from __future__ import annotations

import uuid
from datetime import datetime, timezone

from sqlalchemy import (
    Boolean, Column, DateTime, ForeignKey, Integer, String, Text, Table,
)
from sqlalchemy.orm import DeclarativeBase, Mapped, mapped_column, relationship


class Base(DeclarativeBase):
    pass


def _utcnow() -> datetime:
    return datetime.now(timezone.utc)


def _uuid() -> str:
    return str(uuid.uuid4())


user_roles = Table(
    "user_roles",
    Base.metadata,
    Column("user_id", String(36), ForeignKey("users.id", ondelete="CASCADE"), primary_key=True),
    Column("role_id", String(36), ForeignKey("roles.id", ondelete="CASCADE"), primary_key=True),
)

role_permissions = Table(
    "role_permissions",
    Base.metadata,
    Column("role_id", String(36), ForeignKey("roles.id", ondelete="CASCADE"), primary_key=True),
    Column("permission_id", String(36), ForeignKey("permissions.id", ondelete="CASCADE"), primary_key=True),
)


class Permission(Base):
    __tablename__ = "permissions"

    id: Mapped[str] = mapped_column(String(36), primary_key=True, default=_uuid)
    code: Mapped[str] = mapped_column(String(100), unique=True, index=True, nullable=False)
    description: Mapped[str | None] = mapped_column(String(255), nullable=True)

    roles: Mapped[list[Role]] = relationship(secondary=role_permissions, back_populates="permissions", lazy="selectin")


class Role(Base):
    __tablename__ = "roles"

    id: Mapped[str] = mapped_column(String(36), primary_key=True, default=_uuid)
    name: Mapped[str] = mapped_column(String(50), unique=True, nullable=False)
    description: Mapped[str | None] = mapped_column(String(255), nullable=True)

    users: Mapped[list[User]] = relationship(secondary=user_roles, back_populates="roles", lazy="selectin")
    permissions: Mapped[list[Permission]] = relationship(secondary=role_permissions, back_populates="roles", lazy="selectin")


class User(Base):
    __tablename__ = "users"

    id: Mapped[str] = mapped_column(String(36), primary_key=True, default=_uuid)
    email: Mapped[str] = mapped_column(String(255), unique=True, index=True, nullable=False)
    username: Mapped[str | None] = mapped_column(String(50), unique=True, index=True, nullable=True)
    full_name: Mapped[str | None] = mapped_column(String(255), nullable=True)
    password_hash: Mapped[str] = mapped_column(Text, nullable=False)

    is_active: Mapped[bool] = mapped_column(Boolean, default=True, nullable=False)
    is_verified: Mapped[bool] = mapped_column(Boolean, default=False, nullable=False)

    failed_login_attempts: Mapped[int] = mapped_column(Integer, default=0, nullable=False)
    locked_until: Mapped[datetime | None] = mapped_column(DateTime(timezone=True), nullable=True)
    last_login: Mapped[datetime | None] = mapped_column(DateTime(timezone=True), nullable=True)
    password_changed_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True), nullable=True)

    created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), default=_utcnow, nullable=False)
    updated_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), default=_utcnow, onupdate=_utcnow, nullable=False)
    deleted_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True), nullable=True)

    roles: Mapped[list[Role]] = relationship(secondary=user_roles, back_populates="users", lazy="selectin")
    sessions: Mapped[list[RefreshSession]] = relationship(back_populates="user", cascade="all, delete-orphan", lazy="selectin")


class RefreshSession(Base):
    __tablename__ = "refresh_sessions"

    id: Mapped[str] = mapped_column(String(36), primary_key=True, default=_uuid)
    user_id: Mapped[str] = mapped_column(String(36), ForeignKey("users.id", ondelete="CASCADE"), nullable=False, index=True)
    token_key: Mapped[str] = mapped_column(String(64), unique=True, index=True, nullable=False)
    token_hash: Mapped[str] = mapped_column(String(255), nullable=False)
    device_info: Mapped[str | None] = mapped_column(String(255), nullable=True)
    ip_address: Mapped[str | None] = mapped_column(String(45), nullable=True)
    expires_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), nullable=False)
    revoked_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True), nullable=True)

    created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), default=_utcnow, nullable=False)
    updated_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), default=_utcnow, onupdate=_utcnow, nullable=False)

    user: Mapped[User] = relationship(back_populates="sessions")