import "Stream"
import "Serialization"
include "R/RExp"

"""The effect <R> for a routine means that it needs to be dispatched to an R session using a suitable
R execution routine. (syncExec, asyncExec, withConfiguration.)"""
effect R 
    "r" 
    "org.rosuda.REngine.Rserve.RConnection"

importJava "org.simantics.r.scl.RSessionConfiguration" where
    """SessionConfiguration is a configuration element for the Session.
    
    The fields of the type are: SessionConfiguration <host name> <port number> <user name> <password>"""
    data SessionConfiguration = 
        @FieldNames [host, port, username, password]
        SessionConfiguration String Integer String String

importJava "org.simantics.r.scl.RSession" where
    "Session represents an open R session with an Rserve instance."
    data Session
    "Execute a given R operation synchronously. sychExec <session> <r operation>." 
    syncExec :: Session -> (<R> a) -> <Proc> a
    "Execute a given R operation asynchronously. asychExec <session> <r operation>." 
    asyncExec :: Session -> (<R> a) -> <Proc> ()
    "Get the session id of an open R session." 
    @JavaName getId
    sessionIdOf :: Session -> String
    "Close the given R session." 
    @JavaName close
    closeSession :: Session -> <Proc> ()  
    "Refresh the variables of a given R session." 
    @JavaName refreshVariablesSync
    refreshVariables :: Session -> <Proc> ()

importJava "org.simantics.r.scl.RSessionManager" where
    "Get a session using a given session id." 
    @JavaName getSession
    sessionById :: String -> <Proc> Maybe Session
    "Create a new session with a given configuration." 
    createSession :: SessionConfiguration -> <Proc> Session
    "Execute a given R operation using a temporary session with the given configuration." 
    withConfiguration :: SessionConfiguration-> (<R,e> a) -> <Proc,e> a
    "Get a session with the given session id or create a new session, if not found." 
    getOrCreateSession :: SessionConfiguration -> String -> <Proc> Session
    
importJava "org.rosuda.REngine.Rserve.RConnection" where
    "Evaluate an R expression, returning the result as an RExp object." 
    @JavaName eval
    evalRExp:: String -> <R> RExp
    "Evaluate an R expression and ignore the result." 
    @JavaName voidEval
    evalR_ :: String -> <R> ()
    "Evaluate an R expression and return the result as a string." 
    @JavaName voidEvalS
    evalRS_ :: String -> <R> String
    "Assign an RExp value to a variable in R." 
    @JavaName assign
    assignRExp :: String -> RExp -> <R> ()
    "Create a file on the R server and a return an OutputStream for it." 
    @JavaName createFile
    createFileR :: String -> <R> OutputStream
    "Open a file on the R server for reading and return a InputStream for it." 
    @JavaName openFile
    openFileR :: String -> <R> InputStream

"Evaluate an R expression and return the result as an SCL value. May fail, if the value is not compatible with the expected data type."
evalR :: RCompatible a => String -> <R> a
evalR = fromRExp . evalRExp

"Assign an SCL value to a variable in R." 
assignR :: RCompatible a => String -> a -> <R> ()
assignR name = assignRExp name . toRExp

"Read the contents of a file on the R server into a string."
readFileAsStringR :: String -> <R> String
readFileAsStringR name = runProc (readAllString (openFileR name))