"""assistant_id → 运行时配置(把真 key 在服务端组装好)。

浏览器只传 assistant_id;真 key 在这里从 provider_credentials 取出注入。
助手按 FK(*_credential_id)引用凭证;取不到则回退该 type 默认凭证,再回退 .env。
"""

import config
from db.models import Assistant, ProviderCredential
from models import AssistantConfig
from sqlalchemy import select
from sqlalchemy.ext.asyncio import AsyncSession


async def _default_credential(
    session: AsyncSession, type_: str
) -> ProviderCredential | None:
    """该 type 的默认凭证(is_default 优先,否则按 id 取第一条)。"""
    stmt = (
        select(ProviderCredential)
        .where(ProviderCredential.type == type_)
        .order_by(ProviderCredential.is_default.desc(), ProviderCredential.id.asc())
        .limit(1)
    )
    return (await session.execute(stmt)).scalar_one_or_none()


async def _resolve(
    session: AsyncSession, cred_id: str | None, type_: str
) -> ProviderCredential | None:
    """按 FK id 取凭证;id 为空或失效 → 回退该 type 默认。"""
    if cred_id:
        cred = await session.get(ProviderCredential, cred_id)
        if cred:
            return cred
    return await _default_credential(session, type_)


async def resolve_runtime_config(
    session: AsyncSession, assistant_id: str
) -> AssistantConfig:
    """加载助手 + 解析凭证,产出可直接交给管线的运行时配置(含真 key)。"""
    assistant = await session.get(Assistant, assistant_id)
    if assistant is None:
        raise ValueError(f"助手不存在: {assistant_id}")

    llm = await _resolve(session, assistant.llm_credential_id, "LLM")
    stt = await _resolve(session, assistant.asr_credential_id, "ASR")
    tts = await _resolve(session, assistant.tts_credential_id, "TTS")
    realtime = await _resolve(session, assistant.realtime_credential_id, "Realtime")

    return AssistantConfig(
        name=assistant.name,
        greeting=assistant.greeting,
        # prompt 现在是真列;外部类型由其平台编排,这里给个兜底
        prompt=assistant.prompt or "你是一个有帮助的助手。",
        runtimeMode=assistant.runtime_mode,  # type: ignore[arg-type]
        enableInterrupt=assistant.enable_interrupt,
        # 模型/音色:凭证的模型ID优先
        model=(llm.model_id if llm else ""),
        asr=(stt.model_id if stt else ""),
        voice="",  # 音色无独立列,留空 → service_factory 回退 .env TTS_VOICE
        realtimeModel=(realtime.model_id if realtime else ""),
        # 运行时连接信息(真 key + url):凭证优先,否则 .env 兜底
        llm_api_key=(llm.api_key if llm else config.LLM_API_KEY),
        llm_base_url=(llm.api_url if llm else config.LLM_BASE_URL),
        stt_api_key=(stt.api_key if stt else config.STT_API_KEY),
        stt_base_url=(stt.api_url if stt else config.STT_BASE_URL),
        tts_api_key=(tts.api_key if tts else config.TTS_API_KEY),
        tts_base_url=(tts.api_url if tts else config.TTS_BASE_URL),
    )