package web

import (
	"embed"
	"io/fs"
	"net/http"
	"strings"
)

//go:embed all:html
var htmlFS embed.FS

func Handler() http.HandlerFunc {
	fsys, err := fs.Sub(htmlFS, "html")
	if err != nil {
		panic("failed to create sub filesystem: " + err.Error())
	}
	fileServer := http.FileServer(http.FS(fsys))

	return func(w http.ResponseWriter, r *http.Request) {
		path := r.URL.Path

		if path != "/" {
			cleanPath := strings.TrimPrefix(path, "/")
			if _, err := fs.Stat(fsys, cleanPath); err == nil {
				fileServer.ServeHTTP(w, r)
				return
			}
		}

		r.URL.Path = "/"
		fileServer.ServeHTTP(w, r)
	}
}