*/
    void onError(String phase, String error);

    /**
     * Returns a no-op callback implementation.
     *
     * @return a callback that does nothing
     */
    static ChatPhaseCallback noOp() {
        return new ChatPhaseCallback() {
            @Override
            public void onPhaseStart(final String phase, final String message) {
                // no-op
            }

            @Override

        assertNotNull(ChatPhaseCallback.PHASE_SEARCH);
        assertNotNull(ChatPhaseCallback.PHASE_EVALUATE);
        assertNotNull(ChatPhaseCallback.PHASE_FETCH);
        assertNotNull(ChatPhaseCallback.PHASE_ANSWER);
    }

    @Test
    public void test_phaseConstants_unique() {
        String[] phases = { ChatPhaseCallback.PHASE_INTENT, ChatPhaseCallback.PHASE_SEARCH, ChatPhaseCallback.PHASE_EVALUATE,

                    ComponentUtil.getFessConfig().getSystemProperty("rag.llm.name", "ollama"));

            // Create phase callback for SSE events
            final ChatPhaseCallback phaseCallback = new ChatPhaseCallback() {
                @Override
                public void onPhaseStart(final String phase, final String phaseMessage) {
                    onPhaseStart(phase, phaseMessage, null);
                }

            long phaseStartTime = System.currentTimeMillis();
            callback.onPhaseStart(ChatPhaseCallback.PHASE_INTENT, "Analyzing your question...");
            final IntentDetectionResult intentResult = llmClientManager.detectIntent(userMessage, history);
            callback.onPhaseComplete(ChatPhaseCallback.PHASE_INTENT);

            if (logger.isDebugEnabled()) {