import org.codelibs.fess.util.ComponentUtil;
import org.dbflute.optional.OptionalThing;
import org.lastaflute.web.util.LaRequestUtil;

import jakarta.annotation.Resource;
import jakarta.servlet.http.HttpServletRequest;

/**
 * Client class for RAG (Retrieval-Augmented Generation) chat functionality.
 *
 * Orchestrates the multi-phase RAG workflow including session management,

import org.lastaflute.web.LastaWebKey;
import org.lastaflute.web.util.LaRequestUtil;

import com.fasterxml.jackson.databind.JsonNode;
import com.fasterxml.jackson.databind.ObjectMapper;

import jakarta.servlet.http.HttpSession;

/**
 * Abstract base class for LLM client implementations.
 *
 * Provides shared infrastructure (HTTP client, availability checking) and