from typing import List, Optional, TYPE_CHECKING
if TYPE_CHECKING:
    from .inventory import Inventory

from sqlalchemy import Identity, Integer, Unicode
from sqlalchemy.orm import Mapped, mapped_column, relationship

from . import db

class Brand(db.Model):
    __tablename__ = 'Brands'

    id: Mapped[int] = mapped_column("ID", Integer, Identity(start=1, increment=1), primary_key=True)
    name: Mapped[Optional[str]] = mapped_column("Brand", Unicode(255), nullable=True)

    inventory: Mapped[List['Inventory']] = relationship('Inventory', back_populates='brand')

    def __init__(self, name: Optional[str] = None):
        self.name = name

    def __repr__(self):
        return f"<Brand(id={self.id}, name={repr(self.name)})>"
    
    def serialize(self):
        return {
            'id': self.id,
            'name': self.name
        }
    
    @classmethod
    def sync_from_state(cls, submitted_items: list[dict]):
        """
        Syncs the Brand table with the provided list of dictionaries.
        Adds new brands and removes brands that are not in the list.
        """
        submitted = {
            str(item.get("name", "")).strip()
            for item in submitted_items
            if isinstance(item, dict) and str(item.get("name", "")).strip()
        }
    
        existing_query = db.session.query(cls)
        existing = {brand.name: brand for brand in existing_query.all()}
    
        existing_names = set(existing.keys())
    
        print(f"Existing brands: {existing_names}")
        print(f"Submitted brands: {submitted}")
        print(f"Brands to add: {submitted - existing_names}")
        print(f"Brands to remove: {existing_names - submitted}")
    
        for name in submitted - existing_names:
            db.session.add(cls(name=name))
            print(f"➕ Adding brand: {name}")
    
        for name in existing_names - submitted:
            db.session.delete(existing[name])
            print(f"🗑️ Removing brand: {name}")