import uuid as _uuid
from sqlalchemy import Column, Integer, String, Text, Date, DateTime, Boolean, ForeignKey, Table, desc
from sqlalchemy.orm import relationship
from app.database import Base
from app.utils.datetime import utcnow


# 目标-任务关联表（多对多）
goal_tasks = Table(
    "goal_tasks",
    Base.metadata,
    Column("goal_id", Integer, ForeignKey("goals.id"), primary_key=True),
    Column("task_id", Integer, ForeignKey("tasks.id"), primary_key=True),
)


class Goal(Base):
    """长期目标模型"""
    __tablename__ = "goals"

    id = Column(Integer, primary_key=True, index=True)
    uuid = Column(String(36), default=lambda: str(_uuid.uuid4()), unique=True, index=True)
    title = Column(String(200), nullable=False)
    description = Column(Text, nullable=True)
    status = Column(String(20), default="active")  # active/paused/completed/abandoned
    progress = Column(Integer, default=0)  # 0-100，从里程碑自动计算
    target_date = Column(Date, nullable=True)
    completed_at = Column(DateTime, nullable=True)
    category_id = Column(Integer, ForeignKey("categories.id"), nullable=True)
    color = Column(String(20), default="#FFB7C5")
    icon = Column(String(50), default="flag")
    sort_order = Column(Integer, default=0)
    is_deleted = Column(Boolean, default=False)
    sync_version = Column(Integer, default=1)
    created_at = Column(DateTime, default=utcnow)
    updated_at = Column(DateTime, default=utcnow, onupdate=utcnow)

    # 关联关系
    category = relationship("Category")
    steps = relationship(
        "GoalStep", back_populates="goal",
        cascade="all, delete-orphan",
        order_by="GoalStep.sort_order",
    )
    reviews = relationship(
        "GoalReview", back_populates="goal",
        cascade="all, delete-orphan",
        order_by=lambda: desc(GoalReview.created_at),
    )
    tasks = relationship("Task", secondary=goal_tasks, back_populates="goals")


class GoalStep(Base):
    """目标阶段/里程碑模型（step_type 区分类型）"""
    __tablename__ = "goal_steps"

    id = Column(Integer, primary_key=True, index=True)
    uuid = Column(String(36), default=lambda: str(_uuid.uuid4()), unique=True, index=True)
    goal_id = Column(Integer, ForeignKey("goals.id"), nullable=False)
    parent_id = Column(Integer, ForeignKey("goal_steps.id"), nullable=True)
    title = Column(String(200), nullable=False)
    step_type = Column(String(20), nullable=False)  # "phase" | "milestone"
    status = Column(String(20), default="pending")  # pending/in_progress/completed
    target_date = Column(Date, nullable=True)
    reached_at = Column(DateTime, nullable=True)
    sort_order = Column(Integer, default=0)
    is_deleted = Column(Boolean, default=False)
    sync_version = Column(Integer, default=1)
    created_at = Column(DateTime, default=utcnow)

    # 关联关系
    goal = relationship("Goal", back_populates="steps")
    parent = relationship("GoalStep", remote_side=[id], backref="children")


class GoalReview(Base):
    """目标复盘记录模型"""
    __tablename__ = "goal_reviews"

    id = Column(Integer, primary_key=True, index=True)
    uuid = Column(String(36), default=lambda: str(_uuid.uuid4()), unique=True, index=True)
    goal_id = Column(Integer, ForeignKey("goals.id"), nullable=False)
    content = Column(Text, nullable=False)
    rating = Column(Integer, nullable=True)  # 1-5 自评
    is_deleted = Column(Boolean, default=False)
    sync_version = Column(Integer, default=1)
    created_at = Column(DateTime, default=utcnow)

    # 关联关系
    goal = relationship("Goal", back_populates="reviews")