package main

import (
	"embed"
	"flag"
	"io/fs"
	"log/slog"
	"net/http" // sure, we could use fiber... but for now lets' stick with net/http to keep dependencies to a minimum
	"os"
)

//go:embed static/*
var staticFS embed.FS

func loggingMiddleware(next http.Handler) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		slog.Info("request", "method", r.Method, "path", r.URL.Path)
		next.ServeHTTP(w, r)
	})
}

func cacheMiddleware(next http.Handler) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.Header().Set("Cache-Control", "public, max-age=3600")
		next.ServeHTTP(w, r)
	})
}

func main() {
	addr := flag.String("addr", ":8080", "listen address")
	flag.Parse()

	logger := slog.New(slog.NewTextHandler(os.Stdout, nil))
	slog.SetDefault(logger)

	/* strip "static/" prefix so files are served from root */
	subFS, err := fs.Sub(staticFS, "static")
	if err != nil {
		slog.Error("failed to create sub filesystem", "error", err)
		os.Exit(1)
	}

	fileServer := http.FileServer(http.FS(subFS))
	http.Handle("/", loggingMiddleware(cacheMiddleware(fileServer)))

	slog.Info("starting server", "addr", *addr)
	if err := http.ListenAndServe(*addr, nil); err != nil {
		slog.Error("server failed", "error", err)
		os.Exit(1)
	}
}