Agent、Chain 与 Workflow：什么时候才需要模型自主决策

目标 → 读取状态 → 决策 → 调用工具 → 获得观察 → 更新状态
                      ↑                         ↓
                      └──── 未完成则继续 ──────┘

DEVICES = {
    "AX-3": {"online": False, "temperature": 38.2},
    "AX-8": {"online": True, "temperature": 76.5},
}


def fixed_workflow(device_id: str) -> str:
    device = DEVICES[device_id]
    if not device["online"]:
        return "通知值班人员检查网络"
    if device["temperature"] >= 70:
        return "创建温度复核任务"
    return "无需处理"


def agent_loop(goal: str, decide, max_steps: int = 3) -> dict:
    state = {"goal": goal, "observations": [], "steps": []}
    for _ in range(max_steps):
        action = decide(state)
        state["steps"].append(action)
        if action["name"] == "finish":
            return {**state, "status": "completed", "answer": action["answer"]}
        if action["name"] == "get_device":
            result = DEVICES.get(action["device_id"], {"error": "not_found"})
        else:
            result = {"error": "tool_not_allowed"}
        state["observations"].append(result)
    return {**state, "status": "step_limit", "answer": None}


def demo_decide(state: dict) -> dict:
    if not state["observations"]:
        return {"name": "get_device", "device_id": "AX-8"}
    device = state["observations"][-1]
    return {"name": "finish", "answer": f"当前温度 {device['temperature']}℃，需要复核。"}


print(fixed_workflow("AX-8"))
print(agent_loop("检查 AX-8 是否需要处理", demo_decide))