const STORAGE_KEY = "shelfItems";
const PREFS_KEY = "shelfPrefs";

const shelfEl = document.getElementById("shelf");
const emptyStateEl = document.getElementById("emptyState");
const searchEl = document.getElementById("search");
const sortSelectEl = document.getElementById("sortSelect");
const viewGridBtn = document.getElementById("viewGridBtn");
const viewListBtn = document.getElementById("viewListBtn");
const showArchivedBtn = document.getElementById("showArchivedBtn");
const unreadCountEl = document.getElementById("unreadCount");
const archivedNoteEl = document.getElementById("archivedNote");
const toastEl = document.getElementById("toast");

let items = [];
let prefs = { view: "grid", sort: "newest", showArchived: false };
let toastTimer = null;

// A short, muted palette for the bookshelf "spine" color, chosen per domain
// so the same site always lands on the same color.
const SPINE_COLORS = ["#C47A4A", "#55684B", "#5A6E8C", "#8C5A6E", "#8C7A4A", "#4A7C8C"];

function spineColorFor(domain) {
  let hash = 0;
  for (let i = 0; i < domain.length; i++) hash = (hash * 31 + domain.charCodeAt(i)) >>> 0;
  return SPINE_COLORS[hash % SPINE_COLORS.length];
}

function timeAgo(ts) {
  const diff = Date.now() - ts;
  const min = 60000, hr = 3600000, day = 86400000;
  if (diff < hr) return `${Math.max(1, Math.round(diff / min))}m ago`;
  if (diff < day) return `${Math.round(diff / hr)}h ago`;
  if (diff < day * 30) return `${Math.round(diff / day)}d ago`;
  return new Date(ts).toLocaleDateString(undefined, { month: "short", day: "numeric", year: "numeric" });
}

async function loadAll() {
  const data = await chrome.storage.local.get([STORAGE_KEY, PREFS_KEY]);
  items = data[STORAGE_KEY] || [];
  prefs = { ...prefs, ...(data[PREFS_KEY] || {}) };
}

async function savePrefs() {
  await chrome.storage.local.set({ [PREFS_KEY]: prefs });
}

async function saveItems() {
  await chrome.storage.local.set({ [STORAGE_KEY]: items });
}

function showToast(msg, actionLabel, actionFn) {
  clearTimeout(toastTimer);
  toastEl.textContent = msg + " ";
  if (actionLabel && actionFn) {
    const btn = document.createElement("button");
    btn.textContent = actionLabel;
    btn.style.cssText = "margin-left:8px;background:none;border:none;color:#C47A4A;text-decoration:underline;cursor:pointer;font:inherit;";
    btn.onclick = () => {
      actionFn();
      toastEl.hidden = true;
    };
    toastEl.appendChild(btn);
  }
  toastEl.hidden = false;
  toastTimer = setTimeout(() => (toastEl.hidden = true), 5000);
}

function applyViewButtons() {
  const isGrid = prefs.view === "grid";
  shelfEl.dataset.view = prefs.view;
  viewGridBtn.setAttribute("aria-pressed", String(isGrid));
  viewListBtn.setAttribute("aria-pressed", String(!isGrid));
  sortSelectEl.value = prefs.sort;
  showArchivedBtn.textContent = prefs.showArchived ? "Hide archived" : "Show archived";
  showArchivedBtn.classList.toggle("active", prefs.showArchived);
}

function faviconOrInitial(item) {
  if (item.favicon) {
    const img = document.createElement("img");
    img.src = item.favicon;
    img.alt = "";
    img.style.cssText = "width:20px;height:20px;object-fit:contain;";
    img.onerror = () => { img.replaceWith(initialBadge(item)); };
    return img;
  }
  return initialBadge(item);
}

function initialBadge(item) {
  const span = document.createElement("span");
  span.className = "favicon-fallback";
  span.textContent = (item.domain || item.title || "?").charAt(0).toUpperCase();
  return span;
}

function buildCard(item) {
  const card = document.createElement("div");
  card.className = "card";
  card.dataset.id = item.id;

  if (prefs.view === "list") {
    const spine = document.createElement("div");
    spine.className = "spine";
    spine.style.background = spineColorFor(item.domain);
    card.appendChild(spine);
  }

  const thumb = document.createElement("div");
  thumb.className = "card-thumb";
  if (prefs.view === "grid" && !item.image) {
    thumb.style.background = `linear-gradient(135deg, ${spineColorFor(item.domain)}33, ${spineColorFor(item.domain)}11)`;
  }
  if (item.image) {
    const img = document.createElement("img");
    img.src = item.image;
    img.alt = "";
    thumb.appendChild(img);
  } else {
    thumb.appendChild(faviconOrInitial(item));
  }
  card.appendChild(thumb);

  const perf = document.createElement("div");
  perf.className = "card-perf";

  const body = document.createElement("div");
  body.className = "card-body";

