(() => {
  let isLoading = 0;
  const loading = (val) => {
    isLoading = val;
    loader.$cls(isLoading ? "" : "hidden");
  }
  loader.$click(() => loading(0));

  let error = null;
  function errClose() {
    error = null;
    app.reload();
  }
  let data = {};
  function onerror(err) {
    error = err;
    console.error(err);
    app.reload();
  }
  function parsedata(r) {
    return Object.fromEntries(r.split("\n").map(x=>x.trim()).filter(x=>x).map(x=>x.split('=')));
  }
  function cmd(url, body) {
    return fetch(url, {method:body?'POST':'GET', body})
      .then(r => {
        if (!r.ok){
          throw new Error(r.statusText);
        }
        return r.text();
      })
      .then(r => parsedata(r));
  }; 
  function loadconfig() {
    loading(1);
    cmd("/cgi-bin/getconfig")
      .then(x => {
        data = x;
        app.reload();
      })
      .catch(onerror)
      .then(() => loading(0))
  }
  function saveconfig(groups) {
    cmd("/cgi-bin/setconfig", data)
      .catch(onerror)
      .then(loadconfig)
  }

  function CErr(text) {
    var el = div(
      div("✖").$cls("close").$click(errClose),
      span("⚠ "),
      text,
    ).$cls("err");
    function errClose() {
      error = null;
      el.remove();
    };
    return el;
  }
  function CNav(navs) {
    return (h) => nav(
      labelfor("showmenu", span("☰"), " Menu"),
      input("checkbox").$attr("id", "showmenu"),
      ...navs.map(([href,txt]) => ahref(href,txt).$cls(href===h?"active":""))
    );
  }
  function CRouter(routes) {
    return (h) => {
      const p = h.substr(1) || "/";
      const r = p in routes ? p : "";
      return routes[r]();
    }
  }
  const navbar = CNav([
    ["#", "Home"],
    ["#/network", "Network"],
    ["#/config", "Configuration"],
    ["#/tools", "Tools"],
  ]);
  const router = CRouter({
    "/": () => div(
      h2("Lorem Ipsum"),
      p("Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. "),
      p("Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat."),
    ),
    "/network": () => div(
      h1("Network settings"),
      table(
        tr(
          td("IP"),
          td(input("text").$value(data["cfg.ip"])),
        ),
        tr(
          td("MAC"),
          td(
            input("text").$value(data["cfg.mac"])
              .$change2state(data, "cfg.mac")
          ),
        )
      ).$cls("network"),
      input("button").$value("Save").$click(saveconfig)
    ),
    "/config": () => {
      return div();
    },
    "/waiting": () => {
      loading(1);
      setTimeout(() => {
        loading(0);
      }, 3000);
      return div("");
    },
    "": () => div(
      h1("Not Found"),
      p("The requested page is not available.")
    ),
  });

  mount(app, (h) => {
    loading(isLoading);
    return [
      div(error && CErr(String(error))),
      main(
        navbar(h),
        section(router(h))
      ),
    ];
  });
  loadconfig();
})()