"""用户 AI 接口配置。api_key 用 Fernet 加密存储，不回显明文。"""
from fastapi import APIRouter, Depends
from sqlalchemy import select
from sqlalchemy.ext.asyncio import AsyncSession

from app.db import get_db
from app.deps import get_current_user
from app.models.user import User, UserSettings
from app.schemas.settings import SettingsOut, SettingsUpdate
from app.services import crypto

router = APIRouter(prefix="/api/settings", tags=["settings"])


async def _get_or_create(db: AsyncSession, user_id: str) -> UserSettings:
    row = await db.scalar(
        select(UserSettings).where(UserSettings.user_id == user_id)
    )
    if row is None:
        row = UserSettings(user_id=user_id)
        db.add(row)
        await db.flush()
    return row


def _to_out(s: UserSettings) -> SettingsOut:
    return SettingsOut(
        llm_base_url=s.llm_base_url,
        llm_text_model=s.llm_text_model,
        llm_vision_model=s.llm_vision_model,
        has_api_key=bool(s.llm_api_key_encrypted),
    )


@router.get("", response_model=SettingsOut)
async def get_settings(
    db: AsyncSession = Depends(get_db),
    current: User = Depends(get_current_user),
):
    s = await _get_or_create(db, current.id)
    await db.commit()
    return _to_out(s)


@router.put("", response_model=SettingsOut)
async def update_settings(
    payload: SettingsUpdate,
    db: AsyncSession = Depends(get_db),
    current: User = Depends(get_current_user),
):
    s = await _get_or_create(db, current.id)
    data = payload.model_dump(exclude_unset=True)
    for field in ("llm_base_url", "llm_text_model", "llm_vision_model"):
        if field in data:
            setattr(s, field, data[field])
    # api_key：显式传非空值才更新；传空字符串表示清除
    if "api_key" in data:
        if payload.api_key:
            s.llm_api_key_encrypted = crypto.encrypt(payload.api_key)
        elif payload.api_key == "":
            s.llm_api_key_encrypted = None
    await db.commit()
    await db.refresh(s)
    return _to_out(s)