#! /usr/bin/env python3
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy import Column, Integer, String, DateTime, ForeignKey
from sqlalchemy.orm import relationship, backref

Base = declarative_base()


class Transaction(Base):
    __tablename__ = "Transaction"
    id = Column(Integer, primary_key=True)
    name = Column(String)
    date = Column(DateTime)
    iban = Column(String)
    amount = Column(Integer)
    description = Column(String)
    category_id = Column(Integer, ForeignKey("Category.id"))


class Category(Base):
    __tablename__ = "Category"
    id = Column(Integer, primary_key=True)
    name = Column(String)
    transactions = relationship("Category")
    parent_id = Column(Integer, ForeignKey("Category.id"))
    children = relationship("Category", backref=backref("parent", remote_side=[id]))

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

    def is_child(self):
        # we are a child if we have zero children
        return len(self.children) == 0

    def full_name(self):
        if not self.parent:
            return self.name
        else:
            return f"{self.parent.full_name()}:{self.name}"