diff --git a/README.md b/README.md
new file mode 100644
index 0000000..1a456b8
--- /dev/null
+++ b/README.md
@@ -0,0 +1,3 @@
+# libBeatsaber
+
+a small Library to read and write beatsaber level.
diff --git a/include/beatsaber-impl/beatlevelimpl.h b/include/beatsaber-impl/beatlevelimpl.h
new file mode 100644
index 0000000..bddb1c0
--- /dev/null
+++ b/include/beatsaber-impl/beatlevelimpl.h
@@ -0,0 +1,41 @@
+#pragma once
+
+#include "beatlevel.h"
+
+#include <nlohmann/json_fwd.hpp>
+
+using json = nlohmann::json;
+
+namespace Beatsaber {
+
+class BeatLevelImpl : public BeatLevel, protected std::enable_shared_from_this<BeatLevelImpl> {
+protected:
+	std::weak_ptr<BeatSet> parent;
+
+	Difficulty::Difficulty dif;
+	int32_t diffRank;
+	std::string filename;
+
+	double njs;
+	double nso;
+
+	const json& base;
+
+public:
+	BeatLevelImpl(std::weak_ptr<BeatSet> p, const json& j);
+	virtual ~BeatLevelImpl();
+
+	virtual Difficulty::Difficulty getDifficulty() const override;
+	virtual int32_t getDifficultyRank() const override;
+	virtual std::string getFilename() const override;
+	virtual double getNoteJumpSpeed() const override; // in m
+	virtual double getNoteStartOffset() const override;
+	virtual std::string getCustomData() const override;
+
+	//TODO: get level content
+
+	virtual std::shared_ptr<BeatSet> getBeatSet() const override;
+	virtual std::shared_ptr<BeatMap> getBeatMap() const override;
+};
+
+}
\ No newline at end of file
diff --git a/include/beatsaber-impl/beatmapimpl.h b/include/beatsaber-impl/beatmapimpl.h
index ee498dd..c944361 100644
--- a/include/beatsaber-impl/beatmapimpl.h
+++ b/include/beatsaber-impl/beatmapimpl.h
@@ -2,6 +2,7 @@
 
 #include "beatmap.h"
 
+#include <memory>
 #include <nlohmann/json.hpp>
 
 #include "beatset.h"
@@ -10,7 +11,7 @@ using json = nlohmann::json;
 
 namespace Beatsaber {
 
-class BeatMapImpl : public BeatMap {
+class BeatMapImpl : public BeatMap, protected std::enable_shared_from_this<BeatMapImpl> {
 
 protected:
 	const std::string path;
diff --git a/include/beatsaber-impl/beatsetimpl.h b/include/beatsaber-impl/beatsetimpl.h
index ce33561..3e58549 100644
--- a/include/beatsaber-impl/beatsetimpl.h
+++ b/include/beatsaber-impl/beatsetimpl.h
@@ -6,18 +6,21 @@ using json = nlohmann::json;
 
 namespace Beatsaber {
 
-class BeatSetImpl : public BeatSet {
+class BeatSetImpl : public BeatSet, protected std::enable_shared_from_this<BeatSetImpl> {
 protected:
 
+	std::weak_ptr<BeatMap> parent;
 	BeatmapCharacteristic::BeatmapCharacteristic characteristic;
 
+
 public:
-	BeatSetImpl(const json& j);
+	BeatSetImpl(std::weak_ptr<BeatMap> p, const json& j);
 	BeatSetImpl(const BeatSetImpl& c) = default;
 	BeatSetImpl() = default;
 	virtual ~BeatSetImpl();
 
-	virtual BeatmapCharacteristic::BeatmapCharacteristic getCharacteristic() const;
+	virtual BeatmapCharacteristic::BeatmapCharacteristic getCharacteristic() const override;
+	virtual std::shared_ptr<BeatMap> getBeatMap() const override;
 };
 
 }
\ No newline at end of file
diff --git a/include/beatsaber/beatlevel.h b/include/beatsaber/beatlevel.h
new file mode 100644
index 0000000..61c5a1e
--- /dev/null
+++ b/include/beatsaber/beatlevel.h
@@ -0,0 +1,33 @@
+#pragma once
+
+#include <string>
+#include <memory>
+
+#include "difficulties.h"
+
+namespace Beatsaber {
+
+//fwd
+class BeatSet;
+class BeatMap;
+
+class BeatLevel {
+public:
+
+	virtual ~BeatLevel() {}
+
+	virtual Difficulty::Difficulty getDifficulty() const = 0;
+	virtual int32_t getDifficultyRank() const = 0;
+	virtual std::string getFilename() const = 0;
+	virtual double getNoteJumpSpeed() const = 0; // in m
+	virtual double getNoteStartOffset() const = 0;
+	virtual std::string getCustomData() const = 0;
+
+	//TODO: get level content
+
+	virtual std::shared_ptr<BeatSet> getBeatSet() const = 0; // parent
+	virtual std::shared_ptr<BeatMap> getBeatMap() const = 0; // grandparent
+
+};
+
+}
\ No newline at end of file
diff --git a/include/beatsaber/beatmap.h b/include/beatsaber/beatmap.h
index e6c82cd..2d30e88 100644
--- a/include/beatsaber/beatmap.h
+++ b/include/beatsaber/beatmap.h
@@ -6,15 +6,12 @@
 #include <vector>
 
