import { useMutation, useQueryClient } from "@tanstack/react-query";
import { useTranslation } from "react-i18next";
import { ArrowUpDown, EyeOff, ExternalLink, History, Tags, Tv, UserMinus } from "lucide-react";
import { qk } from "../lib/queryKeys";
import { invalidateSubscription } from "../lib/subscriptionCache";
import { api, type ManagedChannel, type Tag } from "../lib/api";
import { priorityChoices } from "../lib/channelOrder";
import { compareText } from "../lib/collate";
import { channelYouTubeUrl } from "../lib/format";
import { notify } from "../lib/notifications";
import { notifyYouTubeActionError } from "../lib/youtubeErrors";
import { useMe } from "../lib/useMe";
import { useConfirm } from "./confirmContext";
import { useCopyItems } from "./copyItems";
import { type ActionMenuItem } from "./ui/ActionMenu";

// A subscribed channel's ONE action list: the manager row's "…", its right-click, long-press
// and Shift+F10, in the table and in the card layout alike. The row keeps what the reader looks at
// or tunes all the time (priority, tags, the stored count's ✓); everything that was a button on the
// row — full history, hide, unsubscribe — is here, beside open, the pin and the copies. Tags and
// priority are here TOO, as submenus (owner, 2026-09-26): tagging a run of channels, or bubbling one
// up the list, from the menu the hand is already in.

export function useChannelActions({
  onView,
  onOpenWizard,
  tags,
  tagsState = "ready",
  onToggleTag,
  onPickPriority,
}: {
  onView: (c: ManagedChannel) => void;
  onOpenWizard: () => void;
  /** The reader's own tags (no system tags) — the Tags submenu lists them A–Z. */
  tags: readonly Tag[];
  /** Whether `tags` is the answer yet: loading or failed is said as such, never as "no tags yet". */
  tagsState?: "loading" | "error" | "ready";
  onToggleTag: (c: ManagedChannel, tagId: number) => void;
  /** A priority step picked: the caller re-sorts its list and follows the row. */
  onPickPriority: (c: ManagedChannel, priority: number) => void;
}) {
  const qc = useQueryClient();
  const { t, i18n } = useTranslation();
  const lang = i18n.language;
  const confirm = useConfirm();
  const me = useMe();
  const isAdmin = me.role === "admin";
  const copy = useCopyItems();
  const nameOf = (c: ManagedChannel) => c.title ?? t("channels.row.thisChannel");

  const refresh = () => {
    qc.invalidateQueries({ queryKey: qk.channels() });
    qc.invalidateQueries({ queryKey: qk.myStatus() });
    qc.invalidateQueries({ queryKey: qk.feed() });
    qc.invalidateQueries({ queryKey: qk.feedSummary() });
  };

  const patch = useMutation({
    mutationFn: (v: { id: string; body: { hidden?: boolean; deep_requested?: boolean } }) =>
      api.updateChannel(v.id, v.body),
    meta: { failTitle: "errors.writeFailed.channelSettings" },
    onSuccess: refresh,
  });
  // Hiding moves the channel to the Hidden tab, out of sight: the toast's Undo is the way back from
  // where the reader is, so hiding needs no confirm (the same bargain as a playlist row's Remove).
  const hide = useMutation({
    mutationFn: (c: ManagedChannel) => api.updateChannel(c.id, { hidden: true }),
    meta: { failTitle: "errors.writeFailed.hideChannel" },
    onSuccess: (_d, c) => {
      refresh();
      notify({
        level: "success",
        message: t("channels.notify.hidden", { name: nameOf(c) }),
        action: {
          label: t("common.undo"),
          onClick: () => patch.mutate({ id: c.id, body: { hidden: false } }),
        },
      });
    },
  });
  const unsubscribe = useMutation({
    mutationFn: (c: ManagedChannel) => api.unsubscribeChannel(c.id),
    onSuccess: (_d, c) => {
      invalidateSubscription(qc, c.id);
      notify({ level: "success", message: t("channels.notify.unsubscribed", { name: nameOf(c) }) });
    },
    onError: (e) =>
      notifyYouTubeActionError(e, t("channels.notify.unsubscribeFailed"), onOpenWizard),
  });
  const resetBackfill = useMutation({
    mutationFn: (c: ManagedChannel) => api.resetChannelBackfill(c.id),
    onSuccess: (_d, c) => {
      qc.invalidateQueries({ queryKey: qk.channels() });
      qc.invalidateQueries({ queryKey: qk.myStatus() });
      notify({ level: "success", message: t("channels.notify.resetDone", { name: nameOf(c) }) });
    },
    onError: (e) => notifyYouTubeActionError(e, t("channels.notify.resetFailed"), onOpenWizard),
  });

  async function onUnsubscribe(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(c);
  }
  async function onReset(c: ManagedChannel) {
    const ok = await confirm({
      title: t("channels.row.resetBackfill"),
      message: t("channels.confirmReset", { name: c.title ?? c.id }),
      confirmLabel: t("channels.row.resetBackfill"),
    });
    if (ok) resetBackfill.mutate(c);
  }

