import { useEffect } from 'react';

import { notify } from './osNotify';
import { supabase } from './supabase';

interface MentionRow {
  message_id: string;
  mentioned_user_id: string;
  conversation_id: string;
}

// Subscribes to my own message_mentions inserts and fires an OS notification
// for each one. Bypasses per-conv mute (mentions override mute by design).
//
// We don't decrypt the body here — the notification just says "Du wurdest
// erwähnt". The conv list highlight + the in-app navigation reveal context.
export function useMentionNotifications(userId: string | undefined): void {
  useEffect(() => {
    if (!userId) return;
    const channel = supabase
      .channel('mentions:' + userId)
      .on(
        'postgres_changes',
        {
          event: 'INSERT',
          schema: 'public',
          table: 'message_mentions',
          filter: 'mentioned_user_id=eq.' + userId,
        },
        (payload) => {
          const row = payload.new as MentionRow | null;
          if (!row) return;
          void notify({
            title: 'Du wurdest erwähnt',
            body: 'Tippe um die Nachricht zu lesen.',
            force: true,
          });
        },
      )
      .subscribe();
    return () => {
      void supabase.removeChannel(channel);
    };
  }, [userId]);
}