From b8e5d92d823338694ff24e615f8585c2bc944966 Mon Sep 17 00:00:00 2001
From: Jan Romann <jan.romann@uni-bremen.de>
Date: Thu, 26 May 2022 02:15:32 +0200
Subject: [PATCH 01/25] chore!: bump tsc target to es2018

---
 tsconfig.json | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tsconfig.json b/tsconfig.json
index f60306d3c..80c0127d3 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -1,6 +1,6 @@
 {
     "compilerOptions": {
-        "target": "es6",
+        "target": "es2018",
         "lib": ["dom"],
         "skipLibCheck": false,
         "module": "commonjs",

From 10306847664c1b4786f1aea1ac2490db9edfb459 Mon Sep 17 00:00:00 2001
From: Jan Romann <jan.romann@uni-bremen.de>
Date: Thu, 26 May 2022 02:16:53 +0200
Subject: [PATCH 02/25] feat!: add proposal for new discovery API

---
 packages/core/src/wot-impl.ts | 61 ++++++++++++++++++++++++++++-------
 1 file changed, 50 insertions(+), 11 deletions(-)

diff --git a/packages/core/src/wot-impl.ts b/packages/core/src/wot-impl.ts
index 55ac7265b..90268e26c 100644
--- a/packages/core/src/wot-impl.ts
+++ b/packages/core/src/wot-impl.ts
@@ -19,10 +19,58 @@ import Servient from "./servient";
 import ExposedThing from "./exposed-thing";
 import ConsumedThing from "./consumed-thing";
 import Helpers from "./helpers";
+import { ThingDescription } from "wot-thing-description-types";
 import { createLoggers } from "./logger";
 
 const { debug } = createLoggers("core", "wot-impl");
 
+class ThingDiscoveryImpl implements AsyncIterable<ThingDescription> {
+
+    filter: WoT.ThingFilter;
+
+    active = true;
+
+    constructor(filter: WoT.ThingFilter) {
+        this.filter = filter;
+    }
+
+    async*[Symbol.asyncIterator](): AsyncIterator<ThingDescription> {
+        switch (this.filter.method) {
+            case "direct": {
+                if (!this.active) {
+                    return;
+                }
+
+                const response = await fetch(this.filter.url);
+                const parsedTd = await response.json();
+                yield new Promise<ThingDescription>(resolve => resolve(parsedTd));
+                break;
+            }
+            default:
+                throw Error("Only the direct discovery method has been implemented yet.");
+        }
+    }
+
+    public stop(): void {
+        this.active = false;
+    }
+}
+/**
+ * wot-type-definitions does not contain a implementation of Discovery method enums
+ * so we need to create them here. Sadly, we should keep this enum in sync with
+ * WoT.DiscoveryMethod
+ */
+export enum DiscoveryMethod {
+    /** does not provide any restriction */
+    "any",
+    /** for discovering Things defined in the same device */
+    "local",
+    /** for discovery based on a service provided by a directory or repository of Things  */
+    "directory",
+    /** for discovering Things in the device's network by using a supported multicast protocol  */
+    "multicast",
+}
+
 export default class WoTImpl {
     private srv: Servient;
     constructor(srv: Servient) {
@@ -30,17 +78,8 @@ export default class WoTImpl {
     }
 
     /** @inheritDoc */
-    async discover(filter?: WoT.ThingFilter): Promise<WoT.ThingDiscoveryProcess> {
-        throw new Error("not implemented");
-    }
-
-    /** @inheritDoc */
-    async exploreDirectory(url: string, filter?: WoT.ThingFilter): Promise<WoT.ThingDiscoveryProcess> {
-        throw new Error("not implemented");
-    }
-
-    async requestThingDescription(url: string): Promise<WoT.ThingDescription> {
-        throw new Error("not implemented");
+     discover(filter?: WoT.ThingFilter): ThingDiscoveryImpl {
+        return new ThingDiscoveryImpl(filter);
     }
 
     /** @inheritDoc */

From 96be7f497c4bb76c6302664a9839e3ff7495522d Mon Sep 17 00:00:00 2001
From: Jan Romann <jan.romann@uni-bremen.de>
Date: Thu, 26 May 2022 03:03:49 +0200
Subject: [PATCH 03/25] fixup! feat!: add proposal for new discovery API

This commit should probably be dropped
---
 packages/core/example/example.js | 11 +++++++++++
 packages/core/src/wot-impl.ts    |  6 +++---
 2 files changed, 14 insertions(+), 3 deletions(-)
 create mode 100644 packages/core/example/example.js

diff --git a/packages/core/example/example.js b/packages/core/example/example.js
new file mode 100644
index 000000000..66c2ab044
--- /dev/null
+++ b/packages/core/example/example.js
@@ -0,0 +1,11 @@
+const { Servient } = require("@node-wot/core");
+
+async function discover() {
+    const servient = new Servient();
+    const wot = await servient.start();
+    for await(const td of wot.discover({url: "http://plugfest.thingweb.io:8083/smart-coffee-machine", method: "direct"})) {
+        console.log(td);
+    }
+}
+
+discover();
diff --git a/packages/core/src/wot-impl.ts b/packages/core/src/wot-impl.ts
index 90268e26c..a1933b1b6 100644
--- a/packages/core/src/wot-impl.ts
+++ b/packages/core/src/wot-impl.ts
@@ -23,6 +23,7 @@ import { ThingDescription } from "wot-thing-description-types";
 import { createLoggers } from "./logger";
 
 const { debug } = createLoggers("core", "wot-impl");
+import fetch from "node-fetch";
 
 class ThingDiscoveryImpl implements AsyncIterable<ThingDescription> {
 
@@ -40,7 +41,6 @@ class ThingDiscoveryImpl implements AsyncIterable<ThingDescription> {
                 if (!this.active) {
                     return;
                 }
-
                 const response = await fetch(this.filter.url);
                 const parsedTd = await response.json();
                 yield new Promise<ThingDescription>(resolve => resolve(parsedTd));
@@ -78,8 +78,8 @@ export default class WoTImpl {
     }
 
     /** @inheritDoc */
-     discover(filter?: WoT.ThingFilter): ThingDiscoveryImpl {
-        return new ThingDiscoveryImpl(filter);
+    discover(filter?: WoT.ThingFilter): WoT.ThingDiscovery {
+        return new ThingDiscoveryImpl(filter) as unknown as WoT.ThingDiscovery;
     }
 
     /** @inheritDoc */

From 7f403239548df7d60223dd98ae8242129223caf3 Mon Sep 17 00:00:00 2001
From: Jan Romann <jan.romann@uni-bremen.de>
Date: Thu, 26 May 2022 03:06:08 +0200
Subject: [PATCH 04/25] fixup! feat!: add proposal for new discovery API

---
 packages/core/src/wot-impl.ts | 1 +
 1 file changed, 1 insertion(+)

diff --git a/packages/core/src/wot-impl.ts b/packages/core/src/wot-impl.ts
index a1933b1b6..3be559653 100644
--- a/packages/core/src/wot-impl.ts
+++ b/packages/core/src/wot-impl.ts
@@ -43,6 +43,7 @@ class ThingDiscoveryImpl implements AsyncIterable<ThingDescription> {
                 }
                 const response = await fetch(this.filter.url);
                 const parsedTd = await response.json();
+                this.active = false;
                 yield new Promise<ThingDescription>(resolve => resolve(parsedTd));
                 break;
             }

From d68f9dfa6dd2565b0499f78b9b65cbec8aa3b1bb Mon Sep 17 00:00:00 2001
From: Jan Romann <jan.romann@uni-bremen.de>
Date: Thu, 26 May 2022 15:12:24 +0200
Subject: [PATCH 05/25] fixup! feat!: add proposal for new discovery API

---
 packages/binding-coap/src/coap-client.ts      |  5 +++++
 packages/binding-coap/src/coaps-client.ts     |  5 +++++
 packages/binding-file/src/file-client.ts      |  5 +++++
 packages/binding-http/src/http-client-impl.ts | 10 ++++++++++
 packages/binding-mbus/src/mbus-client.ts      |  5 +++++
 packages/binding-modbus/src/modbus-client.ts  |  5 +++++
 packages/binding-mqtt/src/mqtt-client.ts      |  5 +++++
 .../binding-netconf/src/netconf-client.ts     |  5 +++++
 .../src/opcua-protocol-client.ts              |  6 +++++-
 packages/binding-websockets/src/ws-client.ts  |  5 +++++
 packages/core/example/example.js              |  9 ++++++++-
 packages/core/src/protocol-interfaces.ts      |  3 +++
 packages/core/src/wot-impl.ts                 | 19 +++++++++++--------
 13 files changed, 77 insertions(+), 10 deletions(-)

diff --git a/packages/binding-coap/src/coap-client.ts b/packages/binding-coap/src/coap-client.ts
index 4d0740ace..174d9a3c7 100644
--- a/packages/binding-coap/src/coap-client.ts
+++ b/packages/binding-coap/src/coap-client.ts
@@ -38,6 +38,7 @@ import {
     OutgoingMessage,
     ObserveReadStream,
 } from "coap";
+import { ThingDescription } from "wot-thing-description-types";
 
 const { debug, warn } = createLoggers("binding-coap", "coap-client");
 
@@ -55,6 +56,10 @@ export default class CoapClient implements ProtocolClient {
         registerFormat(ContentSerdes.JSON_LD, 2100);
     }
 
+    discoverDirectly(uri: string): Promise<ThingDescription> {
+        throw new Error("Method not implemented.");
+    }
+
     public toString(): string {
         return "[CoapClient]";
     }
diff --git a/packages/binding-coap/src/coaps-client.ts b/packages/binding-coap/src/coaps-client.ts
index 2113c4f4f..5867c2bda 100644
--- a/packages/binding-coap/src/coaps-client.ts
+++ b/packages/binding-coap/src/coaps-client.ts
@@ -25,6 +25,7 @@ import { ProtocolClient, Content, createLoggers, ContentSerdes } from "@node-wot
 import { CoapForm, CoapMethodName, isValidCoapMethod, isSupportedCoapMethod } from "./coap";
 import { CoapClient as coaps, CoapResponse, RequestMethod, SecurityParameters } from "node-coap-client";
 import { Readable } from "stream";
+import { ThingDescription } from "wot-thing-description-types";
 
 const { debug, warn, error } = createLoggers("binding-coap", "coaps-client");
 
@@ -235,4 +236,8 @@ export default class CoapsClient implements ProtocolClient {
 
         return req;
     }
+
+    discoverDirectly(uri: string): Promise<ThingDescription> {
+        throw new Error("Method not implemented.");
+    }
 }
diff --git a/packages/binding-file/src/file-client.ts b/packages/binding-file/src/file-client.ts
index 31c3d005a..55e5fd0de 100644
--- a/packages/binding-file/src/file-client.ts
+++ b/packages/binding-file/src/file-client.ts
@@ -21,6 +21,7 @@ import { ProtocolClient, Content, createLoggers } from "@node-wot/core";
 import { Subscription } from "rxjs/Subscription";
 import fs = require("fs");
 import path = require("path");
+import { ThingDescription } from "wot-typescript-definitions";
 
 const { debug, warn } = createLoggers("binding-file", "file-client");
 
