12 files changed, 294 insertions, 1 deletions

diff --git a/src/crepe/CMakeLists.txt b/src/crepe/CMakeLists.txt
index d938eb8..750a47d 100644
--- a/src/crepe/CMakeLists.txt
+++ b/src/crepe/CMakeLists.txt
@@ -12,8 +12,8 @@ target_sources(crepe PUBLIC
 	CollisionSystem.cpp
 	Collider.cpp
 	SDLContext.cpp
-
 	RenderSystem.cpp
+	DB.cpp
 )
 
 target_sources(crepe PUBLIC FILE_SET HEADERS FILES
@@ -31,6 +31,9 @@ target_sources(crepe PUBLIC FILE_SET HEADERS FILES
 	Collider.h
 	SDLContext.h
 	RenderSystem.h
+	ValueBroker.h
+	ValueBroker.hpp
+	DB.h
 )
 
 add_subdirectory(api)
diff --git a/src/crepe/DB.cpp b/src/crepe/DB.cpp
new file mode 100644
index 0000000..b8448a7
--- /dev/null
+++ b/src/crepe/DB.cpp
@@ -0,0 +1,67 @@
+#include <cstring>
+
+#include "util/log.h"
+
+#include "DB.h"
+
+using namespace std;
+using namespace crepe;
+
+DB::DB(const char * path) {
+	dbg_trace();
+	int ret;
+
+	// init database struct
+	libdb::DB * db;
+	if ((ret = libdb::db_create(&db, NULL, 0)) != 0)
+		throw nullptr; // TODO: exception
+	this->db = { db, [] (libdb::DB * db) { db->close(db, 0); } };
+
+	// load or create database file
+	if ((ret = this->db->open(this->db.get(), NULL, path, NULL, libdb::DB_BTREE, DB_CREATE, 0)) != 0) {
+		throw nullptr;
+	}
+
+	// create cursor
+	libdb::DBC * cursor;
+	if ((ret = this->db->cursor(this->db.get(), NULL, &cursor, 0)) != 0) {
+		throw nullptr;
+	}
+	this->cursor = { cursor, [] (libdb::DBC * cursor) { cursor->close(cursor); } };
+}
+
+
+libdb::DBT DB::to_thing(const string & thing) {
+	libdb::DBT thang;
+	memset(&thang, 0, sizeof(libdb::DBT));
+	thang.data = (void *) thing.data();
+	thang.size = thing.size();
+	return thang;
+}
+
+string DB::get(const string & key) {
+	libdb::DBT db_key = this->to_thing(key);
+	libdb::DBT db_val;
+	memset(&db_val, 0, sizeof(libdb::DBT));
+
+	// int ret = this->cursor->get(this->cursor.get(), NULL, &db_key, &db_val);
+	return "";
+}
+
+void DB::set(const string & key, const string & value) {
+	libdb::DBT db_key = this->to_thing(key);
+	libdb::DBT db_val = this->to_thing(value);
+	int ret = this->db->put(this->db.get(), NULL, &db_key, &db_val, 0);
+	// TODO: check flags
+	// TODO: check ret
+}
+
+bool DB::has(const std::string & key) {
+	try {
+		this->get(key);
+	} catch (...) {
+		return false;
+	}
+	return true;
+}
+
diff --git a/src/crepe/DB.h b/src/crepe/DB.h
new file mode 100644
index 0000000..010ef42
--- /dev/null
+++ b/src/crepe/DB.h
@@ -0,0 +1,34 @@
+#pragma once
+
+#include <string>
+#include <functional>
+#include <memory>
+
+namespace libdb {
+extern "C" {
+#include <db.h>
+}
+}
+
+namespace crepe {
+
+class DB {
+public:
+	DB(const char * path);
+	virtual ~DB() = default;
+
+public:
+	std::string get(const std::string & key);
+	void set(const std::string & key, const std::string & value);
+	bool has(const std::string & key);
+
+private:
+	std::unique_ptr<libdb::DB, std::function<void(libdb::DB *)>> db;
+	std::unique_ptr<libdb::DBC, std::function<void(libdb::DBC *)>> cursor;
+
+private:
+	libdb::DBT to_thing(const std::string & thing);
+};
+
+}
+
diff --git a/src/crepe/ValueBroker.h b/src/crepe/ValueBroker.h
new file mode 100644
index 0000000..9d30a2e
--- /dev/null
+++ b/src/crepe/ValueBroker.h
@@ -0,0 +1,27 @@
+#pragma once
+
+#include <functional>
+
+namespace crepe {
+
+template <typename T>
+class ValueBroker {
+public:
+	virtual void set(const T &);
+	virtual const T & get();
+
+	typedef std::function<void(T & value, const T & target)> setter_t;
+	typedef std::function<const T & (T & value)> getter_t;
+private:
+	T & value;
+	setter_t setter;
+	getter_t getter;
+public:
+	ValueBroker(T &, const setter_t &, const getter_t &);
+	ValueBroker(T &);
+};
+
+}
+
+#include "ValueBroker.hpp"
+
diff --git a/src/crepe/ValueBroker.hpp b/src/crepe/ValueBroker.hpp
new file mode 100644
index 0000000..ef31c17
--- /dev/null
+++ b/src/crepe/ValueBroker.hpp
@@ -0,0 +1,40 @@
+#pragma once
+
+#include <memory>
+
+#include "ValueBroker.h"
+
+namespace crepe {
+
+template <typename T>
+ValueBroker<T>::ValueBroker(T & value) :
+	value(value),
+	setter([] (T & value, const T & target) {
+		value = std::move(target);
+	}),
+	getter([] (T & value) -> const int & {
+		return value;
+	})
+	{
+}
+
+template <typename T>
+ValueBroker<T>::ValueBroker(T & value, const setter_t & setter, const getter_t & getter) :
+	value(value),
+	setter(setter),
+	getter(getter)
+	{
+}
+
+template <typename T>
+const T & ValueBroker<T>::get() {
+	return this->getter(this->value);
+}
+
+template <typename T>
+void ValueBroker<T>::set(const T & value) {
+	this->setter(this->value, value);
+}
+
+}
+
diff --git a/src/crepe/api/CMakeLists.txt b/src/crepe/api/CMakeLists.txt
index 0bb1263..97bc6b1 100644
--- a/src/crepe/api/CMakeLists.txt
+++ b/src/crepe/api/CMakeLists.txt
@@ -11,6 +11,7 @@ target_sources(crepe PUBLIC
 	Texture.cpp
 	AssetManager.cpp
 	Sprite.cpp
+	SaveManager.cpp
 )
 
