[add]: Database connection and migrations

app/api/services/account_service.py

@@ -0,0 +1,15 @@
+from app.models import Account
+
+def check_account_settings(account_id, customer_id):
+    """
+    Checks if the account belongs to the customer and if it has existing liens.
+    """
+    account = Account.query.filter_by(id=account_id, customer_id=customer_id).first()
+
+    if not account:
+        return False, "Account not found or doesn't belong to customer"
+
+    if account.lien_amount > 0:
+        return False, "Account has an existing lien"
+
+    return True, "Account is valid"

app/api/services/customer_service.py

@@ -0,0 +1,7 @@
+from app.models import Customer
+
+def check_customer_eligibility(data):
+    # Verify customer exists
+    customer = Customer.query.filter_by(id=data['customerId']).first()
+    if not customer:
+        return False, "Customer not found"

app/api/services/loan_service.py

@@ -0,0 +1,10 @@
+
+from app.models import Loan
+
+def check_active_loans(data):
+    active_loans = Loan.query.filter_by(
+            customer_id=data['customerId'],
+            status='active'
+        ).count()
+    if active_loans > 0:
+        return False, "Customer has active loans"