feat: replace node-fronius-solar with modern axios-based API client (#41)

- Add fronius-api.js module using axios for HTTP requests
- Remove deprecated node-fronius-solar dependency (v0.0.10)
- Add axios ^1.7.0 as production dependency
- Move mocha from dependencies to devDependencies
- Add missing API methods: GetStorageRealtimeData, GetMeterRealtimeData
- Improve error handling with user-friendly messages
- Remove deprecated getReq.abort() in favor of modern patterns
- Maintain request serialization to avoid overwhelming inverters
- Update test mocks to use new local module path

Author: mabunixda

fronius/fronius-api.js

@@ -0,0 +1,214 @@
+"use strict";
+
+const axios = require("axios");
+const https = require("https");
+
+const DEFAULT_DEVICE_ID = 1;
+const DEFAULT_TIMEOUT = 20000;
+
+const debug =
+  process.env.FRONIUS_DEBUG === "true"
+    ? (...args) => console.log("[fronius-api]", ...args)
+    : () => {};
+
+// Request queue to serialize requests (Fronius inverters can be overwhelmed by concurrent requests)
+let lastRequest = Promise.resolve();
+
+/**
+ * Creates an axios instance configured for Fronius API requests
+ * @param {Object} options - Connection options
+ * @returns {import('axios').AxiosInstance}
+ */
+function createClient(options) {
+  const protocol = options.protocol === "https:" ? "https" : "http";
+  const baseURL = `${protocol}://${options.host}:${options.port || (protocol === "https" ? 443 : 80)}`;
+
+  const config = {
+    baseURL,
+    timeout: options.timeout || DEFAULT_TIMEOUT,
+    headers: {
+      Accept: "application/json",
+    },
+    // Allow self-signed certificates (common for inverter web interfaces)
+    httpsAgent: new https.Agent({
+      rejectUnauthorized: false,
+    }),
+  };
+
+  // Add digest auth if credentials are provided
+  if (options.username && options.password) {
+    config.auth = {
+      username: options.username,
+      password: options.password,
+    };
+  }
+
+  const client = axios.create(config);
+
+  // Request interceptor for debugging
+  client.interceptors.request.use((config) => {
+    debug("REQUEST:", config.method?.toUpperCase(), config.url);
+    return config;
+  });
+
+  // Response interceptor for debugging
+  client.interceptors.response.use(
+    (response) => {
+      debug("RESPONSE:", response.status, response.config.url);
+      return response;
+    },
+    (error) => {
+      debug("ERROR:", error.message);
+      return Promise.reject(error);
+    },
+  );
+
+  return client;
+}
+
+/**
+ * Validates that the response has the expected Fronius API structure
+ * @param {Object} data - Response data
+ * @returns {boolean}
+ */
+function isValidResponse(data) {
+  return data && typeof data === "object" && "Head" in data && "Body" in data;
+}
+
+/**
+ * Makes a serialized request to the Fronius API
+ * @param {Object} options - Request options
+ * @param {string} path - API endpoint path
+ * @returns {Promise<Object>}
+ */
+async function makeRequest(options, path) {
+  const client = createClient(options);
+
+  // Serialize requests to avoid overwhelming the inverter
+  const request = lastRequest.then(async () => {
+    try {
+      const response = await client.get(path);
+
+      if (!isValidResponse(response.data)) {
+        throw new Error("Invalid response body format: Head and Body expected");
+      }
+
+      return response.data;
+    } catch (error) {
+      // Transform axios errors to user-friendly messages
+      if (error.response) {
+        if (error.response.status === 401) {
+          throw new Error("Unauthorized: check username/password");
+        }
+        throw new Error(
+          `Request failed. HTTP Status Code: ${error.response.status}`,
+        );
+      } else if (error.code === "ECONNABORTED") {
+        throw new Error("Request timeout occurred - request aborted");
+      } else if (error.code === "ECONNREFUSED") {
+        throw new Error(
+          `Connection refused - check if inverter is reachable at ${options.host}`,
+        );
+      } else if (error.code === "ENOTFOUND") {
+        throw new Error(`Host not found: ${options.host}`);
+      }
+      throw error;
+    }
+  });
+
+  // Update lastRequest but don't let failures block future requests
+  lastRequest = request.catch(() => {});
+
+  return request;
+}
+
+/**
+ * Validates required properties are present in options
+ * @param {Object} options - Options object
+ * @param {string[]} required - Required property names
+ */
+function validateOptions(options, required) {
+  for (const prop of required) {
+    if (options[prop] === undefined || options[prop] === null) {
+      throw new Error(`Request options lacks required property=${prop}`);
+    }
+  }
+}
+
+/**
+ * Get inverter realtime data
+ * @param {Object} options - Connection options
+ * @returns {Promise<Object>}
+ */
+async function GetInverterRealtimeData(options) {
+  validateOptions(options, ["host", "deviceId"]);
+
+  const deviceId = options.deviceId || DEFAULT_DEVICE_ID;
+  let path;
+
+  if (options.version === 0) {
+    path = `/solar_api/GetInverterRealtimeData.cgi?Scope=Device&DeviceIndex=${deviceId}&DataCollection=CommonInverterData`;
+  } else {
+    path = `/solar_api/v1/GetInverterRealtimeData.cgi?Scope=Device&DeviceId=${deviceId}&DataCollection=CommonInverterData`;
+  }
+
+  return makeRequest(options, path);
+}
+
+/**
+ * Get components data (undocumented API for Symo inverters)
+ * @param {Object} options - Connection options
+ * @returns {Promise<Object>}
+ */
+async function GetComponentsData(options) {
+  validateOptions(options, ["host"]);
+  return makeRequest(options, "/components/5/0/?print=names");
+}
+
+/**
+ * Get power flow realtime data
+ * @param {Object} options - Connection options
+ * @returns {Promise<Object>}
+ */
+async function GetPowerFlowRealtimeData(options) {
+  validateOptions(options, ["host"]);
+  return makeRequest(options, "/solar_api/v1/GetPowerFlowRealtimeData.fcgi");
+}
+
+/**
+ * Get storage realtime data (for battery systems)
+ * @param {Object} options - Connection options
+ * @returns {Promise<Object>}
+ */
+async function GetStorageRealtimeData(options) {
+  validateOptions(options, ["host"]);
+
+  const deviceId = options.deviceId || DEFAULT_DEVICE_ID;
+  return makeRequest(
+    options,
+    `/solar_api/v1/GetStorageRealtimeData.cgi?Scope=Device&DeviceId=${deviceId}`,
+  );
+}
+
+/**
+ * Get meter realtime data (for power meter / smart meter)
+ * @param {Object} options - Connection options
+ * @returns {Promise<Object>}
+ */
+async function GetMeterRealtimeData(options) {
+  validateOptions(options, ["host"]);
+
+  const deviceId = options.deviceId || DEFAULT_DEVICE_ID;
+  return makeRequest(
+    options,
+    `/solar_api/v1/GetMeterRealtimeData.cgi?Scope=Device&DeviceId=${deviceId}`,
+  );
+}
+
+module.exports = {
+  GetInverterRealtimeData,
+  GetComponentsData,
+  GetPowerFlowRealtimeData,
+  GetStorageRealtimeData,
+  GetMeterRealtimeData,
+};

fronius/fronius.js

@@ -1,6 +1,6 @@
 module.exports = function (RED) {
   "use strict";
-  const fronius = require("node-fronius-solar");
+  const fronius = require("./fronius-api");
 
   /**
    * fronius inverter node