from typing import Optional

from aiogram.types import User as TgUser
from sqlalchemy import inspect
from sqlalchemy.ext.asyncio import AsyncSession
from sqlalchemy.orm import make_transient_to_detached

from app.config import get_settings
from app.db.models import User
from app.db.repos import users as repo

SNAPSHOT_COLS = (
    "id", "username", "full_name", "lang", "stream", "year", "referred_by",
    "gate_passed", "points", "streak", "best_streak", "last_active_on", "is_banned",
    "active_days", "week_key", "week_xp", "day_key", "day_xp", "trust",
    "source", "pending_link", "share_prompt_day", "credit_name", "gate_missing",
)


async def get_or_create(
    session: AsyncSession, tg: TgUser, referrer_hint: Optional[int] = None, source: Optional[str] = None
) -> User:
    user = await repo.get(session, tg.id)
    if user:
        return user
    referred_by = None
    if referrer_hint and referrer_hint != tg.id and await repo.get(session, referrer_hint):
        referred_by = referrer_hint
    return await repo.create(
        session,
        user_id=tg.id,
        username=tg.username,
        full_name=tg.full_name or "",
        lang=get_settings().default_lang,
        referred_by=referred_by,
        source=source,
    )


def snapshot(user: User) -> Optional[dict]:
    """Plain-dict copy of the user row, or None if some column is not loaded."""
    loaded = inspect(user).dict
    if any(col not in loaded for col in SNAPSHOT_COLS):
        return None
    return {col: loaded[col] for col in SNAPSHOT_COLS}


def from_snapshot(data: dict) -> User:
    """Rebuild a clean, detached User (no DB query). Attach with session.add()."""
    user = User(**data)
    make_transient_to_detached(user)  # treat attributes as freshly loaded, no pending changes
    return user