package fileops

import (
	"errors"
	"time"

	"golang.org/x/sys/windows"
)

func renameReplacing(oldPath, newPath string) error {
	source, err := windows.UTF16PtrFromString(oldPath)
	if err != nil {
		return err
	}
	target, err := windows.UTF16PtrFromString(newPath)
	if err != nil {
		return err
	}
	// Concurrent replacement, short-lived readers and antivirus scans can hold
	// an NTFS destination briefly. Retry only transient conflicts, preserving
	// both files until the kernel completes one atomic replacement.
	deadline := time.Now().Add(time.Second)
	for {
		err := windows.MoveFileEx(source, target, windows.MOVEFILE_REPLACE_EXISTING|windows.MOVEFILE_WRITE_THROUGH)
		if err == nil || time.Now().After(deadline) ||
			(!errors.Is(err, windows.ERROR_SHARING_VIOLATION) &&
				!errors.Is(err, windows.ERROR_LOCK_VIOLATION) &&
				!errors.Is(err, windows.ERROR_ACCESS_DENIED)) {
			return err
		}
		time.Sleep(20 * time.Millisecond)
	}
}