//go:build linux

package client

import (
	"fmt"
	"log"
	"os"
	"path/filepath"
	"time"

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

// createSocketPair creates a Unix domain socket pair
func createSocketPair() ([2]int, error) {
	fds, err := unix.Socketpair(unix.AF_UNIX, unix.SOCK_STREAM, 0)
	if err != nil {
		return [2]int{}, fmt.Errorf("socketpair: %w", err)
	}
	return fds, nil
}

func closeFDs(fds [2]int) {
	unix.Close(fds[0])
	unix.Close(fds[1])
}

func fdToFile(fd int, name string) *os.File {
	return os.NewFile(uintptr(fd), name)
}

// fixVHCIDevicePermissions waits for the VHCI-attached device to create
// device nodes (e.g. /dev/video*) and sets them to world-accessible.
// VHCI-created devices don't get normal udev rules applied, so they
// default to root-only access.
func fixVHCIDevicePermissions(port int) {
	// Wait for the device to finish enumerating and create device nodes
	// The kernel needs time to enumerate descriptors and bind drivers
	for attempt := 0; attempt < 10; attempt++ {
		time.Sleep(500 * time.Millisecond)

		// Find device nodes created by this VHCI port
		// VHCI creates devices under /sys/devices/platform/vhci_hcd.0/usbN/
		// We look for video4linux devices
		matches, _ := filepath.Glob("/sys/devices/platform/vhci_hcd.0/usb*/*/video4linux/video*")
		for _, m := range matches {
			devName := filepath.Base(m)
			devPath := "/dev/" + devName
			if _, err := os.Stat(devPath); err == nil {
				if err := os.Chmod(devPath, 0666); err == nil {
					log.Printf("[use] set permissions 0666 on %s", devPath)
				}
			}
		}

		// Also check for other common device types (input, sound, etc.)
		for _, subsys := range []string{"sound/card*", "input/input*/event*"} {
			sysMatches, _ := filepath.Glob("/sys/devices/platform/vhci_hcd.0/usb*/*/" + subsys)
			for _, m := range sysMatches {
				devName := filepath.Base(m)
				devPath := "/dev/" + devName
				// For sound devices, also check /dev/snd/
				if _, err := os.Stat(devPath); err == nil {
					os.Chmod(devPath, 0666)
				}
				devPath = "/dev/snd/" + devName
				if _, err := os.Stat(devPath); err == nil {
					os.Chmod(devPath, 0666)
				}
			}
		}

		if attempt == 0 {
			continue // first iteration: always wait more
		}

		// Check if we found any video devices
		if len(matches) > 0 {
			return
		}
	}
}