import { useCallback, useEffect, useLayoutEffect, useRef, useState } from "react";
import { useTranslation } from "react-i18next";
import { useMutation, useQuery, useQueryClient } from "@tanstack/react-query";
import {
  ArrowDown,
  ArrowUp,
  Ban,
  Check,
  Eye,
  EyeOff,
  History,
  LayoutGrid,
  Pencil,
  Plus,
  RefreshCw,
  Table,
  UserMinus,
  X,
} from "lucide-react";
import { api, type ManagedChannel, type Tag } from "../lib/api";
import { notifyYouTubeActionError } from "../lib/youtubeErrors";
import { accountKey, LS } from "../lib/storage";
import { useDismiss } from "../lib/useDismiss";
import { useScrollFade } from "../lib/useScrollFade";
import { formatEta, formatTotalHours, relativeTime } from "../lib/format";
import { subsColumn } from "./channelColumns";
import { notify } from "../lib/notifications";
import Tooltip from "./Tooltip";
import DataTable, { type Column } from "./DataTable";
import ChannelLayoutGrid from "./ChannelLayoutGrid";
import Overlay from "./Overlay";
import ViewSwitcher, { type ViewOption } from "./ViewSwitcher";
import ColumnSortControl from "./ColumnSortControl";
import Pager from "./Pager";
import { CHANNEL_LAYOUTS, type ChannelLayout } from "../lib/channelLayout";
import { sortRows } from "../lib/columnSort";
import { useCardPager } from "../lib/useCardPager";
import { PageToolbar } from "./PageShell";
import ChannelLink from "./ChannelLink";
import AboutCell from "./AboutCell";
import ChannelDiscovery from "./ChannelDiscovery";
import TagManager from "./TagManager";
import { useConfirm } from "./ConfirmProvider";
import { useChannelLayout, useChannels, useChannelsActions } from "./ChannelsProvider";
import { useNavigationActions } from "./NavigationProvider";
import { useFeedFilters, useFeedFiltersActions } from "./FeedFiltersProvider";
import { useWizard } from "./WizardProvider";
import { useMe } from "../lib/useMe";

export type ChannelsView = "subscribed" | "discovery" | "blocked";

export type ChannelStatusFilter = "all" | "needs_full" | "fully_synced" | "hidden";

const STATUS_FILTERS: { id: ChannelStatusFilter; labelKey: string }[] = [
  { id: "all", labelKey: "channels.filters.all" },
  { id: "needs_full", labelKey: "channels.filters.needsFull" },
  { id: "fully_synced", labelKey: "channels.filters.fullySynced" },
  { id: "hidden", labelKey: "channels.filters.hidden" },
];

const LAYOUT_ICON: Record<ChannelLayout, typeof Table> = {
  table: Table,
  cards: LayoutGrid,
};

export default function Channels() {
  const me = useMe();
  const canWrite = me.can_write;
  const isAdmin = me.role === "admin";
  // "Connect YouTube" onboarding lives in WizardProvider (a notify action / a mutation-error CTA).
  const { openWizard: onOpenWizard } = useWizard();
  // The manager's name filter, status chip, active tab, reset token, and focus-channel intent live
  // in ChannelsProvider (shared with the header search box + the cross-module "focus this channel"
  // callers); this page is their primary editor.
  const {
    search,
    statusFilter,
    view,
    sort,
    filtersResetToken,
    focusName: focusChannelName,
    focusToken: focusChannelToken,
  } = useChannels();
  const layout = useChannelLayout();
  const {
    setSearch,
    setStatusFilter,
    setView,
    setLayout,
    setSort,
    focusChannel: onFocusChannel,
  } = useChannelsActions();
  const { openChannel: onViewChannel, setPage } = useNavigationActions();
  const feedFilters = useFeedFilters();
  const { setFilters: setFeedFilters } = useFeedFiltersActions();
  const { t } = useTranslation();
  const qc = useQueryClient();
  const confirm = useConfirm();

  // Clicking a tag chip filters the feed by that tag and jumps there. Internalised (was an App
  // callback) now that Channels reads the feed filters + navigation straight from their providers.
  const onFilterByTag = (tagId: number, name: string) => {
    setFeedFilters({ ...feedFilters, tags: [tagId], channelIds: [] });
    setPage("feed");
    notify({ level: "info", message: t("channels.notify.filteredByTag", { name }) });
  };

  const channelsQuery = useQuery({ queryKey: ["channels"], queryFn: api.channels });
  const tagsQuery = useQuery({ queryKey: ["tags"], queryFn: api.tags });
  const statusQuery = useQuery({ queryKey: ["my-status"], queryFn: api.myStatus });
  const blockedQuery = useQuery({ queryKey: ["blocked-channels"], queryFn: api.blockedChannels });
  const [tagManagerOpen, setTagManagerOpen] = useState(false);
  const unblock = useMutation({
    mutationFn: (id: string) => api.unblockChannel(id),
    onSuccess: () => {
      qc.invalidateQueries({ queryKey: ["blocked-channels"] });
      qc.invalidateQueries({ queryKey: ["feed"] });
    },
  });

  const invalidate = () => {
    qc.invalidateQueries({ queryKey: ["channels"] });
    qc.invalidateQueries({ queryKey: ["tags"] });
    qc.invalidateQueries({ queryKey: ["my-status"] });
    // FB2: syncing subscriptions can change the feed immediately — newly-followed channels may
    // already have videos in the shared catalog, so refresh the feed too (not just the manager).
    qc.invalidateQueries({ queryKey: ["feed"] });
    qc.invalidateQueries({ queryKey: ["feed-count"] });
  };

