import hashlib
import hmac
import uuid
from typing import Annotated

from fastapi import Depends, Header, HTTPException, Request, Response
from sqlalchemy.ext.asyncio import AsyncSession

from app.config import settings
from app.db import get_db
from app.models import WebSession

COOKIE = "shop_session"
SessionDep = Annotated[AsyncSession, Depends(get_db, scope="function")]


def bot_secret_ok(got: str) -> bool:
    return hmac.compare_digest(
        hashlib.sha256(got.encode()).digest(),
        hashlib.sha256(settings.bot_secret.encode()).digest(),
    )


async def require_bot(x_bot_secret: Annotated[str, Header()]) -> None:
    if not bot_secret_ok(x_bot_secret):
        raise HTTPException(status_code=401, detail="Неверный ключ бота")


def web_owner(session_id: uuid.UUID) -> str:
    return f"web:{session_id}"


def telegram_owner(telegram_user_id: int) -> str:
    return f"tg:{telegram_user_id}"


async def ensure_web_session(request: Request, response: Response, db: AsyncSession) -> uuid.UUID:
    raw = request.cookies.get(COOKIE)
    if raw:
        try:
            session_id = uuid.UUID(raw)
        except ValueError:
            session_id = None
        else:
            found = await db.get(WebSession, session_id)
            if found is not None:
                return found.id

    session_id = uuid.uuid4()
    db.add(WebSession(id=session_id))
    await db.flush()
    response.set_cookie(
        COOKIE,
        str(session_id),
        httponly=True,
        samesite="lax",
        secure=settings.cookie_secure,
        path="/",
        max_age=60 * 60 * 24 * 30,
    )
    return session_id