# frozen_string_literal: true

module GraphQLHelpers
  # makes snake_case_field_name look like a graphql camelCaseFieldName
  # "many_pokemon" => "manyPokemon"
  def self.fieldnamerize(underscored_field_name)
    graphql_field_name = underscored_field_name.to_s.camelize
    graphql_field_name[0] = graphql_field_name[0].downcase

    graphql_field_name
  end

  def self.keys_for_klass(klass)
    case klass
    when GraphQL::Field
      klass.type
    else
      klass
    end.fields.keys
  end

  def self.arguments_for_field(field)
    case field
    when GraphQL::Schema::Resolver
      field.instance_variable_get('@arguments_by_keyword').map { |_, v| v.name }
    else
      field.arguments.keys
    end
  end

  def self.plural_arguments_for_field(field)
    keys = arguments_for_field(field)
    # Connections mandate extra fields, which are not owned by a plural based
    # resolver.
    # keys -= %w[after before first last]

    keys.map do |key|
      type_class = field.arguments[key.to_s].metadata[:type_class]
      plurals = type_class.owner.try(:plurals)

      if plurals
        arg = plurals[key.underscore.to_sym]
        fieldnamerize(arg.to_s) if arg
      end
    end.compact
  end

  def self.plural_argument_for_field(field, argument)
    field.arguments[argument.to_s].metadata[:type_class].owner.plurals[argument.to_sym]
  end

  # Shortcut for running resolvers #resolve methods
  def resolve(resolver_class, obj: nil, args: {}, ctx: {})
    resolver_class.new(object: obj, context: ctx).resolve(args)
  end
end