unique_ptr<Component>>> & component_array = this->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()) return component_vector;
-
-	// 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());
-
-		if (casted_component == nullptr) continue;
+	static_assert(is_base_of<Component, T>::value,
+				  "get_components_by_id must recieve a derivative class of Component");
 
-		// Add the dereferenced raw pointer to the vector<>
-		component_vector.push_back(*casted_component);
+	type_index type = typeid(T);
+	if (!this->components.contains(type)) return {};
+
+	const by_id_index<vector<unique_ptr<Component>>> & components_by_id
+		= this->components.at(type);
+	if (id >= components_by_id.size()) return {};
+
+	RefVector<T> out = {};
+	const vector<unique_ptr<Component>> & components = components_by_id.at(id);
+	for (auto & component_ptr : components) {
+		if (component_ptr == nullptr) continue;
+		Component & component = *component_ptr.get();
+		out.push_back(static_cast<T &>(component));
 	}
 
-	return component_vector;
+	return out;
 }
 
 template <typename T>
@@ -158,4 +151,46 @@ RefVector<T> ComponentManager::get_components_by_type() const {
 	return component_vector;
 }
 
+template <typename T>
+std::set<game_object_id_t>
+ComponentManager::get_objects_by_predicate(const std::function<bool(const T &)> & pred) const {
+	using namespace std;
+
+	set<game_object_id_t> objects = {};
+	RefVector<T> components = this->get_components_by_type<T>();
+
+	for (const T & component : components) {
+		game_object_id_t id = dynamic_cast<const Component &>(component).game_object_id;
+		if (objects.contains(id)) continue;
+		if (!pred(component)) continue;
+		objects.insert(id);
+	}
+
+	return objects;
+}
+
+template <typename T>
+RefVector<T>
+ComponentManager::get_components_by_ids(const std::set<game_object_id_t> & ids) const {
+	using namespace std;
+
+	RefVector<T> out = {};
+	for (game_object_id_t id : ids) {
+		RefVector<T> components = get_components_by_id<T>(id);
+		out.insert(out.end(), components.begin(), components.end());
+	}
+
+	return out;
+}
+
+template <typename T>
+RefVector<T> ComponentManager::get_components_by_name(const std::string & name) const {
+	return this->get_components_by_ids<T>(this->get_objects_by_name(name));
+}
+
+template <typename T>
+RefVector<T> ComponentManager::get_components_by_tag(const std::string & tag) const {
+	return this->get_components_by_ids<T>(this->get_objects_by_tag(tag));
+}
+
 } // namespace crepe