  const userTags = (tagsQuery.data ?? []).filter((t) => !t.system);

  const patch = useMutation({
    mutationFn: (v: {
      id: string;
      body: { priority?: number; hidden?: boolean; deep_requested?: boolean };
    }) => api.updateChannel(v.id, v.body),
    // Requesting full history may have just pulled in a channel's recent uploads, so
    // refresh the per-user status and feed too — not only the channel list.
    onSuccess: () => {
      qc.invalidateQueries({ queryKey: ["channels"] });
      qc.invalidateQueries({ queryKey: ["my-status"] });
      qc.invalidateQueries({ queryKey: ["feed"] });
      qc.invalidateQueries({ queryKey: ["feed-count"] });
    },
  });
  // Priority is updated optimistically in place and NOT re-sorted/refetched, so the list
  // doesn't jump (the server list is priority-sorted; refetching would reorder rows and
  // lose your scroll position). The new order takes effect next time the page loads.
  const bumpPriority = (id: string, current: number, delta: number) => {
    const next = current + delta;
    qc.setQueryData<ManagedChannel[]>(["channels"], (old) =>
      (old ?? []).map((ch) => (ch.id === id ? { ...ch, priority: next } : ch)),
    );
    api
      .updateChannel(id, { priority: next })
      .catch(() => qc.invalidateQueries({ queryKey: ["channels"] }));
  };

  // Tagging is updated optimistically in place (no refetch of the whole channel list, which
  // made the toggle feel ~2s slow); only revert by refetching if the server call fails.
  const toggleTag = (id: string, tagId: number, hasTag: boolean) => {
    qc.setQueryData<ManagedChannel[]>(["channels"], (old) =>
      (old ?? []).map((ch) =>
        ch.id === id
          ? {
              ...ch,
              tag_ids: hasTag ? ch.tag_ids.filter((x) => x !== tagId) : [...ch.tag_ids, tagId],
            }
          : ch,
      ),
    );
    const call = hasTag ? api.detachChannelTag(id, tagId) : api.attachChannelTag(id, tagId);
    call.catch(() => qc.invalidateQueries({ queryKey: ["channels"] }));
  };
  const syncSubs = useMutation({
    mutationFn: () => api.syncSubscriptions(),
    onSuccess: (r: { subscriptions?: number }) => {
      invalidate();
      notify({
        level: "success",
        message: t("channels.notify.synced", { count: r.subscriptions ?? 0 }),
      });
    },
    onError: (e) => notifyYouTubeActionError(e, t("channels.notify.syncFailed"), onOpenWizard),
  });
  const unsubscribe = useMutation({
    mutationFn: (v: { id: string; name: string }) => api.unsubscribeChannel(v.id),
    onSuccess: (_d, v) => {
      qc.invalidateQueries({ queryKey: ["channels"] });
      qc.invalidateQueries({ queryKey: ["my-status"] });
      notify({ level: "success", message: t("channels.notify.unsubscribed", { name: v.name }) });
    },
    onError: (e) =>
      notifyYouTubeActionError(e, t("channels.notify.unsubscribeFailed"), onOpenWizard),
  });
  const resetBackfill = useMutation({
    mutationFn: (v: { id: string; name: string }) => api.resetChannelBackfill(v.id),
    onSuccess: (_d, v) => {
      qc.invalidateQueries({ queryKey: ["channels"] });
      qc.invalidateQueries({ queryKey: ["my-status"] });
      notify({ level: "success", message: t("channels.notify.resetDone", { name: v.name }) });
    },
    onError: (e) => notifyYouTubeActionError(e, t("channels.notify.resetFailed"), onOpenWizard),
  });
  const deepAll = useMutation({
    mutationFn: () => api.deepAll(true),
    onSuccess: (r: { updated?: number }) => {
      qc.invalidateQueries({ queryKey: ["channels"] });
      qc.invalidateQueries({ queryKey: ["my-status"] });
      notify({
        level: "success",
        message: t("channels.notify.fullHistoryRequested", { count: r.updated ?? 0 }),
      });
    },
    onError: (e) =>
      notifyYouTubeActionError(e, t("channels.notify.fullHistoryFailed"), onOpenWizard),
  });

  // Channel-name search (from the shared top SearchBar, via props) + tag-chip filtering, applied
  // client-side over the status-filtered list.
  const [tagFilter, setTagFilter] = useState<number[]>([]);
  // A focus-channel intent (header "without full history" / tag manager) seeds the search box.
  useEffect(() => {
    if (focusChannelName) setSearch(focusChannelName);
    // eslint-disable-next-line react-hooks/exhaustive-deps
  }, [focusChannelToken]);
  // The header's reset intent clears the search + tag chips (skip the initial mount).
  const resetRef = useRef(filtersResetToken);
  useEffect(() => {
    if (filtersResetToken === resetRef.current) return;
    resetRef.current = filtersResetToken;
    setSearch("");
    setTagFilter([]);
  }, [filtersResetToken]);

