"""里程碑树模型。

分支路径管理 + 环境变化时 AI 建议路径切换。
"""

import uuid
from datetime import datetime, timezone

from sqlalchemy import DateTime, ForeignKey, String, Text
from sqlalchemy.orm import Mapped, mapped_column

from app.core.database import Base
from app.core.types import JSONBType


class MilestoneTree(Base):
    """里程碑树。"""

    __tablename__ = "milestone_trees"

    id: Mapped[str] = mapped_column(String(36), primary_key=True, default=lambda: str(uuid.uuid4()))
    company_id: Mapped[str] = mapped_column(String(36), ForeignKey("companies.id"), nullable=False, index=True)
    name: Mapped[str] = mapped_column(String(200), nullable=False, comment="里程碑名称")
    parent_id: Mapped[str | None] = mapped_column(String(36), ForeignKey("milestone_trees.id"), nullable=True, comment="父节点")
    is_current: Mapped[bool] = mapped_column(default=False, comment="是否当前路径")
    status: Mapped[str] = mapped_column(String(20), nullable=False, default="planned", comment="planned/in_progress/completed/abandoned")
    target_date: Mapped[datetime | None] = mapped_column(DateTime(timezone=True), nullable=True)
    actual_date: Mapped[datetime | None] = mapped_column(DateTime(timezone=True), nullable=True)
    description: Mapped[str | None] = mapped_column(Text, nullable=True)
    ai_analysis: Mapped[dict | None] = mapped_column(JSONBType, nullable=True, comment="AI 路径分析")
    created_at: Mapped[datetime] = mapped_column(
        DateTime(timezone=True), default=lambda: datetime.now(timezone.utc)
    )
    updated_at: Mapped[datetime] = mapped_column(
        DateTime(timezone=True),
        default=lambda: datetime.now(timezone.utc),
        onupdate=lambda: datetime.now(timezone.utc),
    )