//go:build windows

package runtime

import (
	"path/filepath"
	"syscall"
	"unsafe"
)

var getDiskFreeSpaceEx = syscall.NewLazyDLL("kernel32.dll").NewProc("GetDiskFreeSpaceExW")

func workspaceDiskPercent(workspaceRoot string) (float64, error) {
	volume := filepath.VolumeName(workspaceRoot)
	if volume == "" {
		volume = workspaceRoot
	} else {
		volume += `\`
	}
	var available, total, free uint64
	success, _, callErr := getDiskFreeSpaceEx.Call(uintptr(unsafe.Pointer(syscall.StringToUTF16Ptr(volume))), uintptr(unsafe.Pointer(&available)), uintptr(unsafe.Pointer(&total)), uintptr(unsafe.Pointer(&free)))
	if success == 0 {
		return 0, callErr
	}
	if total == 0 {
		return 0, syscall.EINVAL
	}
	return 100 * float64(total-free) / float64(total), nil
}