class GraphQL::Analysis::FieldUsage

def extract_deprecated_arguments(argument_values)
  argument_values.each_pair do |_argument_name, argument|
    if argument.definition.deprecation_reason
      @used_deprecated_arguments << argument.definition.path
    end
    arg_val = argument.value
    next if arg_val.nil?
    argument_type = argument.definition.type
    if argument_type.non_null?
      argument_type = argument_type.of_type
    end
    if argument_type.kind.input_object?
      extract_deprecated_arguments(argument.original_value.arguments.argument_values) # rubocop:disable Development/ContextIsPassedCop -- runtime args instance
    elsif argument_type.kind.enum?
      extract_deprecated_enum_value(argument_type, arg_val)
    elsif argument_type.list?
      inner_type = argument_type.unwrap
      case inner_type.kind
      when TypeKinds::INPUT_OBJECT
        argument.original_value.each do |value|
          extract_deprecated_arguments(value.arguments.argument_values) # rubocop:disable Development/ContextIsPassedCop -- runtime args instance
        end
      when TypeKinds::ENUM
        arg_val.each do |value|
          extract_deprecated_enum_value(inner_type, value)
        end
      else
        # Not a kind of input that we track
      end
    end
  end
end

def extract_deprecated_enum_value(enum_type, value)
  enum_value = @query.types.enum_values(enum_type).find { |ev| ev.value == value }
  if enum_value&.deprecation_reason
    @used_deprecated_enum_values << enum_value.path
  end
end

def initialize(query)
  super
  @used_fields = Set.new
  @used_deprecated_fields = Set.new
  @used_deprecated_arguments = Set.new
  @used_deprecated_enum_values = Set.new
end

def on_leave_field(node, parent, visitor)
  field_defn = visitor.field_definition
  field = "#{visitor.parent_type_definition.graphql_name}.#{field_defn.graphql_name}"
  @used_fields << field
  @used_deprecated_fields << field if field_defn.deprecation_reason
  arguments = visitor.query.arguments_for(node, field_defn)
  # If there was an error when preparing this argument object,
  # then this might be an error or something:
  if arguments.respond_to?(:argument_values)
    extract_deprecated_arguments(arguments.argument_values)
  end
end

def result
  {
    used_fields: @used_fields.to_a,
    used_deprecated_fields: @used_deprecated_fields.to_a,
    used_deprecated_arguments: @used_deprecated_arguments.to_a,
    used_deprecated_enum_values: @used_deprecated_enum_values.to_a,
  }
end