"""
Slide 49: Slide 22
Section 2: LangGraph 1.0
Source: slides/section2-langgraph/section2.pptx

Сгенерировано автоматически из slide-NN.js / sectionN.pptx.
Паттерн провайдера скопирован из
bro-js/agents/teacher/assistant/src/angry_teacher/llm.py.

Запуск:
  cd langchain-evolution-deck
  cp .env.example .env   # заполни OPENAI_API_KEY
  python examples/slide-049/script.py
"""
import os
from dotenv import load_dotenv
from langchain_openai import ChatOpenAI

load_dotenv()

llm = ChatOpenAI(
    # model="openrouter/free",
    # model="qwen/qwen3.5-35b-a3b",
    model="openai/gpt-oss-20b",
    # model="nvidia/nemotron-3-nano",
    # model="qwen/qwen3.5-9b",
    base_url="https://llm.brojs.ru/v1",
    # base_url="https://api.minimax.io/v1",
    # base_url="http://0.0.0.0:8090/v1",
    # base_url="https://openrouter.ai/api/v1",
    # api_key=os.getenv("MINIMAX_API_KEY"),
    api_key=(os.getenv("OPENAI_API_KEY") or "").strip() or None,
    temperature=0.7,
    stream_usage=True,
)


# === Code from slide 49 ===
  from langgraph.graph import StateGraph, START, END
  from langgraph.checkpoint.memory import InMemorySaver
  # plan, review, execute -- из предыдущего слайда
  g = StateGraph(State)
> g.add_node("plan",    plan)
> g.add_node("review",  review)
  g.add_node("execute", execute)
> g.add_edge(START, "plan")
  g.add_edge("plan", "review")
  g.add_edge("execute", END)
  app = g.compile(checkpointer=InMemorySaver())

  # Цикл: каждый review -- это пауза; Command(goto=...) -- ответвление
> # plan -> review -> (approve: execute | abort: END | else: plan)
> cfg = {"configurable": {"thread_id": "u1"}}
  app.invoke({"plan": "", "executed": False}, cfg)         # пауза 1
  app.invoke(Command(resume="approve"), cfg)               # resume -> execute