# -*- coding: utf-8 -*-
"""공통 FastAPI 의존성: 현재 사용자(필수/선택) + 페이지네이션."""
from dataclasses import dataclass

from fastapi import Depends, HTTPException, Query
from fastapi.security import HTTPAuthorizationCredentials, HTTPBearer
from sqlalchemy import select
from sqlalchemy.ext.asyncio import AsyncSession

from .database import get_session
from .models import User
from .security import decode_token

_bearer = HTTPBearer(auto_error=False)


async def _user_from_token(creds: HTTPAuthorizationCredentials | None, session: AsyncSession) -> User | None:
    if creds is None:
        return None
    payload = decode_token(creds.credentials)
    if not payload or payload.get("type") != "access":
        return None
    user = (
        await session.execute(
            select(User).where(User.user_uuid == payload.get("sub"), User.is_deleted == False)  # noqa: E712
        )
    ).scalar_one_or_none()
    if user is None or not user.is_active:
        return None
    return user


async def get_current_user(
    creds: HTTPAuthorizationCredentials | None = Depends(_bearer),
    session: AsyncSession = Depends(get_session),
) -> User:
    user = await _user_from_token(creds, session)
    if user is None:
        raise HTTPException(401, "로그인이 필요합니다.")
    return user


async def get_current_user_optional(
    creds: HTTPAuthorizationCredentials | None = Depends(_bearer),
    session: AsyncSession = Depends(get_session),
) -> User | None:
    return await _user_from_token(creds, session)


@dataclass
class Pagination:
    page: int
    page_size: int

    @property
    def offset(self) -> int:
        return (self.page - 1) * self.page_size


def get_pagination(
    page: int = Query(1, ge=1),
    page_size: int = Query(20, ge=1, le=100),
) -> Pagination:
    return Pagination(page=page, page_size=page_size)