node-red-contrib-sunpos/sunpos/sunpos.js

A Node-RED node that provides the position of the sun

/**
 * Copyright 2015, 2016 Alisdair Smyth
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 **/
module.exports = function(RED) {
  "use strict";
  var SunCalc = require("suncalc");

  function getSunPosition(config) {
    RED.nodes.createNode(this, config);

    var stConfig = {
      start: config.start,
      startOffset: config.startoffset,
      end: config.end,
      endOffset: config.endoffset
    };

    var location = {
      lat: config.lat,
      lon: config.lon
    };
    var node = this;

    this.on("input", function(msg) {
      var now =
        typeof msg.time != "undefined" ? new Date(msg.time) : new Date();

      var sunPosition = SunCalc.getPosition(now, location.lat, location.lon);
      var sunTimes = SunCalc.getTimes(now, location.lat, location.lon);
      var altitudeDegrees = 180 / Math.PI * sunPosition.altitude;
      var azimuthDegrees = 180 + 180 / Math.PI * sunPosition.azimuth;

      var nowMillis = now.getTime();
      var startMillis =
        sunTimes[stConfig.start].getTime() + stConfig.startOffset * 60000;
      var endMillis =
        sunTimes[stConfig.end].getTime() + stConfig.endOffset * 60000;

      var sunInSky = nowMillis > startMillis && nowMillis < endMillis;
      if (sunInSky) {
        node.status({
          fill: "yellow",
          shape: "dot",
          text:
            RED._("sunpos.status.node-status-day") +
            new Date(startMillis).toLocaleTimeString() +
            RED._("sunpos.status.node-status-end") +
            new Date(endMillis).toLocaleTimeString()
        });
      } else {
        node.status({
          fill: "blue",
          shape: "dot",
          text:
            RED._("sunpos.status.node-status-night") +
            new Date(endMillis).toLocaleTimeString() +
            RED._("sunpos.status.node-status-end") +
            new Date(startMillis).toLocaleTimeString()
        });
      }

      msg.payload = {
        startTime: startMillis,
        endTime: endMillis,
        sunInSky: sunInSky,
        altitude: altitudeDegrees,
        azimuth: azimuthDegrees,
        altitudeRadians: sunPosition.altitude,
        azimuthRadians: sunPosition.azimuth
      };
      msg.location = location;
      msg.topic = "sun";
      msg.time = now.getTime();
      msg.sunTimes = sunTimes;

      for (var key in msg.sunTimes) {
        if (msg.sunTimes[key]) {
          msg.sunTimes[key] = msg.sunTimes[key].getTime();
        }
      }

      node.send(msg);
    });
  }
  RED.nodes.registerType("sunpos", getSunPosition);
};