@@ -90,4 +91,8 @@ export default class FileClient implements ProtocolClient {
     }
 
     public setSecurity = (metadata: Array<SecurityScheme>): boolean => false;
+
+    discoverDirectly(uri: string): Promise<ThingDescription> {
+        throw new Error("Method not implemented.");
+    }
 }
diff --git a/packages/binding-http/src/http-client-impl.ts b/packages/binding-http/src/http-client-impl.ts
index de5c93182..eaa6c17dd 100644
--- a/packages/binding-http/src/http-client-impl.ts
+++ b/packages/binding-http/src/http-client-impl.ts
@@ -409,4 +409,14 @@ export default class HttpClient implements ProtocolClient {
 
         return url;
     }
+
+    async discoverDirectly(uri: string): Promise<ThingDescription> {
+        // Note: This is still work in progress
+        const headers: HeadersInit = {
+            Accept: "application/td+json",
+        };
+        const response = await fetch(uri, { headers });
+        // TODO: Result should be validated
+        return await response.json();
+    }
 }
diff --git a/packages/binding-mbus/src/mbus-client.ts b/packages/binding-mbus/src/mbus-client.ts
index 63a8c24cb..a68edecbe 100644
--- a/packages/binding-mbus/src/mbus-client.ts
+++ b/packages/binding-mbus/src/mbus-client.ts
@@ -23,6 +23,7 @@ import { SecurityScheme } from "@node-wot/td-tools";
 import { MBusConnection, PropertyOperation } from "./mbus-connection";
 
 import { Subscription } from "rxjs/Subscription";
+import { ThingDescription } from "wot-typescript-definitions";
 
 const debug = createDebugLogger("binding-mbus", "mbus-client");
 
@@ -144,4 +145,8 @@ export default class MBusClient implements ProtocolClient {
 
         return result;
     }
+
+    discoverDirectly(uri: string): Promise<ThingDescription> {
+        throw new Error("Method not implemented.");
+    }
 }
diff --git a/packages/binding-modbus/src/modbus-client.ts b/packages/binding-modbus/src/modbus-client.ts
index f375d227d..fbc95bdff 100644
--- a/packages/binding-modbus/src/modbus-client.ts
+++ b/packages/binding-modbus/src/modbus-client.ts
@@ -23,6 +23,7 @@ import { modbusFunctionToEntity } from "./utils";
 import { ModbusConnection, ModbusFormWithDefaults, PropertyOperation } from "./modbus-connection";
 import { Readable } from "stream";
 import { Subscription } from "rxjs/Subscription";
+import { ThingDescription } from "wot-typescript-definitions";
 
 const debug = createDebugLogger("binding-modbus", "modbus-client");
 
@@ -309,4 +310,8 @@ export default class ModbusClient implements ProtocolClient {
 
         return result as ModbusFormWithDefaults;
     }
+
+    discoverDirectly(uri: string): Promise<ThingDescription> {
+        throw new Error("Method not implemented.");
+    }
 }
diff --git a/packages/binding-mqtt/src/mqtt-client.ts b/packages/binding-mqtt/src/mqtt-client.ts
index ef3b5d1c9..c0b352c21 100644
--- a/packages/binding-mqtt/src/mqtt-client.ts
+++ b/packages/binding-mqtt/src/mqtt-client.ts
@@ -25,6 +25,7 @@ import { IPublishPacket, QoS } from "mqtt";
 import * as url from "url";
 import { Subscription } from "rxjs/Subscription";
 import { Readable } from "stream";
+import { ThingDescription } from "wot-typescript-definitions";
 
 const { debug, warn } = createLoggers("binding-mqtt", "mqtt-client");
 
@@ -199,4 +200,8 @@ export default class MqttClient implements ProtocolClient {
                 return (qos = 0);
         }
     }
+
+    discoverDirectly(uri: string): Promise<ThingDescription> {
+        throw new Error("Method not implemented.");
+    }
 }
diff --git a/packages/binding-netconf/src/netconf-client.ts b/packages/binding-netconf/src/netconf-client.ts
index 90d8892cb..5b67840eb 100644
--- a/packages/binding-netconf/src/netconf-client.ts
+++ b/packages/binding-netconf/src/netconf-client.ts
@@ -23,6 +23,7 @@ import * as AsyncNodeNetcon from "./async-node-netconf";
 import Url from "url-parse";
 import { Readable } from "stream";
 import { Subscription } from "rxjs/Subscription";
+import { ThingDescription } from "wot-typescript-definitions";
 
 const { debug, warn } = createLoggers("binding-netconf", "netconf-client");
 
@@ -175,4 +176,8 @@ export default class NetconfClient implements ProtocolClient {
         this.credentials = credentials;
         return true;
     }
+
+    discoverDirectly(uri: string): Promise<ThingDescription> {
+        throw new Error("Method not implemented.");
+    }
 }
diff --git a/packages/binding-opcua/src/opcua-protocol-client.ts b/packages/binding-opcua/src/opcua-protocol-client.ts
index 524564c1c..00b58b9f7 100644
--- a/packages/binding-opcua/src/opcua-protocol-client.ts
+++ b/packages/binding-opcua/src/opcua-protocol-client.ts
@@ -45,7 +45,7 @@ import { makeBrowsePath } from "node-opcua-service-translate-browse-path";
 import { StatusCodes } from "node-opcua-status-code";
 
 import { schemaDataValue } from "./codec";
-import { FormElementProperty } from "wot-thing-description-types";
+import { FormElementProperty, ThingDescription } from "wot-thing-description-types";
 import { opcuaJsonEncodeVariant } from "node-opcua-json";
 import { Argument, BrowseDescription, BrowseResult } from "node-opcua-types";
 import { isGoodish2, ReferenceTypeIds } from "node-opcua";
@@ -620,4 +620,8 @@ export class OPCUAProtocolClient implements ProtocolClient {
 
         return new Content("application/json", Readable.from(JSON.stringify(body)));
     }
+
+    discoverDirectly(uri: string): Promise<ThingDescription> {
+        throw new Error("Method not implemented.");
+    }
 }
diff --git a/packages/binding-websockets/src/ws-client.ts b/packages/binding-websockets/src/ws-client.ts
index cdf79dd12..12b93391b 100644
--- a/packages/binding-websockets/src/ws-client.ts
+++ b/packages/binding-websockets/src/ws-client.ts
@@ -20,6 +20,7 @@
 import { ProtocolClient, Content, createLoggers } from "@node-wot/core";
 import { Form, SecurityScheme } from "@node-wot/td-tools";
 import { Subscription } from "rxjs/Subscription";
+import { ThingDescription } from "wot-thing-description-types";
 
 const { debug, warn } = createLoggers("binding-websockets", "ws-client");
 
@@ -29,6 +30,10 @@ export default class WebSocketClient implements ProtocolClient {
         // TODO: implement and remove eslint-ignore-useless-constructor
     }
 
+    discoverDirectly(uri: string): Promise<ThingDescription> {
+        throw new Error("Method not implemented.");
+    }
+
     public toString(): string {
         return `[WebSocketClient]`;
     }
diff --git a/packages/core/example/example.js b/packages/core/example/example.js
index 66c2ab044..c14d35caf 100644
--- a/packages/core/example/example.js
+++ b/packages/core/example/example.js
@@ -1,9 +1,16 @@
 const { Servient } = require("@node-wot/core");
+const { HttpClientFactory } = require("@node-wot/binding-http");
 
+// Note: This example is just for testing/demonstration purposes and
+//       will eventually be moved to the examples package.
 async function discover() {
     const servient = new Servient();
+    servient.addClientFactory(new HttpClientFactory());
     const wot = await servient.start();
-    for await(const td of wot.discover({url: "http://plugfest.thingweb.io:8083/smart-coffee-machine", method: "direct"})) {
+    for await (const td of wot.discover({
+        url: "http://plugfest.thingweb.io:8083/smart-coffee-machine",
+        method: "direct",
+    })) {
         console.log(td);
     }
 }
diff --git a/packages/core/src/protocol-interfaces.ts b/packages/core/src/protocol-interfaces.ts
index 68ded1233..21e721dcb 100644
--- a/packages/core/src/protocol-interfaces.ts
+++ b/packages/core/src/protocol-interfaces.ts
@@ -20,6 +20,7 @@ import { Subscription } from "rxjs/Subscription";
 import Servient from "./servient";
 import ExposedThing from "./exposed-thing";
 import { Content } from "./content";
+import { ThingDescription } from "wot-typescript-definitions";
 
 export type PropertyContentMap = Map<string, Content>;
 
@@ -59,6 +60,8 @@ export interface ProtocolClient {
     /** this client is requested to perform an "unlink" on the resource with the given URI */
     unlinkResource(form: TD.Form): Promise<void>;
 
+    discoverDirectly(uri: string): Promise<ThingDescription>;
+
     subscribeResource(
         form: TD.Form,
         next: (content: Content) => void,
diff --git a/packages/core/src/wot-impl.ts b/packages/core/src/wot-impl.ts
index 3be559653..f1d1aae93 100644
--- a/packages/core/src/wot-impl.ts
+++ b/packages/core/src/wot-impl.ts
@@ -23,28 +23,31 @@ import { ThingDescription } from "wot-thing-description-types";
 import { createLoggers } from "./logger";
 
 const { debug } = createLoggers("core", "wot-impl");
-import fetch from "node-fetch";
 
 class ThingDiscoveryImpl implements AsyncIterable<ThingDescription> {
-
     filter: WoT.ThingFilter;
 
     active = true;
 
-    constructor(filter: WoT.ThingFilter) {
+    private servient: Servient;
+
+    constructor(filter: WoT.ThingFilter, servient: Servient) {
         this.filter = filter;
+        this.servient = servient;
     }
 
-    async*[Symbol.asyncIterator](): AsyncIterator<ThingDescription> {
+    async *[Symbol.asyncIterator](): AsyncIterator<ThingDescription> {
         switch (this.filter.method) {
             case "direct": {
                 if (!this.active) {
                     return;
                 }
-                const response = await fetch(this.filter.url);
-                const parsedTd = await response.json();
+                // TODO: This needs to refactored
+                const uriScheme = new URL(this.filter.url).protocol.split(":")[0];
+                const client = this.servient.getClientFor(uriScheme);
+                const thingDescription = client.discoverDirectly(this.filter.url);
                 this.active = false;
-                yield new Promise<ThingDescription>(resolve => resolve(parsedTd));
+                yield new Promise<ThingDescription>((resolve) => resolve(thingDescription));
                 break;
             }
             default:
@@ -80,7 +83,7 @@ export default class WoTImpl {
 
