[add]: Loan details and repayment fix

app/models/customer.py

@@ -20,11 +20,11 @@ class Customer(db.Model):
     )
 
     @classmethod
-    def is_eligible(cls, customer_id):
+    def is_valid_customer(cls, customer_id):
         customer = cls.query.filter_by(id=customer_id).first()
         if not customer:
-            return False, "Customer not found"
-        return True, "Customer is eligible"
+            return False
+        return True
 
     @classmethod
     def create_customer(cls, id, msisdn, country_code, account_id, account_type='savings'):

app/models/loan.py

@@ -1,5 +1,7 @@
 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):
@@ -15,6 +17,34 @@ class Loan(db.Model):
     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(
@@ -23,8 +53,8 @@ class Loan(db.Model):
         ).count()
 
         if active_loans > 0:
-            return False, "Customer has active loans"
-        return True, "No active loans"
+            return False
+        return True
     
     
     def __repr__(self):