# typed: strict
# frozen_string_literal: true

module RubyLsp
  module ResponseBuilders
    #: [ResponseType = Array[Interface::DocumentSymbol]]
    class DocumentSymbol < ResponseBuilder
      class SymbolHierarchyRoot
        #: Array[Interface::DocumentSymbol]
        attr_reader :children

        #: -> void
        def initialize
          @children = [] #: Array[Interface::DocumentSymbol]
        end
      end

      #: -> void
      def initialize
        super
        @stack = [SymbolHierarchyRoot.new] #: Array[(SymbolHierarchyRoot | Interface::DocumentSymbol)]
      end

      #: (Interface::DocumentSymbol symbol) -> void
      def push(symbol)
        @stack << symbol
      end

      alias_method(:<<, :push)

      #: -> Interface::DocumentSymbol?
      def pop
        if @stack.size > 1
          @stack.pop #: as Interface::DocumentSymbol
        end
      end

      #: -> (SymbolHierarchyRoot | Interface::DocumentSymbol)
      def last
        @stack.last #: as !nil
      end

      # @override
      #: -> Array[Interface::DocumentSymbol]
      def response
        @stack.first #: as !nil
          .children
      end
    end
  end
end