     /** @inheritDoc */
     discover(filter?: WoT.ThingFilter): WoT.ThingDiscovery {
-        return new ThingDiscoveryImpl(filter) as unknown as WoT.ThingDiscovery;
+        return new ThingDiscoveryImpl(filter, this.srv) as unknown as WoT.ThingDiscovery;
     }
 
     /** @inheritDoc */

From 880558eaab2ecfa4f34a57c33bf3221991738c05 Mon Sep 17 00:00:00 2001
From: Jan Romann <jan.romann@uni-bremen.de>
Date: Thu, 26 May 2022 15:26:13 +0200
Subject: [PATCH 06/25] fixup! feat!: add proposal for new discovery API

---
 packages/core/test/ClientTest.ts | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/packages/core/test/ClientTest.ts b/packages/core/test/ClientTest.ts
index 56a28678a..2768ee7e6 100644
--- a/packages/core/test/ClientTest.ts
+++ b/packages/core/test/ClientTest.ts
@@ -169,6 +169,10 @@ class TDClient implements ProtocolClient {
     public toString(): string {
         return "TDClient";
     }
+
+    discoverDirectly(uri: string): Promise<ThingDescription> {
+        return Promise.reject(new Error("discoverDirectly not implemented"));
+    }
 }
 
 class TDClientFactory implements ProtocolClientFactory {
@@ -239,6 +243,10 @@ class TrapClient implements ProtocolClient {
     }
 
     public setSecurity = (metadata: SecurityScheme[]) => false;
+
+    discoverDirectly(uri: string): Promise<ThingDescription> {
+        return Promise.reject(new Error("discoverDirectly not implemented"));
+    }
 }
 
 class TrapClientFactory implements ProtocolClientFactory {
@@ -306,6 +314,10 @@ class TestProtocolClient implements ProtocolClient {
         this.securitySchemes = securitySchemes;
         return true;
     }
+
+    discoverDirectly(uri: string): Promise<ThingDescription> {
+        return Promise.reject(new Error("discoverDirectly not implemented"));
+    }
 }
 
 @suite("client flow of servient")

From d1ec05f30c9742746def9f54750ad6ab0cf362e9 Mon Sep 17 00:00:00 2001
From: Jan Romann <jan.romann@uni-bremen.de>
Date: Thu, 26 May 2022 15:50:33 +0200
Subject: [PATCH 07/25] fixup! feat!: add proposal for new discovery API

---
 packages/core/example/example.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/packages/core/example/example.js b/packages/core/example/example.js
index c14d35caf..dc7e50e89 100644
--- a/packages/core/example/example.js
+++ b/packages/core/example/example.js
@@ -2,7 +2,7 @@ const { Servient } = require("@node-wot/core");
 const { HttpClientFactory } = require("@node-wot/binding-http");
 
 // Note: This example is just for testing/demonstration purposes and
-//       will eventually be moved to the examples package.
+//       will eventually be removed/moved to the examples package.
 async function discover() {
     const servient = new Servient();
     servient.addClientFactory(new HttpClientFactory());

From 37a16206550c213dad8949a267db0eb8fc8c1fad Mon Sep 17 00:00:00 2001
From: Jan Romann <jan.romann@uni-bremen.de>
Date: Tue, 9 Aug 2022 18:09:24 +0200
Subject: [PATCH 08/25] fixup! feat!: add proposal for new discovery API

---
 packages/binding-coap/src/coap-client.ts            | 2 +-
 packages/binding-coap/src/coaps-client.ts           | 2 +-
 packages/binding-file/src/file-client.ts            | 2 +-
 packages/binding-mbus/src/mbus-client.ts            | 2 +-
 packages/binding-modbus/src/modbus-client.ts        | 2 +-
 packages/binding-mqtt/src/mqtt-client.ts            | 2 +-
 packages/binding-netconf/src/netconf-client.ts      | 2 +-
 packages/binding-opcua/src/opcua-protocol-client.ts | 2 +-
 packages/binding-websockets/src/ws-client.ts        | 2 +-
 9 files changed, 9 insertions(+), 9 deletions(-)

diff --git a/packages/binding-coap/src/coap-client.ts b/packages/binding-coap/src/coap-client.ts
index 174d9a3c7..339f621cb 100644
--- a/packages/binding-coap/src/coap-client.ts
+++ b/packages/binding-coap/src/coap-client.ts
@@ -57,7 +57,7 @@ export default class CoapClient implements ProtocolClient {
     }
 
     discoverDirectly(uri: string): Promise<ThingDescription> {
-        throw new Error("Method not implemented.");
+        return Promise.reject(new Error("Method not implemented."));
     }
 
     public toString(): string {
diff --git a/packages/binding-coap/src/coaps-client.ts b/packages/binding-coap/src/coaps-client.ts
index 5867c2bda..008ef7847 100644
--- a/packages/binding-coap/src/coaps-client.ts
+++ b/packages/binding-coap/src/coaps-client.ts
@@ -238,6 +238,6 @@ export default class CoapsClient implements ProtocolClient {
     }
 
     discoverDirectly(uri: string): Promise<ThingDescription> {
-        throw new Error("Method not implemented.");
+        return Promise.reject(new Error("Method not implemented."));
     }
 }
diff --git a/packages/binding-file/src/file-client.ts b/packages/binding-file/src/file-client.ts
index 55e5fd0de..c1a25af0f 100644
--- a/packages/binding-file/src/file-client.ts
+++ b/packages/binding-file/src/file-client.ts
@@ -93,6 +93,6 @@ export default class FileClient implements ProtocolClient {
     public setSecurity = (metadata: Array<SecurityScheme>): boolean => false;
 
     discoverDirectly(uri: string): Promise<ThingDescription> {
-        throw new Error("Method not implemented.");
+        return Promise.reject(new Error("Method not implemented."));
     }
 }
diff --git a/packages/binding-mbus/src/mbus-client.ts b/packages/binding-mbus/src/mbus-client.ts
index a68edecbe..8bfa51597 100644
--- a/packages/binding-mbus/src/mbus-client.ts
+++ b/packages/binding-mbus/src/mbus-client.ts
@@ -147,6 +147,6 @@ export default class MBusClient implements ProtocolClient {
     }
 
     discoverDirectly(uri: string): Promise<ThingDescription> {
-        throw new Error("Method not implemented.");
+        return Promise.reject(new Error("Method not implemented."));
     }
 }
diff --git a/packages/binding-modbus/src/modbus-client.ts b/packages/binding-modbus/src/modbus-client.ts
index fbc95bdff..52892fb3a 100644
--- a/packages/binding-modbus/src/modbus-client.ts
+++ b/packages/binding-modbus/src/modbus-client.ts
@@ -312,6 +312,6 @@ export default class ModbusClient implements ProtocolClient {
     }
 
     discoverDirectly(uri: string): Promise<ThingDescription> {
-        throw new Error("Method not implemented.");
+        return Promise.reject(new Error("Method not implemented."));
     }
 }
diff --git a/packages/binding-mqtt/src/mqtt-client.ts b/packages/binding-mqtt/src/mqtt-client.ts
index c0b352c21..7d94d2710 100644
--- a/packages/binding-mqtt/src/mqtt-client.ts
+++ b/packages/binding-mqtt/src/mqtt-client.ts
@@ -202,6 +202,6 @@ export default class MqttClient implements ProtocolClient {
     }
 
     discoverDirectly(uri: string): Promise<ThingDescription> {
-        throw new Error("Method not implemented.");
+        return Promise.reject(new Error("Method not implemented."));
     }
 }
diff --git a/packages/binding-netconf/src/netconf-client.ts b/packages/binding-netconf/src/netconf-client.ts
index 5b67840eb..9973bbbc1 100644
--- a/packages/binding-netconf/src/netconf-client.ts
+++ b/packages/binding-netconf/src/netconf-client.ts
@@ -178,6 +178,6 @@ export default class NetconfClient implements ProtocolClient {
     }
 
     discoverDirectly(uri: string): Promise<ThingDescription> {
-        throw new Error("Method not implemented.");
+        return Promise.reject(new Error("Method not implemented."));
     }
 }
diff --git a/packages/binding-opcua/src/opcua-protocol-client.ts b/packages/binding-opcua/src/opcua-protocol-client.ts
index 00b58b9f7..9248d9f40 100644
--- a/packages/binding-opcua/src/opcua-protocol-client.ts
+++ b/packages/binding-opcua/src/opcua-protocol-client.ts
@@ -622,6 +622,6 @@ export class OPCUAProtocolClient implements ProtocolClient {
     }
 
     discoverDirectly(uri: string): Promise<ThingDescription> {
-        throw new Error("Method not implemented.");
+        return Promise.reject(new Error("Method not implemented."));
     }
 }
diff --git a/packages/binding-websockets/src/ws-client.ts b/packages/binding-websockets/src/ws-client.ts
index 12b93391b..f6400ab95 100644
--- a/packages/binding-websockets/src/ws-client.ts
+++ b/packages/binding-websockets/src/ws-client.ts
@@ -31,7 +31,7 @@ export default class WebSocketClient implements ProtocolClient {
     }
 
     discoverDirectly(uri: string): Promise<ThingDescription> {
-        throw new Error("Method not implemented.");
+        return Promise.reject(new Error("Method not implemented."));
     }
 
     public toString(): string {

From 6ee7d4bf52320a04a00de8f2b3a84b9b4a4458a2 Mon Sep 17 00:00:00 2001
From: Jan Romann <jan.romann@uni-bremen.de>
Date: Tue, 9 Aug 2022 18:34:47 +0200
Subject: [PATCH 09/25] fixup! feat!: add proposal for new discovery API

---
 packages/binding-coap/src/coap-client.ts      | 19 ++++++++++++++++---
 packages/binding-coap/src/coaps-client.ts     |  3 +--
 packages/binding-file/src/file-client.ts      |  3 +--
 packages/binding-http/src/http-client-impl.ts |  5 +++--
 packages/binding-mbus/src/mbus-client.ts      |  3 +--
 packages/binding-modbus/src/modbus-client.ts  |  3 +--
 packages/binding-mqtt/src/mqtt-client.ts      |  3 +--
 .../binding-netconf/src/netconf-client.ts     |  3 +--
 .../src/opcua-protocol-client.ts              |  4 ++--
 packages/binding-websockets/src/ws-client.ts  |  3 +--
 packages/core/src/protocol-interfaces.ts      |  2 +-
 packages/core/src/wot-impl.ts                 |  7 +++++--
 12 files changed, 34 insertions(+), 24 deletions(-)

diff --git a/packages/binding-coap/src/coap-client.ts b/packages/binding-coap/src/coap-client.ts
index 339f621cb..bcc9d69cc 100644
--- a/packages/binding-coap/src/coap-client.ts
+++ b/packages/binding-coap/src/coap-client.ts
@@ -38,7 +38,6 @@ import {
     OutgoingMessage,
     ObserveReadStream,
 } from "coap";
-import { ThingDescription } from "wot-thing-description-types";
 
 const { debug, warn } = createLoggers("binding-coap", "coap-client");
 
