import { getPhpRuntimeEntry, getPhpRuntimeString, setPhpRuntimeEntry } from '../_helpers/_phpRuntimeState.ts'
import { isPhpAssocObject, type PhpAssoc, type PhpInput } from '../_helpers/_phpTypes.ts'
import { getenv } from '../info/getenv.ts'

type LocaleDefinition = {
  LC_COLLATE: (str1: string, str2: string) => number
  LC_CTYPE: Record<string, RegExp | string>
  LC_TIME: Record<string, string | string[]>
  LC_MONETARY: Record<string, string | number | number[]>
  LC_NUMERIC: Record<string, string | number[]>
  LC_MESSAGES: Record<string, string>
  nplurals: (n: number) => number
}

type LocaleInput = string | string[] | number | null

const isLocaleDefinitionMap = (value: PhpInput): value is Record<string, LocaleDefinition> =>
  typeof value === 'object' && value !== null && !Array.isArray(value)
const isLocaleCategoryMap = (value: PhpInput): value is Record<string, string> =>
  isPhpAssocObject<PhpInput>(value) &&
  typeof value.LC_COLLATE === 'string' &&
  typeof value.LC_CTYPE === 'string' &&
  typeof value.LC_MONETARY === 'string' &&
  typeof value.LC_NUMERIC === 'string' &&
  typeof value.LC_TIME === 'string' &&
  typeof value.LC_MESSAGES === 'string'

function copyValue<T>(orig: T): T
function copyValue(orig: PhpInput): PhpInput {
  if (orig instanceof RegExp) {
    return new RegExp(orig)
  }
  if (orig instanceof Date) {
    return new Date(orig)
  }
  if (Array.isArray(orig)) {
    return orig.map((item) => copyValue(item))
  }
  if (orig !== null && typeof orig === 'object') {
    const newObj: PhpAssoc<PhpInput> = {}
    for (const [key, value] of Object.entries(orig)) {
      newObj[key] = value !== null && typeof value === 'object' ? copyValue(value) : value
    }
    return newObj
  }
  return orig
}

export function setlocale(category: string, locale: LocaleInput): string | false {
  //  discuss at: https://locutus.io/php/setlocale/
  // original by: Brett Zamir (https://brett-zamir.me)
  // original by: Blues (https://hacks.bluesmoon.info/strftime/strftime.js)
  // original by: YUI Library (https://developer.yahoo.com/yui/docs/YAHOO.util.DateLocale.html)
  //      note 1: Is extensible, but currently only implements locales en,
  //      note 1: en_US, en_GB, en_AU, fr, and fr_CA for LC_TIME only; C for LC_CTYPE;
  //      note 1: C and en for LC_MONETARY/LC_NUMERIC; en for LC_COLLATE
  //      note 1: Uses global: locutus to store locale info
  //      note 1: Consider using https://demo.icu-project.org/icu-bin/locexp as basis for localization (as in i18n_loc_set_default())
  //      note 2: This function tries to establish the locale via the `window` global.
  //      note 2: This feature will not work in Node and hence is Browser-only
  //   example 1: setlocale('LC_ALL', 'en_US')
  //   returns 1: 'en_US'

  const cats: string[] = []
  let i = 0

  // Function usable by a ngettext implementation (apparently not an accessible part of setlocale(),
  // but locale-specific) See https://www.gnu.org/software/gettext/manual/gettext.html#Plural-forms
  // though amended with others from https://developer.mozilla.org/En/Localization_and_Plurals (new
  // categories noted with "MDC" below, though not sure of whether there is a convention for the
  // relative order of these newer groups as far as ngettext) The function name indicates the number
  // of plural forms (nplural) Need to look into https://cldr.unicode.org/ (maybe future JavaScript);
  // Dojo has some functions (under new BSD), including JSON conversions of LDML XML from CLDR:
  // https://bugs.dojotoolkit.org/browser/dojo/trunk/cldr and docs at
  // https://api.dojotoolkit.org/jsdoc/HEAD/dojo.cldr

