class Capybara::Selector::FilterSet

def [](name)
  all.fetch(name.to_sym) { |set_name| raise ArgumentError, "Unknown filter set (:#{set_name})" }
end

def add(name, &block)
  all[name.to_sym] = FilterSet.new(name.to_sym, &block)
end

def add_filter(name, filter_class, *types, matcher: nil, **options, &block)
  types.each { |type| options[type] = true }
  if matcher && options[:default]
    raise 'ArgumentError', ':default option is not supported for filters with a :matcher option'
  end
  filter = filter_class.new(name, matcher, block, **options)
  (filter_class <= Filters::ExpressionFilter ? @expression_filters : @node_filters)[name] = filter
end

def all
  @filter_sets ||= {} # rubocop:disable Naming/MemoizedInstanceVariableName
end

def describe(what = nil, &block)
  case what
  when nil
    undeclared_descriptions.push block
  when :node_filters
    node_filter_descriptions.push block
  when :expression_filters
    expression_filter_descriptions.push block
  else
    raise ArgumentError, 'Unknown description type'
  end
end

def description(node_filters: true, expression_filters: true, **options)
  opts = options_with_defaults(options)
  description = +''
  description << undeclared_descriptions.map { |desc| desc.call(**opts).to_s }.join
  description << expression_filter_descriptions.map { |desc| desc.call(**opts).to_s }.join if expression_filters
  description << node_filter_descriptions.map { |desc| desc.call(**opts).to_s }.join if node_filters
  description
end

def descriptions
  Capybara::Helpers.warn 'DEPRECATED: FilterSet#descriptions is deprecated without replacement'
  [undeclared_descriptions, node_filter_descriptions, expression_filter_descriptions].flatten
end

def expression_filter(name, *types, **options, &block)
  add_filter(name, Filters::ExpressionFilter, *types, **options, &block)
end

def expression_filter_descriptions
  @descriptions[:expression_filters]
end

def import(name, filters = nil)
  filter_selector = filters.nil? ? ->(*) { true } : ->(filter_name, _) { filters.include? filter_name }
  self.class[name].tap do |f_set|
    expression_filters.merge!(f_set.expression_filters.select(&filter_selector))
    node_filters.merge!(f_set.node_filters.select(&filter_selector))
    f_set.undeclared_descriptions.each { |desc| describe(&desc) }
    f_set.expression_filter_descriptions.each { |desc| describe(:expression_filters, &desc) }
    f_set.node_filter_descriptions.each { |desc| describe(:node_filters, &desc) }
  end
  self
end

def initialize(name, &block)
  @name = name
  @node_filters = {}
  @expression_filters = {}
  @descriptions = Hash.new { |hsh, key| hsh[key] = [] }
  instance_eval(&block) if block
end

def node_filter(names, *types, **options, &block)
  Array(names).each do |name|
    add_filter(name, Filters::NodeFilter, *types, **options, &block)
  end
end

def node_filter_descriptions
  @descriptions[:node_filters]
end

def options_with_defaults(options)
  expression_filters
    .chain(node_filters)
    .filter_map { |name, filter| [name, filter.default] if filter.default? }
    .to_h.merge!(options)
end

def remove(name)
  all.delete(name.to_sym)
end

def undeclared_descriptions
  @descriptions[:undeclared]
end