  // The Sync-status filter stays a top-level chip set (not a column filter) because the
  // header's "go to full history" deep-link drives it; search/tag filtering + sort + pagination
  // run over whatever the status chip leaves.
  const channels = (channelsQuery.data ?? []).filter((c) =>
    statusFilter === "needs_full"
      ? !c.backfill_done
      : statusFilter === "fully_synced"
        ? c.backfill_done
        : statusFilter === "hidden"
          ? c.hidden
          : true,
  );
  const q = search.trim().toLowerCase();
  const visibleChannels = channels.filter((c) => {
    if (q && !`${c.title ?? ""} ${c.handle ?? ""}`.toLowerCase().includes(q)) return false;
    if (tagFilter.length && !tagFilter.some((id) => c.tag_ids.includes(id))) return false;
    return true;
  });
  const s = statusQuery.data;

  const onView = (c: ManagedChannel) =>
    onViewChannel(c.id, c.title ?? t("channels.row.thisChannel"));
  const onUnsub = async (c: ManagedChannel) => {
    const ok = await confirm({
      title: t("channels.row.unsubscribeOnYoutube"),
      message: t("channels.confirmUnsubscribe", { name: c.title ?? c.id }),
      confirmLabel: t("channels.row.unsubscribeOnYoutube"),
      danger: true,
    });
    if (ok) unsubscribe.mutate({ id: c.id, name: c.title ?? c.id });
  };
  const onReset = async (c: ManagedChannel) => {
    const ok = await confirm({
      title: t("channels.row.backfillThis"),
      message: t("channels.confirmReset", { name: c.title ?? c.id }),
      confirmLabel: t("channels.row.backfillThis"),
    });
    if (ok) resetBackfill.mutate({ id: c.id, name: c.title ?? c.id });
  };

  // Distinct priority levels present in the catalog → the priority column's filter options.
  const prioOptions = [...new Set((channelsQuery.data ?? []).map((c) => c.priority))]
    .sort((a, b) => b - a)
    .map((p) => ({ value: String(p), label: String(p) }));

  const columns: Column<ManagedChannel>[] = [
    {
      key: "priority",
      header: t("channels.cols.priority"),
      align: "center",
      width: "56px",
      sortable: true,
      hideInCard: true,
      sortValue: (c) => c.priority,
      filter: { kind: "select", options: prioOptions, test: (c, v) => String(c.priority) === v },
      render: (c) => <PriorityCell c={c} onPriority={(d) => bumpPriority(c.id, c.priority, d)} />,
    },
    {
      key: "actions",
      header: t("channels.cols.actions"),
      align: "left",
      nowrap: true,
      width: "104px",
      cardLabel: false,
      render: (c) => (
        <ActionsCell
          c={c}
          isAdmin={isAdmin}
          canWrite={canWrite}
          onHide={() => patch.mutate({ id: c.id, body: { hidden: !c.hidden } })}
          onDeep={() => patch.mutate({ id: c.id, body: { deep_requested: !c.deep_requested } })}
          onReset={() => onReset(c)}
          onUnsubscribe={() => onUnsub(c)}
        />
      ),
    },
    {
      key: "channel",
      header: t("channels.cols.channel"),
      sortable: true,
      sortValue: (c) => (c.title ?? c.id).toLowerCase(),
      filter: { kind: "text", get: (c) => `${c.title ?? ""} ${c.handle ?? ""}` },
      cardPrimary: true,
      // Cap the width so a long-titled channel can't stretch the column (table-layout:auto ignores a
      // cell max-width, but a max-w element INSIDE the cell bounds it — same trick AboutCell uses).
      // Without this a single long name blows the column ~289→429px and overflows the centered table.
      render: (c) => (
        <div className="max-w-[18rem]">
          <ChannelLink
            id={c.id}
            title={c.title}
            handle={c.handle}
            thumbnailUrl={c.thumbnail_url}
            onView={() => onView(c)}
          />
        </div>
      ),
    },
    {
      key: "about",
      header: t("channels.cols.about"),
      hideInCard: true,
      render: (c) => <AboutCell text={c.description} channelId={c.id} />,
    },
    {
      key: "stored",
      header: t("channels.cols.stored"),
      align: "right",
      nowrap: true,
      sortable: true,
      sortValue: (c) => c.stored_videos,
      render: (c) => (
        <span className="text-muted tabular-nums">{c.stored_videos.toLocaleString()}</span>
      ),
    },
    subsColumn<ManagedChannel>(t),
    {
      key: "lastUpload",
      header: t("channels.cols.lastUpload"),
      nowrap: true,
      sortable: true,
      sortValue: (c) => (c.last_video_at ? new Date(c.last_video_at).getTime() : 0),
      render: (c) => <span className="text-muted">{relativeTime(c.last_video_at) || "—"}</span>,
    },
    {
      key: "length",
      header: t("channels.cols.length"),
      align: "right",
      nowrap: true,
      sortable: true,
      sortValue: (c) => c.total_duration_seconds,
      render: (c) => (
        <span className="text-muted tabular-nums">
          {formatTotalHours(c.total_duration_seconds)}
        </span>
      ),
    },
    {
      key: "types",
      header: t("channels.cols.types"),
      nowrap: true,
      render: (c) => (
        <Tooltip hint={t("channels.cols.typesHint")}>
          <span className="text-muted tabular-nums cursor-help">
            {c.count_normal} / {c.count_short} / {c.count_live}
          </span>
        </Tooltip>
      ),
    },
    {
      key: "sync",
      header: t("channels.cols.sync"),
      nowrap: true,
      cardLabel: false,
      filter: {
        kind: "select",
        options: [
          { value: "fully", label: t("channels.filters.fullySynced") },
          { value: "needsFull", label: t("channels.filters.needsFull") },
        ],
        test: (c, v) =>
          v === "fully"
            ? c.recent_synced && c.backfill_done
            : v === "needsFull"
              ? !c.backfill_done
              : true,
      },
      render: (c) => <SyncCell c={c} />,
    },
    {
      key: "tags",
      header: t("channels.cols.tags"),
      cardLabel: false,
      filter: {
        kind: "multi",
        options: userTags.map((tg) => ({ value: String(tg.id), label: tg.name })),
        test: (c, values) => values.some((v) => c.tag_ids.includes(Number(v))),
      },
      render: (c) => (
        <TagsCell
          c={c}
          userTags={userTags}
          onToggleTag={(tagId) => toggleTag(c.id, tagId, c.tag_ids.includes(tagId))}
          onTagClick={onFilterByTag}
        />
      ),
    },
  ];

