Enable conversion from Z2M Exposes API to OpenHAB things

src/index.ts

@@ -1,11 +1,23 @@
-import { fetchModel } from "./mqtt";
+import { fromZ2M } from "./z2m/loader";
 
-async function run(username: string, password: string) {
-  const response = await fetchModel(username, password);
-  console.log(response);
+export type Config = {
+  bridgeID: string;
+  prefix: String;
+  username: string;
+  password: string;
+  clientId?: string;
+};
+
+async function run(config: Config) {
+  const things = await fromZ2M(config);
+  console.log(things);
 }
 
-const username = "test";
-const password = "test";
+const config: Config = {
+  bridgeID: "main",
+  prefix: "zigbee",
+  username: 'test',
+  password: 'test',
+};
 
-run(username, password);
+run(config);

src/mqtt.ts

@@ -1,19 +0,0 @@
-import mqtt from "mqtt";
-import { Device } from "./types/model";
-
-export function fetchModel(username: string, password: string, topic = "zigbee/bridge/devices", clientId = "zigbee2mqtt->openHAB importer"): Promise<Device[]> {
-  const client = mqtt.connect("mqtt://mqtt.lan", { username, password, clientId });
-
-  return new Promise((resolve, reject) => {
-    client.on("connect", () => {
-      client.subscribe(topic, err => {
-        if(err) reject(err);
-      });
-    });
-
-    client.on("message", (topic, message) => {    
-      client.end();
-      resolve(JSON.parse(message.toString()) as Device[]);
-    });
-  });
-}

src/openhab/types.ts

@@ -0,0 +1,66 @@
+export type Thing = {
+  label: string;
+  bridgeUID: string;
+  configuration: ThingConfig;
+  properties: Record<string, string>;
+  UID: string;
+  thingTypeUID: string;
+  location?: string;
+  channels: Channel[];
+};
+
+export type ThingConfig = {
+  availabilityTopic: string;
+  payloadNotAvailable: string;
+  payloadAvailable: string;
+};
+
+export type Channel = {
+  uid: string;
+  id: string;
+  channelTypeUID: string;
+  itemType?: ItemType;
+  kind: 'STATE' | 'TRIGGER';
+  label: string;
+  description: string;
+  defaultTags: string[];
+  configuration: ChannelConfig;
+  properties: Record<string, string>;
+  autoUpdatePolicy?: string;
+};
+
+export type ChannelConfig = {
+  unit?: string;
+  min?: number;
+  max?: number;
+  on?: unknown;
+  off?: unknown;
+  allowedStates?: string;
+  stateTopic?: string;
+  commandTopic?: string;
+  qos?: number;
+  retained?: boolean;
+  postCommand?: boolean;
+  nullValue?: string;
+};
+
+export type ItemType = 
+  'String'
+  | 'Switch'
+  | 'Contact'
+  | 'Number'
+  | 'Dimmer'
+  | 'Color'
+  | 'Image'
+  | 'Location'
+
+export type ChannelType = 
+  'mqtt:string'
+  | 'mqtt:switch'
+  | 'mqtt:contact'
+  | 'mqtt:number'
+  | 'mqtt:dimmer'
+  | 'mqtt:color'
+  | 'mqtt:image'
+  | 'mqtt:location'
+  | 'mqtt:trigger'  