 target_sources(crepe PUBLIC FILE_SET HEADERS FILES
@@ -28,4 +29,6 @@ target_sources(crepe PUBLIC FILE_SET HEADERS FILES
 	Texture.h 
 	AssetManager.h 
 	AssetManager.hpp
+	SaveManager.h
+	SaveManager.hpp
 )
diff --git a/src/crepe/api/SaveManager.cpp b/src/crepe/api/SaveManager.cpp
new file mode 100644
index 0000000..83ff0fa
--- /dev/null
+++ b/src/crepe/api/SaveManager.cpp
@@ -0,0 +1,20 @@
+#include "../DB.h"
+#include "util/log.h"
+
+#include "SaveManager.h"
+
+using namespace std;
+using namespace crepe;
+using namespace crepe::api;
+
+SaveManager::SaveManager() {
+	dbg_trace();
+	this->db = make_unique<DB>("./save.crepe.db");
+}
+
+SaveManager & SaveManager::get_instance() {
+	dbg_trace();
+	static SaveManager instance;
+	return instance;
+}
+
diff --git a/src/crepe/api/SaveManager.h b/src/crepe/api/SaveManager.h
new file mode 100644
index 0000000..110735d
--- /dev/null
+++ b/src/crepe/api/SaveManager.h
@@ -0,0 +1,48 @@
+#pragma once
+
+#include <memory>
+
+#include "../ValueBroker.h"
+
+namespace crepe {
+class DB;
+}
+
+namespace crepe::api {
+
+class SaveManager {
+public:
+	//! Get a reference to a value and initialize it with a value if it does not yet exist
+	template <typename T>
+	ValueBroker<T> & get(const char * key, const T & default_value);
+
+	//! Get a reference to a value
+	template <typename T>
+	ValueBroker<T> & get(const char * key);
+
+	//! Set a value directly
+	template <typename T>
+	void set(const char * key, const T & value);
+
+	//! Check if the save file has a value for this \c key
+	bool has(const char * key);
+
+private:
+	SaveManager();
+	virtual ~SaveManager() = default;
+
+public:
+	// singleton
+	static SaveManager & get_instance();
+	SaveManager(const SaveManager &) = delete;
+	SaveManager(SaveManager &&) = delete;
+	SaveManager & operator = (const SaveManager &) = delete;
+	SaveManager & operator = (SaveManager &&) = delete;
+
+private:
+	std::unique_ptr<DB> db = nullptr;
+};
+
+}
+
+#include "SaveManager.hpp"
diff --git a/src/crepe/api/SaveManager.hpp b/src/crepe/api/SaveManager.hpp
new file mode 100644
index 0000000..44f58ed
--- /dev/null
+++ b/src/crepe/api/SaveManager.hpp
@@ -0,0 +1,4 @@
+#pragma once
+
+#include "SaveManager.h"
+
diff --git a/src/crepe/util/CMakeLists.txt b/src/crepe/util/CMakeLists.txt
index bbeaad9..01d8f22 100644
--- a/src/crepe/util/CMakeLists.txt
+++ b/src/crepe/util/CMakeLists.txt
@@ -8,5 +8,7 @@ target_sources(crepe PUBLIC FILE_SET HEADERS FILES
 	color.h
 	log.h
 	fmt.h
+	Proxy.h
+	Proxy.hpp
 )
 
diff --git a/src/crepe/util/Proxy.h b/src/crepe/util/Proxy.h
new file mode 100644
index 0000000..f8eb1f2
--- /dev/null
+++ b/src/crepe/util/Proxy.h
@@ -0,0 +1,23 @@
+#pragma once
+
+#include "ValueBroker.h"
+
+namespace crepe::util {
+
+template <typename T>
+class Proxy {
+public:
+	Proxy & operator = (const T &);
+	operator const T & () const;
+
+public:
+	Proxy(ValueBroker<T> &);
+
+private:
+	ValueBroker<T> & broker;
+};
+
+}
+
+#include "Proxy.hpp"
+
diff --git a/src/crepe/util/Proxy.hpp b/src/crepe/util/Proxy.hpp
new file mode 100644
index 0000000..5738d9c
--- /dev/null
+++ b/src/crepe/util/Proxy.hpp
@@ -0,0 +1,22 @@
+#pragma once
+
+#include "Proxy.h"
+
+namespace crepe::util {
+
+template <typename T>
+Proxy<T>::Proxy(ValueBroker<T> & broker) : broker(broker) { }
+
+template <typename T>
+Proxy<T> & Proxy<T>::operator = (const T & val) {
+	this->broker.set(val);
+	return *this;
+}
+
+template <typename T>
+Proxy<T>::operator const T & () const {
+	return this->broker.get();
+}
+
+}
+