Add initial implementation of the settler node for Node-RED

- Create package.json to define project metadata and dependencies
- Implement settler.html for the node's UI in Node-RED
- Add settler.js to register the settler node type and handle HTTP requests
- Introduce src/nodeClass.js for the settler node class functionality
- Define src/specificClass.js for settler-specific logic and utilities

src/nodeClass.js

@@ -0,0 +1,114 @@
+const { Settler } = require('./specificClass.js');
+
+
+class nodeClass {
+    /**
+    * Node-RED node class for settler.
+    * @param {object} uiConfig - Node-RED node configuration
+    * @param {object} RED - Node-RED runtime API
+    * @param {object} nodeInstance - Node-RED node instance
+    * @param {string} nameOfNode - Name of the node
+    */
+    constructor(uiConfig, RED, nodeInstance, nameOfNode) {
+        // Preserve RED reference for HTTP endpoints if needed
+        this.node = nodeInstance;
+        this.RED = RED;
+        this.name = nameOfNode;
+        this.source = null;
+
+        this._loadConfig(uiConfig)
+        this._setupClass();
+
+        this._attachInputHandler();
+        this._registerChild();
+        this._startTickLoop();
+        this._attachCloseHandler();
+    }
+
+    /**
+     * Handle node-red input messages
+     */
+    _attachInputHandler() {
+        this.node.on('input', (msg, send, done) => {
+
+            switch (msg.topic) {
+                case 'registerChild':
+                    // Register this node as a parent of the child node
+                    const childId = msg.payload;
+                    const childObj = this.RED.nodes.getNode(childId); 
+                    this.source.childRegistrationUtils.registerChild(childObj.source, msg.positionVsParent);
+                    break;
+                default:
+                    console.log("Unknown topic: " + msg.topic);
+            }
+
+            if (done) {
+                done();
+            }
+        });
+    }
+
+    /**
+     * Parse node configuration
+     * @param {object} uiConfig Config set in UI in node-red
+     */
+    _loadConfig(uiConfig) {
+        this.config = {
+            general: {
+                name: uiConfig.name || this.name,
+                id: this.node.id,
+                unit: null,
+                logging: {
+                    enabled: uiConfig.enableLog,
+                    logLevel: uiConfig.logLevel
+                }
+            },
+            functionality: {
+                positionVsParent: uiConfig.positionVsParent || 'atEquipment', // Default to 'atEquipment' if not specified
+                softwareType: "settler" // should be set in config manager
+            }
+        }
+    }
+
+    /**
+     * Register this node as a child upstream and downstream.
+     * Delayed to avoid Node-RED startup race conditions.
+     */
+    _registerChild() {
+        setTimeout(() => {
+        this.node.send([
+            null,
+            null,
+            { topic: 'registerChild', payload: this.node.id, positionVsParent: this.config?.functionality?.positionVsParent || 'atEquipment' }
+        ]);
+        }, 100);
+    }
+
+    /**
+     * Setup settler class
+     */
+    _setupClass() {
+
+        this.source = new Settler(this.config); // protect from reassignment
+        this.node.source = this.source;
+    }
+
+    _startTickLoop() {
+        setTimeout(() => {
+            this._tickInterval = setInterval(() => this._tick(), 1000);
+        }, 1000);
+    }
+
+    _tick(){
+        this.node.send([null, null, null]);
+    }
+
+    _attachCloseHandler() {
+        this.node.on('close', (done) => {
+            clearInterval(this._tickInterval);
+            done();
+        });
+    }
+}
+
+module.exports = nodeClass;

src/specificClass.js

@@ -0,0 +1,15 @@
+const { childRegistrationUtils, logger, MeasurementContainer } = require('generalFunctions');
+const EventEmitter = require('events');
+
+class Settler {
+  constructor(config) {
+    this.config = config;
+    // EVOLV stuff
+    this.logger = new logger(this.config.general.logging.enabled, this.config.general.logging.logLevel, config.general.name);
+    this.emitter = new EventEmitter();
+    this.measurements = new MeasurementContainer();
+    this.childRegistrationUtils = new childRegistrationUtils(this); // Child registration utility
+  }
+}
+
+module.exports = { Settler };