from __future__ import annotations

from genesis.inference.types import TokenUsage


class FakeLLMClient:
    """可编程的假 LLM 客户端：记录调用，按脚本返回（离线）。"""

    def __init__(self, script=None):
        # script: list[(status, content)]；status: "ok" | "raise_timeout" | "raise_network" | "parse_fail"
        self.script = script or [("ok", "hello")]
        self.calls: list[dict] = []

    async def chat(self, *, model, messages, temperature, max_tokens):
        # 与真实 HttpLLMClient 的 payload 结构一致：{role, content}（T4 防护断言 role）
        self.calls.append({
            "model": model,
            "messages": [{"role": m.role, "content": m.content} for m in messages],
        })
        status, content = self.script.pop(0)
        if status == "raise_timeout":
            from genesis.inference.exceptions import LLMTimeoutError

            raise LLMTimeoutError("timeout")
        if status == "raise_network":
            from genesis.inference.exceptions import LLMNetworkError

            raise LLMNetworkError("network")
        if status == "parse_fail":
            content = "NOT JSON"
        return content, TokenUsage(input_tokens=10, output_tokens=2)