refactor: switch alerts to check polygon not city name (#501)

alert-monitoring.js

@@ -7,21 +7,21 @@ const alertsFromCAP = [];
 const ALERTS_FOLDER = "./alerts";
 const ALERTS_FILE = "alerts.txt";
 
-function startAlertMonitoring(city, app) {
+function startAlertMonitoring(latLong, app) {
   console.log("[ALERT MONITORING] Starting alert monitoring via AMQP...");
 
   const { emitter: listener } = listen({ amqp_subtopic: "alerts.cap.#" });
   listener
     .on("error", (err) => console.warn(err.message))
     .on("message", (date, url) => {
-      console.log("[ALERT MONITORING] Cap file", url, "received at", date);
-      fetchCapFileAndParse(url, city, (alert) => {
+      console.log("[ALERT MONITORING] Cap file", url, "received at", date, "checking against lat/lon of", latLong);
+      fetchCapFileAndParse(url, latLong, (alert) => {
         pushAlertToList(alert);
       });
     });
 
   // load anything we knew about before we rebooted the system
-  loadCurrentAlerts(city);
+  loadCurrentAlerts(latLong);
 
   // setup the endpoint to fetch warnings from
   setupWarningsAPI(app);
@@ -77,7 +77,7 @@ function saveCurrentAlerts() {
   });
 }
 
-function loadCurrentAlerts(city) {
+function loadCurrentAlerts(latLong) {
   const alertFile = `${ALERTS_FOLDER}/${ALERTS_FILE}`;
   fs.stat(alertFile, (err, stat) => {
     if (err || stat.size < 1) console.log("[ALERT MONITORING] No stored alerts");
@@ -89,9 +89,14 @@ function loadCurrentAlerts(city) {
 
           console.log(`[ALERT MONITORING] Refetching ${capFileURLArray.length} CAP files...`);
           capFileURLArray.forEach((url) => {
-            fetchCapFileAndParse(url, city, (alert) => {
-              pushAlertToList(alert);
-            });
+            fetchCapFileAndParse(
+              url,
+              latLong,
+              (alert) => {
+                pushAlertToList(alert);
+              },
+              true
+            );
           });
         }
       });
@@ -126,6 +131,10 @@ function sortAlertsInPriorityOrder(alerts) {
       if (aUrgency > bUrgency) return -1;
       if (bUrgency > aUrgency) return 1;
 
+      // then by date
+      if (a.sent > b.sent) return -1;
+      if (b.sent > a.sent) return 1;
+
       // both the same
       return 0;
     }) || []

backend.js

@@ -1,7 +1,7 @@
 const express = require("express");
 const cors = require("cors");
 const path = require("path");
-const { initCurrentConditions } = require("./current-conditions");
+const { initCurrentConditions, getStationLatLong } = require("./current-conditions");
 const { fetchWeatherForObservedCities, latestObservations } = require("./observations.js");
 const { fetchWeatherForObservedUSCities, latestUSObservations } = require("./us-observations.js");
 const { fetchForecastForSunspotCities, latestSunspotForecasts } = require("./sunspot");
@@ -113,7 +113,7 @@ async function startBackend() {
   });
 
   // start the amqp alert monitoring of cap
-  startAlertMonitoring(config.primaryLocation()?.name, app);
+  startAlertMonitoring(getStationLatLong(), app);
 }
 
 app.listen(port);

cap-file-parser.js

@@ -1,9 +1,9 @@
 const xmljs = require("xml-js");
 const axios = require("axios");
+const pointInPolygon = require("point-in-polygon");
 
-function fetchCapFileAndParse(url, city, callback) {
-  if (!url || !city) return;
-  city = city.toLowerCase();
+function fetchCapFileAndParse(url, latLong, callback, isExisting = false) {
+  if (!url || !latLong) return;
 
   // url for a cap file has been given to us, so now we need to see if it's relevant to us
   axios.get(url).then((resp) => {
@@ -22,24 +22,26 @@ function fetchCapFileAndParse(url, city, callback) {
 
     if (!Array.isArray(areas)) areas = [areas];
 
-    // loop through areas and see if our tracked city is included
-    let isRelevant = false;
-    areas.some((area) => {
-      const areaDesc = (area.areaDesc?._text || "").toLowerCase();
-      const regexString = `\\b${city}\\b`;
-      const regexMatch = new RegExp(regexString, "gmi");
-      const regexResult = areaDesc.match(regexMatch);
-      isRelevant = regexResult && regexResult[0] === city;
-      if (isRelevant) return true;
-    });
+    // loop through areas and see if our tracked city (via lat/long) is included
+    if (!isExisting) {
+      const pointToCheck = [latLong.lat, latLong.long];
+      const isRelevant = areas.some((area) => {
+        const polygon = area.polygon?._text || "";
+        const polygonAsArray = convertPolygonStringTo3DArray(polygon);
+        if (!polygonAsArray) return;
 