  // Status chips sit in the table's controls row (next to paging) — compact and close to
  // where they act.
  const statusChips = (
    <div className="flex flex-wrap items-center gap-1.5">
      {STATUS_FILTERS.map((f) => (
        <button
          key={f.id}
          onClick={() => setStatusFilter(f.id)}
          className={`text-xs px-2.5 py-1 rounded-full border transition ${
            statusFilter === f.id
              ? "bg-accent text-accent-fg border-accent"
              : "bg-card border-border text-muted hover:border-accent"
          }`}
        >
          {t(f.labelKey)}
        </button>
      ))}
    </div>
  );

  // The catalog-wide stats ride on the right of the tab row (subscribed only), leaving room for
  // future tabs on the left.
  const statsBlock = (
    <div className="flex flex-wrap items-center justify-end gap-x-5 gap-y-1 text-sm text-muted">
      {s && (
        <>
          <Stat
            label={t("channels.stats.channels")}
            value={s.channels_total}
            hint={t("channels.stats.channelsHint")}
          />
          <Stat
            label={t("channels.stats.recentSynced")}
            value={`${s.channels_recent_synced}/${s.channels_total}`}
            hint={t("channels.stats.recentSyncedHint")}
          />
          <Stat
            label={t("channels.stats.fullHistory")}
            value={`${s.channels_deep_done}/${s.channels_deep_requested}`}
            hint={t("channels.stats.fullHistoryHint")}
          />
          {s.deep_pending_count > 0 && (
            <Stat
              label={t("channels.stats.left")}
              value={formatEta(s.deep_eta_seconds)}
              hint={t("channels.stats.leftHint", { count: s.deep_pending_count })}
            />
          )}
          <Stat
            label={t("channels.stats.myVideos")}
            value={s.my_videos.toLocaleString()}
            hint={t("channels.stats.myVideosHint")}
          />
          <Stat
            label={t("channels.stats.quotaLeft")}
            value={s.quota_remaining_today.toLocaleString()}
            hint={t("channels.stats.quotaLeftHint")}
          />
        </>
      )}
    </div>
  );

  // Sync + backfill — now share the tags row (right side).
  const actionButtons = (
    <div className="flex items-center gap-2 shrink-0">
      <Tooltip side="bottom" hint={t("channels.syncSubscriptionsHint")}>
        <button
          onClick={() => syncSubs.mutate()}
          disabled={syncSubs.isPending}
          className="glass-card glass-hover flex items-center gap-2 px-3 py-2 rounded-xl text-sm disabled:opacity-50 transition"
        >
          <RefreshCw className={`w-4 h-4 ${syncSubs.isPending ? "animate-spin" : ""}`} />
          {t("channels.syncSubscriptions")}
        </button>
      </Tooltip>
      <Tooltip side="bottom" hint={t("channels.backfillEverythingHint")}>
        <button
          onClick={() => deepAll.mutate()}
          disabled={deepAll.isPending}
          className="glass-card glass-hover flex items-center gap-2 px-3 py-2 rounded-xl text-sm disabled:opacity-50 transition"
        >
          <History className={`w-4 h-4 ${deepAll.isPending ? "animate-pulse" : ""}`} />
          {t("channels.backfillEverything")}
        </button>
      </Tooltip>
    </div>
  );

  // Table / cards density — shared by the subscribed + discovery tables (blocked is a chip list, no
  // layout to switch). Rides the same generic ViewSwitcher the feed uses.
  const layoutOptions: ViewOption<ChannelLayout>[] = CHANNEL_LAYOUTS.map((id) => ({
    id,
    label: t("channels.layout." + id),
    icon: LAYOUT_ICON[id],
  }));
  const layoutSwitcher = (
    <ViewSwitcher
      value={layout}
      options={layoutOptions}
      onChange={setLayout}
      label={t("channels.layoutLabel")}
      labelClassName="hidden lg:inline"
    />
  );
  const hasLayout = view === "subscribed" || view === "discovery";
  // In cards there are no column headers to sort by, so a dropdown drives the SAME shared sort state
  // the table header uses (table ↔ cards stay in sync). Table mode keeps the header clicks.
  const sortControl = (
    <ColumnSortControl
      columns={columns}
      sort={sort}
      onChange={setSort}
      label={t("channels.sort.label")}
      defaultLabel={t("channels.sort.default")}
      ascLabel={t("channels.sort.asc")}
      descLabel={t("channels.sort.desc")}
    />
  );
  // The card layout paginates like the table (a page of cards + a pager), rather than one long
  // infinite scroll. Slice the sorted rows; the Pager reports page/size changes.
  // Only computed for cards: in table mode DataTable sorts and slices internally, so doing it here
  // too would copy+sort the whole ~300-row array on every render for a result nothing reads.
  const isCards = layout === "cards";
  const sortedChannels = isCards ? sortRows(visibleChannels, columns, sort) : visibleChannels;
  const {
    paged: pagedCards,
    pagerProps,
    resetPage,
  } = useCardPager(sortedChannels, LS.channelCardSize, isCards);
  // Changing what you're looking at starts over at the first page, the way DataTable resets its own
  // page on a filter/sort change. Deliberately NOT keyed on the row count: the ["channels"] query
  // refetches on window focus and after every sync, so a catalogue that merely gained a channel would
  // otherwise yank you off page 7 for something you didn't do — a list that shrank past your page is
  // handled by the hook's clamp instead.
  useEffect(() => {
    resetPage();
  }, [statusFilter, search, tagFilter, sort, resetPage]);
  const cardPager = <Pager {...pagerProps} />;

