#Guide to adding custom language packs

// locales/account/zh-CN.cjs — Developer A maintains independently without interfering with each other
module.exports = {
  'account.notFound': { code: 10001, message: 'Account does not exist' },
  'account.locked': { code: 10002, message: 'Account has been locked' },
};

// locales/order/zh-CN.json5 — independently maintained by developer B
const orderZhCN = {
  'order.notFound': { code: 20001, message: 'The order does not exist' },
  'order.notPaid': { code: 20002, message: 'Order not paid' },
}

// app.js
import { s, validate } from 'schema-dsl/pure';
import path from 'path';

// Automatically recursively scan all subdirectories under locales/ and merge the same language files into a complete language package
s.config({
  i18n: path.join(__dirname, 'locales')
});

s.config({
  i18n: path.join(__dirname, 'locales'),
  codeLocaleFiles: 'deny'
});

s.config({
  i18n: path.join(__dirname, 'locales'),
  strict: true // When keys with the same name conflict, an Error will be thrown directly to prevent silent overwriting.
});

//Conflict example output:
// Error: [schema-dsl] i18n key conflict in locale 'zh-CN'
//Conflict key: account.notFound
// Source file: /project/locales/account/zh-CN.cjs

import { s, validate } from 'schema-dsl/pure';
import path from 'path';

// ========== Configuration when the application starts (only executed once) ==========
s.config({
  i18n: path.join(__dirname, 'locales') // Automatically load all language files in the directory
});

// Description:
// 1. Automatically scan `.js` (CommonJS), `.cjs`, `.json`, `.jsonc`, `.json5` in the locales/ directory
// 2. Extract the language code from the file name (such as pt-BR.cjs → pt-BR)
// 3. Automatically load and register all language packages
// 4. The user-defined language pack will be merged with the system default language pack, and the user’s will take precedence.

// ========== Switch language directly during runtime (no need to reload) ==========
const schema = s({ username: 'string:3-32!' });

// use Portuguese
const result1 = validate(schema, { username: 'ab' }, { locale: 'pt-BR' });
// Error message: "username deve ter pelo menos 3 caracteres"

// use Chinese
const result2 = validate(schema, { username: 'ab' }, { locale: 'zh-CN' });
// Error message: "username cannot be less than 3 characters long"

// use English
const result3 = validate(schema, { username: 'ab' }, { locale: 'en-US' });
// Error message: "username length must be at least 3"

// System built-in zh-CN language pack
const systemZhCN = {
  'required': '{{#label}} is required',
  'string.minLength': '{{#label}} cannot be less than {{#limit}} characters'
};

// User-defined locales/zh-CN.cjs
const userZhCN = {
  'required': '{{#label}} must be filled in', // Override the system default
  'custom.myError': 'Custom error' // Add custom message
};

// Final merge result (deep merge)
const finalZhCN = {
  'required': '{{#label}}must be filled in', // ✅ User priority
  'string.minLength': '{{#label}} cannot be less than {{#limit}} characters', // keep the system default
  'custom.myError': 'Custom error' // Add custom message
};

import { s } from 'schema-dsl/pure';
import ptBR from './locales/pt-BR.cjs';
import deDE from './locales/de-DE.cjs';
import koKR from './locales/ko-KR.cjs';

// Configure when application starts
s.config({
  i18n: {
    'pt-BR': ptBR,
    'de-DE': deDE,
    'ko-KR': koKR
  }
});

//Switch directly during runtime
validate(schema, data, { locale: 'pt-BR' });
validate(schema, data, { locale: 'de-DE' });

import { Locale } from 'schema-dsl/pure';

// ❌ Not recommended: dynamically load before each validation
async function validateUser(data, locale) {
  if (locale === 'pt-BR') {
    const { default: ptBR } = await import('./locales/pt-BR.cjs');
    Locale.addLocale('pt-BR', ptBR); // Load every time, poor performance
  }
  return validate(schema, data, { locale });
}

// ✅ Correct: Load once when the app starts
// app.js startup entry
s.config({ i18n: './locales' }); // Only load once

//Switch directly during runtime without reloading
function validateUser(data, locale) {
  return validate(schema, data, { locale }); // ✅ Direct switch, good performance
}

// ========== app.js (application startup entrance) ==========
import express from 'express';
import { s, validate } from 'schema-dsl/pure';
import path from 'path';

//Load all language packs at once when the application starts
s.config({
  i18n: path.join(__dirname, 'locales')
});

const app = express();

// ========== routes/user.js (business routing) ==========
const userSchema = s({
  username: 'string:3-32!',
  email: 'email!',
  age: 'number:18-120'
});

app.post('/api/users', (req, res) => {
  // Get user language preference from request header
  const locale = req.headers['accept-language']?.split(',')[0]?.trim() || 'en-US';

  // Validation (switch language directly, no loading required)
  const result = validate(userSchema, req.body, { locale });

  if (!result.valid) {
    return res.status(400).json({
      errors: result.errors // Automatically use the user's preferred language
    });
  }

  // Handle the request...
});

import { Locale } from 'schema-dsl/pure';

// View Chinese language pack
const zhCN = Locale.getMessages('zh-CN');
console.log(zhCN);

// View English language pack
const enUS = Locale.getMessages('en-US');
console.log(enUS);