  // var _nplurals1 = function (n) {
  //   // e.g., Japanese
  //   return 0
  // }
  const _nplurals2a = function (n: number) {
    // e.g., English
    return n !== 1 ? 1 : 0
  }
  const _nplurals2b = function (n: number) {
    // e.g., French
    return n > 1 ? 1 : 0
  }

  const localesValue = getPhpRuntimeEntry('locales')
  let locales: Record<string, LocaleDefinition> = isLocaleDefinitionMap(localesValue) ? localesValue : {}
  if (localesValue !== locales) {
    setPhpRuntimeEntry('locales', locales)
  }

  // Reconcile Windows vs. *nix locale names?
  // Allow different priority orders of languages, esp. if implement gettext as in
  // LANGUAGE env. var.? (e.g., show German if French is not available)
  if (!locales.fr_CA?.LC_TIME?.x) {
    // Can add to the locales
    locales = {}
    setPhpRuntimeEntry('locales', locales)

    locales.en = {
      LC_COLLATE: function (str1, str2) {
        // @todo: This one taken from strcmp, but need for other locales; we don't use localeCompare
        // since its locale is not settable
        return str1 === str2 ? 0 : str1 > str2 ? 1 : -1
      },
      LC_CTYPE: {
        // Need to change any of these for English as opposed to C?
        an: /^[A-Za-z\d]+$/g,
        al: /^[A-Za-z]+$/g,
        // biome-ignore lint/suspicious/noControlCharactersInRegex: intentional for LC_CTYPE control character class
        ct: /^[\u0000-\u001F\u007F]+$/g,
        dg: /^[\d]+$/g,
        gr: /^[\u0021-\u007E]+$/g,
        lw: /^[a-z]+$/g,
        pr: /^[\u0020-\u007E]+$/g,
        pu: /^[\u0021-\u002F\u003A-\u0040\u005B-\u0060\u007B-\u007E]+$/g,
        sp: /^[\f\n\r\t\v ]+$/g,
        up: /^[A-Z]+$/g,
        xd: /^[A-Fa-f\d]+$/g,
        CODESET: 'UTF-8',
        // Used by sql_regcase
        lower: 'abcdefghijklmnopqrstuvwxyz',
        upper: 'ABCDEFGHIJKLMNOPQRSTUVWXYZ',
      },
      LC_TIME: {
        // Comments include nl_langinfo() constant equivalents and any
        // changes from Blues' implementation
        a: ['Sun', 'Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat'],
        // ABDAY_
        A: ['Sunday', 'Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday'],
        // DAY_
        b: ['Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec'],
        // ABMON_
        B: [
          'January',
          'February',
          'March',
          'April',
          'May',
          'June',
          'July',
          'August',
          'September',
          'October',
          'November',
          'December',
        ],
        // MON_
        c: '%a %d %b %Y %r %Z',
        // D_T_FMT // changed %T to %r per results
        p: ['AM', 'PM'],
        // AM_STR/PM_STR
        P: ['am', 'pm'],
        // Not available in nl_langinfo()
        r: '%I:%M:%S %p',
        // T_FMT_AMPM (Fixed for all locales)
        x: '%m/%d/%Y',
        // D_FMT // switched order of %m and %d; changed %y to %Y (C uses %y)
        X: '%r',
        // T_FMT // changed from %T to %r  (%T is default for C, not English US)
        // Following are from nl_langinfo() or https://www.cptec.inpe.br/sx4/sx4man2/g1ab02e/strftime.4.html
        alt_digits: '',
        // e.g., ordinal
        ERA: '',
        ERA_YEAR: '',
        ERA_D_T_FMT: '',
        ERA_D_FMT: '',
        ERA_T_FMT: '',
      },
      // Assuming distinction between numeric and monetary is thus:
      // See below for C locale
      LC_MONETARY: {
        // based on Windows "english" (English_United States.1252) locale
        int_curr_symbol: 'USD',
        currency_symbol: '$',
        mon_decimal_point: '.',
        mon_thousands_sep: ',',
        mon_grouping: [3],
        // use mon_thousands_sep; "" for no grouping; additional array members
        // indicate successive group lengths after first group
        // (e.g., if to be 1,23,456, could be [3, 2])
        positive_sign: '',
        negative_sign: '-',
        int_frac_digits: 2,
        // Fractional digits only for money defaults?
        frac_digits: 2,
        p_cs_precedes: 1,
        // positive currency symbol follows value = 0; precedes value = 1
        p_sep_by_space: 0,
        // 0: no space between curr. symbol and value; 1: space sep. them unless symb.
        // and sign are adjacent then space sep. them from value; 2: space sep. sign
        // and value unless symb. and sign are adjacent then space separates
        n_cs_precedes: 1,
        // see p_cs_precedes
        n_sep_by_space: 0,
        // see p_sep_by_space
        p_sign_posn: 3,
        // 0: parentheses surround quantity and curr. symbol; 1: sign precedes them;
        // 2: sign follows them; 3: sign immed. precedes curr. symbol; 4: sign immed.
        // succeeds curr. symbol
        n_sign_posn: 0, // see p_sign_posn
      },
      LC_NUMERIC: {
        // based on Windows "english" (English_United States.1252) locale
        decimal_point: '.',
        thousands_sep: ',',
        grouping: [3], // see mon_grouping, but for non-monetary values (use thousands_sep)
      },
      LC_MESSAGES: {
        YESEXPR: '^[yY].*',
        NOEXPR: '^[nN].*',
        YESSTR: '',
        NOSTR: '',
      },
      nplurals: _nplurals2a,
    }
    locales.en_US = copyValue(locales.en)
    locales.en_US.LC_TIME.c = '%a %d %b %Y %r %Z'
    locales.en_US.LC_TIME.x = '%D'
    locales.en_US.LC_TIME.X = '%r'
    // The following are based on *nix settings
    locales.en_US.LC_MONETARY.int_curr_symbol = 'USD '
    locales.en_US.LC_MONETARY.p_sign_posn = 1
    locales.en_US.LC_MONETARY.n_sign_posn = 1
    locales.en_US.LC_MONETARY.mon_grouping = [3, 3]
    locales.en_US.LC_NUMERIC.thousands_sep = ''
    locales.en_US.LC_NUMERIC.grouping = []