  const title = document.createElement("a");
  title.className = "card-title";
  title.href = item.url;
  title.textContent = item.title || item.url;
  title.title = item.url;
  title.addEventListener("click", () => markOpened(item.id));
  body.appendChild(title);

  const meta = document.createElement("div");
  meta.className = "card-meta";
  const domainSpan = document.createElement("span");
  domainSpan.textContent = item.domain || "";
  meta.appendChild(domainSpan);
  const dateSpan = document.createElement("span");
  dateSpan.textContent = timeAgo(item.dateAdded);
  meta.appendChild(dateSpan);
  if (item.archived) {
    const badge = document.createElement("span");
    badge.className = "archived-badge";
    badge.textContent = "archived";
    meta.appendChild(badge);
  }
  body.appendChild(meta);

  if (prefs.view === "grid") {
    const actions = document.createElement("div");
    actions.className = "card-actions";
    actions.appendChild(makeActionBtn(item));
    actions.appendChild(makeDeleteBtn(item));
    body.appendChild(actions);
  }

  perf.appendChild(body);
  card.appendChild(perf);

  if (prefs.view === "list") {
    const actions = document.createElement("div");
    actions.className = "card-actions";
    actions.appendChild(makeActionBtn(item));
    actions.appendChild(makeDeleteBtn(item));
    card.querySelector(".card-body").appendChild(actions);
  }

  return card;
}

function makeActionBtn(item) {
  const btn = document.createElement("button");
  btn.className = "icon-btn";
  btn.textContent = item.archived ? "Unarchive" : "Archive";
  btn.addEventListener("click", (e) => {
    e.preventDefault();
    toggleArchive(item.id);
  });
  return btn;
}

function makeDeleteBtn(item) {
  const btn = document.createElement("button");
  btn.className = "icon-btn danger";
  btn.textContent = "Delete";
  btn.addEventListener("click", (e) => {
    e.preventDefault();
    deleteItem(item.id);
  });
  return btn;
}

async function markOpened(id) {
  // Leave the item in place; opening just navigates. No state change needed,
  // but this hook exists in case future versions want "mark as read on open."
}

async function toggleArchive(id) {
  const it = items.find((i) => i.id === id);
  if (!it) return;
  it.archived = !it.archived;
  await saveItems();
  render();
}

async function deleteItem(id) {
  const idx = items.findIndex((i) => i.id === id);
  if (idx === -1) return;
  const [removed] = items.splice(idx, 1);
  await saveItems();
  render();
  showToast("Removed from shelf.", "Undo", async () => {
    items.splice(idx, 0, removed);
    await saveItems();
    render();
  });
}

function getFilteredSorted() {
  const query = searchEl.value.trim().toLowerCase();
  let list = items.filter((i) => (prefs.showArchived ? true : !i.archived));

  if (query) {
    list = list.filter(
      (i) =>
        (i.title || "").toLowerCase().includes(query) ||
        (i.domain || "").toLowerCase().includes(query) ||
        (i.url || "").toLowerCase().includes(query)
    );
  }

  const sorters = {
    newest: (a, b) => b.dateAdded - a.dateAdded,
    oldest: (a, b) => a.dateAdded - b.dateAdded,
    title: (a, b) => (a.title || "").localeCompare(b.title || ""),
    domain: (a, b) => (a.domain || "").localeCompare(b.domain || ""),
  };
  list.sort(sorters[prefs.sort] || sorters.newest);
  return list;
}

function render() {
  applyViewButtons();
  const list = getFilteredSorted();

  shelfEl.innerHTML = "";
  list.forEach((item) => shelfEl.appendChild(buildCard(item)));

  const unreadTotal = items.filter((i) => !i.archived).length;
  unreadCountEl.textContent = unreadTotal;
  const archivedTotal = items.length - unreadTotal;
  archivedNoteEl.textContent = archivedTotal > 0 ? ` · ${archivedTotal} archived` : "";

  emptyStateEl.hidden = items.length > 0;
  shelfEl.hidden = items.length === 0;
}

// --- Event wiring ---
searchEl.addEventListener("input", render);

sortSelectEl.addEventListener("change", async () => {
  prefs.sort = sortSelectEl.value;
  await savePrefs();
  render();
});

viewGridBtn.addEventListener("click", async () => {
  prefs.view = "grid";
  await savePrefs();
  render();
});
viewListBtn.addEventListener("click", async () => {
  prefs.view = "list";
  await savePrefs();
  render();
});

showArchivedBtn.addEventListener("click", async () => {
  prefs.showArchived = !prefs.showArchived;
  await savePrefs();
  render();
});

// Live-update if items change from another tab / the background worker.
chrome.storage.onChanged.addListener((changes, area) => {
  if (area !== "local") return;
  if (changes[STORAGE_KEY]) {
    items = changes[STORAGE_KEY].newValue || [];
    render();
  }
});

(async function init() {
  await loadAll();
  render();
})();