import Database from 'better-sqlite3';
import fs from 'node:fs';
import path from 'node:path';
import { fileURLToPath } from 'node:url';

const __dirname = path.dirname(fileURLToPath(import.meta.url));

const dataDir = path.join(process.cwd(), 'data');
if (!fs.existsSync(dataDir)) {
  fs.mkdirSync(dataDir, { recursive: true });
}

const dbPath = path.join(dataDir, 'app.db');
const isNewDb = !fs.existsSync(dbPath);

export const db = new Database(dbPath);
db.pragma('foreign_keys = ON');
db.pragma('journal_mode = WAL');

if (isNewDb) {
  const schema = fs.readFileSync(path.join(__dirname, 'schema.sql'), 'utf-8');
  db.exec(schema);
}

const FIRST_ORDER_NUMBER = 8246;

/** Allocates the next order number inside the caller's transaction. */
export function nextOrderNumber(): number {
  const row = db
    .prepare(`SELECT COALESCE(MAX(order_number), ?) + 1 AS next FROM service_orders`)
    .get(FIRST_ORDER_NUMBER) as { next: number };
  return row.next;
}