    locales.en_GB = copyValue(locales.en)
    locales.en_GB.LC_TIME.r = '%l:%M:%S %P %Z'

    locales.en_AU = copyValue(locales.en_GB)
    // Assume C locale is like English (?) (We need C locale for LC_CTYPE)
    locales.C = copyValue(locales.en)
    locales.C.LC_CTYPE.CODESET = 'ANSI_X3.4-1968'
    locales.C.LC_MONETARY = {
      int_curr_symbol: '',
      currency_symbol: '',
      mon_decimal_point: '',
      mon_thousands_sep: '',
      mon_grouping: [],
      p_cs_precedes: 127,
      p_sep_by_space: 127,
      n_cs_precedes: 127,
      n_sep_by_space: 127,
      p_sign_posn: 127,
      n_sign_posn: 127,
      positive_sign: '',
      negative_sign: '',
      int_frac_digits: 127,
      frac_digits: 127,
    }
    locales.C.LC_NUMERIC = {
      decimal_point: '.',
      thousands_sep: '',
      grouping: [],
    }
    // D_T_FMT
    locales.C.LC_TIME.c = '%a %b %e %H:%M:%S %Y'
    // D_FMT
    locales.C.LC_TIME.x = '%m/%d/%y'
    // T_FMT
    locales.C.LC_TIME.X = '%H:%M:%S'
    locales.C.LC_MESSAGES.YESEXPR = '^[yY]'
    locales.C.LC_MESSAGES.NOEXPR = '^[nN]'

    locales.fr = copyValue(locales.en)
    locales.fr.nplurals = _nplurals2b
    locales.fr.LC_TIME.a = ['dim', 'lun', 'mar', 'mer', 'jeu', 'ven', 'sam']
    locales.fr.LC_TIME.A = ['dimanche', 'lundi', 'mardi', 'mercredi', 'jeudi', 'vendredi', 'samedi']
    locales.fr.LC_TIME.b = [
      'jan',
      'f\u00E9v',
      'mar',
      'avr',
      'mai',
      'jun',
      'jui',
      'ao\u00FB',
      'sep',
      'oct',
      'nov',
      'd\u00E9c',
    ]
    locales.fr.LC_TIME.B = [
      'janvier',
      'f\u00E9vrier',
      'mars',
      'avril',
      'mai',
      'juin',
      'juillet',
      'ao\u00FBt',
      'septembre',
      'octobre',
      'novembre',
      'd\u00E9cembre',
    ]
    locales.fr.LC_TIME.c = '%a %d %b %Y %T %Z'
    locales.fr.LC_TIME.p = ['', '']
    locales.fr.LC_TIME.P = ['', '']
    locales.fr.LC_TIME.x = '%d.%m.%Y'
    locales.fr.LC_TIME.X = '%T'

