let selectedProduct = null;
let selectedDevice = null;
let catalogItems = [];
let libraryIds = new Set(); // Produkt-IDs die schon lokal (dauerhaft) vorhanden sind
let mode = "stick"; // "stick" | "download"

const versionSelect = document.getElementById("versionSelect");
const versionDetail = document.getElementById("versionDetail");
const catalogStatus = document.getElementById("catalogStatus");
const deviceSection = document.getElementById("deviceSection");
const deviceList = document.getElementById("deviceList");
const confirmPath = document.getElementById("confirmPath");
const stickConfirm = document.getElementById("stickConfirm");
const downloadHint = document.getElementById("downloadHint");
const step3Title = document.getElementById("step3Title");
const startBtn = document.getElementById("startBtn");
const progressCard = document.getElementById("progressCard");
const progressFill = document.getElementById("progressFill");
const progressPhase = document.getElementById("progressPhase");
const logEl = document.getElementById("log");
const libraryStatus = document.getElementById("libraryStatus");
const modeStickBtn = document.getElementById("modeStick");
const modeDownloadBtn = document.getElementById("modeDownload");

function fmtSize(bytes) {
  if (!bytes) return "?";
  const gb = bytes / 1e9;
  return gb >= 1 ? gb.toFixed(1) + " GB" : (bytes / 1e6).toFixed(0) + " MB";
}

function setMode(next) {
  mode = next;
  modeStickBtn.classList.toggle("active", mode === "stick");
  modeDownloadBtn.classList.toggle("active", mode === "download");
  deviceSection.style.display = mode === "stick" ? "" : "none";
  stickConfirm.style.display = mode === "stick" ? "" : "none";
  downloadHint.style.display = mode === "download" ? "" : "none";
  step3Title.textContent = mode === "stick" ? "3. Bestaetigen & Schreiben" : "3. Herunterladen";
  startBtn.textContent = mode === "stick" ? "Stick erstellen" : "Image herunterladen";
  updateStartEnabled();
}
modeStickBtn.addEventListener("click", () => setMode("stick"));
modeDownloadBtn.addEventListener("click", () => setMode("download"));

async function loadLibrary() {
  const res = await fetch("/api/library");
  const data = await res.json();
  libraryIds = new Set((data.items || []).map((it) => it.id));
  const count = (data.items || []).length;
  const size = fmtSize(data.total_bytes || 0);
  libraryStatus.textContent = count
    ? `${count} Installer bereits dauerhaft lokal vorhanden -- ${size} in ./downloads/library/`
    : "Noch keine Installer dauerhaft lokal gespeichert.";
  renderVersionOptions();
}

function renderVersionOptions() {
  versionSelect.innerHTML = "";
  for (const item of catalogItems) {
    const opt = document.createElement("option");
    opt.value = item.id;
    const modeTag = item.mode === "recovery" ? " [experimentell]" : "";
    const offlineTag = libraryIds.has(item.id) ? " -- bereits offline vorhanden" : "";
    opt.textContent = `${item.title} ${item.version} - ${fmtSize(item.size_bytes)}${modeTag}${offlineTag}`;
    versionSelect.appendChild(opt);
  }
}

async function loadVersions() {
  catalogStatus.textContent = "Lade Apple-Katalog...";
  const res = await fetch("/api/versions");
  const data = await res.json();
  catalogItems = data.items || [];
  if (data.loading) {
    catalogStatus.textContent = "Katalog wird noch geladen, gleich nochmal versuchen...";
    setTimeout(loadVersions, 3000);
    return;
  }
  if (data.error) {
    catalogStatus.textContent = "Fehler beim Laden: " + data.error;
    return;
  }
  catalogStatus.textContent = `${catalogItems.length} macOS-Installer gefunden (Katalog: ${data.catalog_url ? data.catalog_url.split("/").pop() : "?"})`;
  renderVersionOptions();
}

