setup cloud provider strategy pattern

.gitignore

+node_modules/
+config.json

config.json.sample

+{
+  "cloudProvider": {
+    "aws": {
+      "accessKeyId": "",
+      "secretAccessKey": "",
+      "region": "",
+      "deliveryStream": ""
+    }
+  }
+}

index.js

@@ -4,6 +4,8 @@ const noble = require('noble');
 
 const Device = require('./device');
 const rigadoSensorBeacon = require('./rigado-sensor-beacon');
+const CloudProvider = require('./providers/provider');
+const config = require('./config.json');
 
 /**
  * Connected devices
@@ -11,6 +13,12 @@ const rigadoSensorBeacon = require('./rigado-sensor-beacon');
  */
 const devices = {};
 
+/**
+ * Cloud Provider access
+ * @global
+ */
+const provider = new CloudProvider(config);
+
 function startScanning() {
   // Restart scanning
   // https://github.com/sandeepmistry/noble/issues/223
@@ -39,7 +47,11 @@ function onDiscover(beaconInst) {
   device.setUp()
     .then(() => {
       device.onLuxometerChange((d, lux) => {
-        console.log(`Device ${d.id} lux: ${lux.toFixed(1)}`);
+        const telemetry = {
+          deviceID: d.id,
+          light: lux.toFixed(1),
+        };
+        provider.sendTelemetry(telemetry);
       });
 
       // Wait for as long as possible before scanning again to avoid race

providers/aws.js

+'use strict';
+
+const ProviderStrategy = require('./providerStrategy.js');
+
+class AWSProvider extends ProviderStrategy {
+  constructor(config) {
+    super(config);
+    this.name = 'AWS';
+  }
+
+  connectGateway() {
+    console.log('[AWS] connectGateway');
+  }
+
+  sendTelemetry(telemetry) {
+    console.log(`[AWS] sendTelemetry ${JSON.stringify(telemetry)}`);
+  }
+}
+
+module.exports = AWSProvider;

providers/provider.js

+'use strict';
+
+const AWSProvider = require('./aws.js');
+
+class Provider {
+  constructor(config) {
+    if (typeof config.cloudProvider === 'undefined' ||
+        Object.keys(config.cloudProvider).length === 0) {
+      throw new Error('No cloudProvider in config');
+    }
+    const provider = Object.keys(config.cloudProvider)[0];
+    const providerConfig = JSON.stringify(config.cloudProvider[provider], null, 4);
+    console.log(`Provider: ${provider}`);
+    console.log(`Config: ${providerConfig}`);
+    switch (provider) {
+      case 'aws':
+        this.strategy = new AWSProvider(config.cloudProvider[provider]);
+        break;
+      default:
+        throw new Error(`Unrecognized cloud provider '${provider}' in config.`);
+    }
+  }
+
+  connectGateway() {
+    return this.strategy.connectGateway();
+  }
+  sendHeartbeat() {
+    return this.strategy.sendHeartbeat();
+  }
+  sendTelemetry(telemetry) {
+    return this.strategy.sendTelemetry(telemetry);
+  }
+  connectEndDevice(device) {
+    return this.strategy.connectEndDevice(device);
+  }
+}
+
+module.exports = Provider;

providers/providerStrategy.js

+'use strict';
+
+const os = require('os');
+
+/**
+ * Defines the public interface for all Cloud Provider strategies
+ */
+class ProviderStrategy {
+  constructor(config) {
+    this.config = config;
+    this.hostname = os.hostname();
+    this.osName = os.type();
+    this.NotYetImplementedError = new Error('Not yet implemented');
+  }
+
+  /**
+   * Sends information about this gateway to the Cloud Provider
+   * to get it connected. Should return the Gateway's authentication
+   *  credentials.
+   */
+  connectGateway() {
+    return Promise.reject(this.NotYetImplementedError);
+  }
+
+  /**
+   * Inform the Cloud Provider that the Gateway is alive and well
+   */
+  sendHeartbeat() {
+    return Promise.reject(this.NotYetImplementedError);
+  }
+
+  /**
+   * Send sensor telemetry data to the Cloud Provider
+   */
+  sendTelemetry(json) {
+    return Promise.reject(this.NotYetImplementedError);
+  }
+
+  /**
+   * Inform the Cloud Provider about a new sensor device that
+   * this Gateway is connected to
+   */
+  connectEndDevice(device) {
+    return Promise.reject(this.NotYetImplementedError);
+  }
+}
+
+module.exports = ProviderStrategy;