package app

import (
	"context"
	"fmt"
	"io/fs"
	"net"
	"os"
	"os/user"
	"strconv"
	"time"
)

// ---------------------------------------------------------------------
// filesystem helpers
// ---------------------------------------------------------------------

func copyFile(src, dst string) error {
	data, err := os.ReadFile(src)
	if err != nil {
		return err
	}
	return os.WriteFile(dst, data, 0o644)
}

// ---------------------------------------------------------------------
// EN: `chownDev` contains core logic for chown dev.
// RU: `chownDev` - содержит основную логику для chown dev.
// ---------------------------------------------------------------------
func chownDev(paths ...string) {
	usr, err := user.Lookup("dev")
	if err != nil {
		return
	}
	uid, _ := strconv.Atoi(usr.Uid)
	gid, _ := strconv.Atoi(usr.Gid)
	for _, p := range paths {
		_ = os.Chown(p, uid, gid)
	}
}

// ---------------------------------------------------------------------
// EN: `chmodPaths` contains core logic for chmod paths.
// RU: `chmodPaths` - содержит основную логику для chmod paths.
// ---------------------------------------------------------------------
func chmodPaths(mode fs.FileMode, paths ...string) {
	for _, p := range paths {
		_ = os.Chmod(p, mode)
	}
}

// ---------------------------------------------------------------------
// readiness helpers
// ---------------------------------------------------------------------

func waitDNS(attempts int, delay time.Duration) error {
	target := "openai.com"
	for i := 0; i < attempts; i++ {
		ctx, cancel := context.WithTimeout(context.Background(), 2*time.Second)
		_, err := net.DefaultResolver.LookupHost(ctx, target)
		cancel()
		if err == nil {
			return nil
		}
		time.Sleep(delay)
	}
	return fmt.Errorf("dns lookup failed after %d attempts", attempts)
}