 #include "beatmapcharacteristic.h"
+#include "beatlevel.h"
+
 #include "beatset.h"
 
 namespace Beatsaber {
 
-class BeatLevel {
-public:
-
-};
-
 class BeatMap {
 public:
 	virtual ~BeatMap() {}
diff --git a/include/beatsaber/beatset.h b/include/beatsaber/beatset.h
index 0501a57..9168738 100644
--- a/include/beatsaber/beatset.h
+++ b/include/beatsaber/beatset.h
@@ -1,15 +1,21 @@
 #pragma once
 
+#include <memory>
 
 #include "beatmapcharacteristic.h"
+#include "beatlevel.h"
 
 namespace Beatsaber {
 
+//fwd decl.
+class BeatMap;
+
 class BeatSet {
 public:
 	virtual ~BeatSet() {}
 
 	virtual BeatmapCharacteristic::BeatmapCharacteristic getCharacteristic() const = 0;
+	virtual std::shared_ptr<BeatMap> getBeatMap() const = 0;
 };
 
 }
\ No newline at end of file
diff --git a/include/beatsaber/difficulties.h b/include/beatsaber/difficulties.h
index 95ecc48..1dc3f13 100644
--- a/include/beatsaber/difficulties.h
+++ b/include/beatsaber/difficulties.h
@@ -12,5 +12,10 @@ namespace Beatsaber {
 			EXPERT,
 			EXPERTP,
 		};
+
+		const std::string difficultyName[] {"None", "Easy", "Normal", "Hard", "Expert", "ExpertPlus"};
+		const std::uint8_t difficultyNameSize = sizeof(difficultyName)/sizeof(std::string);
+
+		Difficulty getByString(const std::string& str);
 	}
 }
\ No newline at end of file
diff --git a/src/beatlevel.cpp b/src/beatlevel.cpp
new file mode 100644
index 0000000..b5c6857
--- /dev/null
+++ b/src/beatlevel.cpp
@@ -0,0 +1,59 @@
+#include "beatlevelimpl.h"
+
+#include <nlohmann/json.hpp>
+
+#include "beatset.h"
+
+namespace Beatsaber {
+
+BeatLevelImpl::BeatLevelImpl(std::weak_ptr<BeatSet> p, const json& j) : parent(p), base(j) {
+	dif = Difficulty::getByString(j.value("_difficulty", ""));
+	diffRank = j.value("_difficultyRank", 0);
+	filename = j.value("_beatmapFilename", "");
+	njs = j.value("_noteJumpMovementSpeed", -1);
+	nso = j.value("_noteJumpStartBeatOffset", 0);
+
+	//load level content
+	if(!filename.empty()) {
+
+	}
+}
+
+BeatLevelImpl::~BeatLevelImpl() {}
+
+Difficulty::Difficulty BeatLevelImpl::getDifficulty() const {
+	return dif;
+}
+
+int32_t BeatLevelImpl::getDifficultyRank() const {
+	return diffRank;
+}
+
+std::string BeatLevelImpl::getFilename() const {
+	return filename;
+}
+
+double BeatLevelImpl::getNoteJumpSpeed() const {
+	return njs;
+}
+
+double BeatLevelImpl::getNoteStartOffset() const {
+	return nso;
+}
+
+std::string BeatLevelImpl::getCustomData() const {
+	if(base.contains("_customData")) {
+		return base["_customData"].dump();
+	}
+	return "";
+}
+
+std::shared_ptr<BeatSet> BeatLevelImpl::getBeatSet() const {
+	return parent.lock();
+}
+
+std::shared_ptr<BeatMap> BeatLevelImpl::getBeatMap() const {
+	return parent.lock()->getBeatMap();
+}
+
+}
\ No newline at end of file
diff --git a/src/beatmap.cpp b/src/beatmap.cpp
index cef2930..a8916d6 100644
--- a/src/beatmap.cpp
+++ b/src/beatmap.cpp
@@ -24,7 +24,7 @@ bool BeatMapImpl::load() {
 
 			//load all the beatsets
 			for(const json& jsonbeatset : beatsets) {
-				beatSets.push_back(std::make_shared<BeatSetImpl>(jsonbeatset));
+				beatSets.push_back(std::make_shared<BeatSetImpl>(shared_from_this(), jsonbeatset));
 			}
 		}
 
