"use strict";
(function() {
  var pendingRegistration = null;
  var busy = false;
  var $ = function(id) { return document.getElementById(id); };

  function formatSize(value) {
    var units = ["B", "KiB", "MiB", "GiB"];
    var size = Number(value);
    var index = 0;
    while (size >= 1024 && index < units.length - 1) { size /= 1024; index++; }
    return size.toFixed(index ? 1 : 0) + " " + units[index];
  }

  function setStatus(message, error) {
    $("status").textContent = message;
    $("status").classList.toggle("error", Boolean(error));
  }

  async function api(path, options) {
    var response = await fetch(path, Object.assign({cache: "no-store"}, options || {}));
    var value;
    try { value = await response.json(); } catch (_) { value = null; }
    if (!response.ok) throw new Error("Management request failed.");
    return value;
  }

  async function copyUrl(url) {
    await navigator.clipboard.writeText(url);
    setStatus("Share URL copied.", false);
  }

  function actionButton(label, handler, className) {
    var button = document.createElement("button");
    button.type = "button";
    button.textContent = label;
    if (className) button.className = className;
    button.addEventListener("click", handler);
    return button;
  }

  function render(rows) {
    var body = $("drops");
    body.textContent = "";
    $("empty").classList.toggle("hidden", rows.length !== 0);
    rows.forEach(function(row) {
      var tr = document.createElement("tr");
      [row.name, row.type || "application/octet-stream", formatSize(row.size),
        new Date(row.expiresAt * 1000).toLocaleString()].forEach(function(value) {
        var td = document.createElement("td");
        td.textContent = value;
        tr.appendChild(td);
      });
      var actions = document.createElement("td");
      actions.className = "actions";
      actions.appendChild(actionButton("Copy", function() { copyUrl(row.readUrl).catch(function() {
        setStatus("Unable to copy the share URL.", true);
      }); }));
      actions.appendChild(actionButton("Open", function() {
        window.open(row.readUrl, "_blank", "noopener,noreferrer");
      }));
      actions.appendChild(actionButton("Delete", async function() {
        if (!window.confirm("Permanently delete " + row.name + "?")) return;
        try {
          await api("/manage/api/v1/drops/" + row.id, {method: "DELETE"});
          await load();
          setStatus("Drop deleted.", false);
        } catch (_) { setStatus("Delete failed.", true); }
      }, "danger"));
      tr.appendChild(actions);
      body.appendChild(tr);
    });
  }

  async function load() {
    var value = await api("/manage/api/v1/list", {
      method: "POST", headers: {"Content-Type": "application/json"}, body: "{}"
    });
    render(Array.isArray(value.drops) ? value.drops : []);
  }

  async function register(result) {
    await api("/manage/api/v1/register", {
      method: "POST",
      headers: {"Content-Type": "application/json"},
      body: JSON.stringify({readUrl: result.readUrl, deleteCapability: result.deleteCapability})
    });
    pendingRegistration = null;
    $("retry").classList.add("hidden");
    await load();
  }

  $("upload-form").addEventListener("submit", async function(event) {
    event.preventDefault();
    if (busy) return;
    var file = $("file").files[0];
    if (!file) return setStatus("Select a file.", true);
    busy = true;
    $("upload").disabled = true;
    $("progress").style.width = "0";
    setStatus("Encrypting and uploading...", false);
    try {
      var result = await NeoDropCrypto.upload(file, {
        base: location.origin,
        profile: Number($("profile").value),
        onProgress: function(value) { $("progress").style.width = Math.round(value * 100) + "%"; }
      });
      pendingRegistration = result;
      setStatus("Upload complete. Registering encrypted catalog entry...", false);
      try {
        await register(result);
        $("upload-form").reset();
        setStatus("Encrypted drop uploaded and registered.", false);
      } catch (_) {
        $("retry").classList.remove("hidden");
        setStatus("Upload succeeded, but catalog registration must be retried in this tab.", true);
      }
    } catch (error) {
      if (error.name !== "AbortError") setStatus(error.message || "Encrypted upload failed.", true);
    } finally {
      busy = false;
      $("upload").disabled = false;
    }
  });

  $("retry").addEventListener("click", async function() {
    if (!pendingRegistration || busy) return;
    busy = true;
    try {
      await register(pendingRegistration);
      setStatus("Catalog registration completed.", false);
    } catch (_) { setStatus("Catalog registration failed; retry from this tab.", true); }
    finally { busy = false; }
  });

  $("refresh").addEventListener("click", function() {
    load().then(function() { setStatus("Managed drops refreshed.", false); })
      .catch(function() { setStatus("Unable to load managed drops.", true); });
  });

  load().catch(function() { setStatus("Unable to load managed drops.", true); });
}());