implement meshtastic map

src/index.js

@@ -0,0 +1,81 @@
+const path = require('path');
+const axios = require('axios');
+const express = require('express');
+const NodeCache = require("node-cache");
+const cache = new NodeCache();
+
+const app = express();
+
+// serve files inside the public folder from /
+app.use('/', express.static(path.join(__dirname, 'public')));
+
+async function getCached(key, ttl, callback) {
+
+    // find data from cache
+    let data = cache.get(key);
+
+    // update cache
+    if(!data){
+        data = await callback();
+        cache.set(key, data, ttl);
+    }
+
+    // get expiration time in seconds
+    const cacheTtl = cache.getTtl(key);
+    const expiresIn = cacheTtl != null
+        ? Math.ceil((cacheTtl - Date.now()) / 1000)
+        : 0;
+
+    // return data
+    return [ data, expiresIn ];
+
+}
+
+app.get('/', async (req, res) => {
+    res.sendFile(path.join(__dirname, 'public/index.html'));
+});
+
+app.get('/api', async (req, res) => {
+
+    const links = [
+        {
+            "path": "/api",
+            "description": "This page",
+        },
+        {
+            "path": "/api/v1/nodes",
+            "description": "Meshtastic nodes in JSON format.",
+        },
+    ];
+
+    const html = links.map((link) => {
+        return `<li><a href="${link.path}">${link.path}</a> - ${link.description}</li>`;
+    }).join("");
+
+    res.send(html);
+
+});
+
+app.get('/api/v1/nodes', async (req, res) => {
+    try {
+
+        // get nodes from cache, or retrieve from api
+        const [ nodes, expiresIn ] = await getCached('nodes', 10, async () => {
+            const response = await axios.get("https://meshmap.net/nodes2.json");
+            return response.data;
+        });
+
+        res.json({
+            expires_in: expiresIn,
+            nodes: nodes,
+        });
+
+    } catch(err) {
+        console.error(err);
+        res.status(500).json({
+            message: "Something went wrong, try again later.",
+        });
+    }
+});
+
+app.listen(8080);