@@ -56,8 +55,22 @@ export default class CoapClient implements ProtocolClient {
         registerFormat(ContentSerdes.JSON_LD, 2100);
     }
 
-    discoverDirectly(uri: string): Promise<ThingDescription> {
-        return Promise.reject(new Error("Method not implemented."));
+    discoverDirectly(uri: string): Promise<Content> {
+        const options: CoapRequestParams = this.uriToOptions(uri);
+        const req = this.agent.request(options);
+
+        req.setOption("Accept", "application/td+json");
+        return new Promise<Content>((resolve, reject) => {
+            req.on("response", (res: IncomingMessage) => {
+                let contentType = res.headers["Content-Format"];
+                if (typeof contentType !== "string") {
+                    contentType = "application/td+json";
+                }
+                resolve({ type: contentType, body: Readable.from(res.payload) });
+            });
+            req.on("error", (err: Error) => reject(err));
+            req.end();
+        });
     }
 
     public toString(): string {
diff --git a/packages/binding-coap/src/coaps-client.ts b/packages/binding-coap/src/coaps-client.ts
index 008ef7847..0e47ebca3 100644
--- a/packages/binding-coap/src/coaps-client.ts
+++ b/packages/binding-coap/src/coaps-client.ts
@@ -25,7 +25,6 @@ import { ProtocolClient, Content, createLoggers, ContentSerdes } from "@node-wot
 import { CoapForm, CoapMethodName, isValidCoapMethod, isSupportedCoapMethod } from "./coap";
 import { CoapClient as coaps, CoapResponse, RequestMethod, SecurityParameters } from "node-coap-client";
 import { Readable } from "stream";
-import { ThingDescription } from "wot-thing-description-types";
 
 const { debug, warn, error } = createLoggers("binding-coap", "coaps-client");
 
@@ -237,7 +236,7 @@ export default class CoapsClient implements ProtocolClient {
         return req;
     }
 
-    discoverDirectly(uri: string): Promise<ThingDescription> {
+    discoverDirectly(uri: string): Promise<Content> {
         return Promise.reject(new Error("Method not implemented."));
     }
 }
diff --git a/packages/binding-file/src/file-client.ts b/packages/binding-file/src/file-client.ts
index c1a25af0f..c7bcaae4b 100644
--- a/packages/binding-file/src/file-client.ts
+++ b/packages/binding-file/src/file-client.ts
@@ -21,7 +21,6 @@ import { ProtocolClient, Content, createLoggers } from "@node-wot/core";
 import { Subscription } from "rxjs/Subscription";
 import fs = require("fs");
 import path = require("path");
-import { ThingDescription } from "wot-typescript-definitions";
 
 const { debug, warn } = createLoggers("binding-file", "file-client");
 
@@ -92,7 +91,7 @@ export default class FileClient implements ProtocolClient {
 
     public setSecurity = (metadata: Array<SecurityScheme>): boolean => false;
 
-    discoverDirectly(uri: string): Promise<ThingDescription> {
+    discoverDirectly(uri: string): Promise<Content> {
         return Promise.reject(new Error("Method not implemented."));
     }
 }
diff --git a/packages/binding-http/src/http-client-impl.ts b/packages/binding-http/src/http-client-impl.ts
index eaa6c17dd..45f9d3168 100644
--- a/packages/binding-http/src/http-client-impl.ts
+++ b/packages/binding-http/src/http-client-impl.ts
@@ -410,13 +410,14 @@ export default class HttpClient implements ProtocolClient {
         return url;
     }
 
-    async discoverDirectly(uri: string): Promise<ThingDescription> {
+    async discoverDirectly(uri: string): Promise<Content> {
         // Note: This is still work in progress
         const headers: HeadersInit = {
             Accept: "application/td+json",
         };
         const response = await fetch(uri, { headers });
         // TODO: Result should be validated
-        return await response.json();
+        const body = ProtocolHelpers.toNodeStream(response.body as Readable);
+        return { type: response.headers.get("content-type"), body };
     }
 }
diff --git a/packages/binding-mbus/src/mbus-client.ts b/packages/binding-mbus/src/mbus-client.ts
index 8bfa51597..b26ffc217 100644
--- a/packages/binding-mbus/src/mbus-client.ts
+++ b/packages/binding-mbus/src/mbus-client.ts
@@ -23,7 +23,6 @@ import { SecurityScheme } from "@node-wot/td-tools";
 import { MBusConnection, PropertyOperation } from "./mbus-connection";
 
 import { Subscription } from "rxjs/Subscription";
-import { ThingDescription } from "wot-typescript-definitions";
 
 const debug = createDebugLogger("binding-mbus", "mbus-client");
 
@@ -146,7 +145,7 @@ export default class MBusClient implements ProtocolClient {
         return result;
     }
 
-    discoverDirectly(uri: string): Promise<ThingDescription> {
+    discoverDirectly(uri: string): Promise<Content> {
         return Promise.reject(new Error("Method not implemented."));
     }
 }
diff --git a/packages/binding-modbus/src/modbus-client.ts b/packages/binding-modbus/src/modbus-client.ts
index 52892fb3a..4e8811da5 100644
--- a/packages/binding-modbus/src/modbus-client.ts
+++ b/packages/binding-modbus/src/modbus-client.ts
@@ -23,7 +23,6 @@ import { modbusFunctionToEntity } from "./utils";
 import { ModbusConnection, ModbusFormWithDefaults, PropertyOperation } from "./modbus-connection";
 import { Readable } from "stream";
 import { Subscription } from "rxjs/Subscription";
-import { ThingDescription } from "wot-typescript-definitions";
 
 const debug = createDebugLogger("binding-modbus", "modbus-client");
 
@@ -311,7 +310,7 @@ export default class ModbusClient implements ProtocolClient {
         return result as ModbusFormWithDefaults;
     }
 
-    discoverDirectly(uri: string): Promise<ThingDescription> {
+    discoverDirectly(uri: string): Promise<Content> {
         return Promise.reject(new Error("Method not implemented."));
     }
 }
diff --git a/packages/binding-mqtt/src/mqtt-client.ts b/packages/binding-mqtt/src/mqtt-client.ts
index 7d94d2710..53237bb44 100644
--- a/packages/binding-mqtt/src/mqtt-client.ts
+++ b/packages/binding-mqtt/src/mqtt-client.ts
@@ -25,7 +25,6 @@ import { IPublishPacket, QoS } from "mqtt";
 import * as url from "url";
 import { Subscription } from "rxjs/Subscription";
 import { Readable } from "stream";
-import { ThingDescription } from "wot-typescript-definitions";
 
 const { debug, warn } = createLoggers("binding-mqtt", "mqtt-client");
 
@@ -201,7 +200,7 @@ export default class MqttClient implements ProtocolClient {
         }
     }
 
-    discoverDirectly(uri: string): Promise<ThingDescription> {
+    discoverDirectly(uri: string): Promise<Content> {
         return Promise.reject(new Error("Method not implemented."));
     }
 }
diff --git a/packages/binding-netconf/src/netconf-client.ts b/packages/binding-netconf/src/netconf-client.ts
index 9973bbbc1..27b2c74dc 100644
--- a/packages/binding-netconf/src/netconf-client.ts
+++ b/packages/binding-netconf/src/netconf-client.ts
@@ -23,7 +23,6 @@ import * as AsyncNodeNetcon from "./async-node-netconf";
 import Url from "url-parse";
 import { Readable } from "stream";
 import { Subscription } from "rxjs/Subscription";
-import { ThingDescription } from "wot-typescript-definitions";
 
 const { debug, warn } = createLoggers("binding-netconf", "netconf-client");
 
@@ -177,7 +176,7 @@ export default class NetconfClient implements ProtocolClient {
         return true;
     }
 
-    discoverDirectly(uri: string): Promise<ThingDescription> {
+    discoverDirectly(uri: string): Promise<Content> {
         return Promise.reject(new Error("Method not implemented."));
     }
 }
diff --git a/packages/binding-opcua/src/opcua-protocol-client.ts b/packages/binding-opcua/src/opcua-protocol-client.ts
index 9248d9f40..7c053c57d 100644
--- a/packages/binding-opcua/src/opcua-protocol-client.ts
+++ b/packages/binding-opcua/src/opcua-protocol-client.ts
@@ -45,7 +45,7 @@ import { makeBrowsePath } from "node-opcua-service-translate-browse-path";
 import { StatusCodes } from "node-opcua-status-code";
 
 import { schemaDataValue } from "./codec";
-import { FormElementProperty, ThingDescription } from "wot-thing-description-types";
+import { FormElementProperty } from "wot-thing-description-types";
 import { opcuaJsonEncodeVariant } from "node-opcua-json";
 import { Argument, BrowseDescription, BrowseResult } from "node-opcua-types";
 import { isGoodish2, ReferenceTypeIds } from "node-opcua";
@@ -621,7 +621,7 @@ export class OPCUAProtocolClient implements ProtocolClient {
         return new Content("application/json", Readable.from(JSON.stringify(body)));
     }
 
-    discoverDirectly(uri: string): Promise<ThingDescription> {
+    discoverDirectly(uri: string): Promise<Content> {
         return Promise.reject(new Error("Method not implemented."));
     }
 }
diff --git a/packages/binding-websockets/src/ws-client.ts b/packages/binding-websockets/src/ws-client.ts
index f6400ab95..7a3f4c1f6 100644
--- a/packages/binding-websockets/src/ws-client.ts
+++ b/packages/binding-websockets/src/ws-client.ts
@@ -20,7 +20,6 @@
 import { ProtocolClient, Content, createLoggers } from "@node-wot/core";
 import { Form, SecurityScheme } from "@node-wot/td-tools";
 import { Subscription } from "rxjs/Subscription";
-import { ThingDescription } from "wot-thing-description-types";
 
 const { debug, warn } = createLoggers("binding-websockets", "ws-client");
 
@@ -30,7 +29,7 @@ export default class WebSocketClient implements ProtocolClient {
         // TODO: implement and remove eslint-ignore-useless-constructor
     }
 
-    discoverDirectly(uri: string): Promise<ThingDescription> {
+    discoverDirectly(uri: string): Promise<Content> {
         return Promise.reject(new Error("Method not implemented."));
     }
 
diff --git a/packages/core/src/protocol-interfaces.ts b/packages/core/src/protocol-interfaces.ts
index 21e721dcb..364adc403 100644
--- a/packages/core/src/protocol-interfaces.ts
+++ b/packages/core/src/protocol-interfaces.ts
@@ -60,7 +60,7 @@ export interface ProtocolClient {
     /** this client is requested to perform an "unlink" on the resource with the given URI */
     unlinkResource(form: TD.Form): Promise<void>;
 