  const tabs = (
    <div className="px-4 pt-4 max-w-[96rem] mx-auto flex items-center justify-between gap-4 flex-wrap">
      <div className="flex flex-wrap items-center gap-1.5">
        {(["subscribed", "discovery", "blocked"] as ChannelsView[]).map((v) => (
          <button
            key={v}
            onClick={() => setView(v)}
            className={`text-sm px-3 py-1.5 rounded-full border transition ${
              view === v
                ? "bg-accent text-accent-fg border-accent"
                : "bg-card border-border text-muted hover:border-accent"
            }`}
          >
            {t(`channels.tabs.${v}`)}
          </button>
        ))}
      </div>
      <div className="flex items-center gap-3">
        {view === "subscribed" && statsBlock}
        {view === "subscribed" && layout === "cards" && sortControl}
        {hasLayout && layoutSwitcher}
      </div>
    </div>
  );

  return (
    <>
      {/* The tab bar is always fixed chrome (it portals into the shell's fixed band, so it never
        scrolls and doesn't jump between tabs). On Subscriptions the stats/description/tags ride
        with it, and the status-chip + pager row lands just below (DataTable's controlsInBand). */}
      <PageToolbar>
        {tabs}
        {view === "subscribed" && (
          <div className="px-4 pt-2 pb-2 max-w-[96rem] mx-auto">
            {/* Your tags (left) share one row with the two catalog-wide actions (right); the channel-name
          search lives in the shared top SearchBar, tag create/delete in the manager. */}
            <div className="flex items-center justify-between gap-4 flex-wrap">
              <div className="flex flex-wrap items-center gap-1.5">
                <Tooltip hint={t("channels.tags.yourTagsHint")}>
                  <span className="text-xs uppercase tracking-wide text-muted mr-1 cursor-help underline decoration-dotted decoration-muted/40 underline-offset-4">
                    {t("channels.tags.yourTags")}
                  </span>
                </Tooltip>
                {userTags.map((tg) => {
                  const active = tagFilter.includes(tg.id);
                  return (
                    <button
                      key={tg.id}
                      onClick={() =>
                        setTagFilter((f) => (active ? f.filter((x) => x !== tg.id) : [...f, tg.id]))
                      }
                      aria-pressed={active}
                      className={`text-xs px-2 py-1 rounded-full border transition ${
                        active
                          ? "bg-accent text-accent-fg border-accent"
                          : "bg-card border-border text-muted hover:text-fg hover:border-accent"
                      }`}
                    >
                      {tg.name}
                    </button>
                  );
                })}
                {tagFilter.length > 0 && (
                  <button
                    onClick={() => setTagFilter([])}
                    className="text-xs px-2 py-1 text-muted hover:text-accent transition"
                  >
                    {t("datatable.clear")}
                  </button>
                )}
                <button
                  onClick={() => setTagManagerOpen(true)}
                  className="inline-flex items-center gap-1 text-xs px-2 py-1 rounded-full border border-dashed border-border text-muted hover:text-accent hover:border-accent transition"
                >
                  <Pencil className="w-3 h-3" />
                  {t("channels.tags.manage")}
                </button>
              </div>
              {actionButtons}
            </div>
          </div>
        )}
        {/* In table mode the status chips + pager ride in DataTable's own in-band controls row. The card
        layout has no such row, so surface the same status chips (left) and its pager (right) here. */}
        {view === "subscribed" && layout === "cards" && (
          <div className="px-4 pb-2 max-w-[96rem] mx-auto flex items-center justify-between gap-3 flex-wrap">
            {statusChips}
            {cardPager}
          </div>
        )}
      </PageToolbar>
      {tagManagerOpen && (
        <TagManager onClose={() => setTagManagerOpen(false)} onFocusChannel={onFocusChannel} />
      )}

