class GraphQL::Pagination::ActiveRecordRelationConnection

def already_loaded?(relation)
  relation.is_a?(Array) || relation.loaded?
end

def null_relation(relation)
  if relation.respond_to?(:none)
    relation.none
  else
    # Rails 3
    relation.where("1=2")
  end
end

def relation_count(relation)
  int_or_hash = if already_loaded?(relation)
    relation.size
  elsif relation.respond_to?(:unscope)
    relation.unscope(:order).count(:all)
  else
    # Rails 3
    relation.count
  end
  if int_or_hash.is_a?(Integer)
    int_or_hash
  else
    # Grouped relations return count-by-group hashes
    int_or_hash.length
  end
end

def relation_larger_than(relation, initial_offset, size)
  if already_loaded?(relation)
    (relation.size + initial_offset) > size
  else
    set_offset(sliced_nodes, initial_offset + size).exists?
  end
end

def relation_limit(relation)
  if relation.is_a?(Array)
    nil
  else
    relation.limit_value
  end
end

def relation_offset(relation)
  if relation.is_a?(Array)
    nil
  else
    relation.offset_value
  end
end

def set_limit(nodes, limit)
  if already_loaded?(nodes)
    nodes.take(limit)
  else
    super
  end
end

def set_offset(nodes, offset)
  if already_loaded?(nodes)
    # If the client sent a bogus cursor beyond the size of the relation,
    # it might get `nil` from `#[...]`, so return an empty array in that case
    nodes[offset..-1] || []
  else
    super
  end
end