Create a query to traverse a graph tree

Hello, I need a query against an OrientDB graph database. The problem is quite simple, i.e. we need to calculate the cost of an assembly, made of sub-assemblies, made of components, etc. a) we need to know dynamically the cost of the root assembly "mac01" by summing up the cost from the bottom as per .xlsx attached sheed. b) we need to create/update a property on the edges displaying the cost of the leaf element * the quantity of the element. c) we need to create/update a property on the vertices displaying the cost of the element (sum of components) Ideally, we would like this in gremlin-groovy, but other languages would also be accepted if no impact on speed. Thanks. D.