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
from ..temp import is_temp_id

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]) -> dict[str, int]:
        submitted_clean = []
        seen_ids = set()
        temp_id_map = {}
    
        for item in submitted_items:
            if not isinstance(item, dict):
                continue
            name = str(item.get("name", "")).strip()
            if not name:
                continue
            submitted_clean.append({"id": item.get("id"), "name": name})
            if isinstance(item.get("id"), int) and item["id"] >= 0:
                seen_ids.add(item["id"])
    
        existing_by_id = {b.id: b for b in db.session.query(cls).all()}
        existing_ids = set(existing_by_id.keys())
    
        print(f"Existing brand IDs: {existing_ids}")
        print(f"Submitted brand IDs: {seen_ids}")
    
        for entry in submitted_clean:
            submitted_id = entry.get("id")
            name = entry["name"]
    
            if is_temp_id(submitted_id):
                obj = cls(name=name)
                db.session.add(obj)
                db.session.flush()
                temp_id_map[submitted_id] = obj.id
                print(f"➕ Adding brand: {name}")
            elif submitted_id in existing_by_id:
                obj = existing_by_id[submitted_id]
                if obj.name != name:
                    print(f"✏️ Updating brand {obj.id}: '{obj.name}' → '{name}'")
                    obj.name = name
    
        for id_to_remove in existing_ids - seen_ids:
            db.session.delete(existing_by_id[id_to_remove])
            print(f"🗑️ Removing brand ID {id_to_remove}")
    
        return temp_id_map