package main

/*
  #include <stdlib.h>
  #include <stdio.h>
  #include <string.h>

  typedef int(*callbackProc)(char const *name, char const *function, char const *data);

  static inline int bridge_cb(callbackProc cb, char const *name, char const *function, char const *data) {
	return cb(name, function, data);
  }

  static inline uint min(uint a, uint b) { return a < b ? a : b; }
*/
import "C"

import (
	"fmt"
	"log"
	"strings"
	"unsafe"
	"net/http"
)

var cb C.callbackProc
var name = C.CString("a3web")
var serverURL = "https://localhost"

// RVExtensionRegisterCallback on extension load
//export RVExtensionRegisterCallback
func RVExtensionRegisterCallback(cbptr unsafe.Pointer) {
	cb = C.callbackProc(cbptr)

	log.Println("Calling callback function ……")
	function := C.CString("registered")
	defer C.free(unsafe.Pointer(function))
	C.bridge_cb(cb, name, function, function)
}

// RVExtensionVersion on extension load
//export RVExtensionVersion
func RVExtensionVersion(output *C.char, outputsize C.size_t) {
	version := C.CString("Version 0.1")
	defer C.free(unsafe.Pointer(version))
	var size = C.min(C.strlen(version)+1, outputsize-1)
	C.strncpy(output, version, size)
}

// RVExtensionArgs STRING callExtension ARRAY
//export RVExtensionArgs
func RVExtensionArgs(output *C.char, outputsize C.size_t, function *C.char, argv **C.char, argc C.int) {
	var offset = unsafe.Sizeof(uintptr(0))
	var out []string
	for index := C.int(0); index < argc; index++ {
		out = append(out, C.GoString(*argv))
		argv = (**C.char)(unsafe.Pointer(uintptr(unsafe.Pointer(argv)) + offset))
	}
	
	go handleArgs(C.GoString(function), argc, out)
}

// RVExtension STRING callExtension STRING
//export RVExtension
func RVExtension(output *C.char, outputsize C.size_t, function *C.char) {
	result := C.CString(fmt.Sprintf("Hello, %s!", C.GoString(function)))
	defer C.free(unsafe.Pointer(result))
	var size = C.min(C.strlen(result)+1, outputsize-1)
	C.strncpy(output, result, size)
}

func main() {}

func handleArgs(function string, argc C.int, argv []string) {
	fns := strings.Split(strings.ToLower(function), ":")
	if len(fns) == 3 && fns[0] == "http" && fns[1] == "post" {
		resp, err := http.Post(serverURL + fns[2], "", strings.NewReader(argv[0]))
		if err != nil {
			log.Printf("Error Sending HTTP Request: %s", err)
			return
		}
		resp.Body.Close()
	}
}