mercore starter

app/api/services/base_service.py

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+from app.models import Customer, Account, Transaction
+from app.api.enums import TransactionType
+from flask import jsonify
+from marshmallow import ValidationError
+import logging
+from app.api.integrations import KafkaIntegration
+
+logger = logging.getLogger(__name__)
+
+class BaseService:
+    TRANSACTION_TYPE = None
+
+    @classmethod
+    def validate_data(cls, data, schema):
+        """
+        Validate input data based on the provided schema.
+        """
+        logger.info(f"Processing {cls.TRANSACTION_TYPE} request")
+        return schema.load(data)
+
+    @classmethod
+    def get_or_create_customer(cls, validated_data):
+        
+        """
+        Check if a customer exists; if not, create one.
+        """
+
+        customer = Customer.query.filter_by(id=validated_data.get("customerId")).first()
+        if not customer:
+            customer = Customer.create_customer(
+                id=validated_data.get("customerId"),
+                msisdn=validated_data.get("msisdn"),
+                country_code=validated_data.get("countryCode"),
+                account_id=validated_data.get("accountId"),
+            )
+        return customer
+
+    @classmethod
+    def validate_account_ownership(cls, account_id, customer_id):
+        """
+        Check if the provided account belongs to the customer.
+        """
+        is_valid = Account.is_valid_account(account_id, customer_id)
+        return is_valid
+
+    @classmethod
+    def log_transaction(cls, validated_data):
+        """
+        Create a new transaction.
+        """
+        channel = "USSD" if validated_data.get("channel") is None else validated_data.get("channel")
+
+        return Transaction.create_transaction(
+            transaction_id = validated_data.get("transactionId"),
+            customer_id =  validated_data.get('customerId', None),
+            account_id = validated_data.get("accountId", None),  
+            type = cls.TRANSACTION_TYPE,
+            channel = channel,
+        )
+    
+    @classmethod
+    def async_send_to_kafka(cls, loan_data, request_id, topic):
+        KafkaIntegration.send_loan_request(loan_data = loan_data, request_id = request_id, topic = topic)
+        KafkaIntegration.flush()
+
+
+    @classmethod
+    def calculate_charges(cls, offer, amount):
+        """
+        Calculates and returns the charges for the given offer and amount.
+        
+        Args:
+            offer (Offer): The offer object that contains the charges.
+            amount (float): The requested loan amount.
+        
+        Returns:
+            dict: A dictionary containing the calculated charges.
+        """
+        if not offer or not offer.charges:
+            logger.error(f"No charges found for offer ID {offer.id}")
+            return {"error": "No charges found for the offer"}
+
+        loan_charges = offer.charges
+        tenor = offer.schedule # offer.tenor // 30 # Convert to months
+        interest =  cls.get_charge_detail(rates = offer.interest_rate, charges = loan_charges, code = "INTEREST", amount = amount)
+        management = cls.get_charge_detail(rates = offer.management_rate,  charges = loan_charges, code = "MGTFEE", amount = amount)
+        insurance = cls.get_charge_detail(rates = offer.insurance_rate, charges = loan_charges, code = "INSURANCE", amount = amount)
+        vat = cls.get_charge_detail(rates = offer.vat_rate, charges = loan_charges, code = "VAT", amount = amount, management_fee = management["fee"])
+
+        # Separate fees into upfront and postpaid
+        upfront_fees = [
+            fee["fee"]
+            for fee in [interest, management, insurance, vat]
+            if fee["due_days"] == 0
+        ]
+
+        postpaid_fees = [
+            fee["fee"]
+            for fee in [interest, management, insurance, vat]
+            if fee["due_days"] != 0
+        ]
+        vat_test  = vat["fee"]
+        logger.info(f"VAT fee ==  *************** : {vat_test}")
+
+        # Up-front payment: (only those fees due immediately i.e due_days == 0)
+        # upfront_payment = sum(upfront_fees)
+        if offer.schedule == 1:
+            upfront_payment = vat["fee"] + management["fee"] + insurance["fee"] + interest["fee"]
+            interest_amount = interest["fee"]
+            repayment_amount = amount
+        else:
+            upfront_payment = vat["fee"] + insurance["fee"]+management["fee"]
+            interest_amount = interest["fee"]*offer.schedule
+            repayment_amount = amount +  interest_amount
+
+
+        # Repayment amount: (principal + only those fees not due immediately i.e due_days != 0)
+       # repayment_amount = amount + (sum(postpaid_fees) * tenor)
+
+        # Total amount: (upfront_payment + repayment_amount)
+        total_amount = upfront_payment + repayment_amount
+
+        # Calculate the installment amount
+        installment_amount = repayment_amount / offer.schedule
+
+        return {
+            "interest": interest,
+            "interest_amount": interest_amount,
+            "management": management,
+            "insurance": insurance,
+            "vat": vat,
+            "upfront_payment": round(upfront_payment, 2),
+            "repayment_amount": round(repayment_amount, 2),
+            "installment_amount": round(installment_amount, 2),
+            "total_amount": round(total_amount, 2)
+        }
+
+    
+    @classmethod
+    def get_charge_detail(cls, rates, charges, code, amount, management_fee= 0.0):
+        """
+        Get details for a specific charge code from a list of loan charges.
+
+        Returns default values if not found.
+        """
+        fee = 0.0
+
+        if code == "VAT" and management_fee > 0:
+            fee = management_fee * rates / 100
+        else:
+            fee = amount * rates / 100
+
+        return {
+            "rate": rates,
+            "fee": round(fee, 2),
+            "due_days": 30,
+            "code": code,
+            "description" :  "have no idea how to get this yet"
+        }
+
+        # if charge.code == code:
+        #     if code == "VAT" and management_fee > 0:
+        #         fee = management_fee * rates / 100
+        #     else:
+        #         fee = amount * rates / 100
+        #
+        #     return {
+        #         "rate": rates,
+        #         "fee": round(fee, 2),
+        #         "due_days": charge.due
+        #     }
+            
+       # return {"rate": 0, "fee": 0, "due_days": 0}
+
+