Select gas stations

MMM-Fuel.js

@@ -69,6 +69,7 @@ Module.register('MMM-Fuel', {
      * @property {int} updateInterval - Speed of update.
      * @property {string} provider - API provider of the data.
      * @property {boolean} toFixed - Flag to show price with only 2 decimals.
+     * @property {string[]} ids - List of gas stations to display
      */
     defaults: {
         radius: 5,
@@ -89,7 +90,8 @@ Module.register('MMM-Fuel', {
         rotateInterval: 60 * 1000, // every minute
         updateInterval: 15 * 60 * 1000, // every 15 minutes
         provider: 'tankerkoenig',
-        toFixed: false
+        toFixed: false,
+        ids: []
     },
 
     /**

README.md

@@ -60,6 +60,7 @@ Gas Station Price Module for MagicMirror<sup>2</sup>
 | `rotate` | `true` | Boolean to enable/disable rotation between sort by price and distance. |
 | `rotateInterval` | `60000` (1 min) | How fast the sorting should be switched between byPrice and byDistance. |
 | `updateInterval` | `900000` (15 mins) | How often should the data be fetched. |
+| `ids` | `[]` | Only display the specified Gas Stations. Works only with TankerKoenig. |
 
 ### tankerkoenig (Germany only)
 

apis/tankerkoenig.js

@@ -12,12 +12,14 @@
  * @see https://www.npmjs.com/package/request
  */
 const request = require('request');
+const Coordinate = require('./utils/Coordinate.js');
 
 /**
  * @module apis/tankerkoenig
  * @description Queries data from tankerkoenig.de
  *
  * @requires external:request
+ * @requires module:Coordinate
  *
  * @param {Object} config - Configuration.
  * @param {number} config.lat - Latitude of Coordinate.
@@ -31,12 +33,29 @@ const request = require('request');
  */
 module.exports = (config) => {
     /** @member {string} baseUrl - API url */
-    const baseUrl = 'https://creativecommons.tankerkoenig.de/json/list.php';
+    const baseUrl = 'https://creativecommons.tankerkoenig.de/json';
 
-    /** @member {Object} options - API url combined with config options. */
-    const options = {
-        url: `${baseUrl}?lat=${config.lat}&lng=${config.lng}&rad=${config.radius}&type=all&apikey=${
-            config.api_key}&sort=dist`
+    /**
+     * @function generateOptions
+     * @description Helper function to generate the options.
+     *
+     * @param {string} gasStationId - Optional gas station ID
+     * @returns {Object.<string>} Options-object
+     */
+    const generateOptions = (gasStationId) => {
+        let url = baseUrl;
+
+        if (config.ids && gasStationId && config.ids.length > 0) {
+            url += `/detail.php?id=${gasStationId}`;
+        } else {
+            url += `/list.php?lat=${config.lat}&lng=${config.lng}&rad=${config.radius}&type=all&sort=dist`;
+        }
+
+        url += `&apikey=${config.api_key}`;
+
+        return {
+            url
+        };
     };
 
     /**
@@ -95,6 +114,64 @@ module.exports = (config) => {
         /* eslint-enable no-param-reassign */
     };
 