@@ -98,7 +98,10 @@ std::string BeatMapImpl::get360EnvName() const {
 }
 
 std::string BeatMapImpl::getCustomData() const {
-	return infobase["_customData"].dump();
+	if(infobase.contains("_customData")) {
+		return infobase["_customData"].dump();
+	}
+	return "";
 }
 
 const std::vector<std::shared_ptr<BeatSet>>& BeatMapImpl::getBeatSets() const {
diff --git a/src/beatset.cpp b/src/beatset.cpp
index 036847a..61f3a91 100644
--- a/src/beatset.cpp
+++ b/src/beatset.cpp
@@ -4,7 +4,7 @@
 
 namespace Beatsaber {
 
-BeatSetImpl::BeatSetImpl(const json& j) : characteristic(BeatmapCharacteristic::getByString(j["_beatmapCharacteristicName"])) {
+BeatSetImpl::BeatSetImpl(std::weak_ptr<BeatMap> p, const json& j) : parent(p), characteristic(BeatmapCharacteristic::getByString(j["_beatmapCharacteristicName"])) {
 }
 
 BeatSetImpl::~BeatSetImpl() {}
@@ -13,4 +13,8 @@ BeatmapCharacteristic::BeatmapCharacteristic BeatSetImpl::getCharacteristic() co
 	return characteristic;
 }
 
+std::shared_ptr<BeatMap> BeatSetImpl::getBeatMap() const {
+	return parent.lock();
+}
+
 }
\ No newline at end of file
diff --git a/src/enums.cpp b/src/enums.cpp
index 0f5c2dd..8fe0a05 100644
--- a/src/enums.cpp
+++ b/src/enums.cpp
@@ -1,4 +1,5 @@
 #include "beatmapcharacteristic.h"
+#include "difficulties.h"
 
 namespace Beatsaber {
 namespace BeatmapCharacteristic {
@@ -12,5 +13,16 @@ BeatmapCharacteristic getByString(const std::string& str) {
 	return BeatmapCharacteristic::NONE;
 }
 
+}
+
+namespace Difficulty {
+Difficulty getByString(const std::string& str) {
+	for(uint8_t i = 0; i < difficultyNameSize; ++i) {
+		if(str == difficultyName[i]) { //TODO equals ignore Case
+			return (Difficulty) i;
+		}
+	}
+	return Difficulty::NONE;
+}
 }
 }
\ No newline at end of file
diff --git a/tests/main.cpp b/tests/main.cpp
index 0b179c5..371c6d2 100644
--- a/tests/main.cpp
+++ b/tests/main.cpp
@@ -4,8 +4,12 @@
 #include "beatmap.h"
 
 //tests
+int difficulties_test();
+int characteristics_test();
 
-test_t tests[] = {NULL};
+test_t tests[] = {
+	difficulties_test, characteristics_test,
+	NULL};
 
 int main(int argc, char** argv) {
 
diff --git a/tests/test.h b/tests/test.h
index 890d25b..fb492f1 100644
--- a/tests/test.h
+++ b/tests/test.h
@@ -6,6 +6,7 @@
 #define TESTDATA "./tests/data/"
 
 #define ASSERT(BED, ERR) if(!(BED)) { std::cout << __FILE__ << ":" << __LINE__ << "  " << ERR << std::endl; return TESTFAILED; }
-// #define ASSERT(BED) ASSERT(BED, "")
+#define CMPASSERTE(A, B, ERR) if( !((A) == (B))) { std::cout << __FILE__ << ":" << __LINE__ << "  is: \"" << (A) << "\"   should: \"" << (B) << "\""<< std::endl; return TESTFAILED; }
+#define CMPASSERT(A, B) CMPASSERTE(A, B, "")
 
 typedef int (*test_t)();
diff --git a/tests/testenums.cpp b/tests/testenums.cpp
new file mode 100644
index 0000000..dfd5c31
--- /dev/null
+++ b/tests/testenums.cpp
@@ -0,0 +1,38 @@
+#include "test.h"
+
+#include "difficulties.h"
+#include "beatmapcharacteristic.h"
+
+int difficulties_test() {
+
+	using d = Beatsaber::Difficulty::Difficulty;
+	using namespace Beatsaber::Difficulty;
+
+	CMPASSERT(d::EASY, getByString("Easy"));
+	CMPASSERT(d::NORMAL, getByString("Normal"));
+
+	CMPASSERT(d::NONE, getByString(""));
+	CMPASSERT(d::NONE, getByString("abc"));
+
+	CMPASSERT(d::HARD, getByString("Hard"));
+	CMPASSERT(d::EXPERTP, getByString("ExpertPlus"));
+
+	return TESTGOOD;
+}
+
+int characteristics_test() {
+
+	using c = Beatsaber::BeatmapCharacteristic::BeatmapCharacteristic;
+	using namespace Beatsaber::BeatmapCharacteristic;
+
+	CMPASSERT(c::NONE, getByString(""));
+	CMPASSERT(c::NONE, getByString("abc"));
+
+	CMPASSERT(c::STANDARD, getByString("Standard"));
+	CMPASSERT(c::ONESABER, getByString("OneSaber"));
+	CMPASSERT(c::NOARROWS, getByString("NoArrows"));
+	CMPASSERT(c::DEGREE90, getByString("90Degree"));
+	CMPASSERT(c::DEGREE360, getByString("360Degree"));
+
+	return TESTGOOD;
+}
\ No newline at end of file