from sqlalchemy import Column, Integer, String, Text, DateTime, ForeignKey, Enum
from sqlalchemy.orm import relationship
from datetime import datetime
import enum
from .database import Base


class TaskStatus(str, enum.Enum):
    BACKLOG = "backlog"
    IN_PROGRESS = "in_progress"
    BLOCKED = "blocked"
    DONE = "done"


class Project(Base):
    __tablename__ = "projects"

    id = Column(Integer, primary_key=True, index=True)
    name = Column(String(255), nullable=False)
    description = Column(Text, nullable=True)
    created_at = Column(DateTime, default=datetime.utcnow)
    updated_at = Column(DateTime, default=datetime.utcnow, onupdate=datetime.utcnow)

    tasks = relationship("Task", back_populates="project", cascade="all, delete-orphan")


class Task(Base):
    __tablename__ = "tasks"

    id = Column(Integer, primary_key=True, index=True)
    project_id = Column(Integer, ForeignKey("projects.id"), nullable=False)
    parent_task_id = Column(Integer, ForeignKey("tasks.id"), nullable=True)
    title = Column(String(500), nullable=False)
    description = Column(Text, nullable=True)
    status = Column(Enum(TaskStatus), default=TaskStatus.BACKLOG, nullable=False)
    sort_order = Column(Integer, default=0)
    created_at = Column(DateTime, default=datetime.utcnow)
    updated_at = Column(DateTime, default=datetime.utcnow, onupdate=datetime.utcnow)

    project = relationship("Project", back_populates="tasks")
    parent = relationship("Task", remote_side=[id], backref="subtasks")