import { Database } from 'bun:sqlite';
import { mkdirSync, readdirSync, readFileSync } from 'node:fs';
import { dirname, join } from 'node:path';

const MIGRATIONS_DIR = join(import.meta.dir, 'migrations');

export function openDb(path: string): Database {
  if (path !== ':memory:') mkdirSync(dirname(path), { recursive: true });
  const db = new Database(path, { create: true, strict: true });
  db.exec('PRAGMA journal_mode = WAL;');
  db.exec('PRAGMA synchronous = NORMAL;');
  db.exec('PRAGMA foreign_keys = ON;');
  db.exec('PRAGMA busy_timeout = 5000;');
  migrate(db);
  return db;
}

export function migrate(db: Database): void {
  db.exec('CREATE TABLE IF NOT EXISTS schema_migrations (name TEXT PRIMARY KEY, applied_at INTEGER NOT NULL)');
  const applied = new Set(
    db.query<{ name: string }, []>('SELECT name FROM schema_migrations').all().map((r) => r.name),
  );
  const files = readdirSync(MIGRATIONS_DIR).filter((f) => f.endsWith('.sql')).sort();
  for (const file of files) {
    if (applied.has(file)) continue;
    const sql = readFileSync(join(MIGRATIONS_DIR, file), 'utf8');
    db.transaction(() => {
      db.exec(sql);
      db.query('INSERT INTO schema_migrations (name, applied_at) VALUES (?, ?)').run(file, Date.now());
    })();
  }
}