package com.billpaymentservice.bbps.util;

import java.security.SecureRandom;
import java.time.LocalDateTime;
import java.util.ArrayList;
import java.util.List;
import java.util.Optional;
import java.util.function.Function;
import java.util.stream.Collectors;

import org.modelmapper.ModelMapper;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.http.HttpHeaders;
import org.springframework.http.MediaType;
import org.springframework.stereotype.Component;

import com.billpaymentservice.bbps.dto.AdditionalInfoBillDTO;
import com.billpaymentservice.bbps.dto.CustomerParamDAO;
import com.billpaymentservice.bbps.dto.ResponseModel;
import com.billpaymentservice.bbps.dto.request.BillFetchByBillIdRequest;
import com.billpaymentservice.bbps.dto.request.BillPaymentRequest;
import com.billpaymentservice.bbps.dto.request.FetchBillRequest;
import com.billpaymentservice.bbps.dto.request.FetchBillValidatestRequest;
import com.billpaymentservice.bbps.dto.response.BillDataResponse;
import com.billpaymentservice.bbps.dto.response.FetchBillValidateResponse;
import com.billpaymentservice.bbps.dto.sentRequest.BillPaymentForwardRequest;
import com.billpaymentservice.bbps.dto.sentRequest.FetchBillForwardRequest;
import com.billpaymentservice.bbps.dto.sentRequest.FetchBillValidatestForwardRequest;
import com.billpaymentservice.bbps.entites.AdditionalInfoBill;
import com.billpaymentservice.bbps.entites.AdditionalInfoBillValidate;
import com.billpaymentservice.bbps.entites.BBPSMastersData;
import com.billpaymentservice.bbps.entites.BillMaster;
import com.billpaymentservice.bbps.entites.BillValidation;
import com.billpaymentservice.bbps.entites.BillerDetails;
import com.billpaymentservice.bbps.entites.BillerResponse;
import com.billpaymentservice.bbps.entites.CustomerParamBill;
import com.billpaymentservice.bbps.entites.CustomerParamBillValidation;
import com.billpaymentservice.bbps.entites.InboundTraceLog;
import com.billpaymentservice.bbps.entites.OutboundTraceLog;
import com.billpaymentservice.bbps.entites.PaymentChannel;
import com.billpaymentservice.bbps.entites.PaymentMode;
import com.billpaymentservice.bbps.entites.BharatConnectMaster;
import com.billpaymentservice.bbps.exception.CustomException;
import com.billpaymentservice.bbps.repository.BBPSMasterDataRepo;
import com.billpaymentservice.bbps.repository.BillMasterRepository;
import com.billpaymentservice.bbps.repository.BillValidationRepository;
import com.billpaymentservice.bbps.repository.BillerDataRepository;
import com.billpaymentservice.bbps.repository.InboundTraceLogRepository;
import com.billpaymentservice.bbps.repository.OutboundTraceLogRepository;
import com.fasterxml.jackson.databind.ObjectMapper;

@Component
public class Helper {

	private static final Logger LOGGER = LoggerFactory.getLogger(Helper.class);
	private final InboundTraceLogRepository inboundTraceLogRepository;
	private final OutboundTraceLogRepository outboundTraceLogRepository;

	private static final String CHARACTERS = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
	private static final SecureRandom secureRandom = new SecureRandom();
	private final ObjectMapper objectMapper = new ObjectMapper();
	private final BBPSMasterDataRepo bbpsMasterDataRepo;


	// Constructor Injection
	public Helper(BBPSMasterDataRepo bbpsMasterDataRepo, InboundTraceLogRepository inboundTraceLogRepository,
			OutboundTraceLogRepository outboundTraceLogRepository,BillerDataRepository billerDataRepository,
			BillMasterRepository billMasterRepository,BillValidationRepository billValidationRepository) {
		this.inboundTraceLogRepository = inboundTraceLogRepository;
		this.outboundTraceLogRepository = outboundTraceLogRepository;
		this.bbpsMasterDataRepo = bbpsMasterDataRepo;}

	/**
	 * 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 <T> void startPolling(T requestObject, // Request object (any type)
			Function<T, ResponseModel> apiCallFunction, // Function to call API
			int intervalSeconds, // gap between two polls
			int maxDurationSeconds // total polling time
	) {
		new Thread(() -> {
			try {
				int maxAttempts = maxDurationSeconds / intervalSeconds;

				for (int i = 0; i < maxAttempts; i++) {
					LOGGER.info("⏳ Polling attempt {}...", i + 1);

					ResponseModel response = apiCallFunction.apply(requestObject);
					LOGGER.info("📥 Poll response: {}", response);

					if ("SUCCESS".equalsIgnoreCase(response.getStatus())) {
						LOGGER.info("✅ Polling successful, stopping early.");
						break;
					}