-    // if its not relevant stop, otherwise get the data
-    if (!isRelevant) return;
+        return pointInPolygon(pointToCheck, polygonAsArray);
+      });
+
+      // if its not relevant stop, otherwise get the data
+      if (!isRelevant) return;
+    }
 
     // check we have the required information here
     const identifier = alert?.identifier?._text;
     if (!identifier) return;
 
+    const sent = alert?.sent?._text || "";
     const references = alert?.references?._text || "";
 
     const expires = info_en?.expires?._text;
@@ -60,8 +62,14 @@ function fetchCapFileAndParse(url, city, callback) {
     console.log(`[CAP PARSER] CAP ${url} has been parsed, passing along to alert monitor`);
 
     if (typeof callback === "function")
-      callback({ identifier, references, expires, headline, description, severity, urgency, url });
+      callback({ identifier, references, expires, headline, description, severity, urgency, url, sent });
   });
 }
 
+const convertPolygonStringTo3DArray = (polygonString) => {
+  if (!polygonString) return;
+
+  return polygonString.split(" ").map((points) => points.split(",").map((point) => parseFloat(point)));
+};
+
 module.exports = { fetchCapFileAndParse };

current-conditions.js

@@ -29,6 +29,7 @@ const conditions = {
 let eventStreamInterval = null;
 let amqpConnection = null;
 let configRejectInHourConditonUpdates = false;
+let stationLatLong = { lat: 0, long: 0 };
 
 const initCurrentConditions = (primaryLocation, rejectInHourConditionUpdates, app, historicalDataAPI) => {
   // pass in the primary location from the config and make sure its valid
@@ -114,6 +115,12 @@ const fetchCurrentConditions = (url) => {
       return (conditions.forecast = weather.weekly);
     }
 
+    // store the long/lat for later use
+    const {
+      name: { lat, lon },
+    } = allWeatherData.location;
+    parseStationLatLong(lat, lon);
+
     // generate some objects so the FE has less work to do once it receives the data
     const observedDateObject = generateConditionsObserved(weather.current?.dateTime[1]);
     const city = generateObservedCity(allWeatherData.location);
@@ -138,6 +145,17 @@ const fetchCurrentConditions = (url) => {
   });
 };
 
+const parseStationLatLong = (lat, long) => {
+  // we get these in string format with compass directions so we need to convert slightly
+  // N is positive, S is negative
+  if (lat.includes("N")) stationLatLong.lat = parseFloat(lat);
+  else stationLatLong.lat = -parseFloat(lat);
+
+  // E is postive, W is negative
+  if (long.includes("E")) stationLatLong.long = parseFloat(long);
+  else stationLatLong.long = -parseFloat(long);
+};
+
 const generateConditionsObserved = (date) => {
   if (!date) return;
 
@@ -284,6 +302,10 @@ const generateWeatherResponse = () => {
   };
 };
 
+const getStationLatLong = () => {
+  return stationLatLong;
+};
+
 const writeEventStream = (res) => {
   res.write(`id: ${Date.now()}\n`);
   res.write(`event: condition_update\n`);
@@ -297,4 +319,5 @@ module.exports = {
   reloadCurrentConditions,
   generateWindchill,
   generateAlmanac,
+  getStationLatLong,
 };

package.json

@@ -22,6 +22,7 @@
     "ec-weather-js": "^1.2.0",
     "express": "^4.18.2",
     "mitt": "^3.0.0",
+    "point-in-polygon": "^1.1.0",
     "vue": "^3.3.4",
     "vue-axios": "^3.5.2",
     "vue-router": "4",

src/components/severetstormwatch.vue

@@ -22,7 +22,9 @@ export default {
   display: flex;
   flex-direction: column;
   justify-content: center;
+  margin: 0 auto;
   text-align: left;
   text-transform: uppercase;
+  width: 380px;
 }
 </style>

yarn.lock

@@ -10762,6 +10762,11 @@ pnp-webpack-plugin@^1.6.4:
   dependencies:
     ts-pnp "^1.1.6"
 
+point-in-polygon@^1.1.0:
+  version "1.1.0"
+  resolved "https://registry.yarnpkg.com/point-in-polygon/-/point-in-polygon-1.1.0.tgz#b0af2616c01bdee341cbf2894df643387ca03357"
+  integrity sha512-3ojrFwjnnw8Q9242TzgXuTD+eKiutbzyslcq1ydfu82Db2y+Ogbmyrkpv0Hgj31qwT3lbS9+QAAO/pIQM35XRw==
+
 portfinder@^1.0.26:
   version "1.0.28"
   resolved "https://registry.yarnpkg.com/portfinder/-/portfinder-1.0.28.tgz#67c4622852bd5374dd1dd900f779f53462fac778"