// license that can be found in the LICENSE file.

package os

import (
	"internal/syscall/windows"
	"syscall"
)

func getModuleFileName(handle syscall.Handle) (string, error) {
	n := uint32(1024)
	var buf []uint16
	for {
		buf = make([]uint16, n)
		r, err := windows.GetModuleFileName(handle, &buf[0], n)
		if err != nil {
			return "", err
		}
		if r < n {
			break
		}
		// r == n means n not big enough

//sys	GetComputerNameEx(nameformat uint32, buf *uint16, n *uint32) (err error) = GetComputerNameExW
//sys	MoveFileEx(from *uint16, to *uint16, flags uint32) (err error) = MoveFileExW
//sys	GetModuleFileName(module syscall.Handle, fn *uint16, len uint32) (n uint32, err error) = kernel32.GetModuleFileNameW

	n = uint32(r0)
	if n == 0 {
		err = errnoErr(e1)
	}
	return
}

func GetModuleFileName(module syscall.Handle, fn *uint16, len uint32) (n uint32, err error) {
	r0, _, e1 := syscall.Syscall(procGetModuleFileNameW.Addr(), 3, uintptr(module), uintptr(unsafe.Pointer(fn)), uintptr(len))
	n = uint32(r0)
	if n == 0 {

//sys	FreeLibrary(handle Handle) (err error)
//sys	GetProcAddress(module Handle, procname string) (proc uintptr, err error)
//sys	GetModuleFileName(module Handle, filename *uint16, size uint32) (n uint32, err error) = kernel32.GetModuleFileNameW
//sys	GetModuleHandleEx(flags uint32, moduleName *uint16, module *Handle) (err error) = kernel32.GetModuleHandleExW

func GetMaximumProcessorCount(groupNumber uint16) (ret uint32) {
	r0, _, _ := syscall.Syscall(procGetMaximumProcessorCount.Addr(), 1, uintptr(groupNumber), 0, 0)
	ret = uint32(r0)
	return
}

func GetModuleFileName(module Handle, filename *uint16, size uint32) (n uint32, err error) {
	r0, _, e1 := syscall.Syscall(procGetModuleFileNameW.Addr(), 3, uintptr(module), uintptr(unsafe.Pointer(filename)), uintptr(size))
	n = uint32(r0)