from sqlalchemy import Column, String, DateTime, ForeignKey
from sqlalchemy.dialects.postgresql import UUID
from sqlalchemy.sql import func
import uuid
from app.database import Base


class Session(Base):
    """Session model for tracking WebSocket connections and user presence."""

    __tablename__ = "sessions"

    id = Column(UUID(as_uuid=True), primary_key=True, default=uuid.uuid4)
    user_id = Column(UUID(as_uuid=True), ForeignKey("users.id", ondelete="CASCADE"), nullable=True, index=True)
    map_id = Column(UUID(as_uuid=True), ForeignKey("maps.id", ondelete="CASCADE"), nullable=False, index=True)
    socket_id = Column(String(255), nullable=False)

    # Denormalized username for quick access
    username = Column(String(50), nullable=True)

    connected_at = Column(DateTime(timezone=True), server_default=func.now(), nullable=False)
    last_seen = Column(DateTime(timezone=True), server_default=func.now(), onupdate=func.now(), nullable=False)