from __future__ import annotations

from datetime import datetime
from enum import Enum
from typing import Optional

from sqlalchemy import DateTime, ForeignKey, Index, String, UniqueConstraint, text
from sqlalchemy.dialects.mysql import BIGINT, TINYINT
from sqlalchemy.orm import Mapped, mapped_column, relationship

from backend.db.base import Base


class RoleName(str, Enum):
    ADMIN = "ADMIN"
    CUSTOMER_ADMIN = "CUSTOMER_ADMIN"
    CUSTOMER_USER = "CUSTOMER_USER"


class Role(Base):
    __tablename__ = "roles"
    __table_args__ = (UniqueConstraint("name", name="uniq_role_name"),)

    id: Mapped[int] = mapped_column(BIGINT(unsigned=True), primary_key=True, autoincrement=True)
    name: Mapped[str] = mapped_column(String(64), nullable=False)
    description: Mapped[Optional[str]] = mapped_column(String(255))
    created_at: Mapped[datetime] = mapped_column(DateTime, server_default=text("CURRENT_TIMESTAMP"), nullable=False)
    updated_at: Mapped[datetime] = mapped_column(
        DateTime, server_default=text("CURRENT_TIMESTAMP"), onupdate=text("CURRENT_TIMESTAMP"), nullable=False
    )

    users: Mapped[list["User"]] = relationship("User", back_populates="role")


class User(Base):
    __tablename__ = "users"
    __table_args__ = (
        UniqueConstraint("username", name="uniq_username"),
        UniqueConstraint("email", name="uniq_email"),
        Index("idx_users_role", "role_id"),
        Index("idx_users_customer", "customer_id"),
    )

    id: Mapped[int] = mapped_column(BIGINT(unsigned=True), primary_key=True, autoincrement=True)
    username: Mapped[str] = mapped_column(String(64), nullable=False)
    email: Mapped[Optional[str]] = mapped_column(String(128))
    password_hash: Mapped[str] = mapped_column(String(255), nullable=False)
    role_id: Mapped[int] = mapped_column(ForeignKey("roles.id", ondelete="RESTRICT", onupdate="CASCADE"), nullable=False)
    customer_id: Mapped[Optional[int]] = mapped_column(
        ForeignKey("customers.id", ondelete="SET NULL", onupdate="CASCADE")
    )
    is_active: Mapped[int] = mapped_column(TINYINT(1), server_default=text("1"), nullable=False)
    last_login_at: Mapped[Optional[datetime]] = mapped_column(DateTime)
    created_at: Mapped[datetime] = mapped_column(DateTime, server_default=text("CURRENT_TIMESTAMP"), nullable=False)
    updated_at: Mapped[datetime] = mapped_column(
        DateTime, server_default=text("CURRENT_TIMESTAMP"), onupdate=text("CURRENT_TIMESTAMP"), nullable=False
    )

    role: Mapped[Role] = relationship("Role", back_populates="users")
    customer: Mapped[Optional["Customer"]] = relationship("Customer", back_populates="users")