# -*- ruby -*-

require 'sequel/model'

require 'thingfish/mixins'

require 'thingfish/metastore/pggraph' unless defined?( Thingfish::Metastore::PgGraph )

### A row representing a relationship between two node objects.

###

class Thingfish::Metastore::PgGraph::Edge < Sequel::Model( :edges )

	# Related resource associations

	many_to_one :node, :key => :id_p

	# Dataset methods

	#

	dataset_module do

		#########

		protected

		#########

		### Returns a Sequel expression suitable for use as the key of a query against

		### the specified property field.

		###

		def prop_expr( field )

			return Sequel.pg_jsonb( :prop ).get_text( field.to_s )

		end

	end

	### Do some initial attribute setup for new objects.

	###

	def initialize( * )

		super

		self[ :prop ] ||= Sequel.pg_jsonb({})

	end

	#########

	protected

	#########

	### Proxy method -- fetch a value from the edge property hash if it exists.

	###

	def method_missing( sym, *args, &block )

		return self.prop[ sym.to_s ] || super

	end

end # Thingfish::Metastore::PgGraph::Edge