      {view === "discovery" ? (
        <ChannelDiscovery
          canWrite={canWrite}
          search={search}
          onOpenWizard={onOpenWizard}
          onViewChannel={onViewChannel}
        />
      ) : view === "blocked" ? (
        /* Blocked channels — videos from these are hidden everywhere and dropped from live search. */
        <div className="px-4 pb-4 pt-3 max-w-[96rem] mx-auto">
          {(blockedQuery.data?.length ?? 0) === 0 ? (
            <p className="text-sm text-muted py-8">{t("channels.blocked.empty")}</p>
          ) : (
            <>
              <div className="flex items-center gap-2 mb-3">
                <Ban className="w-4 h-4 text-muted" />
                <span className="text-xs uppercase tracking-wide text-muted">
                  {t("channels.blocked.title")}
                </span>
              </div>
              <div className="flex flex-wrap gap-1.5">
                {blockedQuery.data!.map((c) => (
                  <span
                    key={c.id}
                    className="inline-flex items-center gap-1.5 text-xs pl-2.5 pr-1 py-1 rounded-full bg-card border border-border"
                  >
                    {c.title ?? c.id}
                    <button
                      onClick={() => unblock.mutate(c.id)}
                      title={t("channel.unblock")}
                      aria-label={t("channel.unblock")}
                      className="rounded-full p-0.5 text-muted hover:text-danger transition"
                    >
                      <X className="w-3 h-3" />
                    </button>
                  </span>
                ))}
              </div>
              <p className="text-[11px] text-muted mt-2">{t("channels.blocked.hint")}</p>
            </>
          )}
        </div>
      ) : (
        /* No top padding: the sticky header sits flush at the scroller top so it doesn't shift when
         `position: sticky` engages on the first scroll (the band's controls row above gives the
         visual gap). */
        <div className="px-4 pb-4 max-w-[96rem] mx-auto">
          {/* Channel table — only the rows scroll; the header row is sticky, and the controls row
            (status chips + pager) rides in the fixed band right above it (controlsInBand). The
            card layout swaps the table for a virtualized grid over the same rows (its pager and
            status chips ride in the fixed band above instead). */}
          {channelsQuery.isLoading ? (
            <div className="text-muted py-8">{t("channels.loading")}</div>
          ) : layout === "table" ? (
            <DataTable
              rows={visibleChannels}
              columns={columns}
              rowKey={(c) => c.id}
              persistKey={accountKey(LS.channelsTable) ?? undefined}
              controlsPosition="both"
              controlsLeading={statusChips}
              controlsInBand
              controlsBandClassName="px-4 max-w-[96rem] mx-auto"
              sort={sort}
              onSortChange={setSort}
              rowClassName={(c) => (c.hidden ? "opacity-60" : "")}
              emptyText={t("channels.empty")}
            />
          ) : (
            <ChannelLayoutGrid
              rows={pagedCards}
              columns={columns}
              rowKey={(c) => c.id}
              leadKey="priority"
              aboutKey="about"
              actionsKey="actions"
              rowClassName={(c) => (c.hidden ? "opacity-60" : "")}
              emptyText={t("channels.empty")}
            />
          )}
        </div>
      )}
    </>
  );
}

function Stat({ label, value, hint }: { label: string; value: string | number; hint?: string }) {
  return (
    <Tooltip hint={hint ?? ""}>
      <span className={hint ? "cursor-help" : ""}>
        <span className="text-fg font-semibold">{value}</span> {label}
      </span>
    </Tooltip>
  );
}

function SyncBadge({ ok, label, hint }: { ok: boolean; label: string; hint?: string }) {
  return (
    <Tooltip hint={hint ?? ""}>
      <span
        className={`inline-flex items-center gap-1 text-[10px] px-1.5 py-0.5 rounded-full border ${
          ok ? "border-accent/40 text-accent" : "border-border text-muted"
        }`}
      >
        {ok && <Check className="w-3 h-3" />}
        {label}
      </span>
    </Tooltip>
  );
}

function PriorityCell({
  c,
  onPriority,
}: {
  c: ManagedChannel;
  onPriority: (delta: number) => void;
}) {
  const { t } = useTranslation();
  return (
    <Tooltip hint={t("channels.row.priorityHint")}>
      <div className="inline-flex flex-col items-center cursor-help">
        <button
          onClick={() => onPriority(1)}
          className="text-muted hover:text-accent"
          aria-label={t("channels.row.raisePriority")}
        >
          <ArrowUp className="w-3.5 h-3.5" />
        </button>
        <span className="text-xs text-muted tabular-nums">{c.priority}</span>
        <button
          onClick={() => onPriority(-1)}
          className="text-muted hover:text-accent"
          aria-label={t("channels.row.lowerPriority")}
        >
          <ArrowDown className="w-3.5 h-3.5" />
        </button>
      </div>
    </Tooltip>
  );
}

// Status only — the backfill *action* lives in the Actions column. When both recent and
// full history are in, collapse to a single "fully synced" chip; otherwise show what's
// present plus the missing/queued state.
function SyncCell({ c }: { c: ManagedChannel }) {
  const { t } = useTranslation();
  if (c.recent_synced && c.backfill_done) {
    return (
      <SyncBadge
        ok
        label={t("channels.row.fullySynced")}
        hint={t("channels.row.fullySyncedHint")}
      />
    );
  }
  return (
    <div className="flex flex-wrap items-center gap-1">
      <SyncBadge
        ok={c.recent_synced}
        label={t("channels.row.recent")}
        hint={
          c.recent_synced
            ? t("channels.row.recentSyncedHint")
            : t("channels.row.recentNotSyncedHint")
        }
      />
      {c.backfill_done ? (
        <SyncBadge ok label={t("channels.row.full")} hint={t("channels.row.fullHint")} />
      ) : c.deep_requested ? (
        <SyncBadge
          ok={false}
          label={t("channels.row.fullHistoryQueued")}
          hint={t("channels.row.queuedRequestedHint")}
        />
      ) : c.deep_in_queue ? (
        <SyncBadge
          ok={false}
          label={t("channels.row.fullHistoryComing")}
          hint={t("channels.row.queuedByOtherHint")}
        />
      ) : (
        <SyncBadge
          ok={false}
          label={t("channels.row.full")}
          hint={t("channels.row.fullNotFetchedHint")}
        />
      )}
    </div>
  );
}

