package system

func RunScript(code string, shell string, args []string, timeout int) (stdout, stderr string, exitcode int, e error) {

	content := []byte(code)

	dir := filepath.Join(os.TempDir(), "trmm")
	if !trmm.FileExists(dir) {
		a.CreateTRMMTempDir()
	}

	const defaultExitCode = 1

	var (
		outb    bytes.Buffer
		errb    bytes.Buffer
		exe     string
		ext     string
		cmdArgs []string
	)

	switch shell {
	case "powershell":
		ext = "*.ps1"
	case "python":
		ext = "*.py"
	case "cmd":
		ext = "*.bat"
	}

	tmpfn, err := ioutil.TempFile(dir, ext)
	if err != nil {
		a.Logger.Errorln(err)
		return "", err.Error(), 85, err
	}
	defer os.Remove(tmpfn.Name())

	if _, err := tmpfn.Write(content); err != nil {
		a.Logger.Errorln(err)
		return "", err.Error(), 85, err
	}
	if err := tmpfn.Close(); err != nil {
		a.Logger.Errorln(err)
		return "", err.Error(), 85, err
	}

	switch shell {
	case "powershell":
		exe = "Powershell"
		cmdArgs = []string{"-NonInteractive", "-NoProfile", "-ExecutionPolicy", "Bypass", tmpfn.Name()}
	case "python":
		exe = a.PyBin
		cmdArgs = []string{tmpfn.Name()}
	case "cmd":
		exe = tmpfn.Name()
	}

	if len(args) > 0 {
		cmdArgs = append(cmdArgs, args...)
	}

	ctx, cancel := context.WithTimeout(context.Background(), time.Duration(timeout)*time.Second)
	defer cancel()

	var timedOut bool = false
	cmd := exec.Command(exe, cmdArgs...)
	cmd.Stdout = &outb
	cmd.Stderr = &errb

	if cmdErr := cmd.Start(); cmdErr != nil {
		a.Logger.Debugln(cmdErr)
		return "", cmdErr.Error(), 65, cmdErr
	}
	pid := int32(cmd.Process.Pid)

	// custom context handling, we need to kill child procs if this is a batch script,
	// otherwise it will hang forever
	// the normal exec.CommandContext() doesn't work since it only kills the parent process
	go func(p int32) {

		<-ctx.Done()

		_ = KillProc(p)
		timedOut = true
	}(pid)

	cmdErr := cmd.Wait()

	if timedOut {
		stdout = CleanString(outb.String())
		stderr = fmt.Sprintf("%s\nScript timed out after %d seconds", CleanString(errb.String()), timeout)
		exitcode = 98
		a.Logger.Debugln("Script check timeout:", ctx.Err())
	} else {
		stdout = CleanString(outb.String())
		stderr = CleanString(errb.String())

		// get the exit code
		if cmdErr != nil {
			if exitError, ok := cmdErr.(*exec.ExitError); ok {
				if ws, ok := exitError.Sys().(syscall.WaitStatus); ok {
					exitcode = ws.ExitStatus()
				} else {
					exitcode = defaultExitCode
				}
			} else {
				exitcode = defaultExitCode
			}

		} else {
			if ws, ok := cmd.ProcessState.Sys().(syscall.WaitStatus); ok {
				exitcode = ws.ExitStatus()
			} else {
				exitcode = 0
			}
		}
	}
	return stdout, stderr, exitcode, nil
}