from sqlalchemy.orm import Session
from app.models.customer import Customer
from app.schemas.customer import CustomerCreate, CustomerUpdate
from typing import List, Optional


class CustomerService:
    def __init__(self, db: Session):
        self.db = db

    def get_customers(
        self, user_id: int, skip: int = 0, limit: int = 100
    ) -> List[Customer]:
        return (
            self.db.query(Customer)
            .filter(Customer.user_id == user_id)
            .offset(skip)
            .limit(limit)
            .all()
        )

    def get_customer(self, customer_id: int, user_id: int) -> Optional[Customer]:
        return (
            self.db.query(Customer)
            .filter(Customer.id == customer_id, Customer.user_id == user_id)
            .first()
        )

    def create_customer(self, customer_data: CustomerCreate, user_id: int) -> Customer:
        customer = Customer(**customer_data.dict(), user_id=user_id)
        self.db.add(customer)
        self.db.commit()
        self.db.refresh(customer)
        return customer

    def update_customer(
        self, customer_id: int, customer_data: CustomerUpdate, user_id: int
    ) -> Optional[Customer]:
        customer = self.get_customer(customer_id, user_id)
        if not customer:
            return None

        update_data = customer_data.dict(exclude_unset=True)
        for field, value in update_data.items():
            setattr(customer, field, value)

        self.db.commit()
        self.db.refresh(customer)
        return customer

    def delete_customer(self, customer_id: int, user_id: int) -> bool:
        customer = self.get_customer(customer_id, user_id)
        if not customer:
            return False

        self.db.delete(customer)
        self.db.commit()
        return True