function TagsCell({
  c,
  userTags,
  onToggleTag,
  onTagClick,
}: {
  c: ManagedChannel;
  userTags: Tag[];
  onToggleTag: (tagId: number) => void;
  onTagClick: (tagId: number, name: string) => void;
}) {
  const { t } = useTranslation();
  const [open, setOpen] = useState(false);
  // Anchor for the portalled menu. It renders through <Overlay> (i.e. at <body>) rather than
  // `absolute` inside the cell, because in the CARD layout every VirtualGrid row carries a
  // `transform` — which makes it a stacking context and traps a z-indexed child, so the menu drew
  // UNDER the next card. Same hazard, same blessed fix as the players in E3.
  const [coords, setCoords] = useState<{ left: number; top?: number; bottom?: number } | null>(
    null,
  );
  const fade = useScrollFade();
  const ref = useRef<HTMLDivElement | null>(null);
  const popRef = useRef<HTMLDivElement | null>(null);
  const btnRef = useRef<HTMLButtonElement | null>(null);
  // The menu is no longer a DOM descendant of `ref`, so dismiss has to watch both.
  useDismiss(open, () => setOpen(false), [ref, popRef]);
  // Keep the scroll-fade hook's callback ref working alongside our own.
  const setPopRef = useCallback(
    (node: HTMLDivElement | null) => {
      popRef.current = node;
      fade.ref(node);
    },
    [fade.ref],
  );

  // ONE placement rule, so the position the menu opens at and the one it keeps while scrolling can't
  // drift apart. `flip` keeps it anchored above the trigger once it has been flipped; the horizontal
  // clamp uses the MEASURED width (`w-44` is rem — it grows with the text-size slider, so a px guess
  // reads short at 1.3). Before first paint the menu isn't measurable yet; the layout effect below
  // re-runs this once it is.
  const coordsFrom = useCallback((r: DOMRect, flip: boolean) => {
    const w = popRef.current?.offsetWidth ?? 0;
    const left =
      w && r.left + w > window.innerWidth - 8 ? Math.max(8, window.innerWidth - 8 - w) : r.left;
    return flip ? { left, bottom: window.innerHeight - r.top + 4 } : { left, top: r.bottom + 4 };
  }, []);

  const place = useCallback(() => {
    const r = btnRef.current?.getBoundingClientRect();
    if (!r) return false;
    setCoords(coordsFrom(r, false));
    return true;
  }, [coordsFrom]);
  const toggle = () => {
    if (open) setOpen(false);
    else if (place()) setOpen(true);
  };

  // Correct the placement against the MEASURED box: flip above when it would run off the bottom (and
  // there is room above), and apply the width clamp now that the menu can actually be measured.
  useLayoutEffect(() => {
    const pop = popRef.current;
    const r = btnRef.current?.getBoundingClientRect();
    if (!open || !pop || !coords || !r) return;
    const h = pop.offsetHeight; // the width is read inside coordsFrom, off the same node
    const fitsBelow = r.bottom + 4 + h <= window.innerHeight - 8;
    const fitsAbove = r.top - 4 - h >= 8;
    // Decide BOTH ways, every time. Prefer the side it is already on (no flapping while scrolling),
    // but leave it as soon as that side stops fitting and the other one does — a one-way flip would
    // keep an above-anchored menu above a row scrolling toward the top and push it off the screen.
    const above = coords.bottom !== undefined;
    const flip = above ? fitsAbove || !fitsBelow : !fitsBelow && fitsAbove;
    const next = coordsFrom(r, flip);
    if (next.left !== coords.left || next.top !== coords.top || next.bottom !== coords.bottom) {
      setCoords(next);
    }
  }, [open, coords, coordsFrom]);