+    /**
+     * @function requestPrice
+     * @description Function to fetch the details for a given station.
+     *
+     * @param {string} gasStationId - ID of the gas station
+     *
+     * @returns {Promise} Data or error message
+     */
+    const requestPrice = gasStationId => new Promise((resolve, reject) => {
+        request(generateOptions(gasStationId), (error, response, body) => {
+            if (response.statusCode === 200) {
+                const parsedBody = JSON.parse(body);
+
+                if (parsedBody.ok) {
+                    parsedBody.station.dist = Coordinate.getDistance({
+                        lat: config.lat,
+                        lng: config.lng
+                    }, {
+                        lat: parsedBody.station.lat,
+                        lng: parsedBody.station.lng
+                    });
+                    resolve(parsedBody.station);
+                } else {
+                    reject(`Error getting station details ${parsedBody.status}`);
+                }
+            } else {
+                reject(`Error getting fuel data ${response.statusCode}`);
+            }
+        });
+    });
+
+    /**
+     * @function parseStationList
+     * @description Helper function to pars the list of gas stations.
+     *
+     * @param {Object[]} stationList - List of gas stations
+     * @param {getDataCallback} callback - Callback that handles the API data.
+     *
+     * @returns {Promise} Data or error message
+     */
+    const parseStationList = (stationList, callback) => {
+        const stations = stationList.filter(filterStations);
+
+        stations.forEach(normalizeStations);
+
+        const price = stations.slice(0);
+        price.sort(sortByPrice);
+
+
+        callback(null, {
+            types: ['diesel', 'e5', 'e10'],
+            unit: 'km',
+            currency: 'EUR',
+            byPrice: price,
+            byDistance: stations
+        });
+    };
+
     return {
         /**
          * @callback getDataCallback
@@ -111,31 +188,26 @@ module.exports = (config) => {
          * @param {getDataCallback} callback - Callback that handles the API data.
          */
         getData(callback) {
-            request(options, (error, response, body) => {
-                if (response.statusCode === 200) {
-                    const parsedBody = JSON.parse(body);
-                    if (parsedBody.ok) {
-                        const stations = parsedBody.stations.filter(filterStations);
-
-                        stations.forEach(normalizeStations);
-
-                        const price = stations.slice(0);
-                        price.sort(sortByPrice);
-
-                        callback(null, {
-                            types: ['diesel', 'e5', 'e10'],
-                            unit: 'km',
-                            currency: 'EUR',
-                            byPrice: price,
-                            byDistance: stations
-                        });
+            if (config.ids && config.ids.length > 0) {
+                Promise
+                    .all(config.ids.map(requestPrice))
+                    .then((stationList) => {
+                        parseStationList(stationList, callback);
+                    }, callback);
+            } else {
+                request(generateOptions(), (error, response, body) => {
+                    if (response.statusCode === 200) {
+                        const parsedBody = JSON.parse(body);
+                        if (parsedBody.ok) {
+                            parseStationList(parsedBody.stations, callback);
+                        } else {
+                            callback('Error no fuel data');
+                        }
                     } else {
-                        callback('Error no fuel data');
+                        callback(`Error getting fuel data ${response.statusCode}`);
                     }
-                } else {
-                    callback(`Error getting fuel data ${response.statusCode}`);
-                }
-            });
+                });
+            }
         }
     };
 };

apis/utils/Coordinate.js

@@ -90,5 +90,28 @@ module.exports = {
         const λ2 = λ1 + Math.atan2(y, x);
 
         return { lat: rad2deg(φ2), lng: ((rad2deg(λ2) + 540) % 360) - 180 };
+    },
+
+    /**
+     * @function getDistance
+     * @description Calculates the distance between two points.
+     *
+     * @param {Object.<number, number>} - Start point
+     * @param {Object.<number, number>} - Target point
+     * @returns {number} - Distance in kilometers
+     */
+    getDistance(pos1, pos2) {
+        // Algorithm taken from https://stackoverflow.com/a/27943
+        /* eslint-disable no-mixed-operators */
+
+        const dLat = deg2rad(pos2.lat - pos1.lat);
+        const dLon = deg2rad(pos2.lng - pos1.lng);
+
+        const distance = Math.sin(dLat / 2) * Math.sin(dLat / 2) +
+            Math.cos(deg2rad(pos1.lat)) * Math.cos(deg2rad(pos2.lat)) *
+            Math.sin(dLon / 2) * Math.sin(dLon / 2);
+        const c = 2 * Math.atan2(Math.sqrt(distance), Math.sqrt(1 - distance));
+
+        return earth * c / 1000;
     }
 };