* @param userMessage the user's original message
     * @param failedQuery the query that failed
     * @param failureReason the reason for failure ("no_results" or "no_relevant_results")
     * @param history the conversation history
     * @return a new query string, or the userMessage if regeneration fails
     */
    String regenerateQuery(String userMessage, String failedQuery, String failureReason, List<LlmMessage> history);

    /**

            final List<LlmMessage> history) {
        final long startTime = System.currentTimeMillis();
        if (logger.isDebugEnabled()) {
            logger.debug("[RAG:REGEN] Starting query regeneration. userMessage={}, failedQuery={}, failureReason={}", userMessage,
                    failedQuery, failureReason);
        }

        try {

     * @param userMessage the user's original message
     * @param failedQuery the query that failed
     * @param failureReason the reason for failure
     * @param history the conversation history
     * @return a new query string
     * @throws LlmException if LLM is not available
     */
    public String regenerateQuery(final String userMessage, final String failedQuery, final String failureReason,

        assertTrue(systemPrompt.contains("no_results"));
        // Verify placeholders are replaced
        assertFalse(systemPrompt.contains("{{userMessage}}"));
        assertFalse(systemPrompt.contains("{{failedQuery}}"));
        assertFalse(systemPrompt.contains("{{failureReason}}"));
    }

    @Test
    public void test_regenerateQuery_noRelevantResults_reason() {