  // A fixed menu doesn't travel with its row, so FOLLOW the trigger on scroll rather than closing:
  // in the table the menu used to scroll with the row, and closing on every wheel tick would make
  // attaching several tags a reopen-per-tag chore. Closes only once the trigger leaves the SCROLLER
  // (not the window — the page scroller starts below ~230px of fixed chrome, so a row hidden behind
  // the toolbar is still "on screen" by window coords and the menu would float over the chrome).
  // Scrolling INSIDE the menu must not move it.
  useEffect(() => {
    if (!open) return;
    let raf = 0;
    const reposition = () => {
      raf = 0;
      const r = btnRef.current?.getBoundingClientRect();
      const scroller = document.querySelector("main")?.getBoundingClientRect();
      const topEdge = scroller ? scroller.top : 0;
      const bottomEdge = scroller ? scroller.bottom : window.innerHeight;
      if (!r || r.bottom < topEdge || r.top > bottomEdge) {
        setOpen(false);
        return;
      }
      // Keep whichever side it is anchored to, so the layout effect has nothing left to correct —
      // resetting to "below" every frame would make it flip back and forth, two renders per frame.
      setCoords((cur) => (cur ? coordsFrom(r, cur.bottom !== undefined) : cur));
    };
    const onScroll = (e: Event) => {
      if (popRef.current && e.target instanceof Node && popRef.current.contains(e.target)) return;
      if (!raf) raf = requestAnimationFrame(reposition); // coalesce a scroll burst into one move
    };
    const onResize = () => setOpen(false);
    window.addEventListener("scroll", onScroll, true);
    window.addEventListener("resize", onResize);
    return () => {
      if (raf) cancelAnimationFrame(raf);
      window.removeEventListener("scroll", onScroll, true);
      window.removeEventListener("resize", onResize);
    };
  }, [open, coordsFrom]);
  if (userTags.length === 0) return null;
  // Show only the tags actually attached to this channel; the “+” opens a per-channel
  // picker to attach/detach (kept the convenient "kirakás" without listing every tag
  // on every row). Tag create/delete still lives in the top "YOUR TAGS" row.
  const attached = userTags.filter((tg) => c.tag_ids.includes(tg.id));
  return (
    <div ref={ref} className="relative flex flex-wrap items-center gap-1 min-w-[160px]">
      {attached.map((tg) => (
        <button
          key={tg.id}
          onClick={() => onTagClick(tg.id, tg.name)}
          title={t("channels.row.filterFeedByTag", { name: tg.name })}
          className="text-[10px] px-1.5 py-0.5 rounded-full bg-accent text-accent-fg border border-accent hover:opacity-80 transition"
        >
          {tg.name}
        </button>
      ))}
      <button
        ref={btnRef}
        onClick={toggle}
        title={t("channels.row.editTags")}
        aria-label={t("channels.row.editTags")}
        className="w-5 h-5 inline-flex items-center justify-center rounded-full border border-dashed border-border text-muted hover:text-accent hover:border-accent transition"
      >
        <Plus className="w-3 h-3" />
      </button>
      {open && coords && (
        <Overlay>
          <div
            ref={setPopRef}
            style={{
              ...fade.style,
              position: "fixed",
              left: coords.left,
              top: coords.top,
              bottom: coords.bottom,
            }}
            className="glass-menu z-popover w-44 max-h-[264px] overflow-y-auto no-scrollbar rounded-xl p-1.5 animate-[popIn_0.16s_ease]"
          >
            {userTags.map((tg) => {
              const on = c.tag_ids.includes(tg.id);
              return (
                <button
                  key={tg.id}
                  onClick={() => onToggleTag(tg.id)}
                  className={`w-full flex items-center gap-2 text-left text-xs px-2 py-1.5 rounded-md transition ${
                    on ? "text-fg" : "text-muted hover:bg-card"
                  }`}
                >
                  <span
                    className={`w-3.5 h-3.5 rounded border flex items-center justify-center shrink-0 ${
                      on ? "bg-accent border-accent text-accent-fg" : "border-border"
                    }`}
                  >
                    {on && <Check className="w-2.5 h-2.5" />}
                  </span>
                  {tg.name}
                </button>
              );
            })}
          </div>
        </Overlay>
      )}
    </div>
  );
}

function ActionsCell({
  c,
  isAdmin,
  canWrite,
  onHide,
  onDeep,
  onReset,
  onUnsubscribe,
}: {
  c: ManagedChannel;
  isAdmin: boolean;
  canWrite: boolean;
  onHide: () => void;
  onDeep: () => void;
  onReset: () => void;
  onUnsubscribe: () => void;
}) {
  const { t } = useTranslation();
  // Admins get a "reset" trigger that re-fetches the channel from scratch regardless of
  // state — always actionable. Regular users get the per-user "request full history" opt-in,
  // which only applies until the back-catalog is in (or already coming for everyone).
  const done = c.backfill_done;
  const requested = !done && c.deep_requested;
  const optInActionable = !done && !c.deep_in_queue;
  const backfillHint = isAdmin
    ? t("channels.row.resetHint")
    : c.deep_in_queue
      ? t("channels.row.queuedByOtherHint")
      : requested
        ? t("channels.row.queuedRequestedHint")
        : done
          ? t("channels.row.fullHint")
          : t("channels.row.backfillThisHint");
  const enabled = isAdmin || optInActionable;
  return (
    <div className="inline-flex items-center gap-2">
      <Tooltip hint={backfillHint}>
        <button
          onClick={!enabled ? undefined : isAdmin ? onReset : onDeep}
          disabled={!enabled}
          className={`shrink-0 transition ${
            requested
              ? "text-accent"
              : enabled
                ? "text-muted hover:text-fg"
                : "text-muted/40 cursor-default"
          }`}
          aria-label={isAdmin ? t("channels.row.resetBackfill") : t("channels.row.backfillThis")}
        >
          <History className="w-4 h-4" />
        </button>
      </Tooltip>
      <Tooltip hint={c.hidden ? t("channels.row.hiddenHint") : t("channels.row.hideHint")}>
        <button
          onClick={onHide}
          className="text-muted hover:text-fg shrink-0"
          aria-label={c.hidden ? t("channels.row.unhide") : t("channels.row.hideFromFeed")}
        >
          {c.hidden ? <EyeOff className="w-4 h-4" /> : <Eye className="w-4 h-4" />}
        </button>
      </Tooltip>
      {canWrite && (
        <Tooltip hint={t("channels.row.unsubscribeHint")}>
          <button
            onClick={onUnsubscribe}
            className="text-muted hover:text-red-400 shrink-0"
            aria-label={t("channels.row.unsubscribeOnYoutube")}
          >
            <UserMinus className="w-4 h-4" />
          </button>
        </Tooltip>
      )}
    </div>
  );
}
