From 2fd55f11836bc4b4490421e336c79f3ceeaeaede Mon Sep 17 00:00:00 2001
From: Matthias Fulz <mfulz@olznet.de>
Date: Wed, 6 Nov 2019 01:16:23 +0100
Subject: [PATCH] Basic handling of input and output arguments for registered
 functions

---
 server.go | 60 +++++++++++++++++++++++++++++++++++++++++++++----------
 1 file changed, 50 insertions(+), 10 deletions(-)

diff --git a/server.go b/server.go
index 98770ae..dc99fa5 100644
--- a/server.go
+++ b/server.go
@@ -2,6 +2,7 @@ package srpc
 
 import (
 	"bytes"
+	"errors"
 	"fmt"
 	"olznet.de/ssob"
 	"reflect"
@@ -31,10 +32,12 @@ type responseHeader struct {
 }
 
 type parseInputsFunc func(in []byte) (ret []reflect.Value)
+type parseOutputsFunc func(in []reflect.Value) (ret []byte)
 
 type service struct {
-	f   reflect.Value
-	fin parseInputsFunc
+	f    reflect.Value
+	fin  parseInputsFunc
+	fout parseOutputsFunc
 }
 
 type Server struct {
@@ -48,6 +51,9 @@ func NewServer() *Server {
 var DefaultServer = NewServer()
 
 func (server *Server) RegisterName(name string, rcvr interface{}) (err error) {
+	if _, ok := server.serviceMap.Load(name); ok {
+		return errors.New("srpc: Function with name '" + name + "' already registerd")
+	}
 	ft := reflect.TypeOf(rcvr)
 	fv := reflect.ValueOf(rcvr)
 
@@ -56,7 +62,7 @@ func (server *Server) RegisterName(name string, rcvr interface{}) (err error) {
 
 	fs := service{}
 
-	f := func(in []byte) (ret []reflect.Value) {
+	fs.fin = func(in []byte) (ret []reflect.Value) {
 		var b bytes.Buffer
 		if _, err = b.Write(in); err != nil {
 			return nil
@@ -76,19 +82,53 @@ func (server *Server) RegisterName(name string, rcvr interface{}) (err error) {
 		return ret
 	}
 
-	fs.fin = f
+	fs.fout = func(in []reflect.Value) (ret []byte) {
+		var b bytes.Buffer
+		encoder := ssob.NewEncoder(&b)
+
+		for _, v := range in {
+			if v.Type() == reflect.TypeOf((*error)(nil)).Elem() {
+				if v.IsNil() {
+					if err := encoder.Encode(string("")); err != nil {
+						fmt.Println(err)
+						return nil
+					}
+				} else {
+					if err := encoder.Encode(v.Interface().(error).Error()); err != nil {
+						fmt.Println(err)
+						return nil
+					}
+				}
+			} else {
+				if err := encoder.Encode(v.Interface()); err != nil {
+					fmt.Println(err)
+					return nil
+				}
+			}
+		}
+
+		return b.Bytes()
+	}
+
 	fs.f = fv
 	server.serviceMap.Store(name, fs)
 
 	return nil
 }
 
-func (server *Server) CallName(name string, in []byte) {
+func (server *Server) CallName(name string, args ...interface{}) (ret []byte) {
+	var b bytes.Buffer
+	encoder := ssob.NewEncoder(&b)
+
 	fs, _ := server.serviceMap.Load(name)
 
-	fmt.Printf("3. ")
-	fmt.Println(in)
-	inputs := fs.(service).fin(in)
-	fmt.Println(inputs)
-	fs.(service).f.Call(inputs)
+	for _, a := range args {
+		if err := encoder.Encode(a); err != nil {
+			fmt.Println(err)
+			return nil
+		}
+	}
+	inputs := fs.(service).fin(b.Bytes())
+	outputs := fs.(service).f.Call(inputs)
+	return fs.(service).fout(outputs)
 }