5 files changed, 65 insertions, 29 deletions

diff --git a/Node.cpp b/Node.cpp
index 092d05d..a65a636 100644
--- a/Node.cpp
+++ b/Node.cpp
@@ -16,7 +16,11 @@ void Node::addInput(Net * net) {
 }
 
 void Node::setOutput(Net * net){
-	this->output = net;
+	if (this->output == nullptr) {
+		this->output = net;
+	} else {
+		throw CircuitException("Net already assigned");
+	}
 }
 
 void Node::sim() {
diff --git a/Node.h b/Node.h
index 3496851..59affcf 100644
--- a/Node.h
+++ b/Node.h
@@ -29,7 +29,7 @@ protected:
 	string label;
 
 	vector<Net *> inputs;
-	Net * output;
+	Net * output = nullptr;
 
 private:
 	int min_inputs = -1;
diff --git a/NodeInput.cpp b/NodeInput.cpp
index 2d1d517..ea328e3 100644
--- a/NodeInput.cpp
+++ b/NodeInput.cpp
@@ -1,8 +1,8 @@
 #include "NodeInput.h"
 #include "prut.h"
 
-#include <iostream>
 
+NodeInput NodeInput::instance(NodeInput::type);
 NodeInputLow NodeInputLow::instance(NodeInputLow::type);
 NodeInputHigh NodeInputHigh::instance(NodeInputHigh::type);
 
@@ -13,15 +13,15 @@ NodeInput * NodeInput::clone() const {
 }
 
 SignalLevel NodeInput::level() {
-	prutprint("");
-	return UNDEFINED;
+	prutprint("BaseInput");
+	return HIGH;
 }
 SignalLevel NodeInputLow::level() {
-	prutprint("");
+	prutprint("LOW");
 	return LOW;
 }
 SignalLevel NodeInputHigh::level() {
-	prutprint("");
+	prutprint("HIGH");
 	return HIGH;
 }
 
diff --git a/NodeInput.h b/NodeInput.h
index e176fa7..5c13133 100644
--- a/NodeInput.h
+++ b/NodeInput.h
@@ -6,34 +6,66 @@
 
 class NodeInput : public Node {
 public:
-	using Node::Node;
+	NodeInput() = default;
 	NodeInput(const NodeInput * prototype);
-
+	~NodeInput() = default;
 	virtual NodeInput * clone() const;
 
+protected:
+	SignalLevel level();
+
 private:
-	NodeInput(const char * type);
+	using Node::Node;
+	constexpr static const char * type = "input";
+	static NodeInput instance;
 
-	SignalLevel input = UNDEFINED;
+private:
+	int min_inputs = -1;
+	int max_inputs = 0;
 };
 
+// class NodeInput : public Node {
+// public:
+// 	using Node::Node;
+// 	NodeInput(const NodeInput * prototype);
+
+// 	virtual NodeInput * clone() const;
+
+// protected:
+// 	SignalLevel level() = 0;
+
+// private:
+// 	NodeInput(const char * type);
+
+// 	SignalLevel input = UNDEFINED;
+// };
+
 class NodeInputLow : public NodeInput {
-public:
-	using NodeInput::NodeInput;
-	virtual SignalLevel level();
+protected:
+	SignalLevel level();
 
 private:
+	using NodeInput::NodeInput;
 	constexpr static const char * type = "input_low";
 	static NodeInputLow instance;
 };
 
 class NodeInputHigh : public NodeInput {
-public:
-	using NodeInput::NodeInput;
-	virtual SignalLevel level();
-
 private:
+	SignalLevel level();
+
+	using NodeInput::NodeInput;
 	constexpr static const char * type = "input_high";
 	static NodeInputHigh instance;
 };
 
+// class NodeInputHigh : public NodeInput {
+// public:
+// 	using NodeInput::NodeInput;
+// 	virtual SignalLevel level();
+
+// private:
+// 	constexpr static const char * type = "input_high";
+// 	static NodeInputHigh instance;
+// };
+
diff --git a/readme.md b/readme.md
index 3ae509d..4bf2686 100644
--- a/readme.md
+++ b/readme.md
@@ -17,19 +17,19 @@ make
 
 ## TODO
 
-- [ ] abstract class Node
-- [ ] class CircuitFactory
-- [ ] class GateAnd
-- [ ] class GateNand
-- [ ] class GateNor
+- [x] class Node
+- [x] class CircuitFactory
+- [x] class GateAnd
+- [x] class GateNand
+- [X] class GateNor
 - [ ] class GateNot
-- [ ] class GateOr
+- [x] class GateOr
 - [ ] class GateXor
-- [ ] class Net
+- [x] class Net
 - [ ] class NodeInput
 - [ ] class NodeOutput
-- [ ] class Parser
-- [ ] class Subject
-- [ ] enum SignalLevel
-- [ ] interface Observer
+- [x] class Parser
+- [x] class Subject
+- [x] enum SignalLevel
+- [x] interface Observer