class Ransack::Adapters::ActiveRecord::Context

def build_joins(relation)
  buckets = relation.joins_values + relation.left_outer_joins_values
  buckets = buckets.group_by do |join|
    case join
    when String
      :string_join
    when Hash, Symbol, Array
      :association_join
    when Polyamorous::JoinDependency, Polyamorous::JoinAssociation
      :stashed_join
    when Arel::Nodes::Join
      :join_node
    else
      raise 'unknown class: %s' % join.class.name
    end
  end
  buckets.default = []
  association_joins         = buckets[:association_join]
  stashed_association_joins = buckets[:stashed_join]
  join_nodes                = buckets[:join_node].uniq
  string_joins              = buckets[:string_join].map(&:strip)
  string_joins.uniq!
  join_list = join_nodes + convert_join_strings_to_ast(relation.table, string_joins)
  alias_tracker = ::ActiveRecord::Associations::AliasTracker.create(self.klass.connection, relation.table.name, join_list)
  join_dependency = Polyamorous::JoinDependency.new(relation.klass, relation.table, association_joins, Arel::Nodes::OuterJoin)
  join_dependency.instance_variable_set(:@alias_tracker, alias_tracker)
  join_nodes.each do |join|
    join_dependency.send(:alias_tracker).aliases[join.left.name.downcase] = 1
  end
  join_dependency
end