# typed: strict
# frozen_string_literal: true

module RBI
  module Rewriters
    class SortNodes < Visitor
      extend T::Sig

      sig { override.params(node: T.nilable(Node)).void }
      def visit(node)
        return unless node.is_a?(Tree)
        visit_all(node.nodes)
        original_order = node.nodes.map.with_index.to_h
        node.nodes.sort! do |a, b|
          res = node_rank(a) <=> node_rank(b)
          res = node_name(a) <=> node_name(b) if res == 0
          res = (original_order[a] || 0) <=> (original_order[b] || 0) if res == 0
          res || 0
        end
      end

      private

      sig { params(node: Node).returns(Integer) }
      def node_rank(node)
        case node
        when Group                then group_rank(node.kind)
        when Include, Extend      then 10
        when Helper               then 20
        when TypeMember           then 30
        when MixesInClassMethods  then 40
        when TStructField         then 50
        when TEnumBlock           then 60
        when Method
          if node.name == "initialize"
            71
          elsif !node.is_singleton
            72
          else
            73
          end
        when Scope, Const then 80
        else
          100
        end
      end

      sig { params(kind: Group::Kind).returns(Integer) }
      def group_rank(kind)
        case kind
        when Group::Kind::Mixins              then 0
        when Group::Kind::Helpers             then 1
        when Group::Kind::TypeMembers         then 2
        when Group::Kind::MixesInClassMethods then 3
        when Group::Kind::TStructFields       then 4
        when Group::Kind::TEnums              then 5
        when Group::Kind::Inits               then 6
        when Group::Kind::Methods             then 7
        when Group::Kind::Consts              then 8
        else
          T.absurd(kind)
        end
      end

      sig { params(node: Node).returns(T.nilable(String)) }
      def node_name(node)
        case node
        when Module, Class, Struct, Const, Method, Helper, TStructField
          node.name
        end
      end
    end
  end

  class Tree
    extend T::Sig

    sig { void }
    def sort_nodes!
      visitor = Rewriters::SortNodes.new
      visitor.visit(self)
    end
  end
end