import sharedLang from "~/assets/langs/shared.js"

/**
 * Server-side access to the shared translation bundles keyed by the language of a
 * RECORD (typically `c_bpartner.AD_Language`, iDempiere format `de_DE`) instead of
 * the logged-in user's UI language. Used wherever text is persisted onto a document
 * the partner will read (order/line descriptions, invoice period-of-performance, …).
 */

export const MONTH_KEYS = ['january', 'february', 'march', 'april', 'may', 'june',
  'july', 'august', 'september', 'october', 'november', 'december']

const DEFAULT_LANG = 'en-US'

// Regional variants without their own bundle (de_CH, en_GB, es_MX, …) → base-language bundle
const BUNDLE_BY_BASE: Record<string, string> = { de: 'de-DE', en: 'en-US', es: 'es-ES', ne: 'ne-NP' }

/**
 * Normalises a language value to a sharedLang bundle key, or null when nothing matches.
 * Accepts iDempiere codes (`de_DE`), browser codes (`de-DE`) and the expanded REST
 * object form (`{ id: 'de_DE', identifier: 'German (Germany)' }`).
 */
export const toBundleKey = (code: any): string | null => {
  const raw = code !== null && typeof code === 'object' ? (code.id ?? code.AD_Language ?? '') : code
  const normalized = String(raw ?? '').trim().replace('_', '-')
  if (!normalized) return null
  if (sharedLang(normalized)) return normalized
  const base = normalized.split('-')[0].toLowerCase()
  const byBase = BUNDLE_BY_BASE[base]
  return byBase && sharedLang(byBase) ? byBase : null
}

/** Translation bundle of the first resolvable code in `codes`, falling back to en-US. */
export const resolveLangBundle = (...codes: any[]): Record<string, string> => {
  for (const code of codes) {
    const key = toBundleKey(code)
    if (key) return sharedLang(key)
  }
  return sharedLang(DEFAULT_LANG)
}

/** The logged-in user's language (`logship_language` cookie, iDempiere format e.g. `de_DE`). */
export const sessionLanguage = (event: any): string =>
  getCookie(event, 'logship_language') || getCookie(event, 'language') || DEFAULT_LANG

/**
 * `YYYY-MM-DD` of the last day of `month` (1-12), built from local date parts.
 * NB `new Date(y, m, 0).toISOString()` shifts to the PREVIOUS day on any host east of UTC
 * (Europe/Berlin: 31 Aug 00:00 local → "2026-08-30T22:00Z"), which is how prod orders ended
 * up with PeriodPerformanceDate 2026-08-30 for August.
 */
export const lastDayOfMonthIso = (year: number, month: number): string => {
  const day = new Date(year, month, 0).getDate()
  return `${year}-${String(month).padStart(2, '0')}-${String(day).padStart(2, '0')}`
}