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

class LoanRepaymentSchedule(db.Model):
    __tablename__ = 'loan_repayment_schedules'

    id = db.Column(db.Integer, primary_key=True, autoincrement=True)
    loan_id = db.Column(db.Integer, nullable=False)
    product_id = db.Column(db.String(20), nullable=True)
    installment_number = db.Column(db.Integer, nullable=False)
    due_date = db.Column(db.DateTime, nullable=False)
    installment_amount= db.Column(db.Float, default=0.0)
    total_repayment_amount = db.Column(db.Float, default=0.0)
    paid = db.Column(db.Boolean, default=False)
    paid_at = 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))

    loan = relationship(
        "Loan",
        primaryjoin="LoanRepaymentSchedule.loan_id == Loan.id",
        foreign_keys=[loan_id],
        back_populates="loan_repayment_schedules",
    )



    def to_dict(self):
        return {
            'id': self.id,
            'loanId': self.loan_id,
            'installmentNumber': self.installment_number,
            'dueDate': self.due_date.isoformat(),
            'principalAmount': self.principal_amount,
            'interestAmount': self.interest_amount,
            'totalInstallment': self.total_installment,
            'paid': self.paid,
            'paidAt': self.paid_at.isoformat() if self.paid_at else None
        }

    def __repr__(self):
        return f'<LoanRepaymentSchedule Loan:{self.loan_id} Installment:{self.installment_number}>'