create viewcounter

.gitignore

@@ -1,3 +1,6 @@
+# view count
+.count.json
+
 # ---> Node
 # Logs
 logs
@@ -129,4 +132,3 @@ dist
 .yarn/build-state.yml
 .yarn/install-state.gz
 .pnp.*
-

conf.json

@@ -0,0 +1,7 @@
+{
+	"port": 8001,
+	"path": "/viewcounter",
+	"site": "zvava.org",
+	"db": ".count.json",
+	"saveTimeout": 5000
+}

index.js

@@ -0,0 +1,94 @@
+import * as fs from "fs"
+import * as http from "http"
+import { request } from "https"
+
+// read configuration
+let config = readJson("conf.json", {
+	port: 8001,
+	path: "/viewcounter",
+	site: "zvava.org",
+	db: ".count.json",
+	saveTimeout: 5000,
+})
+// read existing view count
+let count = readJson(config.db)
+// store the save timeout
+let saveTimeout
+
+let server = new http.Server((request, response) => {
+	try {
+		if (request.url != config.path)
+			return close(response, 404)
+
+		switch (request.method) {
+			case "GET":
+				close(response, 200, JSON.stringify(count))
+				break
+
+			case "POST":
+				const chunks = []
+				request.on("data", chunk => chunks.push(chunk))
+				request.on("end", async () => {
+					let page = Buffer.concat(chunks).toString()
+
+					// check if page is a valid url
+					if (/\/[a-zA-Z0-9_-]+.html/.test(page) && await validateUrl(page)) {
+						count[page]++
+						saveCount()
+						close(response, 200, "counted page view", { views: count[page] })
+					} else {
+						close(response, 300, "invalid url provided")
+					}
+				})
+				break
+
+			default: resolve(close(response))
+		}
+	} catch (e) {
+		console.log(e)
+	}
+})
+
+server.listen(config.port)
+
+function saveCount() {
+	// if a timeout
+	saveTimeout && clearTimeout(saveTimeout)
+	saveTimeout = setTimeout(() => {
+		fs.writeFile(config.db, JSON.stringify(count), (err) =>
+			err && console.error(err))
+	}, config.saveTimeout)
+}
+
+// read file, if it exists return it as an object, otherwise return a default object
+function readJson(file, defaultJson = {}) {
+	try { return JSON.parse(fs.readFileSync(file, "utf-8")) } catch {}
+
+	return defaultJson
+}
+
+// helper function to close an incoming http request
+function close(res, code = 300, message = "", extraData = {}) {
+	res.setHeader("Content-type", "application/json")
+	res.writeHead(code)
+	res.end(JSON.stringify({
+		code,
+		message: message || code.toString(),
+		...extraData
+	}))
+}
+
+// ping the target site and ensure that the url exists
+function validateUrl(url) {
+	console.log(url)
+	return new Promise((resolve) => {
+		request({
+			method: "HEAD",
+			host: config.site,
+			path: url,
+		}, (response) => {
+			console.log(response.statusCode, response.headers)
+			resolve(response.statusCode == 200)
+		}).end()
+	})
+}

package.json

@@ -0,0 +1,4 @@
+{
+  "main": "index.js",
+  "type": "module"
+}