import initSqlJs from 'sql.js';
import path from 'path';
import fs from 'fs';
import { fileURLToPath } from 'url';

const __dirname = path.dirname(fileURLToPath(import.meta.url));
const dataDir = path.join(__dirname, '..', 'data');
if (!fs.existsSync(dataDir)) fs.mkdirSync(dataDir, { recursive: true });
const dbPath = process.env.DATABASE_PATH || path.join(dataDir, 'configurateur.db');

let db = null;

function toSqlitePlaceholders(sql) {
  return sql.replace(/\$(\d+)/g, '?');
}

function save() {
  if (db && dbPath) {
    const data = db.export();
    fs.writeFileSync(dbPath, Buffer.from(data));
  }
}

async function getDb() {
  if (db) return db;
  const SQL = await initSqlJs({
    locateFile: (file) => path.join(__dirname, '..', 'node_modules', 'sql.js', 'dist', file)
  });
  let buffer;
  if (fs.existsSync(dbPath)) {
    buffer = fs.readFileSync(dbPath);
  }
  db = new SQL.Database(buffer || null);
  return db;
}

export const dbReady = getDb();

export const query = async (sql, params = []) => {
  const database = await getDb();
  const sqliteSql = toSqlitePlaceholders(sql);
  const stmt = database.prepare(sqliteSql);
  stmt.bind(Array.isArray(params) ? params : []);
  const rows = [];
  while (stmt.step()) rows.push(stmt.getAsObject());
  stmt.free();
  return { rows };
};

export const run = async (sql, params = []) => {
  const database = await getDb();
  const sqliteSql = toSqlitePlaceholders(sql);
  database.run(sqliteSql, Array.isArray(params) ? params : []);
  save();
  return {};
};

const pool = {
  query: (sql, params) => query(sql, params)
};

export default pool;