Add some real messages to ASN.1 and handle pings on server

server/.gitignore

@@ -1,3 +1,4 @@
 _build/*
 *.beam
 src/StudySystemProtocol.erl
+include/*

server/asn1/StudySystemProtocol.asn1

@@ -1,11 +1,40 @@
 StudySystemProtocol DEFINITIONS EXPLICIT TAGS ::= BEGIN
 
+ActivityType ::= ENUMERATED {
+	reading(0),
+	exercises(1)
+}
+
+Session ::= SEQUENCE {
+	subjectId INTEGER,
+	type ActivityType,
+	timestamp INTEGER,
+	minutes INTEGER
+}
+
 Request ::= CHOICE {
-	foo [0] NULL
+	ping [0] NULL,
+	listPrioritizedActivities [1] NULL,
+	logSession [2] Session
+}
+
+PrioritizedActivity ::= SEQUENCE {
+	subjectId INTEGER,
+	subjectName UTF8String,
+	type ActivityType,
+	priority INTEGER
+}
+
+Error ::= ENUMERATED {
+	invalidRequest(0),
+	invalidArguments(1),
+	serverError(2)
 }
 
 Response ::= CHOICE {
-	msg [0] UTF8String
+	error [0] Error,
+	ack [1] NULL,
+	prioritizedActivities [2] SEQUENCE OF PrioritizedActivity
 }
 
 END

server/src/session_server.erl

@@ -23,13 +23,14 @@ handle_cast(_Msg, State) ->
 
 handle_info({ssl, Socket, Data}, State) ->
 	case 'StudySystemProtocol':decode('Request', Data) of
-		{ok, {foo, _}} ->
-			{ok, Encoded}
-				= 'StudySystemProtocol':encode('Response', {msg, "Foo"}),
+		{ok, {ping, _}} ->
+			{ok, Encoded} = 'StudySystemProtocol':encode(
+							  'Response', {ack, 'NULL'}),
 			ok = ssl:send(Socket, Encoded);
-		Result ->
-			io:format("Invalid message: ~p~n", [Result]),
-			ok
+		{error, {asn1, _Reason}} ->
+			{ok, Encoded} = 'StudySystemProtocol':encode(
+							  'Response', {error, invalidRequest}),
+			ok = ssl:send(Socket, Encoded)
 	end,
 	{noreply, State};
 handle_info({ssl_closed, _Socket}, State) ->