class ActionView::Helpers::Tags::Base

def add_default_name_and_id(options)
  index = name_and_id_index(options)
  options["name"] = options.fetch("name") { tag_name(options["multiple"], index) }
  if generate_ids?
    options["id"] = options.fetch("id") { tag_id(index, options.delete("namespace")) }
    if namespace = options.delete("namespace")
      options["id"] = options["id"] ? "#{namespace}_#{options['id']}" : namespace
    end
  end
end

def add_default_name_and_id_for_value(tag_value, options)
  if tag_value.nil?
    add_default_name_and_id(options)
  else
    specified_id = options["id"]
    add_default_name_and_id(options)
    if specified_id.blank? && options["id"].present?
      options["id"] += "_#{sanitized_value(tag_value)}"
    end
  end
end

def generate_ids?
  !@skip_default_ids
end

def initialize(object_name, method_name, template_object, options = {})
  @object_name, @method_name = object_name.to_s.dup, method_name.to_s.dup
  @template_object = template_object
  @object_name.sub!(/\[\]$/, "") || @object_name.sub!(/\[\]\]$/, "]")
  @object = retrieve_object(options.delete(:object))
  @skip_default_ids = options.delete(:skip_default_ids)
  @allow_method_names_outside_object = options.delete(:allow_method_names_outside_object)
  @options = options
  if Regexp.last_match
    @generate_indexed_names = true
    @auto_index = retrieve_autoindex(Regexp.last_match.pre_match)
  else
    @generate_indexed_names = false
    @auto_index = nil
  end
end

def name_and_id_index(options)
  if options.key?("index")
    options.delete("index") || ""
  elsif @generate_indexed_names
    @auto_index || ""
  end
end

def render
  raise NotImplementedError, "Subclasses must implement a render method"
end

def retrieve_autoindex(pre_match)
  object = self.object || @template_object.instance_variable_get("@#{pre_match}")
  if object && object.respond_to?(:to_param)
    object.to_param
  else
    raise ArgumentError, "object[] naming but object param and @object var don't exist or don't respond to to_param: #{object.inspect}"
  end
end

def retrieve_object(object)
  if object
    object
  elsif @template_object.instance_variable_defined?("@#{@object_name}")
    @template_object.instance_variable_get("@#{@object_name}")
  end
rescue NameError
  # As @object_name may contain the nested syntax (item[subobject]) we need to fallback to nil.
  nil
end

def sanitized_method_name
  @sanitized_method_name ||= @method_name.delete_suffix("?")
end

def sanitized_value(value)
  value.to_s.gsub(/[\s.]/, "_").gsub(/[^-[[:word:]]]/, "").downcase
end

def tag_id(index = nil, namespace = nil)
  @template_object.field_id(@object_name, @method_name, index: index, namespace: namespace)
end

def tag_name(multiple = false, index = nil)
  @template_object.field_name(@object_name, sanitized_method_name, multiple: multiple, index: index)
end

def value
  return unless object
  if @allow_method_names_outside_object
    object.public_send @method_name if object.respond_to?(@method_name)
  else
    object.public_send @method_name
  end
end

def value_before_type_cast
  return unless object
  method_before_type_cast = @method_name + "_before_type_cast"
  if value_came_from_user? && object.respond_to?(method_before_type_cast)
    object.public_send(method_before_type_cast)
  else
    value
  end
end

def value_came_from_user?
  method_name = "#{@method_name}_came_from_user?"
  !object.respond_to?(method_name) || object.public_send(method_name)
end