module I18n::Backend::Base

def available_locales
  raise NotImplementedError
end

def deep_interpolate(locale, data, values = EMPTY_HASH)
  return data if values.empty?
  case data
  when ::String
    I18n.interpolate(data, values)
  when ::Hash
    data.each_with_object({}) do |(k, v), result|
      result[k] = deep_interpolate(locale, v, values)
    end
  when ::Array
    data.map do |v|
      deep_interpolate(locale, v, values)
    end
  else
    data
  end
end

def default(locale, object, subject, options = EMPTY_HASH)
  if options.size == 1 && options.has_key?(:default)
    options = {}
  else
    options = Utils.except(options, :default)
  end
  case subject
  when Array
    subject.each do |item|
      result = resolve(locale, object, item, options)
      return result unless result.nil?
    end and nil
  else
    resolve(locale, object, subject, options)
  end
end

def eager_load!
  @eager_loaded = true
end

def eager_loaded?
  @eager_loaded ||= false
end

def exists?(locale, key, options = EMPTY_HASH)
  lookup(locale, key, options[:scope]) != nil
end

def interpolate(locale, subject, values = EMPTY_HASH)
  return subject if values.empty?
  case subject
  when ::String then I18n.interpolate(subject, values)
  when ::Array then subject.map { |element| interpolate(locale, element, values) }
  else
    subject
  end
end

def load_file(filename)
  type = File.extname(filename).tr('.', '').downcase
  raise UnknownFileType.new(type, filename) unless respond_to?(:"load_#{type}", true)
  data, keys_symbolized = send(:"load_#{type}", filename)
  unless data.is_a?(Hash)
    raise InvalidLocaleData.new(filename, 'expects it to return a hash, but does not')
  end
  data.each { |locale, d| store_translations(locale, d || {}, skip_symbolize_keys: keys_symbolized) }
  data
end

def load_json(filename)
  begin
    # Use #load_file as a proxy for a version of JSON where symbolize_names and freeze are supported.
    if ::JSON.respond_to?(:load_file)
      [::JSON.load_file(filename, symbolize_names: true, freeze: true), true]
    else
      [::JSON.parse(File.read(filename)), false]
    end
  rescue TypeError, StandardError => e
    raise InvalidLocaleData.new(filename, e.inspect)
  end
end

def load_rb(filename)
  translations = eval(IO.read(filename), binding, filename.to_s)
  [translations, false]
end

def load_translations(*filenames)
  filenames = I18n.load_path if filenames.empty?
  filenames.flatten.each do |filename|
    loaded_translations = load_file(filename)
    yield filename, loaded_translations if block_given?
  end
end

def load_yml(filename)
  begin
    if YAML.respond_to?(:unsafe_load_file) # Psych 4.0 way
      [YAML.unsafe_load_file(filename, symbolize_names: true, freeze: true), true]
    else
      [YAML.load_file(filename), false]
    end
  rescue TypeError, ScriptError, StandardError => e
    raise InvalidLocaleData.new(filename, e.inspect)
  end
end

def localize(locale, object, format = :default, options = EMPTY_HASH)
  if object.nil? && options.include?(:default)
    return options[:default]
  end
  raise ArgumentError, "Object must be a Date, DateTime or Time object. #{object.inspect} given." unless object.respond_to?(:strftime)
  if Symbol === format
    key  = format
    type = object.respond_to?(:sec) ? 'time' : 'date'
    options = options.merge(:raise => true, :object => object, :locale => locale)
    format  = I18n.t(:"#{type}.formats.#{key}", **options)
  end
  format = translate_localization_format(locale, object, format, options)
  object.strftime(format)
end

def lookup(locale, key, scope = [], options = EMPTY_HASH)
  raise NotImplementedError
end

def pluralization_key(entry, count)
  key = :zero if count == 0 && entry.has_key?(:zero)
  key ||= count == 1 ? :one : :other
end

