import { locale as activeLocale, defaultLocale, type Locale } from './locale'
import { type MessageKey, messages } from './messages'

export type MessageParams = Record<string, string | number>

function fill(template: string, params?: MessageParams) {
  if (!params) return template
  return template.replace(/\{(\w+)\}/g, (placeholder, name: string) =>
    name in params ? String(params[name]) : placeholder,
  )
}

export function createTranslator(locale: Locale) {
  const catalog = messages[locale] || messages[defaultLocale]
  return (key: MessageKey, params?: MessageParams) => fill(catalog[key], params)
}

export const isMessageKey = (key: string): key is MessageKey => key in messages[defaultLocale]

export function t(key: MessageKey, params?: MessageParams) {
  return fill(messages[activeLocale()][key], params)
}