// Export kampaní (templates) a šablón cenoviek (badges) zo Supabase do supabase/data/
// pre prenos na nový server. Stiahne aj obrázky z úložiska newsletter-assets, na ktoré
// dáta odkazujú a nie sú medzi statickými obrázkami v supabase/assets/.
// Spustenie: npm run db:export   (číta .env.local pôvodného projektu)
import { createClient } from '@supabase/supabase-js';
import { mkdir, writeFile, access } from 'node:fs/promises';
import path from 'node:path';

const BUCKET = 'newsletter-assets';
const TABLES = ['templates', 'badges'];
const DATA_DIR = path.join(process.cwd(), 'supabase', 'data');
const FILES_DIR = path.join(DATA_DIR, 'files');
const ASSETS_DIR = path.join(process.cwd(), 'supabase', 'assets');

const url = (process.env.NEXT_PUBLIC_SUPABASE_URL || '').replace(/\/$/, '');
const key = process.env.SUPABASE_SERVICE_ROLE_KEY || process.env.NEXT_PUBLIC_SUPABASE_ANON_KEY;
if (!url || !key) {
  console.error('Chýba NEXT_PUBLIC_SUPABASE_URL alebo kľúč (SUPABASE_SERVICE_ROLE_KEY / NEXT_PUBLIC_SUPABASE_ANON_KEY) v .env.local');
  process.exit(1);
}

const supabase = createClient(url, key);
const storageBase = `${url}/storage/v1/object/public/${BUCKET}/`;
await mkdir(FILES_DIR, { recursive: true });

const referenced = new Set();
for (const table of TABLES) {
  const { data, error } = await supabase.from(table).select('*').order('created_at', { ascending: true });
  if (error) {
    console.error(`✗ ${table}: ${error.message}`);
    process.exit(1);
  }
  await writeFile(path.join(DATA_DIR, `${table}.json`), JSON.stringify(data, null, 2) + '\n');
  console.log(`✓ ${table}: ${data.length} záznamov`);

  // Odkazy na súbory v úložisku (cesta v rámci bucketu)
  const json = JSON.stringify(data);
  let i = 0;
  while ((i = json.indexOf(storageBase, i)) !== -1) {
    const start = i + storageBase.length;
    let end = start;
    while (end < json.length && !`"'()\\ `.includes(json[end])) end++;
    referenced.add(decodeURIComponent(json.slice(start, end)));
    i = end;
  }
}

const exists = (p) => access(p).then(() => true, () => false);
let downloaded = 0;
for (const filePath of referenced) {
  // Statické obrázky šablóny sú už v supabase/assets a nahrajú sa cez db:upload-assets
  if (!filePath.includes('/') && (await exists(path.join(ASSETS_DIR, filePath)))) continue;
  const res = await fetch(storageBase + filePath.split('/').map(encodeURIComponent).join('/'));
  if (!res.ok) {
    console.warn(`! ${filePath}: HTTP ${res.status} (preskočené)`);
    continue;
  }
  const target = path.join(FILES_DIR, filePath);
  await mkdir(path.dirname(target), { recursive: true });
  await writeFile(target, Buffer.from(await res.arrayBuffer()));
  downloaded++;
}

await writeFile(
  path.join(DATA_DIR, 'meta.json'),
  JSON.stringify({ exportedAt: new Date().toISOString(), sourceStorageBase: storageBase }, null, 2) + '\n'
);
console.log(`✓ obrázky: ${referenced.size} odkazov, ${downloaded} stiahnutých do supabase/data/files/`);
console.log('\nHotovo. Commitnite priečinok supabase/data/ a na novom serveri spustite npm run db:import.');