Caching Server for waeather

.gitignore

@@ -0,0 +1,2 @@
+# Ignore Node Deps
+node_modules

cache/cache.js

@@ -0,0 +1,90 @@
+const http = require('http')
+const https = require('https')
+
+// GET YOUR OWN AT: https://openweathermap.org/appid
+const APP_KEY = 'myAppId'
+
+const REGEXP = {
+  URL: /^\/[\d]{1,8}$/
+}
+
+const API = {
+  // Define max 60 calls per 1 Minute
+  MAX_CALLS: 60,
+  INTERVAL: 1000 * 60, // 1 Minute
+  current_calls: 0,
+  last_reset: Date.now(),
+}
+
+const CACHE = {}
+const MAX_AGE = 60 * 1000 // 1 Minute
+const LAST_UPDATE_KEY = 'last_update'
+
+function getForZip(zip) {
+  return new Promise((resolve, reject) => {
+
+    // If interval is over, reset max count
+    if (Date.now() - API.last_reset > API.INTERVAL) {
+      API.last_reset = Date.now()
+      API.current_calls = 0
+    }
+
+    // Check if too many calls were already made
+    if (API.current_calls > API.MAX_CALLS)
+      resolve()
+
+    API.current_calls++;
+
+    // Make the call
+    https.get({
+      host: 'api.openweathermap.org',
+      path: `/data/2.5/forecast?APPID=${APP_KEY}&zip=${zip},DE&units=metric`,
+      timeout: 15 * 1000,
+    }, res => {
+      res.setEncoding('utf8')
+      let body = ''
+      res.on('data', data => {
+        body += data
+      })
+      res.on('end', () => {
+        const data = JSON.parse(body)
+        data[LAST_UPDATE_KEY] = Date.now()
+        resolve(data)
+      })
+    })
+
+  })
+}
+
+function getUrlFromPath(path) {
+  // Check if url is valid
+  if (!REGEXP.URL.test(path))
+    return false
+  else
+    // Exctract ZIP code
+    return path.replace('/', '')
+}
+
+const server = http.createServer(async(req, res) => {
+
+  const zip = getUrlFromPath(req.url)
+  // Check if url is valid
+  if (zip === false) {
+    res.writeHead(400, {})
+    res.end()
+    return
+  }
+
+  // If there is no cached version, get it
+  // If the last cached version is older than MAX_AGE, get it
+  if (CACHE[zip] === undefined || Date.now() - CACHE[zip][LAST_UPDATE_KEY] > MAX_AGE)
+    CACHE[zip] = await getForZip(zip)
+
+  res.writeHead(200, {
+    'Content-Type': 'application/json',
+  })
+  res.write(JSON.stringify(CACHE[zip] || {}))
+  res.end()
+})
+
+server.listen(8000)

cache/package.json

@@ -0,0 +1,18 @@
+{
+  "name": "dvb",
+  "version": "1.0.0",
+  "description": "DVB Monitor App",
+  "dependencies": {},
+  "devDependencies": {
+    "css-loader": "latest",
+    "forever": "latest",
+    "style-loader": "latest",
+    "webpack": "latest"
+  },
+  "repository": {
+    "type": "git",
+    "url": "https://github.com/CupCakeArmy/dvb"
+  },
+  "author": "",
+  "license": "MIT"
+}