-    discoverDirectly(uri: string): Promise<ThingDescription>;
+    discoverDirectly(uri: string): Promise<Content>;
 
     subscribeResource(
         form: TD.Form,
diff --git a/packages/core/src/wot-impl.ts b/packages/core/src/wot-impl.ts
index f1d1aae93..71db14f9a 100644
--- a/packages/core/src/wot-impl.ts
+++ b/packages/core/src/wot-impl.ts
@@ -21,6 +21,7 @@ import ConsumedThing from "./consumed-thing";
 import Helpers from "./helpers";
 import { ThingDescription } from "wot-thing-description-types";
 import { createLoggers } from "./logger";
+import contentSerdes from "./content-serdes";
 
 const { debug } = createLoggers("core", "wot-impl");
 
@@ -45,9 +46,11 @@ class ThingDiscoveryImpl implements AsyncIterable<ThingDescription> {
                 // TODO: This needs to refactored
                 const uriScheme = new URL(this.filter.url).protocol.split(":")[0];
                 const client = this.servient.getClientFor(uriScheme);
-                const thingDescription = client.discoverDirectly(this.filter.url);
+                const result = await client.discoverDirectly(this.filter.url);
+                // TODO: Add TD validation
+                const thingDescription = contentSerdes.contentToValue(result as any, {});
                 this.active = false;
-                yield new Promise<ThingDescription>((resolve) => resolve(thingDescription));
+                yield new Promise<ThingDescription>((resolve) => resolve(thingDescription as ThingDescription));
                 break;
             }
             default:

From cf5a3914ae596f49a1c4f1a386b57c8b5d82fe03 Mon Sep 17 00:00:00 2001
From: Jan Romann <jan.romann@uni-bremen.de>
Date: Tue, 9 Aug 2022 19:12:10 +0200
Subject: [PATCH 10/25] fixup! feat!: add proposal for new discovery API

---
 packages/core/example/example.js | 18 +++++++++++++-----
 packages/core/src/wot-impl.ts    | 23 +++++++++++++++--------
 2 files changed, 28 insertions(+), 13 deletions(-)

diff --git a/packages/core/example/example.js b/packages/core/example/example.js
index dc7e50e89..dfcaa955d 100644
--- a/packages/core/example/example.js
+++ b/packages/core/example/example.js
@@ -1,17 +1,25 @@
 const { Servient } = require("@node-wot/core");
 const { HttpClientFactory } = require("@node-wot/binding-http");
+const { CoapClientFactory } = require("@node-wot/binding-coap");
 
 // Note: This example is just for testing/demonstration purposes and
 //       will eventually be removed/moved to the examples package.
 async function discover() {
     const servient = new Servient();
     servient.addClientFactory(new HttpClientFactory());
+    servient.addClientFactory(new CoapClientFactory());
     const wot = await servient.start();
-    for await (const td of wot.discover({
-        url: "http://plugfest.thingweb.io:8083/smart-coffee-machine",
-        method: "direct",
-    })) {
-        console.log(td);
+
+    const httpUrl = "http://plugfest.thingweb.io:8083/smart-coffee-machine";
+    const coapUrl = "coap://plugfest.thingweb.io:5683/smart-coffee-machine";
+
+    for (const url of [httpUrl, coapUrl]) {
+        for await (const td of wot.discover({
+            url,
+            method: "direct",
+        })) {
+            console.log(td);
+        }
     }
 }
 
diff --git a/packages/core/src/wot-impl.ts b/packages/core/src/wot-impl.ts
index 71db14f9a..f6ee8b224 100644
--- a/packages/core/src/wot-impl.ts
+++ b/packages/core/src/wot-impl.ts
@@ -21,7 +21,9 @@ import ConsumedThing from "./consumed-thing";
 import Helpers from "./helpers";
 import { ThingDescription } from "wot-thing-description-types";
 import { createLoggers } from "./logger";
-import contentSerdes from "./content-serdes";
+import ContentManager from "./content-serdes";
+import { InteractionOutput } from "./interaction-output";
+import ProtocolHelpers from "./protocol-helpers";
 
 const { debug } = createLoggers("core", "wot-impl");
 
@@ -40,17 +42,21 @@ class ThingDiscoveryImpl implements AsyncIterable<ThingDescription> {
     async *[Symbol.asyncIterator](): AsyncIterator<ThingDescription> {
         switch (this.filter.method) {
             case "direct": {
-                if (!this.active) {
+                const url = this.filter.url;
+                if (!this.active || url == null) {
                     return;
                 }
-                // TODO: This needs to refactored
-                const uriScheme = new URL(this.filter.url).protocol.split(":")[0];
+                const uriScheme = new URL(url).protocol.split(":")[0];
                 const client = this.servient.getClientFor(uriScheme);
-                const result = await client.discoverDirectly(this.filter.url);
+                const result = await client.discoverDirectly(url);
+                const data = await ProtocolHelpers.readStreamFully(result.body);
+
                 // TODO: Add TD validation
-                const thingDescription = contentSerdes.contentToValue(result as any, {});
+                // FIXME: application/td+json can't be handled at the moment
+
+                const value = ContentManager.contentToValue({ type: "application/json", body: data }, {});
                 this.active = false;
-                yield new Promise<ThingDescription>((resolve) => resolve(thingDescription as ThingDescription));
+                yield new Promise<ThingDescription>((resolve) => resolve(value as ThingDescription));
                 break;
             }
             default:
@@ -86,7 +92,8 @@ export default class WoTImpl {
 
     /** @inheritDoc */
     discover(filter?: WoT.ThingFilter): WoT.ThingDiscovery {
-        return new ThingDiscoveryImpl(filter, this.srv) as unknown as WoT.ThingDiscovery;
+        // TODO: Should filter really be nullable?
+        return new ThingDiscoveryImpl(filter as any, this.srv) as unknown as WoT.ThingDiscovery;
     }
 
     /** @inheritDoc */

From 734f86b098c0f203b42b290059fc9f6343ad3a40 Mon Sep 17 00:00:00 2001
From: Jan Romann <jan.romann@uni-bremen.de>
Date: Tue, 9 Aug 2022 19:17:37 +0200
Subject: [PATCH 11/25] fixup! feat!: add proposal for new discovery API

---
 packages/core/test/ClientTest.ts | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/packages/core/test/ClientTest.ts b/packages/core/test/ClientTest.ts
index 2768ee7e6..b9dc67d1d 100644
--- a/packages/core/test/ClientTest.ts
+++ b/packages/core/test/ClientTest.ts
@@ -170,7 +170,7 @@ class TDClient implements ProtocolClient {
         return "TDClient";
     }
 
-    discoverDirectly(uri: string): Promise<ThingDescription> {
+    discoverDirectly(uri: string): Promise<Content> {
         return Promise.reject(new Error("discoverDirectly not implemented"));
     }
 }
@@ -244,7 +244,7 @@ class TrapClient implements ProtocolClient {
 
     public setSecurity = (metadata: SecurityScheme[]) => false;
 
-    discoverDirectly(uri: string): Promise<ThingDescription> {
+    discoverDirectly(uri: string): Promise<Content> {
         return Promise.reject(new Error("discoverDirectly not implemented"));
     }
 }
@@ -315,7 +315,7 @@ class TestProtocolClient implements ProtocolClient {
         return true;
     }
 
-    discoverDirectly(uri: string): Promise<ThingDescription> {
+    discoverDirectly(uri: string): Promise<Content> {
         return Promise.reject(new Error("discoverDirectly not implemented"));
     }
 }

From 04b7b2fe76c08dd1457584feb09c6957006e6a7c Mon Sep 17 00:00:00 2001
From: Jan Romann <jan.romann@uni-bremen.de>
Date: Tue, 9 Aug 2022 19:20:51 +0200
Subject: [PATCH 12/25] fixup! feat!: add proposal for new discovery API

---
 packages/core/src/wot-impl.ts | 1 -
 1 file changed, 1 deletion(-)

diff --git a/packages/core/src/wot-impl.ts b/packages/core/src/wot-impl.ts
index f6ee8b224..b72b63f9c 100644
--- a/packages/core/src/wot-impl.ts
+++ b/packages/core/src/wot-impl.ts
@@ -22,7 +22,6 @@ import Helpers from "./helpers";
 import { ThingDescription } from "wot-thing-description-types";
 import { createLoggers } from "./logger";
 import ContentManager from "./content-serdes";
-import { InteractionOutput } from "./interaction-output";
 import ProtocolHelpers from "./protocol-helpers";
 
 const { debug } = createLoggers("core", "wot-impl");

From 5440bea0c10c151266e13757dfc6669ce8470e72 Mon Sep 17 00:00:00 2001
From: Jan Romann <jan.romann@uni-bremen.de>
Date: Mon, 7 Nov 2022 16:10:07 +0100
Subject: [PATCH 13/25] fixup! feat!: add proposal for new discovery API

---
 packages/core/example/example.js | 12 ++---
 packages/core/src/wot-impl.ts    | 75 +++++++++++++++++---------------
 2 files changed, 48 insertions(+), 39 deletions(-)

diff --git a/packages/core/example/example.js b/packages/core/example/example.js
index dfcaa955d..c4bd661ba 100644
--- a/packages/core/example/example.js
+++ b/packages/core/example/example.js
@@ -14,11 +14,13 @@ async function discover() {
     const coapUrl = "coap://plugfest.thingweb.io:5683/smart-coffee-machine";
 
     for (const url of [httpUrl, coapUrl]) {
-        for await (const td of wot.discover({
-            url,
-            method: "direct",
-        })) {
-            console.log(td);
+        console.log(await wot.discovery.direct(url));
+    }
+
+    // Alternative approach
+    for (const url of [httpUrl, coapUrl]) {
+        for await (const result of wot.discovery.directIterator(url)) {
+            console.log(result);
         }
     }
 }
diff --git a/packages/core/src/wot-impl.ts b/packages/core/src/wot-impl.ts
index b72b63f9c..9c973b53b 100644
--- a/packages/core/src/wot-impl.ts
+++ b/packages/core/src/wot-impl.ts
@@ -26,47 +26,48 @@ import ProtocolHelpers from "./protocol-helpers";
 
 const { debug } = createLoggers("core", "wot-impl");
 
-class ThingDiscoveryImpl implements AsyncIterable<ThingDescription> {
-    filter: WoT.ThingFilter;
-
-    active = true;
+class ThingDiscovery {
 
     private servient: Servient;
-
-    constructor(filter: WoT.ThingFilter, servient: Servient) {
-        this.filter = filter;
+    constructor(servient: Servient) {
         this.servient = servient;
     }
 