  /** The full-history row. An admin re-fetches any channel from scratch (a confirm: it spends
   *  quota). A reader asks for the back-catalogue, or takes the ask back; once it is in, or someone
   *  else's ask already brings it, the row stays in place, off, and says why. */
  function backfillItem(c: ManagedChannel): ActionMenuItem {
    const icon = <History className="w-4 h-4" />;
    if (isAdmin)
      return {
        id: "backfill",
        label: t("channels.row.resetBackfill"),
        title: t("channels.row.resetHint"),
        icon,
        disabled: resetBackfill.isPending,
        onSelect: () => void onReset(c),
      };
    const requested = !c.backfill_done && c.deep_requested;
    const note = c.backfill_done
      ? t("channels.row.fullHint")
      : c.deep_in_queue && !requested
        ? t("channels.row.queuedByOtherHint")
        : undefined;
    return {
      id: "backfill",
      label: requested ? t("channels.row.cancelBackfill") : t("channels.row.backfillThis"),
      title: requested ? t("channels.row.queuedRequestedHint") : t("channels.row.backfillThisHint"),
      icon,
      disabled: !!note || patch.isPending,
      note,
      onSelect: () => patch.mutate({ id: c.id, body: { deep_requested: !requested } }),
    };
  }

  /** Tags A–Z, one check each, toggled in place (the menu stays open for the next one). With no tag
   *  yet the row stays, off, and says where tags are made. */
  function tagsItem(c: ManagedChannel): ActionMenuItem {
    const base = {
      id: "tags",
      label: t("channels.tags.label"),
      icon: <Tags className="w-4 h-4" />,
    };
    if (tags.length === 0) {
      const note =
        tagsState === "loading"
          ? t("common.loading")
          : tagsState === "error"
            ? t("common.loadError")
            : t("channels.row.noTagsYet");
      return { ...base, disabled: true, note, onSelect: () => {} };
    }
    const on = new Set(c.tag_ids);
    return {
      ...base,
      items: [...tags]
        .sort((a, b) => compareText(a.name, b.name, lang))
        .map((tg) => ({
          id: `tag-${tg.id}`,
          label: tg.name,
          check: { kind: "many" as const, checked: on.has(tg.id) },
          onSelect: () => onToggleTag(c, tg.id),
        })),
    };
  }

  /** The fixed priority steps, the current one ticked; a pick re-sorts the list (the caller). */
  function priorityItem(c: ManagedChannel): ActionMenuItem {
    return {
      id: "priority",
      label: t("channels.row.priority"),
      icon: <ArrowUpDown className="w-4 h-4" />,
      items: priorityChoices(c.priority).map((p) => ({
        id: `priority-${p}`,
        label: String(p),
        check: { kind: "one" as const, checked: p === c.priority },
        onSelect: () => {
          if (p !== c.priority) onPickPriority(c, p);
        },
      })),
    };
  }

  /** The channel's menu rows; `pin` is the caller's comfort-shelf row (its "is it pinned?" read
   *  follows the caller's own menu). */
  function items(c: ManagedChannel, { pin }: { pin: ActionMenuItem[] }): ActionMenuItem[] {
    const url = channelYouTubeUrl(c.id, c.handle);
    return [
      {
        id: "open",
        label: t("card.menu.openChannel"),
        icon: <Tv className="w-4 h-4" />,
        onSelect: () => onView(c),
      },
      ...pin,
      { ...tagsItem(c), separatorBefore: true },
      priorityItem(c),
      ...[
        {
          id: "open-youtube",
          label: t("channels.row.openOnYouTube"),
          icon: <ExternalLink className="w-4 h-4" />,
          // A new tab only opens inside the click (a popup blocker refuses one a task later).
          inGesture: true,
          onSelect: () => void window.open(url, "_blank", "noopener,noreferrer"),
        },
        ...copy(c.title, url, "name"),
      ].map((it, i) => ({ ...it, separatorBefore: i === 0 })),
      { ...backfillItem(c), separatorBefore: true },
      {
        id: "hide",
        label: t("channels.row.hideFromFeed"),
        title: t("channels.row.hideHint"),
        icon: <EyeOff className="w-4 h-4" />,
        disabled: hide.isPending,
        onSelect: () => hide.mutate(c),
      },
      ...(me.can_write
        ? [
            {
              id: "unsubscribe",
              label: t("channels.row.unsubscribeOnYoutube"),
              title: t("channels.row.unsubscribeHint"),
              icon: <UserMinus className="w-4 h-4" />,
              danger: true,
              separatorBefore: true,
              onSelect: () => void onUnsubscribe(c),
            },
          ]
        : []),
    ];
  }

  /** Unhide from the Hidden tab — the same flag, the same refresh. */
  const unhide = (id: string) => patch.mutate({ id, body: { hidden: false } });

  return { items, unhide };
}