import "Simantics/DB"
import "Simantics/Ontologies"

importJava "org.simantics.datatypes.literal.GUID" where
    
    data GUID

instance Show GUID where
    show guid = guidIndexString guid

importJava "org.simantics.datatypes.literal.GUID" where
    @JavaName "BINDING"
    guidBinding :: Binding a
    @JavaName random
    randomGUID :: <Proc> GUID
    @JavaName indexString
    guidIndexString :: GUID -> String
    
guidOf :: Resource -> <ReadGraph> GUID
guidOf res = relatedValue_ res L0.identifier guidBinding
    
possibleGUIDOf :: Resource -> <ReadGraph> Maybe GUID
possibleGUIDOf res = possibleRelatedValue_ res L0.identifier guidBinding

claimGUID :: Resource -> <WriteGraph, Proc> ()
claimGUID res = do
    match possibleGUIDOf res with
      Nothing -> claimRelatedValueWithType_ res L0.identifier L0.GUID randomGUID guidBinding
      _ -> ()