    locales.fr_CA = copyValue(locales.fr)
    locales.fr_CA.LC_TIME.x = '%Y-%m-%d'
  }
  let currentLocale = getPhpRuntimeString('locale', '')
  if (!currentLocale) {
    currentLocale = 'en_US'
    // Try to establish the locale via the `window` global
    if (typeof window !== 'undefined' && window.document) {
      const d = window.document
      const NS_XHTML = 'https://www.w3.org/1999/xhtml'
      const NS_XML = 'https://www.w3.org/XML/1998/namespace'
      const htmlNsElement = d.getElementsByTagNameNS ? d.getElementsByTagNameNS(NS_XHTML, 'html')[0] : undefined
      if (htmlNsElement) {
        const xmlLang = htmlNsElement.getAttributeNS(NS_XML, 'lang')
        if (xmlLang) {
          currentLocale = xmlLang
        } else {
          const htmlLang = htmlNsElement.getAttribute('lang')
          if (htmlLang) {
            currentLocale = htmlLang
          }
        }
      } else {
        const htmlElement = d.getElementsByTagName('html')[0]
        const htmlLang = htmlElement?.getAttribute('lang')
        if (htmlLang) {
          currentLocale = htmlLang
        }
      }
    }
  }
  // PHP-style
  currentLocale = currentLocale.replace('-', '_')
  // @todo: locale if declared locale hasn't been defined
  if (!(currentLocale in locales)) {
    const languageLocale = currentLocale.replace(/_[a-zA-Z]+$/, '')
    if (languageLocale in locales) {
      currentLocale = languageLocale
    }
  }
  setPhpRuntimeEntry('locale', currentLocale)

  const localeCategoriesValue = getPhpRuntimeEntry('localeCategories')
  const localeCategories: Record<string, string> = isLocaleCategoryMap(localeCategoriesValue)
    ? localeCategoriesValue
    : {
        LC_COLLATE: currentLocale,
        // for string comparison, see strcoll()
        LC_CTYPE: currentLocale,
        // for character classification and conversion, for example strtoupper()
        LC_MONETARY: currentLocale,
        // for localeconv()
        LC_NUMERIC: currentLocale,
        // for decimal separator (See also localeconv())
        LC_TIME: currentLocale,
        // for date and time formatting with strftime()
        // for system responses (available if PHP was compiled with libintl):
        LC_MESSAGES: currentLocale,
      }
  if (localeCategoriesValue !== localeCategories) {
    setPhpRuntimeEntry('localeCategories', localeCategories)
  }

  let requestedLocale: LocaleInput | false = locale

  if (requestedLocale === null || requestedLocale === '') {
    requestedLocale = getenv(category) || getenv('LANG')
  } else if (Array.isArray(requestedLocale)) {
    for (i = 0; i < requestedLocale.length; i++) {
      const candidate = requestedLocale[i]
      if (typeof candidate !== 'string') {
        if (i === requestedLocale.length - 1) {
          return false
        }
        continue
      }
      if (!(candidate in locales)) {
        if (i === requestedLocale.length - 1) {
          // none found
          return false
        }
        continue
      }
      requestedLocale = candidate
      break
    }
  }

  // Just get the locale
  if (requestedLocale === '0' || requestedLocale === 0) {
    if (category === 'LC_ALL') {
      for (const categ of Object.keys(localeCategories)) {
        // Add ".UTF-8" or allow ".@latint", etc. to the end?
        cats.push(categ + '=' + localeCategories[categ])
      }
      return cats.join(';')
    }
    return localeCategories[category] ?? false
  }

  if (typeof requestedLocale !== 'string' || !(requestedLocale in locales)) {
    // Locale not found
    return false
  }

  // Set and get locale
  if (category === 'LC_ALL') {
    for (const categ of Object.keys(localeCategories)) {
      localeCategories[categ] = requestedLocale
    }
  } else {
    localeCategories[category] = requestedLocale
  }

  return requestedLocale
}