implemented customerParam Api

src/main/java/com/billpaymentservice/bbps/util/Helper.java

@@ -0,0 +1,51 @@
+package com.billpaymentservice.bbps.util;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.stereotype.Component;
+import com.billpaymentservice.bbps.dto.request.MerchantRequestModel;
+import com.billpaymentservice.bbps.entites.BBPSMerchantValidation;
+import com.billpaymentservice.bbps.exception.CustomException;
+import com.billpaymentservice.bbps.repository.MerchantRepository;
+
+
+@Component
+public class Helper {
+
+	private static final Logger LOGGER = LoggerFactory.getLogger(Helper.class);
+
+	@Autowired
+	private MerchantRepository merchantRegisterRepo;
+
+	/**
+	 * Validates whether the merchant exists and is active.
+	 *
+	 * @param requestModel MerchantRequestModel containing merchant details
+	 * @return true if merchant exists and is active
+	 * @throws CustomException if merchant is invalid or inactive
+	 */
+	public boolean isMerchantValidAndActive(MerchantRequestModel requestModel) {
+
+		if (requestModel == null || requestModel.getMid() == null) {
+			LOGGER.warn("MerchantRequestModel or MID is null");
+			throw new CustomException("Invalid request: MID is required");
+		}
+
+		// Fetch merchant details
+		BBPSMerchantValidation merchantValidation = merchantRegisterRepo.findByMid(requestModel.getMid());
+
+		if (merchantValidation == null) {
+			LOGGER.warn("Merchant not found for MID: {}", requestModel.getMid());
+			throw new CustomException("Merchant not found");
+		}
+
+		if (!Boolean.TRUE.equals(merchantValidation.isActive())) {
+			LOGGER.warn("Merchant inactive for MID: {}", requestModel.getMid());
+			throw new CustomException("Merchant inactive");
+		}
+
+		LOGGER.info("Merchant is valid and active for MID: {}", requestModel.getMid());
+		return true;
+	}
+}