/**
 * Start teleporter to the specified target.
 *
 * @returns COM status code.
 *
 * @param   aHostname       The name of the target host.
 * @param   aPort           The TCP port number.
 * @param   aPassword       The password.
 * @param   aMaxDowntime    Max allowed "downtime" in milliseconds.
 * @param   aProgress       Where to return the progress object.
 */
STDMETHODIMP
Console::Teleport(IN_BSTR aHostname, ULONG aPort, IN_BSTR aPassword, ULONG aMaxDowntime, IProgress **aProgress)
{
    /*
     * Validate parameters, check+hold object status, write lock the object
     * and validate the state.
     */
    CheckComArgOutPointerValid(aProgress);
    CheckComArgStrNotEmptyOrNull(aHostname);
    CheckComArgStrNotEmptyOrNull(aPassword);
    CheckComArgExprMsg(aPort, aPort > 0 && aPort <= 65535, ("is %u", aPort));
    CheckComArgExprMsg(aMaxDowntime, aMaxDowntime > 0, ("is %u", aMaxDowntime));

    Utf8Str strPassword(aPassword);
    if (!strPassword.isEmpty())
    {
        if (VBoxIsPasswordHashed(&strPassword))
            return setError(E_INVALIDARG, tr("The specified password resembles a hashed password, expected plain text"));
        VBoxHashPassword(&strPassword);
    }

    AutoCaller autoCaller(this);
    if (FAILED(autoCaller.rc())) return autoCaller.rc();

    AutoWriteLock autoLock(this COMMA_LOCKVAL_SRC_POS);
    LogFlowThisFunc(("mMachineState=%d\n", mMachineState));

    switch (mMachineState)
    {
    case MachineState_Running:
    case MachineState_Paused:
        break;

    default:
        return setError(VBOX_E_INVALID_VM_STATE,
                        tr("Invalid machine state: %s (must be Running or Paused)"),
                        Global::stringifyMachineState(mMachineState));
    }


    /*
     * Create a progress object, spawn a worker thread and change the state.
     * Note! The thread won't start working until we release the lock.
     */
    LogFlowThisFunc(("Initiating TELEPORT request...\n"));

    ComObjPtr<Progress> ptrProgress;
    HRESULT hrc = ptrProgress.createObject();
    if (SUCCEEDED(hrc))
        hrc = ptrProgress->init(static_cast<IConsole *>(this),
                                Bstr(tr("Teleporter")).raw(),
                                TRUE /*aCancelable*/);
    if (FAILED(hrc))
        return hrc;

    TeleporterStateSrc *pState = new TeleporterStateSrc(this, mpUVM, ptrProgress, mMachineState);
    pState->mstrPassword    = strPassword;
    pState->mstrHostname    = aHostname;
    pState->muPort          = aPort;
    pState->mcMsMaxDowntime = aMaxDowntime;

    void *pvUser = static_cast<void *>(static_cast<TeleporterState *>(pState));
    ptrProgress->setCancelCallback(teleporterProgressCancelCallback, pvUser);

    int vrc = RTThreadCreate(NULL, Console::teleporterSrcThreadWrapper, (void *)pState, 0 /*cbStack*/,
                             RTTHREADTYPE_EMULATION, 0 /*fFlags*/, "Teleport");
    if (RT_SUCCESS(vrc))
    {
        if (mMachineState == MachineState_Running)
            hrc = setMachineState(MachineState_Teleporting);
        else
            hrc = setMachineState(MachineState_TeleportingPausedVM);
        if (SUCCEEDED(hrc))
        {
            ptrProgress.queryInterfaceTo(aProgress);
            mptrCancelableProgress = ptrProgress;
        }
        else
            ptrProgress->Cancel();
    }
    else
    {
        ptrProgress->setCancelCallback(NULL, NULL);
        delete pState;
        hrc = setError(E_FAIL, tr("RTThreadCreate -> %Rrc"), vrc);
    }

    return hrc;
}