# frozen_string_literal: true

module LocaleResolver
  COOKIE_NAME = "mltv_locale"
  COOKIE_MAX_AGE = 2.years.to_i

  module_function

  def available
    I18n.available_locales.map(&:to_sym)
  end

  def normalize(value)
    code = value.to_s.strip.downcase.split(/[-_]/).first
    return nil if code.blank?

    sym = code.to_sym
    available.include?(sym) ? sym : nil
  end

  def from_cookie(cookies)
    return nil if cookies.nil?

    value = if cookies.respond_to?(:[])
              cookies[COOKIE_NAME]
            elsif cookies.respond_to?(:fetch)
              cookies.fetch(COOKIE_NAME, nil)
            end
    normalize(value)
  end

  def from_accept_language(header)
    return nil if header.blank?

    header.to_s.split(",").each do |part|
      tag = part.split(";").first.to_s.strip
      locale = normalize(tag)
      return locale if locale
    end
    nil
  end

  def resolve(cookie_jar: nil, cookies: nil, accept_language: nil)
    jar = cookie_jar || cookies
    from_cookie(jar) || from_accept_language(accept_language) || I18n.default_locale
  end

  def persist!(cookie_jar, locale)
    normalized = normalize(locale) || I18n.default_locale
    cookie_jar[COOKIE_NAME] = {
      value: normalized.to_s,
      expires: COOKIE_MAX_AGE.seconds.from_now,
      path: "/",
      same_site: :lax,
      httponly: false
    }
    normalized
  end

  def language_options
    [
      { code: :it, label: "Italiano", native: "Italiano", flag: "🇮🇹" },
      { code: :en, label: "English", native: "English", flag: "🇬🇧" },
      { code: :fr, label: "Français", native: "Français", flag: "🇫🇷" },
      { code: :de, label: "Deutsch", native: "Deutsch", flag: "🇩🇪" },
      { code: :es, label: "Español", native: "Español", flag: "🇪🇸" }
    ].select { |opt| available.include?(opt[:code]) }
  end

  def current_language_option
    language_options.find { |opt| opt[:code] == I18n.locale.to_sym } || language_options.first
  end
end