-    async *[Symbol.asyncIterator](): AsyncIterator<ThingDescription> {
-        switch (this.filter.method) {
-            case "direct": {
-                const url = this.filter.url;
-                if (!this.active || url == null) {
-                    return;
-                }
-                const uriScheme = new URL(url).protocol.split(":")[0];
-                const client = this.servient.getClientFor(uriScheme);
-                const result = await client.discoverDirectly(url);
-                const data = await ProtocolHelpers.readStreamFully(result.body);
-
-                // TODO: Add TD validation
-                // FIXME: application/td+json can't be handled at the moment
-
-                const value = ContentManager.contentToValue({ type: "application/json", body: data }, {});
-                this.active = false;
-                yield new Promise<ThingDescription>((resolve) => resolve(value as ThingDescription));
-                break;
-            }
-            default:
-                throw Error("Only the direct discovery method has been implemented yet.");
+    async direct(url: string, filter?: WoT.ThingFilter): Promise<ThingDescription> {
+        const uriScheme = new URL(url).protocol.split(":")[0];
+        const client = this.servient.getClientFor(uriScheme);
+        const result = await client.discoverDirectly(url);
+        const data = await ProtocolHelpers.readStreamFully(result.body);
+
+        // TODO: Add TD validation
+        // FIXME: application/td+json can't be handled at the moment
+
+        const value = ContentManager.contentToValue({ type: "application/json", body: data }, {});
+        return new Promise<ThingDescription>((resolve) => resolve(value as ThingDescription));
+    }
+
+    // Alternative approach.
+    async *directIterator(url: string, filter?: WoT.ThingFilter): AsyncGenerator<ThingDescription> {
+        const uriScheme = new URL(url).protocol.split(":")[0];
+        const client = this.servient.getClientFor(uriScheme);
+        const result = await client.discoverDirectly(url);
+        const data = await ProtocolHelpers.readStreamFully(result.body);
+
+        // TODO: Add TD validation
+        // FIXME: application/td+json can't be handled at the moment
+
+        const value = ContentManager.contentToValue({ type: "application/json", body: data }, {});
+
+        if (value instanceof Object) {
+            yield value as ThingDescription;
         }
     }
 
-    public stop(): void {
-        this.active = false;
+    async *directory(url: string, filter?: WoT.ThingFilter): AsyncGenerator<ThingDescription> {
+        // Not implemented, do nothing
     }
 }
+
 /**
  * wot-type-definitions does not contain a implementation of Discovery method enums
  * so we need to create them here. Sadly, we should keep this enum in sync with
@@ -85,14 +86,20 @@ export enum DiscoveryMethod {
 
 export default class WoTImpl {
     private srv: Servient;
+    DiscoveryMethod: typeof WoT.DiscoveryMethod;
+
+    discovery: ThingDiscovery;
+
     constructor(srv: Servient) {
         this.srv = srv;
+        // force casting cause tsc does not allow to use DiscoveryMethod as WoT.DiscoveryMethod even if they are the same
+        this.DiscoveryMethod = DiscoveryMethod as unknown as typeof WoT.DiscoveryMethod;
+
+        this.discovery = new ThingDiscovery(srv);
     }
 
-    /** @inheritDoc */
     discover(filter?: WoT.ThingFilter): WoT.ThingDiscovery {
-        // TODO: Should filter really be nullable?
-        return new ThingDiscoveryImpl(filter as any, this.srv) as unknown as WoT.ThingDiscovery;
+        throw new Error("REMOVE ME.");
     }
 
     /** @inheritDoc */

From db320c1daa1528e095593ea0e9f1b6018336707d Mon Sep 17 00:00:00 2001
From: Jan Romann <jan.romann@uni-bremen.de>
Date: Mon, 7 Nov 2022 16:56:38 +0100
Subject: [PATCH 14/25] fixup! feat!: add proposal for new discovery API

---
 packages/core/src/wot-impl.ts | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/packages/core/src/wot-impl.ts b/packages/core/src/wot-impl.ts
index 9c973b53b..432ce829e 100644
--- a/packages/core/src/wot-impl.ts
+++ b/packages/core/src/wot-impl.ts
@@ -43,7 +43,11 @@ class ThingDiscovery {
         // FIXME: application/td+json can't be handled at the moment
 
         const value = ContentManager.contentToValue({ type: "application/json", body: data }, {});
-        return new Promise<ThingDescription>((resolve) => resolve(value as ThingDescription));
+        if (value instanceof Object) {
+            return value as ThingDescription;
+        }
+
+        throw Error(`Could not parse Thing Description obtained from ${url}`);
     }
 
     // Alternative approach.

From 74b0e3751967542d245a67a7652a11e3a5cab857 Mon Sep 17 00:00:00 2001
From: Jan Romann <jan.romann@uni-bremen.de>
Date: Mon, 7 Nov 2022 17:00:28 +0100
Subject: [PATCH 15/25] fixup! feat!: add proposal for new discovery API

---
 packages/binding-coap/src/coaps-client.ts           | 4 ++--
 packages/binding-file/src/file-client.ts            | 4 ++--
 packages/binding-mbus/src/mbus-client.ts            | 4 ++--
 packages/binding-modbus/src/modbus-client.ts        | 4 ++--
 packages/binding-mqtt/src/mqtt-client.ts            | 4 ++--
 packages/binding-netconf/src/netconf-client.ts      | 4 ++--
 packages/binding-opcua/src/opcua-protocol-client.ts | 4 ++--
 packages/binding-websockets/src/ws-client.ts        | 4 ++--
 8 files changed, 16 insertions(+), 16 deletions(-)

diff --git a/packages/binding-coap/src/coaps-client.ts b/packages/binding-coap/src/coaps-client.ts
index 0e47ebca3..ea93d3318 100644
--- a/packages/binding-coap/src/coaps-client.ts
+++ b/packages/binding-coap/src/coaps-client.ts
@@ -236,7 +236,7 @@ export default class CoapsClient implements ProtocolClient {
         return req;
     }
 
-    discoverDirectly(uri: string): Promise<Content> {
-        return Promise.reject(new Error("Method not implemented."));
+    async discoverDirectly(uri: string): Promise<Content> {
+        throw new Error("Method not implemented.");
     }
 }
diff --git a/packages/binding-file/src/file-client.ts b/packages/binding-file/src/file-client.ts
index c7bcaae4b..0b721adf5 100644
--- a/packages/binding-file/src/file-client.ts
+++ b/packages/binding-file/src/file-client.ts
@@ -91,7 +91,7 @@ export default class FileClient implements ProtocolClient {
 
     public setSecurity = (metadata: Array<SecurityScheme>): boolean => false;
 
-    discoverDirectly(uri: string): Promise<Content> {
-        return Promise.reject(new Error("Method not implemented."));
+    async discoverDirectly(uri: string): Promise<Content> {
+        throw new Error("Method not implemented.");
     }
 }
diff --git a/packages/binding-mbus/src/mbus-client.ts b/packages/binding-mbus/src/mbus-client.ts
index b26ffc217..ebd021c18 100644
--- a/packages/binding-mbus/src/mbus-client.ts
+++ b/packages/binding-mbus/src/mbus-client.ts
@@ -145,7 +145,7 @@ export default class MBusClient implements ProtocolClient {
         return result;
     }
 
-    discoverDirectly(uri: string): Promise<Content> {
-        return Promise.reject(new Error("Method not implemented."));
+    async discoverDirectly(uri: string): Promise<Content> {
+        throw new Error("Method not implemented.");
     }
 }
diff --git a/packages/binding-modbus/src/modbus-client.ts b/packages/binding-modbus/src/modbus-client.ts
index 4e8811da5..207676aaa 100644
--- a/packages/binding-modbus/src/modbus-client.ts
+++ b/packages/binding-modbus/src/modbus-client.ts
@@ -310,7 +310,7 @@ export default class ModbusClient implements ProtocolClient {
         return result as ModbusFormWithDefaults;
     }
 
-    discoverDirectly(uri: string): Promise<Content> {
-        return Promise.reject(new Error("Method not implemented."));
+    async discoverDirectly(uri: string): Promise<Content> {
+        throw new Error("Method not implemented.");
     }
 }
diff --git a/packages/binding-mqtt/src/mqtt-client.ts b/packages/binding-mqtt/src/mqtt-client.ts
index 53237bb44..8d7aba6b1 100644
--- a/packages/binding-mqtt/src/mqtt-client.ts
+++ b/packages/binding-mqtt/src/mqtt-client.ts
@@ -200,7 +200,7 @@ export default class MqttClient implements ProtocolClient {
         }
     }
 
-    discoverDirectly(uri: string): Promise<Content> {
-        return Promise.reject(new Error("Method not implemented."));
+    async discoverDirectly(uri: string): Promise<Content> {
+        throw new Error("Method not implemented.");
     }
 }
diff --git a/packages/binding-netconf/src/netconf-client.ts b/packages/binding-netconf/src/netconf-client.ts
index 27b2c74dc..93d7cbdcf 100644
--- a/packages/binding-netconf/src/netconf-client.ts
+++ b/packages/binding-netconf/src/netconf-client.ts
@@ -176,7 +176,7 @@ export default class NetconfClient implements ProtocolClient {
         return true;
     }
 
-    discoverDirectly(uri: string): Promise<Content> {
-        return Promise.reject(new Error("Method not implemented."));
+    async discoverDirectly(uri: string): Promise<Content> {
+        throw new Error("Method not implemented.");
     }
 }
diff --git a/packages/binding-opcua/src/opcua-protocol-client.ts b/packages/binding-opcua/src/opcua-protocol-client.ts
index 7c053c57d..37a1ae019 100644
--- a/packages/binding-opcua/src/opcua-protocol-client.ts
+++ b/packages/binding-opcua/src/opcua-protocol-client.ts
@@ -621,7 +621,7 @@ export class OPCUAProtocolClient implements ProtocolClient {
         return new Content("application/json", Readable.from(JSON.stringify(body)));
     }
 
-    discoverDirectly(uri: string): Promise<Content> {
-        return Promise.reject(new Error("Method not implemented."));
+    async discoverDirectly(uri: string): Promise<Content> {
+        throw new Error("Method not implemented.");
     }
 }
diff --git a/packages/binding-websockets/src/ws-client.ts b/packages/binding-websockets/src/ws-client.ts
index 7a3f4c1f6..7938f35f9 100644
--- a/packages/binding-websockets/src/ws-client.ts
+++ b/packages/binding-websockets/src/ws-client.ts
@@ -29,8 +29,8 @@ export default class WebSocketClient implements ProtocolClient {
         // TODO: implement and remove eslint-ignore-useless-constructor
     }
 
