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

const MULTIBOOT_MAX = 8;

const step1Title = document.getElementById("step1Title");
const versionList = document.getElementById("versionList");
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 multibootHint = document.getElementById("multibootHint");
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");
const modeMultibootBtn = document.getElementById("modeMultiboot");

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");
  modeMultibootBtn.classList.toggle("active", mode === "multiboot");

  const needsDevice = mode === "stick" || mode === "multiboot";
  deviceSection.style.display = needsDevice ? "" : "none";
  stickConfirm.style.display = needsDevice ? "" : "none";
  downloadHint.style.display = mode === "download" ? "" : "none";
  multibootHint.style.display = mode === "multiboot" ? "" : "none";

  step1Title.textContent = mode === "multiboot" ? "1. macOS-Versionen (2-8 auswaehlen)" : "1. macOS-Version";
  step3Title.textContent = mode === "download" ? "3. Herunterladen" : "3. Bestaetigen & Schreiben";
  startBtn.textContent = mode === "download" ? "Image herunterladen" : (mode === "multiboot" ? "Multiboot-Stick erstellen" : "Stick erstellen");

  renderVersionOptions();
  updateStartEnabled();
}
modeStickBtn.addEventListener("click", () => setMode("stick"));
modeDownloadBtn.addEventListener("click", () => setMode("download"));
modeMultibootBtn.addEventListener("click", () => setMode("multiboot"));

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 updateMultibootSummary() {
  const items = catalogItems.filter((i) => selectedProductIds.has(i.id));
  const totalBytes = items.reduce((sum, i) => sum + (i.size_bytes || 0), 0);
  versionDetail.textContent = items.length
    ? `${items.length} Versionen ausgewaehlt, Original-Images zusammen ca. ${fmtSize(totalBytes)} -- Stick muss inkl. Partitions-Puffer entsprechend groesser sein.`
    : `Waehle 2-${MULTIBOOT_MAX} macOS-Versionen fuer den Multiboot-Stick aus.`;
}

function renderVersionOptions() {
  versionList.innerHTML = "";
  for (const item of catalogItems) {
    const row = document.createElement("label");
    row.className = "version-row";

    const input = document.createElement("input");
    const modeTag = item.mode === "recovery" ? " [experimentell]" : "";
    const offlineTag = libraryIds.has(item.id) ? " -- bereits offline vorhanden" : "";
    const labelText = `${item.title} ${item.version} - ${fmtSize(item.size_bytes)}${modeTag}${offlineTag}`;

    if (mode === "multiboot") {
      input.type = "checkbox";
      input.checked = selectedProductIds.has(item.id);
      input.addEventListener("change", () => {
        if (input.checked) {
          if (selectedProductIds.size >= MULTIBOOT_MAX) {
            input.checked = false;
            return;
          }
          selectedProductIds.add(item.id);
        } else {
          selectedProductIds.delete(item.id);
        }
        row.classList.toggle("selected", input.checked);
        updateMultibootSummary();
        updateStartEnabled();
      });
      row.classList.toggle("selected", input.checked);
    } else {
      input.type = "radio";
      input.name = "versionPick";
      input.checked = !!selectedProduct && selectedProduct.id === item.id;
      input.addEventListener("change", () => {
        selectedProduct = item;
        const modeText = item.mode === "recovery"
          ? "Big Sur+ Pfad: experimentell, Extraktion kann fehlschlagen."
          : "Klassischer dd-Pfad: robust und gut getestet.";
        const offlineText = libraryIds.has(item.id) ? " | bereits offline vorhanden, kein erneuter Download noetig." : "";
        versionDetail.textContent = `${item.title} ${item.version} | ${fmtSize(item.size_bytes)} | ${modeText}${offlineText}`;
        document.querySelectorAll(".version-row").forEach((r) => r.classList.remove("selected"));
        row.classList.add("selected");
        updateStartEnabled();
      });
      row.classList.toggle("selected", input.checked);
    }

    const span = document.createElement("span");
    span.textContent = labelText;
    row.appendChild(input);
    row.appendChild(span);
    versionList.appendChild(row);
  }
  if (mode === "multiboot") updateMultibootSummary();
}

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();
}

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() {
  let ok;
  if (mode === "download") {
    ok = !!selectedProduct;
  } else if (mode === "multiboot") {
    ok = selectedProductIds.size >= 2 && !!selectedDevice && confirmPath.value.trim() === selectedDevice.path;
  } else {
    ok = !!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 = { job_type: mode };
  if (mode === "multiboot") {
    payload.product_ids = Array.from(selectedProductIds);
  } else {
    payload.product_id = selectedProduct.id;
  }
  if (mode === "stick" || mode === "multiboot") {
    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();