class Polyamorous::Join

def add_to_tree(hash)
  hash[self] ||= {}
end

def convert_to_arel_join_type(type)
  case type
  when 'inner', :inner
    InnerJoin
  when 'outer', :outer
    OuterJoin
  when Class
    if [InnerJoin, OuterJoin].include? type
      type
    else
      raise ArgumentError, "#{type} cannot be converted to an ARel join type"
    end
  else
    raise ArgumentError, "#{type} cannot be converted to an ARel join type"
  end
end

def convert_to_class(value)
  case value
  when String, Symbol
    Kernel.const_get(value)
  when Class
    value
  else
    raise ArgumentError, "#{value} cannot be converted to a Class"
  end
end

def eql?(other)
  self.class == other.class &&
  self.name  == other.name &&
  self.type  == other.type &&
  self.klass == other.klass
end

def hash
  [@name, @type, @klass].hash
end

def initialize(name, type = InnerJoin, klass = nil)
  @name = name
  @type = convert_to_arel_join_type(type)
  @klass = convert_to_class(klass) if klass
end

def klass=(klass)
  @klass = convert_to_class(klass) if klass
end

def type=(type)
  @type = convert_to_arel_join_type(type) if type
end