implementation

backend/src/services/wx.service.ts

@@ -0,0 +1,134 @@
+import axios from "axios";
+import { WxFix } from "./config.service";
+import regionsService from "./regions.service";
+
+const cachedData: {[key: string]: WxData} = {};
+
+const qnhLevelMapping = {
+  200: 390,
+  250: 340,
+  300: 300,
+  400: 240,
+  500: 180,
+  600: 140,
+  700: 100,
+  850: 50
+};
+
+const necessaryDatapoints = [
+  'winddirection',
+  'windspeed',
+  'temperature',
+];
+
+const requestedData: string[] = [
+  'temperature_2m',
+  'windspeed_10m',
+  'winddirection_10m',
+];
+
+for (const qnh of Object.keys(qnhLevelMapping)) {
+  for (const necessaryDatapoint of necessaryDatapoints) {
+    requestedData.push(`${necessaryDatapoint}_${qnh}hPa`);
+  }
+}
+
+interface WxLevelData {
+  "T(K)": string;
+  windspeed: string;
+  windhdg: string;
+};
+
+export interface WxFixData {
+  coords: {
+    lat: string;
+    long: string;
+  };
+
+  levels: {
+    [key: string]: WxLevelData;
+  }
+}
+
+export interface WxData {
+  info: {
+    date: string;
+    datestring: string;
+  };
+  data: {
+    [key: string]: WxFixData;
+  }
+}
+
+export async function getDataAtFix(fix: WxFix, index: number): Promise<WxFixData> {
+  const response = await axios.get(`https://api.open-meteo.com/v1/forecast?latitude=${fix.lat}&longitude=${fix.lon}&windspeed_unit=kn&forecast_days=1&hourly=${requestedData.join(',')}`);
+  const hourlyData = response.data.hourly;
+
+  const data: WxFixData = {
+    coords: {
+      lat: String(fix.lat),
+      long: String(fix.lon)
+    },
+    levels: {}
+  }
+
+  data.levels["0"] = {
+    "T(K)": String(Number(hourlyData?.[`temperature_2m`]?.[index]) + 273.15),
+    "windspeed": String(hourlyData?.[`windspeed_10m`]?.[index]),
+    "windhdg": String(hourlyData?.[`winddirection_10m`]?.[index]),
+  };
+
+  for(const [qnh, fl] of Object.entries(qnhLevelMapping)) {
+    const temp = Number(hourlyData?.[`temperature_${qnh}hPa`]?.[index]) + 273.15;
+    const dir = hourlyData?.[`windspeed_${qnh}hPa`]?.[index];
+    const speed = hourlyData?.[`winddirection_${qnh}hPa`]?.[index]; 
+
+    data.levels[String(fl)] = {
+      "T(K)": String(temp),
+      "windspeed": String(speed),
+      "windhdg": String(dir),
+    }
+  }
+
+  return data;
+}
+
+export async function generateData() {
+  const regions = regionsService.getRegions();
+
+  for (const region of regions) {
+    const now = new Date();
+
+    const regionData: WxData = {
+      info: {
+        date: now.toISOString(),
+        datestring: `${now.getUTCDate()}${now.getUTCHours()}`,
+      },
+      data: {}
+    }
+
+    for (const fix of region.fixes) {
+      regionData.data[fix.name] = await getDataAtFix(fix, now.getUTCHours());
+    }
+
+    cachedData[region.identifier] = regionData;
+  }
+
+  return cachedData;
+}
+
+export function wrappedGenerateData() {
+  generateData().catch((...params) => console.error(...params));
+}
+
+export function getWx(region: string): WxData | null {
+  const data = cachedData[region];
+
+  return data;
+}
+
+export default {
+  getWx,
+  generateData,
+  wrappedGenerateData,
+}