from datetime import datetime, timezone
from app.extensions import db
from app.models.customer import Customer
from app.models.account import Account


class Loan(db.Model):
    __tablename__ = 'loans'

    id = db.Column(db.String(50), primary_key=True) 
    customer_id = db.Column(db.String(50), nullable=False)
    account_id = db.Column(db.String(50), nullable=False)
    product_id = db.Column(db.String(20), nullable=False)
    principal_amount = db.Column(db.Float, nullable=False)
    status = db.Column(db.String(20), default='pending')
    created_at = db.Column(db.DateTime, default=datetime.now(timezone.utc))
    updated_at = db.Column(db.DateTime, default=datetime.now(timezone.utc), onupdate=datetime.now(timezone.utc))


    @classmethod
    def create_loan(cls, id, customer_id, account_id, product_id, principal_amount, status='pending'):

        # Check if customer exists
        is_valid = Customer.is_valid_customer(customer_id)
        if not is_valid:
            raise ValueError("Customer does not exist")
        
        # # Check for active loans
        # has_active_loans = cls.has_active_loans(customer_id)
        # if has_active_loans:
        #     raise ValueError("Customer has active loans")

        # Create and save the loan
        loan = cls(
            id=id,
            customer_id=customer_id,
            account_id=account_id,
            product_id=product_id,
            principal_amount=principal_amount,
            status=status
        )

        db.session.add(loan)
        db.session.commit()
        return loan


    @classmethod
    def has_active_loans(cls, customer_id):
        active_loans = cls.query.filter_by(
            customer_id=customer_id,
            status='active'
        ).count()

        if active_loans > 0:
            return False
        return True
    
    
    def __repr__(self):
        return f'<Loan {self.id}>'