import secrets
import string
from typing import TYPE_CHECKING

from sqlalchemy import BIGINT, INTEGER, REAL, TEXT, VARCHAR, ForeignKey
from sqlalchemy.orm import Mapped, mapped_column, relationship

from db.base import Base

if TYPE_CHECKING:
    from db.models import Order, Session, Subscription


def generate_ref_code(length: int = 8):
    alphabet = string.ascii_letters + string.digits
    return "".join(secrets.choice(alphabet) for _ in range(length))


class User(Base):
    __tablename__ = "users"

    id: Mapped[int] = mapped_column(
        INTEGER, unique=True, autoincrement=True, nullable=False, primary_key=True
    )
    username: Mapped[str] = mapped_column(TEXT, unique=True, nullable=True)
    hashed_password: Mapped[str] = mapped_column(VARCHAR(255), nullable=True)
    telegram_id: Mapped[int] = mapped_column(BIGINT, unique=True, nullable=True)
    referal_id: Mapped[int] = mapped_column(ForeignKey("users.id"), nullable=True)
    referal_code: Mapped[str] = mapped_column(
        TEXT, nullable=False, unique=True, default=generate_ref_code
    )

    balance: Mapped[float] = mapped_column(REAL, nullable=False, default=0)

    orders: Mapped[list["Order"]] = relationship("Order", back_populates="user", lazy="selectin")
    subscription: Mapped["Subscription"] = relationship(
        "Subscription", back_populates="user", lazy="selectin"
    )
    sessions: Mapped[list["Session"]] = relationship(back_populates="user", lazy="selectin")
    referal: Mapped["User | None"] = relationship("User", remote_side=[id], lazy="selectin")