First release

src/index.ts

@@ -0,0 +1,148 @@
+import express from "express";
+import axios from "axios";
+
+const app = express();
+const port = 3000;
+
+enum IpLookupStatus {
+  success = "success",
+  fail = "fail",
+}
+
+interface GeoIpLookupCache {
+  [key: string]: {
+    status: IpLookupStatus;
+    country: string;
+    countryCode: string;
+    region: string;
+    regionName: string;
+    city: string;
+    zip: string;
+    lat: number;
+    lon: number;
+    timezone: string;
+    isp: string;
+    org: string;
+    as: string;
+    query: string;
+    cacheExpireAt: Date;
+  };
+}
+
+interface WeatherLookupCache {
+  [key: string]: {
+    latitude: number;
+    longitude: number;
+    generationtime_ms: number;
+    utc_offset_seconds: number;
+    timezone: string;
+    timezone_abbreviation: string;
+    elevation: number;
+    current_weather: {
+      temperature: number;
+      windspeed: number;
+      winddirection: number;
+      weathercode: number;
+      is_day: boolean;
+      time: string;
+    };
+    cacheExpireAt: Date;
+  };
+}
+
+const geoIpCacheTime = 1000 * 60 * 60 * 24; // 24 hours
+const weatherCacheTime = 1000 * 60 * 15; // 15 minutes
+const geoIpLookupCache: GeoIpLookupCache = {};
+const weatherLookupCache: WeatherLookupCache = {};
+
+const isReservedIpRange = (ipAddress: string) => {
+  // Check for IPv4
+  const ipv4Pattern =
+    /^(10\..*|172\.(1[6-9]|2[0-9]|3[0-1])\..*|192\.168\..*|127\..*|169\.254\..*|192\.88\.99\..*)$/;
+  if (ipv4Pattern.test(ipAddress)) {
+    return true;
+  }
+
+  // Check for IPv6
+  const ipv6LocalPattern =
+    /^fe[89ab][0-9a-fA-F]:.*|^::1$|^fc[0-9a-fA-F]{2}:.*$/;
+  if (ipv6LocalPattern.test(ipAddress.toLowerCase())) {
+    return true;
+  }
+
+  return false;
+};
+
+const getGeoIp = async (ip: string) => {
+  const response = await axios.get(`http://ip-api.com/json/${ip}`);
+  let data = response.data;
+
+  data.cacheExpireAt = new Date(Date.now() + geoIpCacheTime);
+  geoIpLookupCache[ip] = data;
+
+  return data;
+};
+
+const getWeather = async (lat: number, lon: number) => {
+  const response = await axios.get(
+    `https://api.open-meteo.com/v1/forecast?latitude=${lat}&longitude=${lon}&current_weather=true`
+  );
+  let data = response.data;
+
+  data.cacheExpireAt = new Date(Date.now() + weatherCacheTime);
+  weatherLookupCache[`${lat},${lon}`] = data;
+
+  return data;
+};
+
+app.get("/", async (req, res) => {
+  // Get the user's IP address
+  let ip = req.headers["x-forwarded-for"] || req.socket.remoteAddress;
+  ip = ip?.toString().split(",")[0];
+
+  if (!ip) return res.status(500).send("Error fetching location data");
+
+  // Check if the IP address is in a reserved range, assume Japan IP if so (Linode IP address)
+  if (isReservedIpRange(ip)) {
+    ip = "139.162.65.37";
+  }
+
+  // Check if geo IP is cached
+  let geoIp = geoIpLookupCache[ip];
+  if (geoIp) {
+    console.log(`Cache is valid for: ${geoIp.cacheExpireAt}`);
+    // Check if cached response is expired
+    if (geoIp.cacheExpireAt < new Date()) {
+      delete geoIpLookupCache[ip];
+    }
+  } else {
+    console.log("Fetching GeoIP fresh response");
+    try {
+      geoIp = await getGeoIp(ip);
+    } catch (e) {
+      return res.status(500).send("Error fetching location data");
+    }
+  }
+
+  // Check if weather is cached
+  let weather = weatherLookupCache[`${geoIp.lat},${geoIp.lon}`];
+  if (weather) {
+    // Check if cached response is expired
+    if (weather.cacheExpireAt < new Date()) {
+      delete weatherLookupCache[`${geoIp.lat},${geoIp.lon}`];
+    }
+  } else {
+    console.log("Fetching weather fresh response");
+    try {
+      weather = await getWeather(geoIp.lat, geoIp.lon);
+    } catch (e) {
+      return res.status(500).send("Error fetching location data");
+    }
+  }
+
+  return res.json(weather);
+});
+
+app.listen(port, () => {
+  console.log(`Server running at port: ${port}`);
+});