-    discoverDirectly(uri: string): Promise<Content> {
-        return Promise.reject(new Error("Method not implemented."));
+    async discoverDirectly(uri: string): Promise<Content> {
+        throw new Error("Method not implemented.");
     }
 
     public toString(): string {

From 2207a91e87d3243527b571642b35998cc4bfad47 Mon Sep 17 00:00:00 2001
From: Jan Romann <jan.romann@uni-bremen.de>
Date: Mon, 7 Nov 2022 17:04:26 +0100
Subject: [PATCH 16/25] fixup! feat!: add proposal for new discovery API

---
 packages/core/test/ClientTest.ts | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/packages/core/test/ClientTest.ts b/packages/core/test/ClientTest.ts
index b9dc67d1d..380114273 100644
--- a/packages/core/test/ClientTest.ts
+++ b/packages/core/test/ClientTest.ts
@@ -170,8 +170,8 @@ class TDClient implements ProtocolClient {
         return "TDClient";
     }
 
-    discoverDirectly(uri: string): Promise<Content> {
-        return Promise.reject(new Error("discoverDirectly not implemented"));
+    async discoverDirectly(uri: string): Promise<Content> {
+        throw new Error("discoverDirectly not implemented.");
     }
 }
 
@@ -244,8 +244,8 @@ class TrapClient implements ProtocolClient {
 
     public setSecurity = (metadata: SecurityScheme[]) => false;
 
-    discoverDirectly(uri: string): Promise<Content> {
-        return Promise.reject(new Error("discoverDirectly not implemented"));
+    async discoverDirectly(uri: string): Promise<Content> {
+        throw new Error("discoverDirectly not implemented.");
     }
 }
 
@@ -315,8 +315,8 @@ class TestProtocolClient implements ProtocolClient {
         return true;
     }
 
-    discoverDirectly(uri: string): Promise<Content> {
-        return Promise.reject(new Error("discoverDirectly not implemented"));
+    async discoverDirectly(uri: string): Promise<Content> {
+        throw new Error("discoverDirectly not implemented.");
     }
 }
 

From ad43508d8c6b10df1e8533ec66957677a761e03d Mon Sep 17 00:00:00 2001
From: Jan Romann <jan.romann@uni-bremen.de>
Date: Mon, 7 Nov 2022 17:15:32 +0100
Subject: [PATCH 17/25] fixup! feat!: add proposal for new discovery API

---
 packages/core/src/wot-impl.ts | 1 -
 1 file changed, 1 deletion(-)

diff --git a/packages/core/src/wot-impl.ts b/packages/core/src/wot-impl.ts
index 432ce829e..a5fe3576c 100644
--- a/packages/core/src/wot-impl.ts
+++ b/packages/core/src/wot-impl.ts
@@ -27,7 +27,6 @@ import ProtocolHelpers from "./protocol-helpers";
 const { debug } = createLoggers("core", "wot-impl");
 
 class ThingDiscovery {
-
     private servient: Servient;
     constructor(servient: Servient) {
         this.servient = servient;

From b869b5ce51e648e687bf98a307bc73af70e42c80 Mon Sep 17 00:00:00 2001
From: Jan Romann <jan.romann@uni-bremen.de>
Date: Tue, 19 Sep 2023 08:19:40 +0200
Subject: [PATCH 18/25] fixup! feat!: add proposal for new discovery API

---
 packages/core/src/protocol-interfaces.ts | 1 -
 1 file changed, 1 deletion(-)

diff --git a/packages/core/src/protocol-interfaces.ts b/packages/core/src/protocol-interfaces.ts
index 364adc403..5eb246866 100644
--- a/packages/core/src/protocol-interfaces.ts
+++ b/packages/core/src/protocol-interfaces.ts
@@ -20,7 +20,6 @@ import { Subscription } from "rxjs/Subscription";
 import Servient from "./servient";
 import ExposedThing from "./exposed-thing";
 import { Content } from "./content";
-import { ThingDescription } from "wot-typescript-definitions";
 
 export type PropertyContentMap = Map<string, Content>;
 

From 961606ecd4d3e85d99902b0f2f202260c9448cf7 Mon Sep 17 00:00:00 2001
From: Jan Romann <jan.romann@uni-bremen.de>
Date: Tue, 19 Sep 2023 08:26:33 +0200
Subject: [PATCH 19/25] fixup! feat!: add proposal for new discovery API

---
 packages/binding-coap/src/coap-client.ts      | 7 ++-----
 packages/binding-http/src/http-client-impl.ts | 2 +-
 2 files changed, 3 insertions(+), 6 deletions(-)

diff --git a/packages/binding-coap/src/coap-client.ts b/packages/binding-coap/src/coap-client.ts
index bcc9d69cc..c7156d7d6 100644
--- a/packages/binding-coap/src/coap-client.ts
+++ b/packages/binding-coap/src/coap-client.ts
@@ -62,11 +62,8 @@ export default class CoapClient implements ProtocolClient {
         req.setOption("Accept", "application/td+json");
         return new Promise<Content>((resolve, reject) => {
             req.on("response", (res: IncomingMessage) => {
-                let contentType = res.headers["Content-Format"];
-                if (typeof contentType !== "string") {
-                    contentType = "application/td+json";
-                }
-                resolve({ type: contentType, body: Readable.from(res.payload) });
+                const contentType = (res.headers["Content-Format"] as string) ?? "application/td+json";
+                resolve(new Content(contentType, Readable.from(res.payload)));
             });
             req.on("error", (err: Error) => reject(err));
             req.end();
diff --git a/packages/binding-http/src/http-client-impl.ts b/packages/binding-http/src/http-client-impl.ts
index 45f9d3168..f489f77e0 100644
--- a/packages/binding-http/src/http-client-impl.ts
+++ b/packages/binding-http/src/http-client-impl.ts
@@ -418,6 +418,6 @@ export default class HttpClient implements ProtocolClient {
         const response = await fetch(uri, { headers });
         // TODO: Result should be validated
         const body = ProtocolHelpers.toNodeStream(response.body as Readable);
-        return { type: response.headers.get("content-type"), body };
+        return new Content(response.headers.get("content-type") ?? "application/td+json", body);
     }
 }

From 950faa31a2e52d90a4d6a4a11c3cd6d9d6ecee7f Mon Sep 17 00:00:00 2001
From: Jan Romann <jan.romann@uni-bremen.de>
Date: Tue, 19 Sep 2023 09:15:33 +0200
Subject: [PATCH 20/25] fixup! feat!: add proposal for new discovery API

---
 packages/core/src/wot-impl.ts | 21 +++++++++++++++++----
 1 file changed, 17 insertions(+), 4 deletions(-)

diff --git a/packages/core/src/wot-impl.ts b/packages/core/src/wot-impl.ts
index a5fe3576c..3f51b4598 100644
--- a/packages/core/src/wot-impl.ts
+++ b/packages/core/src/wot-impl.ts
@@ -54,20 +54,33 @@ class ThingDiscovery {
         const uriScheme = new URL(url).protocol.split(":")[0];
         const client = this.servient.getClientFor(uriScheme);
         const result = await client.discoverDirectly(url);
-        const data = await ProtocolHelpers.readStreamFully(result.body);
 
         // TODO: Add TD validation
         // FIXME: application/td+json can't be handled at the moment
 
-        const value = ContentManager.contentToValue({ type: "application/json", body: data }, {});
+        const value = ContentManager.contentToValue({ type: "application/json", body: await result.toBuffer() }, {});
 
         if (value instanceof Object) {
             yield value as ThingDescription;
         }
     }
 
-    async *directory(url: string, filter?: WoT.ThingFilter): AsyncGenerator<ThingDescription> {
-        // Not implemented, do nothing
+    async *exploreDirectory(url: string, filter?: WoT.ThingFilter): AsyncGenerator<ThingDescription> {
+        yield Promise.reject(new Error("Unimplemented"));
+    }
+
+    async requestThingDescription(url: string): Promise<ThingDescription> {
+        const uriScheme = new URL(url).protocol.split(":")[0];
+        const client = this.servient.getClientFor(uriScheme);
+        const result = await client.discoverDirectly(url);
+
+        const value = ContentManager.contentToValue({ type: result.type, body: await result.toBuffer() }, {});
+
+        if (value instanceof Object) {
+            return value as ThingDescription;
+        }
+
+        throw new Error("Not found.");
     }
 }
 

From 56369833f7a0110b55b1dd48b9a89af88bba9304 Mon Sep 17 00:00:00 2001
From: Jan Romann <jan.romann@uni-bremen.de>
Date: Mon, 23 Oct 2023 12:27:44 +0200
Subject: [PATCH 21/25] fixup! feat!: add proposal for new discovery API

---
 packages/core/src/wot-impl.ts | 114 +++++++++++++---------------------
 1 file changed, 42 insertions(+), 72 deletions(-)

diff --git a/packages/core/src/wot-impl.ts b/packages/core/src/wot-impl.ts
index 3f51b4598..1d2b0fb62 100644
--- a/packages/core/src/wot-impl.ts
+++ b/packages/core/src/wot-impl.ts
@@ -22,100 +22,47 @@ import Helpers from "./helpers";
 import { ThingDescription } from "wot-thing-description-types";
 import { createLoggers } from "./logger";
 import ContentManager from "./content-serdes";
-import ProtocolHelpers from "./protocol-helpers";
 
 const { debug } = createLoggers("core", "wot-impl");
 
-class ThingDiscovery {
-    private servient: Servient;
-    constructor(servient: Servient) {
-        this.servient = servient;
-    }
-
-    async direct(url: string, filter?: WoT.ThingFilter): Promise<ThingDescription> {
-        const uriScheme = new URL(url).protocol.split(":")[0];
-        const client = this.servient.getClientFor(uriScheme);
-        const result = await client.discoverDirectly(url);
-        const data = await ProtocolHelpers.readStreamFully(result.body);
+interface ThingFilter {
+    fragment?: object;
+}
 
-        // TODO: Add TD validation
-        // FIXME: application/td+json can't be handled at the moment
+class ThingDiscoveryProcess {
+    #done = false;
 
-        const value = ContentManager.contentToValue({ type: "application/json", body: data }, {});
-        if (value instanceof Object) {
-            return value as ThingDescription;
-        }
-
-        throw Error(`Could not parse Thing Description obtained from ${url}`);
+    get done() {
+        return this.#done;
     }
 
-    // Alternative approach.
-    async *directIterator(url: string, filter?: WoT.ThingFilter): AsyncGenerator<ThingDescription> {
-        const uriScheme = new URL(url).protocol.split(":")[0];
-        const client = this.servient.getClientFor(uriScheme);
-        const result = await client.discoverDirectly(url);
-
-        // TODO: Add TD validation
-        // FIXME: application/td+json can't be handled at the moment
-
-        const value = ContentManager.contentToValue({ type: "application/json", body: await result.toBuffer() }, {});
+    #error?: Error;
 
-        if (value instanceof Object) {
-            yield value as ThingDescription;
-        }
+    get error() {
+        return this.#error;
     }
 
