import uuid
from datetime import datetime
from typing import Optional
from sqlalchemy import String, DateTime, ForeignKey
from sqlalchemy.orm import Mapped, mapped_column, relationship
from sqlalchemy.dialects.postgresql import UUID
from app.core.database import Base


class User(Base):
    __tablename__ = "users"

    id: Mapped[uuid.UUID] = mapped_column(
        UUID(as_uuid=True),
        primary_key=True,
        default=uuid.uuid4
    )
    email: Mapped[str] = mapped_column(String(255), unique=True, nullable=False, index=True)
    password_hash: Mapped[str] = mapped_column(String(255), nullable=False)
    name: Mapped[str] = mapped_column(String(255), nullable=False)
    role: Mapped[str] = mapped_column(String(50), nullable=False, default="engineer")  # admin, engineer, viewer
    team_id: Mapped[Optional[uuid.UUID]] = mapped_column(
        UUID(as_uuid=True),
        ForeignKey("teams.id"),
        nullable=True
    )
    created_at: Mapped[datetime] = mapped_column(
        DateTime,
        default=datetime.utcnow
    )
    last_login: Mapped[Optional[datetime]] = mapped_column(DateTime, nullable=True)

    # Relationships
    team: Mapped[Optional["Team"]] = relationship("Team", back_populates="users")
    trees: Mapped[list["Tree"]] = relationship("Tree", back_populates="author")
    sessions: Mapped[list["Session"]] = relationship("Session", back_populates="user")