from datetime import datetime, timezone
from app.extensions import db


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 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, "Customer has active loans"
        return True, "No active loans"
    
    @classmethod
    def get_customer_loan(cls, loan_id, customer_id):
        """
        Check if a loan with the given ID exists and if the loan belongs to the specified customer_id.
        """
        loan = cls.query.filter_by(id=loan_id, customer_id=customer_id).first()
        if not loan:
            raise ValueError(f"Loan with ID {loan_id} does not exist or does not belong to customer {customer_id}.")
        return loan
    
    
    def __repr__(self):
        return f'<Loan {self.id}>'