from datetime import UTC, datetime

from sqlalchemy.dialects.postgresql import JSONB

from app import db


class Epic(db.Model):
    """Epic model for tracking large features across multiple cards"""

    __tablename__ = "epics"

    id = db.Column(db.Integer, primary_key=True)
    name = db.Column(db.String(200), nullable=False, index=True)
    description = db.Column(db.Text)
    content = db.Column(JSONB)  # Rich text content (Slate.js JSON)
    color = db.Column(db.String(7))  # Hex color for epic badge
    closed = db.Column(db.Boolean, default=False, index=True)
    pos = db.Column(db.Float)  # Position for sorting in epic list
    depth_limit = db.Column(db.Integer, default=5)  # Max nesting depth

    # Foreign keys
    board_id = db.Column(
        db.Integer,
        db.ForeignKey("boards.id", ondelete="CASCADE"),
        nullable=False,
        index=True,
    )
    parent_epic_id = db.Column(
        db.Integer, db.ForeignKey("epics.id", ondelete="SET NULL")
    )

    # Timestamps
    date_last_activity = db.Column(db.DateTime)
    created_at = db.Column(db.DateTime, default=lambda: datetime.now(UTC))
    updated_at = db.Column(
        db.DateTime,
        default=lambda: datetime.now(UTC),
        onupdate=lambda: datetime.now(UTC),
    )

    # JSON fields for metrics
    metrics = db.Column(JSONB)  # {"card_count": 10}

    # Relationships
    board = db.relationship("Board", backref="epics")
    parent_epic = db.relationship("Epic", remote_side=[id], backref="child_epics")
    cards = db.relationship("Card", backref="epic", cascade="all, delete-orphan")
    attachments = db.relationship(
        "FileAttachment",
        foreign_keys="FileAttachment.attachable_id",
        primaryjoin="""and_(FileAttachment.attachable_id == Epic.id,
        FileAttachment.attachable_type == 'Epic')""",
        cascade="all, delete-orphan",
        lazy="dynamic",
    )

    def to_dict(self):
        """Convert epic to dictionary"""
        return {
            "id": self.id,
            "name": self.name,
            "description": self.description,
            "content": self.content,
            "color": self.color,
            "closed": self.closed,
            "pos": self.pos,
            "depth_limit": self.depth_limit,
            "board_id": self.board_id,
            "parent_epic_id": self.parent_epic_id,
            "date_last_activity": self.date_last_activity.isoformat()
            if self.date_last_activity
            else None,
            "created_at": self.created_at.isoformat() if self.created_at else None,
            "updated_at": self.updated_at.isoformat() if self.updated_at else None,
            "metrics": self.metrics or {"card_count": 0},
        }

    def __repr__(self):
        return f"<Epic {self.name}>"