from app.extensions import db
from datetime import datetime


class Category(db.Model):
    __tablename__ = 'categories'

    id = db.Column(db.Integer, primary_key=True)
    name = db.Column(db.String(100), nullable=False)
    category_type = db.Column(
        db.Enum('income', 'expense', 'both'),
        nullable=False,
        default='expense'
    )
    parent_id = db.Column(db.Integer, db.ForeignKey('categories.id'), nullable=True)
    color = db.Column(db.String(7), default='#6B7280')
    icon = db.Column(db.String(50), default='bi-tag')
    is_system = db.Column(db.Boolean, default=False)  # system categories can't be deleted
    is_active = db.Column(db.Boolean, default=True)
    created_at = db.Column(db.DateTime, default=datetime.utcnow)

    # Self-referential relationship for subcategories
    subcategories = db.relationship('Category', backref=db.backref('parent', remote_side=[id]),
                                    lazy='dynamic')
    transactions = db.relationship('Transaction', back_populates='category', lazy='dynamic')

    def __repr__(self):
        return f'<Category {self.name}>'