package main

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

const (
	MAX_BUFFER_SIZE = 16
)

func DdeCallback(wType int, wFmt int, hConv uintptr, hsz1 uintptr, hsz2 uintptr, hData uintptr, dwData1 int64, dwData2 int64) int {
	switch wType {
	case XTYP_CONNECT:
		//接受客户端链接；
		return 0 //接受客户端链接
	case XTYP_ADVSTART:
		//客户端启动咨询循环。
		return 0 //接受客户端链接
	case XTYP_ADVREQ:
		//广播数据；
	case XTYP_REQUEST:
		//数据请求；
	case XTYP_POKE:
		//接受客户端发送的数据；
	default:
		return 0
	}
	return 0
}

var callbacks FNCALLBACK = func(
	Type UINT,
	Fmt UINT,
	Conv HCONV,
	Sz1 HSZ,
	Sz2 HSZ,
	Data HDDEDATA,
	Data1 ULONG_PTR,
	Data2 ULONG_PTR) HDDEDATA {
	return 0
}

func DDERequest(idInst DWORD, hConv HCONV, hszItem HSZ, sDesc string) string {
	hData := dde.DdeClientTransaction(nil, 0, hConv, hszItem, UINT(CF_TEXT),
		UINT(XTYP_REQUEST), 5000, nil)
	if hData == 0 {
		return "Request failed"
	} else {
		size := dde.DdeGetData(hData, nil, 0, 0)
		var str BYTE
		dde.DdeGetData(hData, &str, size, 0)
		buffer := (*[MAX_BUFFER_SIZE]byte)(unsafe.Pointer(&str))[:size-1]
		//szResult := *(*[]byte)(unsafe.Pointer(&str))
		return string(buffer)
	}
}
func DDEPoke(idInst DWORD, hConv HCONV, hszItem HSZ, szData string) {
	var data []byte = []byte(szData)
	dde.DdeClientTransaction((unsafe.Pointer(&data)),
		DWORD(len(data)+1),
		hConv, hszItem, UINT(CF_TEXT),
		UINT(XTYP_POKE), 3000, nil)
}

var idInst DWORD = 0
var szApp VString = "Server"
var szTopic VString = "MyTopic"
var items []VString = []VString{"MyItem0", "MyItem1", "MyItem2", "MyItem3", "MyItem4", "MyItem5", "MyItem6"}
var hszItem []HSZ = make([]HSZ, len(items))

func runClient() {
	// AddApis(dde.DdeApis)
	// AddApis(dde.DdeANSIApis)
	// AddApis(dde.DdeUnicodeApis)
	var cmd DWORD = DWORD(APPCLASS_STANDARD | APPCMD_CLIENTONLY)
	var res DWORD = 0
	iReturn := dde.DdeInitialize(&idInst, DdeCallback, cmd, res)
	if iReturn != UINT(DMLERR_NO_ERROR) {

	}
	if int(iReturn) != DMLERR_NO_ERROR {
		fmt.Printf("DDE Initialization Failed")
	}
	var hConv HCONV // 会话句柄
	hszApp := dde.DdeCreateStringHandle(idInst, szApp, 0)
	hszTopic := dde.DdeCreateStringHandle(idInst, szTopic, 0)
	for i := 0; i < len(items); i++ {
		hszItem[i] = dde.DdeCreateStringHandle(idInst, items[i], 0)
	}
	hConv = dde.DdeConnect(idInst, hszApp, hszTopic, nil)
	dde.DdeFreeStringHandle(idInst, hszApp)
	dde.DdeFreeStringHandle(idInst, hszTopic)
	if hConv == 0 {
		fmt.Printf("DDE Connection Failed.\n")
		time.Sleep(2e9) //2e9 相当于2秒
		dde.DdeUninitialize(idInst)
	}
	for i := 0; i < len(items); i++ {
		data := DDERequest(idInst, hConv, hszItem[i], "请求到服务端数据: ")
		fmt.Printf("data: %v\n", data)
		DDEPoke(idInst, hConv, hszItem[i], data)
		time.Sleep(1e9)
	}
	fmt.Printf("客户端关闭")
	dde.DdeDisconnect(hConv)
	dde.DdeUninitialize(idInst)
}

func main() {
	runClient()
}