add model file

app/models/loan_repayment_schedule.py

@@ -0,0 +1,45 @@
+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}>'