import { createHash } from 'node:crypto';
import { readFile, readdir, writeFile } from 'node:fs/promises';
import { resolve, join } from 'node:path';

const root = resolve(
  process.argv.find((value) => value.startsWith('--root='))?.slice(7) ?? '.',
);
const folder = join(root, 'prisma', 'migrations');
const manifest = join(root, 'prisma', 'migration-checksums.json');
const hashes = JSON.parse(await readFile(manifest, 'utf8'));
const canonicalHash = (sql) =>
  createHash('sha256').update(sql.replaceAll('\r\n', '\n')).digest('hex');

for (const [name, expected] of Object.entries(hashes)) {
  const actual = canonicalHash(
    await readFile(join(folder, name, 'migration.sql'), 'utf8'),
  );
  if (actual !== expected)
    throw new Error(`Immutable migration changed: ${name}`);
}
const names = (await readdir(folder, { withFileTypes: true }))
  .filter((entry) => entry.isDirectory())
  .map((entry) => entry.name)
  .sort();
const stamps = new Set();
for (const name of names) {
  const stamp = name.split('_')[0];
  if (stamps.has(stamp))
    throw new Error(`Duplicate migration timestamp: ${stamp}`);
  stamps.add(stamp);
  if (hashes[name]) continue;
  if (!/^\d{14}_[a-z0-9_]+$/.test(name))
    throw new Error(`New migration requires YYYYMMDDHHmmss timestamp: ${name}`);
  if (!process.argv.includes('--record-new'))
    throw new Error(`New migration checksum not recorded: ${name}`);
  hashes[name] = canonicalHash(
    await readFile(join(folder, name, 'migration.sql'), 'utf8'),
  );
}
if (process.argv.includes('--record-new'))
  await writeFile(manifest, JSON.stringify(hashes, null, 2) + '\n');
console.log(`Verified ${Object.keys(hashes).length} immutable migrations`);