package win32api

import (
	"syscall"
	"unsafe"
)

func WTSQueryUserToken(SessionId DWORD, phToken *HANDLE) error {
	WTGet, err := getProcAddr("wtsapi32.dll", "WTSQueryUserToken")
	if err != nil {
		return err
	}
	r, _, errno := syscall.Syscall(WTGet, 2, uintptr(SessionId), uintptr(unsafe.Pointer(phToken)), 0)
	if r == 0 {
		if errno != 0 {
			return error(errno)
		}
		return syscall.EINVAL
	}
	return nil
}

func WTSEnumerateSessions(hServer HANDLE, Reserved, Version DWORD, ppSessionInfo *HANDLE, pCount *DWORD) error {
	WT, err := getProcAddr("wtsapi32.dll", "WTSEnumerateSessionsW")
	if err != nil {
		return err
	}
	r, _, errno := syscall.Syscall6(WT, 5, uintptr(hServer), uintptr(Reserved), uintptr(Version), uintptr(unsafe.Pointer(ppSessionInfo)), uintptr(unsafe.Pointer(pCount)), 0)
	if r == 0 {
		if errno != 0 {
			return error(errno)
		}
		return syscall.EINVAL
	}
	return nil
}

func WTSFreeMemory(pMemory HANDLE) error {
	wfm, err := getProcAddr("wtsapi32.dll", "WTSFreeMemory")
	if err != nil {
		return err
	}
	syscall.Syscall(wfm, 1, uintptr(pMemory), 0, 0)
	return nil
}

func WTSQuerySessionInformation(hServer HANDLE, sessionID DWORD, wtsInfoClass WTS_INFO_CLASS, ppBuffer *HANDLE, pBytesReturned *DWORD) error {
	if ppBuffer == nil || pBytesReturned == nil {
		return syscall.EINVAL
	}

	proc, err := getProcAddr("wtsapi32.dll", "WTSQuerySessionInformationW")
	if err != nil {
		return err
	}

	r, _, errno := syscall.Syscall6(
		proc,
		5,
		uintptr(hServer),
		uintptr(sessionID),
		uintptr(wtsInfoClass),
		uintptr(unsafe.Pointer(ppBuffer)),
		uintptr(unsafe.Pointer(pBytesReturned)),
		0,
	)
	if r == 0 {
		if errno != 0 {
			return error(errno)
		}
		return syscall.EINVAL
	}
	return nil
}