"""
React 推理节点
使用 intent.py 进行意图推理
"""

from typing import Optional
from datetime import datetime
from langchain_core.runnables.config import RunnableConfig

from backend.app.core.intent import react_reason_async, ReasoningResult, ReasoningAction
from ..state import MainGraphState
from backend.app.logger import info
from ._utils import dispatch_custom_event, make_react_event


async def react_reason_node(state: MainGraphState, config: Optional[RunnableConfig] = None) -> MainGraphState:
    """React 模式推理节点：判断下一步做什么"""
    state.current_phase = "react_reasoning"
    state.reasoning_step += 1

    info(f"[推理] 第 {state.reasoning_step} 次推理开始")

    # ==================================================
    # 优化：如果是第一次推理，检查 hybrid_router 的结果！
    # 避免重复推理！
    # ==================================================
    if state.reasoning_step == 1 and state.hybrid_router.decision and state.hybrid_router.decision.reasoning_result:
        # 有保存的推理结果，直接复用！
        decision = state.hybrid_router.decision
        result: ReasoningResult = decision.reasoning_result

        info(f"[推理] 第1次推理，复用 hybrid_router 结果: action={result.action.name}, confidence={result.confidence}")
        if result.reasoning:
            info(f"[推理] 推理过程: {result.reasoning}")

        # 记录推理历史
        state.reasoning_history.append({
            "step": state.reasoning_step,
            "action": result.action.name,
            "confidence": result.confidence,
            "reasoning": result.reasoning,
            "timestamp": datetime.now().isoformat()
        })

        # 更新状态
        state.react_reasoning.last_reasoning = {
            "action": result.action.name,
            "confidence": result.confidence,
            "reasoning": result.reasoning
        }
        state.react_reasoning.reasoning_result = result
        state.last_action = result.action.name

        # 发送推理事件
        await dispatch_custom_event(
            "react_reasoning",
            make_react_event(
                state.reasoning_step,
                result.action.name,
                result.confidence,
                result.reasoning
            ),
            config
        )

        return state

    # ==================================================
    # 原来的逻辑（第二次推理或没有保存结果时使用）
    # ==================================================

    # 步骤1: 准备上下文
    context = {
        "retrieved_docs": state.rag_docs,
        "rag_confidence": getattr(state, "rag_confidence", 0.0),
        "rag_attempts": getattr(state, "rag_attempts", 0),
        "previous_actions": [h.get("action") for h in state.reasoning_history],
        "reasoning_history": state.reasoning_history,
        "messages": state.messages,
        "errors": state.errors
    }

    # 步骤2: 执行推理
    result: ReasoningResult = await react_reason_async(state.user_query, context)

    info(f"[推理] 推理结果: action={result.action.name}, confidence={result.confidence}")
    if result.reasoning:
        info(f"[推理] 推理过程: {result.reasoning}")

    # 步骤3: 记录推理历史
    state.reasoning_history.append({
        "step": state.reasoning_step,
        "action": result.action.name,
        "confidence": result.confidence,
        "reasoning": result.reasoning,
        "timestamp": datetime.now().isoformat()
    })

    # 步骤4: 更新状态 - 只使用新的结构化字段
    state.react_reasoning.last_reasoning = {
        "action": result.action.name,
        "confidence": result.confidence,
        "reasoning": result.reasoning
    }
    state.react_reasoning.reasoning_result = result
    state.last_action = result.action.name

    # 步骤5: 发送推理事件
    await dispatch_custom_event(
        "react_reasoning",
        make_react_event(
            state.reasoning_step,
            result.action.name,
            result.confidence,
            result.reasoning
        ),
        config
    )

    return state