// import mariadb from 'mariadb';
import * as mariadb from 'mariadb';

// Fix para BigInt en la serialización JSON (necesario para IDs grandes en MariaDB)
BigInt.prototype.toJSON = function () {
  return this.toString();
};

// Configuración del Pool
export const pool = mariadb.createPool({
  host: process.env.DB_HOST,
  user: process.env.DB_USER,
  password: process.env.DB_PASSWORD,
  database: 'Reale',
  connectionLimit: 20,
  timezone: 'Z',
  insertIdAsNumber: true
});

// Helper para escapar identificadores (tablas/columnas)
const b = (id) => `\`${id.replace(/`/g, '``')}\``;

export class Database {
  constructor(connector) {
    /** @type {mariadb.Pool | mariadb.PoolConnection} */
    this.connector = connector;
  }

  async insert(table, data) {
    const rows = Array.isArray(data) ? data : [data];
    if (!rows.length) return null;
    const fields = Object.keys(rows[0]);
    const query = `INSERT INTO ${b(table)} (${fields.map(b).join(',')}) VALUES (${fields.map(() => '?').join(',')})`;
    return this.connector.batch(query, rows.map(r => fields.map(f => r[f])));
  }

  async update(table, data, where) {
    const fields = Object.keys(data);
    const wFields = Object.keys(where);
    const query = `UPDATE ${b(table)} SET ${fields.map(f => `${b(f)}=?`).join(',')} WHERE ${wFields.map(f => `${b(f)}=?`).join(' AND ')}`;
    return this.connector.query(query, [...fields.map(f => data[f]), ...wFields.map(f => where[f])]);
  }

  async upsert(table, data, ignore = false) {
    const rows = Array.isArray(data) ? data : [data];
    if (!rows.length) return null;
    const fields = Object.keys(rows[0]);
    const set = fields.filter(f => f !== 'id').map(f => `${b(f)}=VALUES(${b(f)})`).join(',');
    const query = `INSERT ${ignore ? 'IGNORE' : ''} INTO ${b(table)} (${fields.map(b).join(',')}) VALUES (${fields.map(() => '?').join(',')}) ON DUPLICATE KEY UPDATE ${set}`;
    return this.connector.batch(query, rows.map(r => fields.map(f => r[f])));
  }

  async delete(table, where) {
    const keys = Object.keys(where);
    if (!keys.length) throw new Error('Delete requiere condiciones');
    return this.connector.query(`DELETE FROM ${b(table)} WHERE ${keys.map(k => `${b(k)}=?`).join(' AND ')}`, keys.map(k => where[k]));
  }

  async select(table, where = {}, opts = { limit: 5000, order: null }) {
    const keys = Object.keys(where);
    let sqlStr = `SELECT * FROM ${b(table)}`;
    if (keys.length) sqlStr += ` WHERE ${keys.map(k => `${b(k)}=?`).join(' AND ')}`;
    if (opts.order) sqlStr += ` ORDER BY ${b(opts.order)}`;
    return this.connector.query(sqlStr + ` LIMIT ${opts.limit}`, keys.map(k => where[k]));
  }

  async one(table, where) {
    const res = await this.select(table, where, { limit: 1 });
    return res[0] || null;
  }

  async count(table, where = {}) {
    const keys = Object.keys(where);
    let sqlStr = `SELECT COUNT(*) as total FROM ${b(table)}`;
    if (keys.length) sqlStr += ` WHERE ${keys.map(k => `${b(k)}=?`).join(' AND ')}`;
    const res = await this.connector.query(sqlStr, keys.map(k => where[k]));
    return Number(res[0].total);
  }

  async search(table, fields, term, limit = 1000) {
    if (!fields.length || !term) return [];
    const where = fields.map(f => `${b(f)} LIKE ?`).join(' OR ');
    return this.connector.query(`SELECT * FROM ${b(table)} WHERE ${where} LIMIT ${limit}`, fields.map(() => `%${term}%`));
  }

  async unique(table, fields, where = {}) {
    const f = Array.isArray(fields) ? fields.map(b).join(',') : b(fields);
    const keys = Object.keys(where);
    let sqlStr = `SELECT DISTINCT ${f} FROM ${b(table)}`;
    if (keys.length) sqlStr += ` WHERE ${keys.map(k => `${b(k)}=?`).join(' AND ')}`;
    const sort = Array.isArray(fields) ? b(fields[0]) : f;
    return this.connector.query(sqlStr + ` ORDER BY ${sort} ASC`, keys.map(k => where[k]));
  }

  async raw(query, data = {}) {
    const params = [];
    const sqlStr = query.replace(/:(\w+)/g, (_, key) => {
      params.push(data[key]);
      return '?';
    });
    return this.connector.query(sqlStr, params);
  }
}

/**
 * Lógica de Transacciones
 */
export const trx = async (opts, actions) => {
  const tasks = Array.isArray(opts) ? opts : [opts];
  const conn = await pool.getConnection();
  try {
    await conn.beginTransaction();
    const transactionDb = new Database(conn);
    const results = {};

    for (const item of tasks) {
      if (typeof actions[item.action] !== 'function') {
        throw new Error(`Acción ${item.action} no existe`);
      }
      results[item.action] = await actions[item.action](transactionDb, item);
    }

    await conn.commit();
    return results;
  } catch (err) {
    console.error('Error en la transacción:', err);
    await conn.rollback();
    throw err;
  } finally {
    if (conn) conn.release();
  }
};

// Exportamos la instancia principal vinculada al Pool
export const db = new Database(pool);