// The Install page: asks the project's Gitea for the latest release, and gives ESP Web Tools a
// manifest for its factory image, built here, so the page offers a new release as soon as it exists
// and nothing is copied to this site (docs/milestones/W1.md, Q180). Gitea sits behind Caddy, which
// allows this origin to read the release API and the downloads.
(function () {
  var box = document.getElementById("flasher");
  if (!box) return;
  var $ = function (id) { return document.getElementById(id); };
  var status = $("flasher-status");
  var apiOrigin = new URL(box.dataset.api).origin;
  var downloads = box.dataset.releasesPath;

  // A network error (which is also what a browser makes of a missing CORS header) and a release this
  // page won't offer are different things to tell the visitor.
  function fail(error) {
    var unreachable = error instanceof TypeError;
    status.textContent = (unreachable ? "Couldn't reach the release server (" + error.message + ")" : "This page can't offer the latest release (" + error.message + ")") +
      ". Use the esptool steps below, or take the file from the downloads page.";
    status.className = "msg";
  }
  function human(bytes) {
    return bytes >= 1048576 ? (bytes / 1048576).toFixed(2) + " MB" : Math.round(bytes / 1024) + " KB";
  }
  // Only a download from the project's own server, for this repository, is ever handed to the flasher.
  function trusted(url) {
    try {
      var u = new URL(url);
      return u.origin === apiOrigin && u.pathname.indexOf(downloads) === 0 && u.pathname.indexOf("..") < 0 && !u.search;
    } catch (e) { return false; }
  }

  fetch(box.dataset.api + "/releases/latest", { headers: { Accept: "application/json" } })
    .then(function (r) {
      if (!r.ok) throw new Error("answer " + r.status);
      return r.json();
    })
    .then(function (rel) {
      var assets = rel.assets || [];
      var bin = assets.filter(function (a) { return /-factory\.bin$/.test(a.name); })[0];
      if (!bin) throw new Error("the latest release has no factory image");
      if (!trusted(bin.browser_download_url)) throw new Error("its download isn't on the project's server");
      var sums = assets.filter(function (a) { return a.name === "SHA256SUMS" && trusted(a.browser_download_url); })[0];

      $("f-version").textContent = rel.tag_name;
      $("f-size").textContent = human(bin.size);
      if (rel.html_url) $("f-link").href = rel.html_url;
      var manifest = {
        name: "roro9stack",
        version: rel.tag_name,
        builds: [{ chipFamily: "ESP32-S3", parts: [{ path: bin.browser_download_url, offset: 0 }] }]
      };
      var url = URL.createObjectURL(new Blob([JSON.stringify(manifest)], { type: "application/json" }));
      var button = $("f-button");
      button.setAttribute("manifest", url);
      button.hidden = false;
      $("flasher-info").hidden = false;
      status.textContent = "Latest release: " + rel.tag_name + ".";

      if (!sums) { $("f-sha").textContent = "not published"; return; }
      return fetch(sums.browser_download_url)
        .then(function (r) { return r.ok ? r.text() : ""; })
        .then(function (text) {
          var line = text.split("\n").filter(function (l) { return l.indexOf(bin.name) >= 0; })[0];
          $("f-sha").textContent = line ? line.split(/\s+/)[0] : "not listed";
        })
        .catch(function () { $("f-sha").textContent = "unavailable"; });
    })
    .catch(fail);
})();