import uuid
from datetime import datetime

from sqlalchemy import Boolean, DateTime, ForeignKey, String, Text, func
from sqlalchemy.dialects.postgresql import UUID
from sqlalchemy.orm import Mapped, mapped_column, relationship

from app.db.base_class import Base


class WorkflowTemplate(Base):
    __tablename__ = "workflow_templates"

    id: Mapped[uuid.UUID] = mapped_column(UUID(as_uuid=True), primary_key=True, default=uuid.uuid4)
    trial_id: Mapped[uuid.UUID | None] = mapped_column(UUID(as_uuid=True), ForeignKey("studies.id"), nullable=True)
    name: Mapped[str] = mapped_column(String(200), nullable=False)
    description: Mapped[str | None] = mapped_column(Text, nullable=True)
    is_active: Mapped[bool] = mapped_column(Boolean, nullable=False, server_default="true")
    created_by: Mapped[uuid.UUID | None] = mapped_column(UUID(as_uuid=True), ForeignKey("users.id"), nullable=True)
    created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), nullable=False, server_default=func.now())
    updated_at: Mapped[datetime] = mapped_column(
        DateTime(timezone=True),
        nullable=False,
        server_default=func.now(),
        onupdate=func.now(),
    )

    nodes = relationship(
        "WorkflowNode",
        back_populates="template",
        cascade="all, delete-orphan",
        order_by="WorkflowNode.node_order",
    )