/**
 * useStashShowcase
 * ─────────────────────────────────────────────────────────────────────────────
 * Public visibility for Stash items (the public Stash shown on a profile).
 *
 * The private Stash (kind 30001) is a single NIP-44 encrypted blob — nothing in
 * it is ever readable by others. To make a Stash item genuinely *public*, we
 * publish it as a SEPARATE, unencrypted NIP-99 classified listing (kind 30402),
 * exactly like the marketplace. This hook keeps those public events in sync with
 * the encrypted Stash and lets any profile query another user's public Stash.
 *
 * Hybrid model:
 *   • Public + NOT for sale  → showcase-only. Tagged `t: stash-showcase` with a
 *     `["showcase", "true"]` marker and `["price", "0", "SATS"]`. Shows in the
 *     profile's public Stash, but is filtered OUT of the sellable marketplace.
 *   • Public + willingToSell/Trade → full listing. Shows in the profile's public
 *     Stash (badged "For Sale") AND flows into the marketplace like any listing.
 *
 * Each public event's `d` tag is the Stash item's stable `id`, so re-publishing
 * updates in place and we can delete (NIP-09) when an item goes private/removed.
 */

import { useCallback } from 'react';
import { useQuery } from '@tanstack/react-query';
import { useNostr } from '@nostrify/react';
import { useCurrentUser } from './useCurrentUser';
import { useNostrPublish } from './useNostrPublish';
import type { StashItem } from './useStash';
import type { NostrEvent } from '@nostrify/nostrify';

const LISTING_KIND = 30402; // NIP-99 Classified Listing
const SHOWCASE_TAG = 'stash-showcase';
const WANT_TAG = 'stash-want';
const D_PREFIX = 'stash-'; // public event d-tag = `stash-<itemId>`

/** A public gear item as seen on someone's profile (their public Stash). */
export interface PublicStashItem {
  id: string;
  identifier: string; // d-tag
  pubkey: string;
  title: string;
  category: string;
  condition?: string;
  brand?: string;
  size?: string;
  description?: string;
  images: string[];
  /** true when the owner marked it for sale/trade (has a real price or trade flag) */
  forSale: boolean;
  willingToTrade: boolean;
  priceSats?: number;
  createdAt: number;
  event: NostrEvent;
}

function tag(event: NostrEvent, name: string): string | undefined {
  return event.tags.find((t) => t[0] === name)?.[1];
}

/** Parse a kind-30402 event that originated from a Stash item. */
export function parsePublicStashItem(event: NostrEvent): PublicStashItem | null {
  if (event.kind !== LISTING_KIND) return null;
  // Must be one of our showcase events.
  const isShowcase = event.tags.some((t) => t[0] === 't' && t[1] === SHOWCASE_TAG);
  if (!isShowcase) return null;

  const identifier = tag(event, 'd');
  const title = tag(event, 'title');
  if (!identifier || !title) return null;

  const showcaseOnly = tag(event, 'showcase') === 'true';
  const willingToTrade = tag(event, 'trade') === 'true';
  const priceTag = event.tags.find((t) => t[0] === 'price');
  const priceSats = priceTag ? parseInt(priceTag[1] || '0', 10) : 0;

  const images = event.tags.filter((t) => t[0] === 'image').map((t) => t[1]).filter(Boolean);
  const categoryTags = event.tags.filter((t) => t[0] === 't' && t[1] !== SHOWCASE_TAG && t[1] !== 'skateboarding');
  const category = tag(event, 'category') || categoryTags[0]?.[1] || 'other';

  return {
    id: event.id,
    identifier,
    pubkey: event.pubkey,
    title,
    category,
    condition: tag(event, 'condition'),
    brand: tag(event, 'brand'),
    size: tag(event, 'size'),
    description: event.content || undefined,
    images,
    forSale: !showcaseOnly,
    willingToTrade,
    priceSats: priceSats > 0 ? priceSats : undefined,
    createdAt: event.created_at,
    event,
  };
}

/** Build the tag set for a public showcase/listing/want event from a Stash item. */
function buildListingTags(item: StashItem): string[][] {
  const isWtb = item.itemType === 'wtb';
  const forSale = !!(item.willingToSell || item.willingToTrade);
  // A want advertises the most they'd PAY (maxPrice); a sale the least they'd TAKE.
  const priceSats = isWtb
    ? (item.maxPrice && item.maxPrice > 0 ? item.maxPrice : 0)
    : (item.minPrice && item.minPrice > 0 ? item.minPrice : 0);

