[add]: loan charges and offers. Fix RACCheck

app/models/loan_charge.py

@@ -8,7 +8,6 @@ class LoanCharge(db.Model):
 
     id = db.Column(db.Integer, primary_key=True, autoincrement=True)
     loan_id = db.Column(db.Integer, nullable=False)
-    transaction_id = db.Column(db.String(50), nullable=True) 
     code = db.Column(db.String(50), nullable=False) 
     amount = db.Column(db.Float, default=0.0)
     percent = db.Column(db.Float, default=0.0)
@@ -24,7 +23,38 @@ class LoanCharge(db.Model):
         back_populates="loan_charges",
     )
 
- 
+    @classmethod
+    def create_charges_for_loan(cls, loan_id, charges):
+        """
+        Create loan charges for a given loan.
+
+        Args:
+            loan_id (int): ID of the loan to associate charges with.
+            charges (list): A list of dictionaries with keys: 
+            code (str), amount (float), percent (float), description (str), due (int)
+        """
+        if not charges or not isinstance(charges, list):
+            raise ValueError("Charges must be a non-empty list of dictionaries")
+        
+        if loan_id is None:
+            raise ValueError("loan_id cannot be None")
+
+        loan_charges = []
+        for charge in charges:
+            charge_obj = cls(
+                loan_id=loan_id,
+                code=charge.get("code"),
+                amount=charge.get("amount", 0.0),
+                percent=charge.get("percent", 0.0),
+                description=charge.get("description", ""),
+                due=charge.get("due", 0)
+            )
+            db.session.add(charge_obj)
+            loan_charges.append(charge_obj)
+
+        return loan_charges
+
+    
 
     def to_dict(self):
         return {