remote-local-storage/main.go

// Save and serve HTML local storage in server
package main

import (
	"bytes"
	_ "embed"
	"flag"
	"io"
	"log"
	"net/http"
	"os"
	"time"

	"go.balki.me/anyhttp"
)

//go:embed wrap.html
var html []byte

func main() {

	addr := flag.String("address", "localhost:3242", "Listen address. See go.balki.me/anyhttp for usage")
	dumpFile := flag.String("dumpfile", "dump.json", "Path where local storage is saved in server")

	flag.Parse()

	http.HandleFunc("/", func(w http.ResponseWriter, _ *http.Request) {
		w.Write([]byte("<h2>Error!</h2><p>Check your webserver config, You should not see this!</p>"))
	})

	http.HandleFunc("/wrap/", func(w http.ResponseWriter, r *http.Request) {
		http.ServeContent(w, r, "index.html", time.Now(), bytes.NewReader(html))
	})

	http.HandleFunc("/wrap/saveLS", func(w http.ResponseWriter, r *http.Request) {

		data, err := io.ReadAll(r.Body)
		if err != nil {
			log.Panic(err)
		}

		if err := os.WriteFile(*dumpFile, data, 0o400); err != nil {
			log.Panic(err)
		}

		if err != nil {
			log.Panic(err)
		}

		log.Println("Saved!")

		if _, err := w.Write([]byte("OK")); err != nil {
			log.Panic(err)
		}
	})

	http.HandleFunc("/wrap/loadLS", func(w http.ResponseWriter, _ *http.Request) {
		w.Header().Set("Content-Type", "application/json")
		data, err := os.ReadFile(*dumpFile)
		if err != nil { // First time
			data = []byte("{}")
		}
		if _, err := w.Write(data); err != nil {
			log.Panic(err)
		}
		log.Println("Sent!")
	})

	err := anyhttp.ListenAndServe(*addr, nil)
	if err != nil {
		log.Panic(err)
	}
}