"""테스트 더블 — ScriptedLlm: 정해진 응답을 순서대로 내놓는 BaseLlm.

LLM 호출 없이 파이프라인(가드→캐릭터→디렉터→도구→state)을 결정적으로 검증한다.
프로덕션 경로는 LiteLlm(engine/model.py) 그대로이며, 이 더블은 tests/ 전용이다.
"""

from __future__ import annotations

from typing import AsyncGenerator

from google.adk.models.base_llm import BaseLlm
from google.adk.models.llm_request import LlmRequest
from google.adk.models.llm_response import LlmResponse
from google.genai import types
from pydantic import ConfigDict


def text_response(text: str) -> LlmResponse:
    return LlmResponse(content=types.Content(role="model", parts=[types.Part(text=text)]))


def tool_call(name: str, **args) -> types.Part:
    return types.Part(function_call=types.FunctionCall(name=name, args=args))


def tool_response(*parts: types.Part) -> LlmResponse:
    return LlmResponse(content=types.Content(role="model", parts=list(parts)))


class ScriptedLlm(BaseLlm):
    model_config = ConfigDict(arbitrary_types_allowed=True)

    model: str = "scripted"
    script: list[LlmResponse] = []
    requests: list[LlmRequest] = []  # 검증용: 실제로 주입된 instruction 확인

    async def generate_content_async(
        self, llm_request: LlmRequest, stream: bool = False
    ) -> AsyncGenerator[LlmResponse, None]:
        self.requests.append(llm_request)
        if not self.script:
            yield text_response("(대본 소진)")
            return
        yield self.script.pop(0)