-    async *exploreDirectory(url: string, filter?: WoT.ThingFilter): AsyncGenerator<ThingDescription> {
-        yield Promise.reject(new Error("Unimplemented"));
-    }
+    #filter: ThingFilter;
 
-    async requestThingDescription(url: string): Promise<ThingDescription> {
-        const uriScheme = new URL(url).protocol.split(":")[0];
-        const client = this.servient.getClientFor(uriScheme);
-        const result = await client.discoverDirectly(url);
 
-        const value = ContentManager.contentToValue({ type: result.type, body: await result.toBuffer() }, {});
 
-        if (value instanceof Object) {
-            return value as ThingDescription;
-        }
+    constructor(filter?: ThingFilter) {
+        this.#filter = filter ?? {};
+    };
 
-        throw new Error("Not found.");
+    stop(): void  {
+        this.#done = true;
     }
-}
 
-/**
- * wot-type-definitions does not contain a implementation of Discovery method enums
- * so we need to create them here. Sadly, we should keep this enum in sync with
- * WoT.DiscoveryMethod
- */
-export enum DiscoveryMethod {
-    /** does not provide any restriction */
-    "any",
-    /** for discovering Things defined in the same device */
-    "local",
-    /** for discovery based on a service provided by a directory or repository of Things  */
-    "directory",
-    /** for discovering Things in the device's network by using a supported multicast protocol  */
-    "multicast",
-}
+    // TODO: Implement AsyncIterable
+    // async iterable<ThingDescription>;
+  };
 
 export default class WoTImpl {
     private srv: Servient;
-    DiscoveryMethod: typeof WoT.DiscoveryMethod;
-
-    discovery: ThingDiscovery;
 
     constructor(srv: Servient) {
         this.srv = srv;
-        // force casting cause tsc does not allow to use DiscoveryMethod as WoT.DiscoveryMethod even if they are the same
-        this.DiscoveryMethod = DiscoveryMethod as unknown as typeof WoT.DiscoveryMethod;
-
-        this.discovery = new ThingDiscovery(srv);
-    }
-
-    discover(filter?: WoT.ThingFilter): WoT.ThingDiscovery {
-        throw new Error("REMOVE ME.");
     }
 
     /** @inheritDoc */
@@ -165,6 +112,29 @@ export default class WoTImpl {
             }
         });
     }
+
+    async discover(filter?: WoT.ThingFilter): Promise<ThingDiscoveryProcess> {
+        // TODO: Implement this function
+        return new ThingDiscoveryProcess(filter);
+    }
+
+    async *exploreDirectory(url: string, filter?: WoT.ThingFilter): AsyncGenerator<ThingDiscoveryProcess> {
+        yield Promise.reject(new Error("Unimplemented"));
+    }
+
+    async requestThingDescription(url: string): Promise<ThingDescription> {
+        const uriScheme = new URL(url).protocol.split(":")[0];
+        const client = this.srv.getClientFor(uriScheme);
+        const result = await client.discoverDirectly(url);
+
+        const value = ContentManager.contentToValue({ type: result.type, body: await result.toBuffer() }, {});
+
+        if (value instanceof Object) {
+            return value as ThingDescription;
+        }
+
+        throw new Error("Not found.");
+    }
 }
 
 /** Instantiation of the WoT.DataType declaration */

From 88252f0e5bf665b132f683b29b138b8786e54a93 Mon Sep 17 00:00:00 2001
From: Jan Romann <jan.romann@uni-bremen.de>
Date: Mon, 23 Oct 2023 12:29:45 +0200
Subject: [PATCH 22/25] fixup! feat!: add proposal for new discovery API

---
 packages/core/src/wot-impl.ts | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/packages/core/src/wot-impl.ts b/packages/core/src/wot-impl.ts
index 1d2b0fb62..6e2be936f 100644
--- a/packages/core/src/wot-impl.ts
+++ b/packages/core/src/wot-impl.ts
@@ -44,19 +44,17 @@ class ThingDiscoveryProcess {
 
     #filter: ThingFilter;
 
-
-
     constructor(filter?: ThingFilter) {
         this.#filter = filter ?? {};
-    };
+    }
 
-    stop(): void  {
+    stop(): void {
         this.#done = true;
     }
 
     // TODO: Implement AsyncIterable
     // async iterable<ThingDescription>;
-  };
+}
 
 export default class WoTImpl {
     private srv: Servient;

From 44af6199bc305b1be91369bab675574828c28a07 Mon Sep 17 00:00:00 2001
From: Jan Romann <jan.romann@uni-bremen.de>
Date: Tue, 21 Nov 2023 14:17:14 +0100
Subject: [PATCH 23/25] fixup! feat!: add proposal for new discovery API

---
 packages/core/src/wot-impl.ts | 65 +++++++++++++++++------------------
 1 file changed, 32 insertions(+), 33 deletions(-)

diff --git a/packages/core/src/wot-impl.ts b/packages/core/src/wot-impl.ts
index 6e2be936f..79d631c56 100644
--- a/packages/core/src/wot-impl.ts
+++ b/packages/core/src/wot-impl.ts
@@ -25,11 +25,7 @@ import ContentManager from "./content-serdes";
 
 const { debug } = createLoggers("core", "wot-impl");
 
-interface ThingFilter {
-    fragment?: object;
-}
-
-class ThingDiscoveryProcess {
+class ThingDiscoveryProcess implements WoT.ThingDiscoveryProcess {
     #done = false;
 
     get done() {
@@ -42,18 +38,21 @@ class ThingDiscoveryProcess {
         return this.#error;
     }
 
-    #filter: ThingFilter;
+    #filter: WoT.ThingFilter;
 
-    constructor(filter?: ThingFilter) {
+    constructor(filter?: WoT.ThingFilter) {
         this.#filter = filter ?? {};
     }
 
+    filter?: WoT.ThingFilter | undefined;
+
+    [Symbol.asyncIterator](): AsyncIterator<ThingDescription> {
+            throw new Error("Method not implemented.");
+    }
+
     stop(): void {
         this.#done = true;
     }
-
-    // TODO: Implement AsyncIterable
-    // async iterable<ThingDescription>;
 }
 
 export default class WoTImpl {
@@ -63,6 +62,29 @@ export default class WoTImpl {
         this.srv = srv;
     }
 
+    async discover(filter?: WoT.ThingFilter): Promise<WoT.ThingDiscoveryProcess> {
+        // TODO: Implement this function
+        return new ThingDiscoveryProcess(filter);
+    }
+
+    async *exploreDirectory(url: string, filter?: WoT.ThingFilter): AsyncGenerator<ThingDiscoveryProcess> {
+        yield Promise.reject(new Error("Unimplemented"));
+    }
+
+    async requestThingDescription(url: string): Promise<ThingDescription> {
+        const uriScheme = new URL(url).protocol.split(":")[0];
+        const client = this.srv.getClientFor(uriScheme);
+        const result = await client.discoverDirectly(url);
+
+        const value = ContentManager.contentToValue({ type: result.type, body: await result.toBuffer() }, {});
+
+        if (value instanceof Object) {
+            return value as ThingDescription;
+        }
+
+        throw new Error("Not found.");
+    }
+
     /** @inheritDoc */
     async consume(td: WoT.ThingDescription): Promise<ConsumedThing> {
         try {
@@ -110,29 +132,6 @@ export default class WoTImpl {
             }
         });
     }
-
-    async discover(filter?: WoT.ThingFilter): Promise<ThingDiscoveryProcess> {
-        // TODO: Implement this function
-        return new ThingDiscoveryProcess(filter);
-    }
-
-    async *exploreDirectory(url: string, filter?: WoT.ThingFilter): AsyncGenerator<ThingDiscoveryProcess> {
-        yield Promise.reject(new Error("Unimplemented"));
-    }
-
-    async requestThingDescription(url: string): Promise<ThingDescription> {
-        const uriScheme = new URL(url).protocol.split(":")[0];
-        const client = this.srv.getClientFor(uriScheme);
-        const result = await client.discoverDirectly(url);
-
-        const value = ContentManager.contentToValue({ type: result.type, body: await result.toBuffer() }, {});
-
-        if (value instanceof Object) {
-            return value as ThingDescription;
-        }
-
-        throw new Error("Not found.");
-    }
 }
 
 /** Instantiation of the WoT.DataType declaration */

From 495b857c4b53780e40ce4e8d4265d921fed9afef Mon Sep 17 00:00:00 2001
From: Jan Romann <jan.romann@uni-bremen.de>
Date: Tue, 21 Nov 2023 14:19:36 +0100
Subject: [PATCH 24/25] fixup! feat!: add proposal for new discovery API

---
 packages/core/src/wot-impl.ts | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/packages/core/src/wot-impl.ts b/packages/core/src/wot-impl.ts
index 79d631c56..1728260cb 100644
--- a/packages/core/src/wot-impl.ts
+++ b/packages/core/src/wot-impl.ts
@@ -62,15 +62,18 @@ export default class WoTImpl {
         this.srv = srv;
     }
 
+    /** @inheritDoc */
     async discover(filter?: WoT.ThingFilter): Promise<WoT.ThingDiscoveryProcess> {
         // TODO: Implement this function
         return new ThingDiscoveryProcess(filter);
     }
 
+    /** @inheritDoc */
     async *exploreDirectory(url: string, filter?: WoT.ThingFilter): AsyncGenerator<ThingDiscoveryProcess> {
         yield Promise.reject(new Error("Unimplemented"));
     }
 
+    /** @inheritDoc */
     async requestThingDescription(url: string): Promise<ThingDescription> {
         const uriScheme = new URL(url).protocol.split(":")[0];
         const client = this.srv.getClientFor(uriScheme);

From ccd7751b1e42072903f52f44a38c1d926b0a3ff9 Mon Sep 17 00:00:00 2001
From: Jan Romann <jan.romann@uni-bremen.de>
Date: Tue, 21 Nov 2023 14:21:36 +0100
Subject: [PATCH 25/25] fixup! feat!: add proposal for new discovery API

---
 packages/core/src/wot-impl.ts | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/packages/core/src/wot-impl.ts b/packages/core/src/wot-impl.ts
index 1728260cb..1b9a05339 100644
--- a/packages/core/src/wot-impl.ts
+++ b/packages/core/src/wot-impl.ts
@@ -69,8 +69,8 @@ export default class WoTImpl {
     }
 
     /** @inheritDoc */
-    async *exploreDirectory(url: string, filter?: WoT.ThingFilter): AsyncGenerator<ThingDiscoveryProcess> {
-        yield Promise.reject(new Error("Unimplemented"));
+    async exploreDirectory(url: string, filter?: WoT.ThingFilter): Promise<WoT.ThingDiscoveryProcess> {
+        return new ThingDiscoveryProcess(filter);
     }
 
     /** @inheritDoc */