src/z2m/loader.ts

@@ -0,0 +1,139 @@
+import mqtt from "mqtt";
+import { Device, Feature, FeatureType } from "./types";
+import { Config } from "..";
+import { Channel, ChannelType, ItemType, Thing } from "../openhab/types";
+
+/**
+ * Fetches devices from Exposes API of Zigbee2MQTT and converts them
+ * to OpenHAB Thing payload.
+ * @param config - the configuration of MQTT network
+ * @returns promise with list of OpenHAB things payload
+ */
+export const fromZ2M = async (config: Config): Promise<Thing[]> => {
+  const devices = await fetchModel(config);
+
+  return devices.flatMap(toThing(config));
+}
+
+/**
+ * Fetches devices model from Exposes API of Zigbee2MQTT service.
+ * @param config - the configuration of MQTT network
+ * @returns promise with list of Z2M devices discovered on Exposes API
+ */
+const fetchModel = ({ username, password, prefix, clientId }: Config): Promise<Device[]> => new Promise((resolve, reject) => {    
+  const client = mqtt.connect("mqtt://mqtt.lan", { username, password, clientId: clientId || "zigbee2mqtt->openHAB importer" });
+
+  client.on("message", (_, message) => {    
+    client.end();
+    resolve(JSON.parse(message.toString()) as Device[]);      
+  });
+
+  client.on("connect", () => {
+    client.subscribe(`${prefix}/bridge/devices`, err => {
+      if(err) reject(err);
+    });
+  });
+});
+
+const isBitSet = (bit: number) => (code: number) => !!(code & (1<<bit));
+
+/**
+ * Checks whether the access code allows to read the published state of the device (bit 0)
+ * @param accessCode access code to test
+ * @returns true if accessible
+ */
+const isPassiveReadable = isBitSet(0);
+
+/**
+ * Checks whether the access code allows to set the state of the device (bit 1)
+ * @param accessCode access code to test
+ * @returns true if accessible
+ */
+const isWriteable = isBitSet(1);
+/**
+  * Checks whether the access code allows to read the device state on demand (bit 2)
+ * @param accessCode access code to test
+ * @returns true if accessible
+ */
+const isActiveReadable = isBitSet(2);
+
+const toChannels = (parentTopic: string, parentUID: string, type?: string) => (feature: Feature): Channel[] => {
+  if (feature.features) {
+    const topic = feature.property ? `${parentTopic}/${feature.property}` : parentTopic;
+    return feature.features.flatMap(parseAtomFeature(topic, parentUID, type));
+  }
+
+  return parseAtomFeature(parentTopic, parentUID, type)(feature);
+};
+
+const parseAtomFeature = (parentTopic: string, parentUID: string, type?: string) => (feature: Feature): Channel[] => {
+  const readable = isPassiveReadable(feature.access);
+  const writeable = isWriteable(feature.access); 
+  
+  const channelTypes: Partial<Record<FeatureType, ChannelType|undefined>> = {
+    binary: writeable ? 'mqtt:switch' : 'mqtt:contact',
+    numeric: 'mqtt:number',
+    enum: 'mqtt:string',
+    text: 'mqtt:string',
+  };
+
+  const itemTypes: Partial<Record<FeatureType, ItemType|undefined>> = {
+    binary: writeable ? 'Switch' : 'Contact',
+    numeric: 'Number',
+    enum: 'String',
+    text: 'String',
+  };
+  
+
+  const channelTypeUID = channelTypes[feature.type];
+  
+  if (channelTypeUID === undefined) {
+    throw new Error(`Unsupported feature type ${feature.type} for: ${JSON.stringify(feature)}`)
+  }
+  
+  const category = type ?? feature.category;
+  const prefix = category ? `${category[0].toUpperCase()}${category.slice(1)}: ` : "";
+
+  return [{
+    channelTypeUID,
+    itemType: itemTypes[feature.type],
+    id: feature.name,
+    uid: `${parentUID}:${feature.name}`,
+    kind: "STATE",
+    label: feature.label,
+    description: `${prefix}${feature.description}`,        
+    configuration: {
+      unit: feature.unit,
+      min: feature.value_min,
+      max: feature.value_max,
+      on: feature.value_on,
+      off: feature.value_off,
+      allowedStates: feature.values?.join(","),
+      stateTopic: readable ? `${parentTopic}/${feature.property}` : undefined,
+      commandTopic: writeable ? `${parentTopic}/set/${feature.property}` : undefined,        
+    },
+    properties: {},
+    defaultTags: [],
+  }];
+};
+
+const toThing = (config: Config) => (device: Device): Thing => {
+  const UID = `mqtt:topic:${config.bridgeID}:${device.friendly_name}`;
+  const thingTopic = `${config.prefix}/${device.friendly_name}`
+  const exposes = device.definition?.exposes?.flatMap(toChannels(thingTopic, UID)) ?? [];
+  const options = device.definition?.options?.flatMap(toChannels(thingTopic, UID, "option")) ?? [];
+
+  return {
+    UID,
+    bridgeUID: `mqtt:broker:${config.bridgeID}`,
+    thingTypeUID: "mqtt:topic",
+    label: device.description || device.friendly_name,    
+    configuration: {
+      availabilityTopic: `${thingTopic}/availability`,
+      payloadNotAvailable: "offline",      
+      payloadAvailable: "online"
+    },
+    properties: {},
+    channels: [...exposes, ...options]
+  }
+}

src/z2m/types.ts

@@ -26,13 +26,28 @@ export type Definition = {
   vendor: string;
 };
 
+export type FeatureType = 
+    'binary'
+  | 'numeric'
+  | 'enum'
+  | 'text'
+  | 'composite'
+  | 'list'
+  | 'light'
+  | 'switch'
+  | 'fan'
+  | 'cover'
+  | 'lock'
+  | 'climate'
+
 export type Feature = {
   access: number;
   description: string;
   label: string;
   name: string;
   property: string;
-  type: string;
+  type: FeatureType;
+  category?: FeatureCategory;
   value_max?: number;
   value_min?: number;
   value_off?: boolean;
@@ -41,6 +56,18 @@ export type Feature = {
   values?: string[];
   unit?: string;
   features?: Feature[];
+  presets?: Preset[];
+  item_type?: Feature;
+  length_min?: number;
+  length_max?: number;
+};
+
+export type FeatureCategory = 'diagnostic' | 'config';
+
+export type Preset = {
+  name: string;
+  value: number;
+  description?: number;
 };
 
 export type Endpoints = Record<string, Endpoint>;