/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

/*!
 * \brief Sample golang application to demonstrate converted packed
 * function handle passed to another packed function.
 * \file pack_func_handle_arg.go
 */

package main

import (
    "fmt"
    "./gotvm"
)

// sampleCb is a simple golang callback function like C = A + B.
func sampleCb(args ...*gotvm.Value) (retVal interface{}, err error) {
    for _, v := range args {
        fmt.Printf("ARGS:%T : %v\n", v.AsInt64(), v.AsInt64())
    }
    val1 := args[0].AsInt64()
    val2 := args[1].AsInt64()
    retVal = int64(val1+val2)
    return
}

// sampleFunctionArg receives a Packed Function handle and calls it.
func sampleFunctionArg(args ...*gotvm.Value) (retVal interface{}, err error) {
    // Reveive Packed Function Handle
    pfunc := args[0].AsFunction()

    // Call Packed Function
    retVal, err = pfunc.Invoke(args[1], args[2])
    return
}

// main
func main() {
    // Simple convert to a packed function
    fhandle, err := gotvm.ConvertFunction(sampleCb)
    if err != nil {
        fmt.Print(err)
        return
    }

    gotvm.RegisterFunction(sampleFunctionArg);
    fmt.Printf("Registered: sampleFunctionArg\n")

    funp, err := gotvm.GetGlobalFunction("main.sampleFunctionArg")
    if err != nil {
        fmt.Print(err)
        return
    }

    retVal, err := funp.Invoke(fhandle, 10, 20)
    if err != nil {
        fmt.Print(err)
        return
    }
    fmt.Printf("Result:%v\n", retVal.AsInt64())
}