import uuid
from sqlalchemy import Column, String, Text, DateTime, ForeignKey, UniqueConstraint
from sqlalchemy.sql import func
from sqlalchemy.orm import relationship
from app.core.database import Base


class TaskCustomValue(Base):
    __tablename__ = "pjctrl_task_custom_values"

    id = Column(String(36), primary_key=True, default=lambda: str(uuid.uuid4()))
    task_id = Column(String(36), ForeignKey("pjctrl_tasks.id", ondelete="CASCADE"), nullable=False)
    field_id = Column(String(36), ForeignKey("pjctrl_custom_fields.id", ondelete="CASCADE"), nullable=False)
    value = Column(Text, nullable=True)  # Stored as text, parsed based on field_type
    updated_at = Column(DateTime, server_default=func.now(), onupdate=func.now(), nullable=False)

    # Unique constraint: one value per task-field combination
    __table_args__ = (
        UniqueConstraint('task_id', 'field_id', name='uq_task_field'),
    )

    # Relationships
    task = relationship("Task", back_populates="custom_values")
    field = relationship("CustomField", back_populates="values")