// ── DOM refs ──────────────────────────────────────────────────────────────────
const dlUrl    = document.querySelector("#dl-url");
const dlTitle  = document.querySelector("#dl-title");
const dlBtn    = document.querySelector("#dl-btn");
const dlStatus = document.querySelector("#dl-status");
const dlProgress = document.querySelector("#dl-progress");

const renameSelect = document.querySelector("#rename-select");
const renameInput  = document.querySelector("#rename-input");
const renameBtn    = document.querySelector("#rename-btn");
const renameStatus = document.querySelector("#rename-status");

const manageList = document.querySelector("#manage-list");

// ── Download ──────────────────────────────────────────────────────────────────
dlBtn.addEventListener("click", async () => {
  const url   = dlUrl.value.trim();
  const title = dlTitle.value.trim();
  if (!url) { dlStatus.textContent = "Please enter a URL."; return; }

  dlStatus.textContent = "Starting download\u2026";
  dlBtn.disabled = true;
  dlProgress.hidden = false;
  dlProgress.removeAttribute("value");

  try {
    const res  = await fetch("/api/download", {
      method:  "POST",
      headers: { "Content-Type": "application/json" },
      body:    JSON.stringify({ url, title }),
    });
    const data = await res.json();
    if (data.error) {
      dlStatus.textContent = `Error: ${data.error}`;
      dlBtn.disabled = false;
      dlProgress.hidden = true;
      return;
    }
    pollDownload(data.track_id);
  } catch {
    dlStatus.textContent = "Request failed.";
    dlBtn.disabled = false;
    dlProgress.hidden = true;
  }
});

function pollDownload(trackId) {
  const iv = setInterval(async () => {
    try {
      const res  = await fetch(`/api/download/status/${encodeURIComponent(trackId)}`);
      const data = await res.json();
      if (data.status === "done") {
        clearInterval(iv);
        dlProgress.value = 100;
        dlStatus.textContent = "Download complete!";
        dlBtn.disabled = false;
        dlUrl.value   = "";
        dlTitle.value = "";
        setTimeout(() => { dlProgress.hidden = true; }, 800);
        refresh();
      } else if (data.status === "error") {
        clearInterval(iv);
        dlStatus.textContent = `Error: ${data.error || "unknown"}`;
        dlBtn.disabled = false;
        dlProgress.hidden = true;
      } else {
        if (typeof data.progress === "number") {
          dlProgress.value = data.progress;
        } else {
          dlProgress.removeAttribute("value");
        }
        const phase = data.phase === "converting" ? "Converting" : "Downloading";
        const pctTxt = typeof data.progress === "number" ? ` ${data.progress}%` : "";
        dlStatus.textContent = `${phase}${pctTxt}\u2026`;
      }
    } catch {
      clearInterval(iv);
      dlStatus.textContent = "Status check failed.";
      dlBtn.disabled = false;
      dlProgress.hidden = true;
    }
  }, 750);
}

// ── Rename ────────────────────────────────────────────────────────────────────
async function loadRenameDropdown() {
  const [downloads, tracks] = await Promise.all([fetchDownloads(), fetchTracks()]);
  renameSelect.innerHTML = "";

  if (tracks.length) {
    const grp = document.createElement("optgroup");
    grp.label = "Playlist";
    tracks.forEach(t => {
      const opt       = document.createElement("option");
      opt.value       = JSON.stringify({ type: "playlist", src: t.src, title: t.title });
      opt.textContent = t.title;
      grp.appendChild(opt);
    });
    renameSelect.appendChild(grp);
  }

  if (downloads.length) {
    const grp = document.createElement("optgroup");
    grp.label = "Downloads";
    downloads.forEach(t => {
      const opt       = document.createElement("option");
      opt.value       = JSON.stringify({ type: "download", filename: t.filename, title: t.title });
      opt.textContent = t.title;
      grp.appendChild(opt);
    });
    renameSelect.appendChild(grp);
  }

  syncRenameInput();
}

function syncRenameInput() {
  try { renameInput.value = JSON.parse(renameSelect.value).title; } catch {}
}

renameSelect.addEventListener("change", syncRenameInput);

renameBtn.addEventListener("click", async () => {
  const newTitle = renameInput.value.trim();
  if (!newTitle) return;
  let item;
  try { item = JSON.parse(renameSelect.value); } catch { return; }

  renameStatus.textContent = "Saving\u2026";

  try {
    let res;
    if (item.type === "playlist") {
      res = await fetch("/api/tracks/rename", {
        method:  "POST",
        headers: { "Content-Type": "application/json" },
        body:    JSON.stringify({ src: item.src, title: newTitle }),
      });
    } else {
      res = await fetch(`/api/downloads/${encodeURIComponent(item.filename)}/rename`, {
        method:  "POST",
        headers: { "Content-Type": "application/json" },
        body:    JSON.stringify({ title: newTitle }),
      });
    }
    if (res.ok) {
      renameStatus.textContent = "Saved!";
      refresh();
    } else {
      renameStatus.textContent = "Save failed.";
    }
  } catch {
    renameStatus.textContent = "Request failed.";
  }
});

// ── Manage downloads ──────────────────────────────────────────────────────────
async function loadManageList() {
  const tracks = await fetchDownloads();
  if (!tracks.length) {
    manageList.innerHTML = "<p class='hint'>No tracks downloaded yet.</p>";
    return;
  }
  manageList.innerHTML = "";
  tracks.forEach(t => {
    const item = document.createElement("div");
    item.className = "track-item track-item--col";
    const sourceLink = t.source
      ? `<a class="track-source" href="${escapeAttr(t.source)}" target="_blank" rel="noopener noreferrer">Source</a>`
      : "";
    item.innerHTML = `
      <div class="track-row">
        <span class="track-title">${escapeHtml(t.title)}</span>
        ${sourceLink}
        <button class="btn-danger" type="button">Delete</button>
      </div>
      <div class="track-skip">
        <label class="skip-label">Skip intro</label>
        <input type="number" class="skip-input" min="0" step="1" value="${t.skip || 0}" placeholder="0">
        <span class="skip-unit">sec</span>
        <button class="btn-save" type="button">Save</button>
      </div>`;

    item.querySelector(".btn-danger").addEventListener("click", async () => {
      await fetch(`/api/downloads/${encodeURIComponent(t.filename)}`, { method: "DELETE" });
      refresh();
    });

    const skipInput = item.querySelector(".skip-input");
    item.querySelector(".btn-save").addEventListener("click", async () => {
      const seconds = parseInt(skipInput.value, 10) || 0;
      await fetch(`/api/downloads/${encodeURIComponent(t.filename)}/skip`, {
        method:  "POST",
        headers: { "Content-Type": "application/json" },
        body:    JSON.stringify({ seconds }),
      });
    });

    manageList.appendChild(item);
  });
}

// ── Helpers ───────────────────────────────────────────────────────────────────
function escapeHtml(s) {
  return String(s).replace(/[&<>"']/g, c => ({
    "&": "&amp;", "<": "&lt;", ">": "&gt;", '"': "&quot;", "'": "&#39;",
  }[c]));
}
function escapeAttr(s) { return escapeHtml(s); }

async function fetchDownloads() {
  try {
    const res = await fetch("/api/downloads");
    return res.ok ? await res.json() : [];
  } catch { return []; }
}

async function fetchTracks() {
  try {
    const res = await fetch("/api/tracks");
    return res.ok ? await res.json() : [];
  } catch { return []; }
}

function refresh() {
  loadRenameDropdown();
  loadManageList();
}

// ── Init ──────────────────────────────────────────────────────────────────────
refresh();