  const tags: string[][] = [
    ['d', `${D_PREFIX}${item.id}`],
    ['title', item.title],
    ['t', 'skateboarding'],
    ['t', isWtb ? WANT_TAG : SHOWCASE_TAG],
    ['t', item.category],
    ['category', item.category],
    ['published_at', String(item.addedAt || Math.floor(Date.now() / 1000))],
    ['alt', isWtb
      ? `${item.title} — gear wanted by a SkateSpots skater`
      : `${item.title} — public gear from a SkateSpots stash`],
  ];

  if (item.brand) tags.push(['brand', item.brand]);
  if (item.size) tags.push(['size', item.size]);
  if (item.geohash) tags.push(['g', item.geohash]);
  for (const img of item.images || []) tags.push(['image', img]);
  // A "condition" is meaningless for something you're looking for.
  if (!isWtb && item.condition) tags.push(['condition', item.condition]);

  if (isWtb) {
    // Public WANT → a real NIP-99 `wtb` listing, so sellers find it in the
    // Marketplace (the stash Wishlist tab keeps the private copy).
    tags.push(['listing_type', 'wtb']);
    tags.push(['price', String(priceSats), 'SATS']);
    tags.push(['price_type', priceSats > 0 ? 'fixed' : item.willingToTrade ? 'trade' : 'offer']);
    tags.push(['status', 'active']);
    if (item.willingToTrade) tags.push(['trade', 'true']);
    return tags;
  }

  if (forSale) {
    // Real, sellable listing → appears in the marketplace.
    tags.push(['price', String(priceSats), 'SATS']);
    tags.push(['price_type', priceSats > 0 ? 'fixed' : (item.willingToTrade ? 'trade' : 'offer')]);
    tags.push(['listing_type', 'selling']);
    tags.push(['status', 'active']);
    if (item.willingToTrade) tags.push(['trade', 'true']);
  } else {
    // Showcase only → visible on profile, filtered out of the sellable market.
    tags.push(['price', '0', 'SATS']);
    tags.push(['showcase', 'true']);
    tags.push(['status', 'active']);
  }

  return tags;
}

/**
 * Actions to keep public events in sync with the encrypted Stash.
 * Call syncItem whenever an item is added/edited, and unpublishItem when it
 * goes private or is removed.
 */
export function useStashShowcaseSync() {
  const { user } = useCurrentUser();
  const { mutateAsync: createEvent } = useNostrPublish();

  /** Publish (or refresh) an item's public event when visibility === 'public'. */
  const syncItem = useCallback(
    async (item: StashItem) => {
      if (!user?.pubkey) return;
      if (item.visibility !== 'public') return; // only public items get a public event
      // Public gear → profile showcase / marketplace listing.
      // Public WANT → a NIP-99 `wtb` listing so sellers find it in the Marketplace.
      await createEvent({
        kind: LISTING_KIND,
        content: item.description || '',
        tags: buildListingTags(item),
      });
    },
    [user, createEvent],
  );

  /** Remove an item's public event (NIP-09) when it goes private or is deleted. */
  const unpublishItem = useCallback(
    async (itemId: string) => {
      if (!user?.pubkey) return;
      const dTag = `${D_PREFIX}${itemId}`;
      await createEvent({
        kind: 5, // NIP-09 deletion request
        content: 'Removed from public showcase',
        tags: [['a', `${LISTING_KIND}:${user.pubkey}:${dTag}`]],
      });
    },
    [user, createEvent],
  );

  return { syncItem, unpublishItem };
}

/**
 * Query a user's public Stash items for their profile.
 * Returns showcase + for-sale items, newest first.
 */
export function useUserPublicStash(pubkey: string | undefined) {
  const { nostr } = useNostr();

  return useQuery({
    queryKey: ['public-stash', pubkey],
    enabled: !!pubkey,
    staleTime: 60_000,
    queryFn: async ({ signal }): Promise<PublicStashItem[]> => {
      if (!pubkey) return [];
      const timeout = AbortSignal.any([signal, AbortSignal.timeout(6000)]);

      const events = await nostr.query(
        [{ kinds: [LISTING_KIND], authors: [pubkey], '#t': [SHOWCASE_TAG], limit: 100 }],
        { signal: timeout },
      );

      // Deduplicate addressable events by d-tag (keep newest), drop deleted/sold.
      const byD = new Map<string, NostrEvent>();
      for (const ev of events) {
        const d = tag(ev, 'd');
        if (!d) continue;
        const existing = byD.get(d);
        if (!existing || ev.created_at > existing.created_at) byD.set(d, ev);
      }

      const items: PublicStashItem[] = [];
      for (const ev of byD.values()) {
        const status = tag(ev, 'status');
        if (status === 'sold') continue;
        const parsed = parsePublicStashItem(ev);
        if (parsed) items.push(parsed);
      }

      return items.sort((a, b) => b.createdAt - a.createdAt);
    },
  });
}