def pluralize(locale, entry, count)
  entry = entry.reject { |k, _v| k == :attributes } if entry.is_a?(Hash)
  return entry unless entry.is_a?(Hash) && count
  key = pluralization_key(entry, count)
  raise InvalidPluralizationData.new(entry, count, key) unless entry.has_key?(key)
  entry[key]
end

def reload!
  eager_load! if eager_loaded?
end

def resolve(locale, object, subject, options = EMPTY_HASH)
  return subject if options[:resolve] == false
  result = catch(:exception) do
    case subject
    when Symbol
      I18n.translate(
        subject,
        **options.merge(
          :locale => locale,
          :throw => true,
          :skip_interpolation => true
        )
      )
    when Proc
      date_or_time = options.delete(:object) || object
      resolve(locale, object, subject.call(date_or_time, **options))
    else
      subject
    end
  end
  result unless result.is_a?(MissingTranslation)
end

def store_translations(locale, data, options = EMPTY_HASH)
  raise NotImplementedError
end

def subtrees?
  true
end

def translate(locale, key, options = EMPTY_HASH)
  raise I18n::ArgumentError if (key.is_a?(String) || key.is_a?(Symbol)) && key.empty?
  raise InvalidLocale.new(locale) unless locale
  return nil if key.nil? && !options.key?(:default)
  entry = lookup(locale, key, options[:scope], options) unless key.nil?
  if entry.nil? && options.key?(:default)
    entry = default(locale, key, options[:default], options)
  else
    entry = resolve_entry(locale, key, entry, options)
  end
  count = options[:count]
  if entry.nil? && (subtrees? || !count)
    if (options.key?(:default) && !options[:default].nil?) || !options.key?(:default)
      throw(:exception, I18n::MissingTranslation.new(locale, key, options))
    end
  end
  entry = entry.dup if entry.is_a?(String)
  entry = pluralize(locale, entry, count) if count
  if entry.nil? && !subtrees?
    throw(:exception, I18n::MissingTranslation.new(locale, key, options))
  end
  deep_interpolation = options[:deep_interpolation]
  skip_interpolation = options[:skip_interpolation]
  values = Utils.except(options, *RESERVED_KEYS) unless options.empty?
  if !skip_interpolation && values && !values.empty?
    entry = if deep_interpolation
      deep_interpolate(locale, entry, values)
    else
      interpolate(locale, entry, values)
    end
  elsif entry.is_a?(String) && entry =~ I18n.reserved_keys_pattern
    raise ReservedInterpolationKey.new($1.to_sym, entry)
  end
  entry
end

def translate_localization_format(locale, object, format, options)
  format.to_s.gsub(/%(|\^)[aAbBpP]/) do |match|
    case match
    when '%a' then I18n.t!(:"date.abbr_day_names",                  :locale => locale, :format => format)[object.wday]
    when '%^a' then I18n.t!(:"date.abbr_day_names",                 :locale => locale, :format => format)[object.wday].upcase
    when '%A' then I18n.t!(:"date.day_names",                       :locale => locale, :format => format)[object.wday]
    when '%^A' then I18n.t!(:"date.day_names",                      :locale => locale, :format => format)[object.wday].upcase
    when '%b' then I18n.t!(:"date.abbr_month_names",                :locale => locale, :format => format)[object.mon]
    when '%^b' then I18n.t!(:"date.abbr_month_names",               :locale => locale, :format => format)[object.mon].upcase
    when '%B' then I18n.t!(:"date.month_names",                     :locale => locale, :format => format)[object.mon]
    when '%^B' then I18n.t!(:"date.month_names",                    :locale => locale, :format => format)[object.mon].upcase
    when '%p' then I18n.t!(:"time.#{(object.respond_to?(:hour) ? object.hour : 0) < 12 ? :am : :pm}", :locale => locale, :format => format).upcase
    when '%P' then I18n.t!(:"time.#{(object.respond_to?(:hour) ? object.hour : 0) < 12 ? :am : :pm}", :locale => locale, :format => format).downcase
    end
  end
rescue MissingTranslationData => e
  e.message
end