models.py

from sqlalchemy import ForeignKey, Column, Integer, String, MetaData
from sqlalchemy.orm import relationship, backref
from sqlalchemy.ext.declarative import declarative_base

convention = {
    "fk": "fk_%(table_name)s_%(column_0_name)s_%(referred_table_name)s",
}
metadata = MetaData(naming_convention=convention)

Base = declarative_base(metadata=metadata)

class Company(Base):
    __tablename__ = 'companies'

    id = Column(Integer(), primary_key=True)
    name = Column(String())
    founding_year = Column(Integer())
    
    freebies = relationship("Freebie", back_populates="company")
    
    @property
    def devs(self):
        """All devs who received freebies from this company"""
        return [freebie.dev for freebie in self.freebies]

    def give_freebie(self, dev, item_name, value):
        """Create a new freebie association (caller handles session)"""
        return Freebie(
            item_name=item_name, 
            value=value, 
            dev=dev, 
            company=self
        )

    @classmethod
    def oldest_company(cls, session):
        """Class method to find oldest company (requires session parameter)"""
        return session.query(cls).order_by(cls.founding_year).first()

    @classmethod
    def oldest_company(cls, session):
        """Class method to find oldest company (requires session parameter)"""
        return session.query(cls).order_by(cls.founding_year).first()



class Dev(Base):
    __tablename__ = 'devs'

    id = Column(Integer(), primary_key=True)
    name= Column(String())

    freebies = relationship("Freebie", back_populates="dev")
    
    @property
    def companies(self):
        """All companies where dev received freebies"""
        return [freebie.company for freebie in self.freebies]

    def received_one(self, item_name):
        """Check if dev has any freebie with given item name"""
        return any(f.item_name == item_name for f in self.freebies)

    def give_away(self, other_dev, freebie):
        """Transfer freebie to another dev if it belongs to current dev"""
        if freebie.dev == self:
            freebie.dev = other_dev
            return True
        return False
    
class Freebie(Base):
    __tablename__ = 'freebies'

    id = Column(Integer, primary_key=True)
    item_name = Column(String)
    value = Column(Integer)
    company_id = Column(Integer, ForeignKey('companies.id'))
    dev_id = Column(Integer, ForeignKey('devs.id'))

    dev = relationship("Dev", back_populates="freebies")
    company = relationship("Company", back_populates="freebies")

    def print_details(self):
        """Format freebie details as string"""
        return f"{self.dev.name} owns a {self.item_name} from {self.company.name}"