WIP: Implement CoAP over TCP

example/tcp_test.dart

@@ -0,0 +1,26 @@
+// ignore_for_file: avoid_print
+
+import 'dart:core';
+
+import 'package:coap/coap.dart';
+
+/// Tests the basic functionality of the TCP network.
+/// Will be replaced with a "real" example later.
+Future<void> main() async {
+  await connect();
+}
+
+Future<void> connect() async {
+  final coapClient =
+      CoapClient(Uri.parse('coap+tcp://californium.eclipseprojects.io'));
+
+  final response = await coapClient.post(
+    Uri(path: 'test'),
+    format: CoapMediaType.applicationJson,
+    accept: CoapMediaType.applicationCbor,
+    payload: 'Hello?',
+  );
+  print(response);
+
+  coapClient.close();
+}

lib/src/coap_empty_message.dart

@@ -44,13 +44,13 @@ class CoapEmptyMessage extends CoapMessage {
         ..destination = message.source;
 
   CoapEmptyMessage.fromParsed({
-    required final CoapMessageType type,
-    required final int id,
     required final Uint8Buffer token,
     required final List<Option<Object?>> options,
     required final Uint8Buffer? payload,
     required final bool hasUnknownCriticalOption,
     required final bool hasFormatError,
+    final int? id,
+    final CoapMessageType? type,
   }) : super.fromParsed(
           RequestMethod.empty.coapCode,
           type,

lib/src/coap_message.dart

@@ -17,6 +17,7 @@ import 'coap_code.dart';
 import 'coap_media_type.dart';
 import 'coap_message_type.dart';
 import 'coap_response.dart';
+import 'codec/tcp/message_encoder.dart';
 import 'codec/udp/message_decoder.dart';
 import 'codec/udp/message_encoder.dart';
 import 'event/coap_event_bus.dart';
@@ -38,7 +39,7 @@ typedef HookFunction = void Function();
 abstract class CoapMessage {
   CoapMessage(
     this.code,
-    this._type, {
+    this.type, {
     final Iterable<int>? payload,
     final CoapMediaType? contentFormat,
   }) : payload = Uint8Buffer()..addAll(payload ?? []) {
@@ -47,15 +48,14 @@ abstract class CoapMessage {
 
   CoapMessage.fromParsed(
     this.code,
-    this._type, {
-    required final int id,
+    this.type, {
     required final Uint8Buffer token,
     required final List<Option<Object?>> options,
     required final Uint8Buffer? payload,
     required this.hasUnknownCriticalOption,
     required this.hasFormatError,
+    this.id,
   }) : payload = payload ?? Uint8Buffer() {
-    this.id = id;
     this.token = token;
     setOptions(options);
   }
@@ -64,26 +64,17 @@ abstract class CoapMessage {
 
   bool hasFormatError = false;
 
-  CoapMessageType _type;
-
-  @internal
-  set type(final CoapMessageType type) => _type = type;
-
   /// The type of this CoAP message.
-  CoapMessageType get type => _type;
+  CoapMessageType? type;
 
   /// The code of this CoAP message.
   final CoapCode code;
 
   /// The codestring
   String get codeString => code.toString();
 
-  int? _id;
-
   /// The ID of this CoAP message.
-  int? get id => _id;
-  @internal
-  set id(final int? val) => _id = val;
+  int? id;
 
   final List<Option<Object?>> _options = [];
 
@@ -635,18 +626,8 @@ abstract class CoapMessage {
   /// Is also used for DTLS.
   Uint8Buffer toUdpPayload() => serializeUdpMessage(this);
 
-  /// Serializes this CoAP message from the TCP message format.
-  ///
-  /// Is also used for TLS.
-  static CoapMessage? fromTcpPayload(final Uint8Buffer data) =>
-      throw UnimplementedError(
-        'TCP segment deserialization is not implemented yet.',
-      );
-
   /// Serializes this CoAP message into the TCP message format.
   ///
   /// Is also used for TLS.
-  Uint8Buffer toTcpPayload() => throw UnimplementedError(
-        'TCP segment serialization is not implemented yet.',
-      );
+  Uint8Buffer toTcpPayload() => serializeTcpMessage(this);
 }

lib/src/coap_request.dart

@@ -42,7 +42,7 @@ class CoapRequest extends CoapMessage {
   final RequestMethod method;
 
   @override
-  CoapMessageType get type {
+  CoapMessageType? get type {
     if (super.type == CoapMessageType.con && isMulticast) {
       return CoapMessageType.non;
     }
@@ -73,8 +73,10 @@ class CoapRequest extends CoapMessage {
   Endpoint? get endpoint => _endpoint;
   @internal
   set endpoint(final Endpoint? endpoint) {
-    super.id = endpoint!.nextMessageId;
-    super.destination = endpoint.destination;
+    if (['coap', 'coaps'].contains(uri.scheme)) {
+      super.id = endpoint!.nextMessageId;
+    }
+    super.destination = endpoint!.destination;
     _endpoint = endpoint;
   }
 
@@ -199,13 +201,13 @@ class CoapRequest extends CoapMessage {
   CoapRequest.fromParsed(
     this.uri,
     this.method, {
-    required final CoapMessageType type,
-    required final int id,
     required final Uint8Buffer token,
     required final List<Option<Object?>> options,
     required final Uint8Buffer? payload,
     required final bool hasUnknownCriticalOption,
     required final bool hasFormatError,
+    final CoapMessageType? type,
+    final int? id,
   }) : super.fromParsed(
           method.coapCode,
           type,

lib/src/coap_response.dart

@@ -22,7 +22,7 @@ class CoapResponse extends CoapMessage {
   /// Initializes a response message.
   CoapResponse(
     this.responseCode,
-    final CoapMessageType type, {
+    final CoapMessageType? type, {
     final Uri? location,
     super.payload,
   })  : location = location ?? Uri(path: '/'),
@@ -43,8 +43,10 @@ class CoapResponse extends CoapMessage {
   final Uri location;
 
   @override
-  List<Option<Object?>> getAllOptions() =>
-      locationToOptions(location)..addAll(super.getAllOptions());
+  List<Option<Object?>> getAllOptions() => locationToOptions(location)
+    ..addAll(
+      super.getAllOptions().where((final element) => !element.isLocationOption),
+    );
 
   /// Status code as a string
   String get statusCodeString => code.toString();
@@ -100,14 +102,14 @@ class CoapResponse extends CoapMessage {
 
   CoapResponse.fromParsed(
     this.responseCode, {
-    required final CoapMessageType type,
-    required final int id,
     required final Uint8Buffer token,
     required final List<Option<Object?>> options,
     required final Uint8Buffer? payload,
     required final bool hasUnknownCriticalOption,
     required final bool hasFormatError,
     final Uri? location,
+    final int? id,
+    final CoapMessageType? type,
   })  : location = location ?? Uri(path: '/'),
         super.fromParsed(
           responseCode.coapCode,