package dde

/*
#include <stdio.h>
#include <stdlib.h>
*/
import "C"

import (
	ddeml "go-dde/ddeml"
	. "go-dde/types"
	"unsafe"
)

const (
	MAX_BUFFER_SIZE = 16
)

func DDERequest(idInst DWORD, hConv HCONV, hszItem HSZ, sDesc string) string {
	hData := ddeml.DdeClientTransaction(nil, 0, hConv, hszItem, UINT(CF_TEXT),
		UINT(XTYP_REQUEST), 5000, nil)
	if hData == 0 {
		return "Request failed"
	} else {
		return DDEGetMessage(hData)
	}
}
func DDEPoke(idInst DWORD, hConv HCONV, hszItem HSZ, szData string) {
	cs := C.CString(szData)
	ddeml.DdeClientTransaction((*BYTE)(unsafe.Pointer(cs)),
		DWORD(len(szData)+1),
		hConv, hszItem, UINT(CF_TEXT),
		UINT(XTYP_POKE), 3000, nil)
	C.free(unsafe.Pointer(cs))
}
func DDESendMessage(Inst DWORD, Src string, Item HSZ, Fmt UINT) HDDEDATA {
	cs := C.CString(Src)
	hdata := ddeml.DdeCreateDataHandle(Inst, (*BYTE)(unsafe.Pointer(cs)), DWORD(len(Src)+1), 0, Item, Fmt, 0)
	C.free(unsafe.Pointer(cs))
	return hdata
}
func DDEGetMessage(hData HDDEDATA) string {
	size := ddeml.DdeGetData(hData, nil, 0, 0)
	var str BYTE
	ddeml.DdeGetData(hData, &str, size, 0)
	buffer := (*[MAX_BUFFER_SIZE]byte)(unsafe.Pointer(&str))[:size-1]
	return string(buffer)
}