					Thread.sleep(intervalSeconds * 1000L);
				}
			} catch (Exception e) {
				LOGGER.error("❌ Error in polling thread: {}", e.getMessage(), e);
			}
		}).start();
	}

	public void validateMerchant(String mid) {
		if (mid == null || mid == "") {
			LOGGER.warn("MerchantRequestModel or MID is null");
			throw new CustomException("Mid is required", "FAILED", BBPSConstant.BADREQUEST, null);
		}

		BBPSMastersData merchantValidation = bbpsMasterDataRepo.findByMid(mid);

		if (merchantValidation == null) {
			LOGGER.warn("Merchant not found for MID: {}", mid);
			throw new CustomException("Merchant not found by id", "FAILED", BBPSConstant.BADREQUEST, null);
		}

		if (merchantValidation.getApiKey() == null && merchantValidation.getSecreteKey() == null) {
			LOGGER.warn("Merchant BBPS service is not active MID: {}", mid);
			throw new CustomException("Merchant BBPS Service is not active by mid", "FAILED", BBPSConstant.BADREQUEST,
					null);
		}

		if (!Boolean.TRUE.equals(merchantValidation.getIsActive())) {
			LOGGER.warn("Merchant inactive for MID: {}", mid);
			throw new CustomException("Merchant is inactive", "FAILED", BBPSConstant.BADREQUEST, null);
		}

		LOGGER.info("Merchant is valid and active for MID: {}", mid);
		// Agar exception nahi throw hua, merchant valid hai
	}

	public static String generateTxnId(int n) {
		StringBuilder sb = new StringBuilder(n);

		for (int i = 0; i < n; i++) {
			int index = secureRandom.nextInt(CHARACTERS.length());
			sb.append(CHARACTERS.charAt(index));
		}
		return sb.toString(); // Prefix
	}

	public String convertObjectToJson(Object obj) {
		if (obj == null)
			return "null";
		try {
			return new com.fasterxml.jackson.databind.ObjectMapper().writeValueAsString(obj);
		} catch (com.fasterxml.jackson.core.JsonProcessingException e) {
			// log appropriately (use your existing logger)
			System.err.println("JSON conversion failed: " + e.getMessage());
			return "{}"; // or "N/A" depending on your needs
		}
	}
	
	/* ---------- Trace helper methods ---------- */
	
	public InboundTraceLog createInboundLog(String requestId, String txnId, String apiName, String mid,
			String httpMethod, String requestPayload) {
		   if(inboundTraceLogRepository.findByRequestId(requestId) != null) {
	           throw new CustomException("Duplicate Request ID: " + requestId);
	        }
		InboundTraceLog inboundLog = new InboundTraceLog(requestId, txnId, apiName, mid == null ? "N/A" : mid,
				"BBPS_ORG", httpMethod, requestPayload == null ? "N/A" : requestPayload);
		inboundTraceLogRepository.save(inboundLog);
		return inboundLog;
	}

	public void updateInboundLogSuccess(InboundTraceLog inboundLog, String responsePayload, String responseCode) {
		if (inboundLog == null)
			return;
		inboundLog.setResponsePayload(responsePayload);
		inboundLog.setResponseCode(responseCode);
		inboundLog.setStatus("SUCCESS");
		inboundLog.setResponseTime(LocalDateTime.now());
		inboundTraceLogRepository.save(inboundLog);
	}

	 public void updateInboundLogFailure(InboundTraceLog inboundLog, String responsePayload, String responseCode) {
		if (inboundLog == null)
			return;
		inboundLog.setResponsePayload(responsePayload);
		inboundLog.setResponseCode(responseCode);
		inboundLog.setStatus("FAILED");
		inboundLog.setResponseTime(LocalDateTime.now());
		inboundTraceLogRepository.save(inboundLog);
	}

	public OutboundTraceLog createOutboundLog(String txnId, String requestId, String apiName, String url,
			String httpMethod, String requestPayload) {
		OutboundTraceLog outboundLog = new OutboundTraceLog(txnId, requestId, apiName, url, httpMethod,
				requestPayload == null ? "N/A" : requestPayload);
		outboundTraceLogRepository.save(outboundLog);
		return outboundLog;
	}

	public void updateOutboundLogResponse(OutboundTraceLog outboundLog, String responsePayload) {
		if (outboundLog == null)
			return;
		outboundLog.setResponsePayload(responsePayload);
		outboundLog.setResponseReceiveTime(LocalDateTime.now());
		outboundTraceLogRepository.save(outboundLog);
		
	}
	/* ---------- End helpers ---------- */

	// New reusable header builder for BBPS calls
    public HttpHeaders buildHeaders(BharatConnectMaster headersData) {
        HttpHeaders headers = new HttpHeaders();
        if (headersData != null) {
            headers.set("x-digiledge-key", headersData.getXDigiledgeKey());
            headers.set("agentId", headersData.getAgentId());
            headers.set("tenantId", headersData.getTenantId());
        }
        headers.setContentType(MediaType.APPLICATION_JSON);
        return headers;
    }

}