from datetime import datetime, timezone
from app.extensions import db
from sqlalchemy.orm import relationship

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

    id = db.Column(
        db.Integer,
        primary_key=True,
        autoincrement=True,
    )
    customer_id = db.Column(db.String(50), nullable=False)
    transaction_id = db.Column(db.String(50), nullable=True)
    account_id = db.Column(db.String(50), nullable=False)
    offer_id = db.Column(db.String(20), nullable=False)
    product_id = db.Column(db.String(20), nullable=True)
    collection_type = db.Column(db.String(20), nullable=True)
    current_loan_amount = db.Column(db.Float, nullable=True)
    initial_loan_amount = db.Column(db.Float, nullable=False)
    default_penalty_fee = db.Column(db.Float, default=0)
    continuous_fee = db.Column(db.Float, default=0)
    status = db.Column(db.String(20), default='pending')
    due_date = db.Column(db.DateTime, nullable=True)
    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))

    customer = relationship(
        "Customer",
        primaryjoin="Customer.id == Loan.customer_id",
        foreign_keys=[customer_id],
        back_populates="loans",
    )

    loan_charges = relationship(
        "LoanCharge",
        primaryjoin="Loan.id == LoanCharge.loan_id",
        foreign_keys="LoanCharge.loan_id",
        back_populates="loan",
    )

    def __repr__(self):
        return f"<Loan {self.id}>"

    def to_dict(self):
        """
        Convert the Loan object to a dictionary format for JSON serialization.
        """
        return {
            'debtId': self.id,
            'initialLoanAmount': self.initial_loan_amount,
            'currentLoanAmount': self.current_loan_amount,
            'defaultPenaltyFee': self.default_penalty_fee,
            'continuousFee': self.continuous_fee,
            'collectionType': self.collection_type,
            'status': self.status,
            'productId': self.product_id,
            'dueDate': self.due_date.isoformat() if self.due_date else None,
            'loanDate': self.created_at.isoformat if self.created_at else None
        }

    @classmethod
    def get_loan_by_transaction_id(cls, transaction_id):
        return cls.query.filter_by(transaction_id=transaction_id).first()