import { useNostr } from '@nostrify/react';
import { useQuery } from '@tanstack/react-query';
import type { NostrEvent } from '@nostrify/nostrify';
import { useRelays } from '@/lib/relays';

const REPORT_KIND = 1984; // NIP-56 Report kind

export interface ListingReport {
  id: string;
  pubkey: string;
  reportedEventId: string;
  reportedPubkey: string;
  reason: string;
  content: string;
  createdAt: number;
}

/**
 * Hook to fetch reports for a specific listing event.
 * Returns the count and details of reports.
 */
export function useListingReports(eventId: string, pubkey: string) {
  const { nostr } = useNostr();
  const { read } = useRelays();

  const relayUrls = read.slice().sort().join(',');

  return useQuery({
    queryKey: ['listing-reports', eventId, relayUrls],
    queryFn: async (c) => {
      const signal = AbortSignal.any([c.signal, AbortSignal.timeout(8000)]);

      try {
        const readRelays = read;

        const allEvents: NostrEvent[] = [];

        for (const relayUrl of readRelays) {
          try {
            const relay = nostr.relay(relayUrl);
            const relayEvents = await relay.query(
              [
                {
                  kinds: [REPORT_KIND],
                  '#e': [eventId],
                  limit: 50,
                },
              ],
              { signal }
            );
            allEvents.push(...relayEvents);
          } catch (error) {
            console.warn(`[useListingReports] Failed to query relay ${relayUrl}:`, error);
          }
        }

        // Deduplicate by event ID
        const eventMap = new Map<string, NostrEvent>();
        for (const event of allEvents) {
          if (!eventMap.has(event.id)) {
            eventMap.set(event.id, event);
          }
        }

        const reports: ListingReport[] = [];
        for (const event of Array.from(eventMap.values())) {
          // Extract reason from e tag (3rd element) or p tag
          const eTag = event.tags.find(([t, id]: [string, string]) => t === 'e' && id === eventId);
          const pTag = event.tags.find(([t]: [string]) => t === 'p');
          
          const reason = eTag?.[2] || pTag?.[2] || 'other';

          reports.push({
            id: event.id,
            pubkey: event.pubkey,
            reportedEventId: eventId,
            reportedPubkey: pubkey,
            reason,
            content: event.content,
            createdAt: event.created_at,
          });
        }

        return {
          reports,
          count: reports.length,
          isReported: reports.length > 0,
          shouldHide: reports.length >= 3, // Auto-hide threshold
        };
      } catch (error) {
        console.warn('[useListingReports] Error fetching reports:', error);
        return {
          reports: [],
          count: 0,
          isReported: false,
          shouldHide: false,
        };
      }
    },
    enabled: !!eventId,
    staleTime: 60000, // Cache for 1 minute
    gcTime: 300000, // Keep in cache for 5 minutes
  });
}

/**
 * Hook to batch fetch report counts for multiple listings.
 * More efficient than calling useListingReports multiple times.
 */
export function useBatchListingReports(eventIds: string[]) {
  const { nostr } = useNostr();
  const { read } = useRelays();

  const relayUrls = read.slice().sort().join(',');

  return useQuery({
    queryKey: ['batch-listing-reports', eventIds.sort().join(','), relayUrls],
    queryFn: async (c) => {
      const signal = AbortSignal.any([c.signal, AbortSignal.timeout(10000)]);
      const reportCounts = new Map<string, number>();

      // Initialize all to 0
      eventIds.forEach(id => reportCounts.set(id, 0));

      if (eventIds.length === 0) {
        return reportCounts;
      }

      try {
        const readRelays = read;

        const allEvents: NostrEvent[] = [];

        for (const relayUrl of readRelays) {
          try {
            const relay = nostr.relay(relayUrl);
            const relayEvents = await relay.query(
              [
                {
                  kinds: [REPORT_KIND],
                  '#e': eventIds,
                  limit: 200,
                },
              ],
              { signal }
            );
            allEvents.push(...relayEvents);
          } catch (error) {
            console.warn(`[useBatchListingReports] Failed to query relay ${relayUrl}:`, error);
          }
        }

        // Deduplicate by event ID
        const eventMap = new Map<string, NostrEvent>();
        for (const event of allEvents) {
          if (!eventMap.has(event.id)) {
            eventMap.set(event.id, event);
          }
        }

        // Count reports per listing
        for (const event of Array.from(eventMap.values())) {
          const eTags = event.tags.filter(([t]: [string]) => t === 'e');
          for (const [, eventId] of eTags) {
            if (eventIds.includes(eventId)) {
              reportCounts.set(eventId, (reportCounts.get(eventId) || 0) + 1);
            }
          }
        }

        return reportCounts;
      } catch (error) {
        console.warn('[useBatchListingReports] Error fetching batch reports:', error);
        return reportCounts;
      }
    },
    enabled: eventIds.length > 0,
    staleTime: 60000,
    gcTime: 300000,
  });
}