versionSelect.addEventListener("change", () => {
  selectedProduct = catalogItems.find((i) => i.id === versionSelect.value) || null;
  if (selectedProduct) {
    const modeText = selectedProduct.mode === "recovery"
      ? "Big Sur+ Pfad: experimentell, Extraktion kann fehlschlagen."
      : "Klassischer dd-Pfad: robust und gut getestet.";
    const offlineText = libraryIds.has(selectedProduct.id) ? " | bereits offline vorhanden, kein erneuter Download noetig." : "";
    versionDetail.textContent = `${selectedProduct.title} ${selectedProduct.version} | ${fmtSize(selectedProduct.size_bytes)} | ${modeText}${offlineText}`;
  }
  updateStartEnabled();
});

async function loadDevices() {
  deviceList.innerHTML = "<div class='detail'>Scanne USB-Geraete...</div>";
  const res = await fetch("/api/devices");
  const data = await res.json();
  deviceList.innerHTML = "";
  if (!data.items || data.items.length === 0) {
    deviceList.innerHTML = "<div class='detail'>Keine USB-Sticks gefunden. Stick einstecken, dann 'neu scannen'.</div>";
    return;
  }
  for (const dev of data.items) {
    const el = document.createElement("div");
    const blocked = dev.is_root_disk || dev.mounted;
    el.className = "device" + (blocked ? " disabled" : "");
    el.innerHTML = `<div>
        <div class="path">${dev.path} ${dev.is_root_disk ? "(SYSTEM-PLATTE - gesperrt)" : ""}</div>
        <div class="meta">${dev.vendor || ""} ${dev.model || ""} - ${fmtSize(dev.size_bytes)} - ${dev.transport || "?"}${dev.mounted ? " - GEMOUNTET" : ""}</div>
      </div>`;
    if (!blocked) {
      el.addEventListener("click", () => {
        document.querySelectorAll(".device").forEach((d) => d.classList.remove("selected"));
        el.classList.add("selected");
        selectedDevice = dev;
        updateStartEnabled();
      });
    }
    deviceList.appendChild(el);
  }
}

function updateStartEnabled() {
  const ok = mode === "download"
    ? !!selectedProduct
    : selectedProduct && selectedDevice && confirmPath.value.trim() === selectedDevice.path;
  startBtn.disabled = !ok;
}
confirmPath.addEventListener("input", updateStartEnabled);

document.getElementById("refreshVersions").addEventListener("click", async () => {
  await fetch("/api/versions/refresh", { method: "POST" });
  setTimeout(loadVersions, 1500);
});
document.getElementById("refreshDevices").addEventListener("click", loadDevices);

startBtn.addEventListener("click", async () => {
  startBtn.disabled = true;
  progressCard.style.display = "block";
  logEl.textContent = "";
  const payload = { product_id: selectedProduct.id, job_type: mode };
  if (mode === "stick") {
    payload.device_path = selectedDevice.path;
    payload.confirm_device_path = confirmPath.value.trim();
  }
  const res = await fetch("/api/jobs", {
    method: "POST",
    headers: { "Content-Type": "application/json" },
    body: JSON.stringify(payload),
  });
  const data = await res.json();
  if (data.error) {
    logEl.textContent = "FEHLER: " + data.error;
    updateStartEnabled();
    return;
  }
  streamJob(data.job_id);
});

function streamJob(jobId) {
  const es = new EventSource(`/api/jobs/${jobId}/stream`);
  es.onmessage = (ev) => {
    const data = JSON.parse(ev.data);
    progressFill.style.width = (data.progress || 0) + "%";
    progressPhase.textContent = `${data.phase} (${data.progress || 0}%) - ${data.status}`;
    if (data.msg) {
      logEl.textContent += data.msg + "\n";
      logEl.scrollTop = logEl.scrollHeight;
    }
    if (data.status === "done" || data.status === "failed" || data.status === "aborted") {
      es.close();
      if (data.status === "done") {
        loadLibrary();
      }
      updateStartEnabled();
    }
  };
  es.onerror = () => {
    es.close();
  };
}

setMode("stick");
loadLibrary().then(loadVersions);
loadDevices();