module ISO3166::CountryFinderMethods

def [](query)
  search(query)
end

def find_all_by(attribute, val)
  attributes, lookup_value = parse_attributes(attribute, val)
  ISO3166::Data.cache.select do |_k, value|
    country = Country.new(value)
    attributes.any? do |attr|
      Array(country.send(attr)).any? do |attr_value|
        lookup_value === cached(attr_value) { parse_value(attr_value) }
      end
    end
  end
end

def find_by(attribute, value, obj = nil)
  find_all_by(attribute.downcase, value).map do |country|
    obj ? new(country.last) : country
  end
end

def method_missing(method_name, *arguments)
  matches = method_name.to_s.match(FIND_BY_REGEX)
  super unless matches
  return_all = matches[1]
  method = matches[3]
  countries = find_by(method, arguments[0], matches[2])
  return_all ? countries : countries.last
end

def parse_attributes(attribute, val)
  raise "Invalid attribute name '#{attribute}'" unless searchable_attribute?(attribute.to_sym)
  attribute = attribute.to_s
  attributes = Array(attribute)
  attributes = %w[iso_long_name iso_short_name unofficial_names translated_names] if attribute == 'any_name'
  [attributes, parse_value(val)]
end

def parse_value(value)
  value = value.gsub(SEARCH_TERM_FILTER_REGEX, '').freeze if value.respond_to?(:gsub)
  strip_accents(value)
end

def respond_to_missing?(method_name, include_private = false)
  matches = method_name.to_s.match(FIND_BY_REGEX)
  method = matches[3]
  if matches && method
    instance_methods.include?(method.to_sym)
  else
    super
  end
end

def search(query)
  query = query.to_s if query.is_a?(Symbol)
  query = query.upcase if query.match?(/[a-z]/)
  country = new(query)
  country&.valid? ? country : nil
end

def searchable_attribute?(attribute)
  searchable_attributes.include?(attribute.to_sym)
end

def searchable_attributes
  instance_methods - UNSEARCHABLE_METHODS + %i[any_name]
end