package com.tourguide.modules.order.service;

import com.alibaba.fastjson.JSONObject;
import com.tourguide.common.exception.BusinessException;
import com.tourguide.common.huifu.properties.HuiFuProperties;
import com.tourguide.modules.order.domain.OrderStatus;
import com.tourguide.modules.order.domain.RefundAmountCalculator;
import com.tourguide.modules.order.domain.RefundStatus;
import com.tourguide.modules.order.entity.TourOrder;
import com.tourguide.modules.order.entity.TourOrderRefund;
import com.tourguide.modules.order.mapper.TourOrderMapper;
import com.tourguide.modules.order.mapper.TourOrderRefundMapper;
import com.tourguide.modules.finance.service.GuideBalanceSettlementService;
import org.springframework.stereotype.Service;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.transaction.annotation.Transactional;
import org.springframework.util.StringUtils;

import java.math.BigDecimal;
import java.time.LocalDateTime;
import java.time.format.DateTimeFormatter;
import java.time.format.DateTimeParseException;

@Service
public class HuifuRefundCallbackService {
    private static final DateTimeFormatter TIME_FORMAT = DateTimeFormatter.ofPattern("yyyyMMddHHmmss");

    private final HuiFuProperties properties;
    private final TourOrderMapper orderMapper;
    private final TourOrderRefundMapper refundMapper;
    private final GuideBalanceSettlementService balanceSettlementService;
    private final GuideSessionTransitionService sessionTransitionService;

    public HuifuRefundCallbackService(HuiFuProperties properties, TourOrderMapper orderMapper) {
        this(properties, orderMapper, null, null, null);
    }

    public HuifuRefundCallbackService(HuiFuProperties properties, TourOrderMapper orderMapper,
                                      TourOrderRefundMapper refundMapper) {
        this(properties, orderMapper, refundMapper, null, null);
    }

    public HuifuRefundCallbackService(HuiFuProperties properties, TourOrderMapper orderMapper,
                                      TourOrderRefundMapper refundMapper,
                                      GuideBalanceSettlementService balanceSettlementService) {
        this(properties, orderMapper, refundMapper, balanceSettlementService, null);
    }

    @Autowired
    public HuifuRefundCallbackService(HuiFuProperties properties, TourOrderMapper orderMapper,
                                      TourOrderRefundMapper refundMapper,
                                      GuideBalanceSettlementService balanceSettlementService,
                                      GuideSessionTransitionService sessionTransitionService) {
        this.properties = properties;
        this.orderMapper = orderMapper;
        this.refundMapper = refundMapper;
        this.balanceSettlementService = balanceSettlementService;
        this.sessionTransitionService = sessionTransitionService;
    }

    @Transactional
    public boolean handle(JSONObject body) {
        String refundOrderNo = first(body, "req_seq_id", "refund_req_seq_id");
        if (!StringUtils.hasText(refundOrderNo)) {
            throw new BusinessException(400, "Huifu refund callback request sequence is missing");
        }
        validateMerchant(first(body, "huifu_id", "out_huifu_id"));
        TourOrderRefund refundRecord = refundMapper == null
                ? null : refundMapper.selectByRefundOrderNoForUpdate(refundOrderNo);
        TourOrder order = refundRecord == null
                ? orderMapper.selectByRefundOrderNoForUpdate(refundOrderNo)
                : orderMapper.selectForUpdate(refundRecord.getOrderId());
        if (order == null) throw new BusinessException(404, "Refund order does not exist");

        String status = first(body, "refund_stat", "trans_stat");
        String result = StringUtils.hasText(status) ? status : first(body, "resp_code", "code");
        if (!isSuccess(result)) {
            if (isRefunding(order, refundRecord)) {
                order.setRefundStatus(RefundStatus.REFUND_FAILED.getCode());
                updateRefundRecord(refundRecord, RefundStatus.REFUND_FAILED.getCode(), null);
                orderMapper.updateById(order);
            }
            return false;
        }
        if (!isRefunding(order, refundRecord)) {
            return false;
        }
        boolean restoreSession = OrderStatus.PENDING_MEETING.matches(order.getStatus())
                && order.getGuideId() != null && order.getReceivingSessionId() != null;
        BigDecimal callbackAmount = amount(body);
        BigDecimal expectedAmount = refundRecord == null
                ? order.getRefundAmount() : refundRecord.getRefundAmount();
        if (expectedAmount == null || expectedAmount.compareTo(callbackAmount) != 0) {
            throw new BusinessException(409, "Refund amount does not match order");
        }
        BigDecimal previousRefundedAmount = RefundAmountCalculator.refundedAmount(order);
        BigDecimal refundedAmount = previousRefundedAmount.add(callbackAmount);
        BigDecimal paidAmount = RefundAmountCalculator.paidAmount(order);
        if (refundedAmount.compareTo(paidAmount) > 0) {
            throw new BusinessException(409, "Refund amount exceeds order payment");
        }
        order.setRefundedAmount(refundedAmount);
        order.setRefundAmount(callbackAmount);
        if (refundedAmount.compareTo(paidAmount) >= 0) {
            order.setRefundStatus(RefundStatus.REFUNDED.getCode());
            order.setStatus(OrderStatus.REFUNDED.getCode());
        } else {
            order.setRefundStatus(RefundStatus.PARTIAL.getCode());
            order.setStatus(OrderStatus.CANCELLED.getCode());
        }
        LocalDateTime refundCompletedAt = callbackTime(body);
        order.setRefundTime(refundCompletedAt);
        if (order.getCancelledAt() == null) order.setCancelledAt(refundCompletedAt);
        if (balanceSettlementService != null) {
            balanceSettlementService.reverseRefund(order, previousRefundedAmount, refundedAmount);
        }
        // 回调确认的是当前退款流水，明细必须单独标记为已完成；订单状态仍表示累计退款进度。
        updateRefundRecord(refundRecord, RefundStatus.REFUNDED.getCode(), refundCompletedAt);
        orderMapper.updateById(order);
        if (restoreSession && sessionTransitionService != null) {
            sessionTransitionService.restoreAfterOrderCancellation(order);
        }
        return true;
    }

    private boolean isRefunding(TourOrder order, TourOrderRefund refund) {
        return refund == null
                ? RefundStatus.REFUNDING.matches(order.getRefundStatus())
                : RefundStatus.REFUNDING.matches(refund.getRefundStatus());
    }

    private void updateRefundRecord(TourOrderRefund refund, String status, LocalDateTime refundTime) {
        if (refund == null) return;
        refund.setRefundStatus(status);
        refund.setRefundTime(refundTime);
        refundMapper.updateById(refund);
    }

    private void validateMerchant(String callbackHuifuId) {
        if (!StringUtils.hasText(callbackHuifuId)
                || !callbackHuifuId.equals(properties.getHuifuId())) {
            throw new BusinessException(400, "Huifu refund callback merchant does not match");
        }
    }

    private BigDecimal amount(JSONObject body) {
        String value = first(body, "ord_amt", "refund_amt", "trans_amt");
        if (!StringUtils.hasText(value)) {
            throw new BusinessException(400, "Huifu refund callback amount is missing");
        }
        try {
            return new BigDecimal(value);
        } catch (NumberFormatException exception) {
            throw new BusinessException(400, "Huifu refund callback amount is invalid");
        }
    }

    private LocalDateTime callbackTime(JSONObject body) {
        String value = first(body, "end_time", "trans_time", "refund_time");
        if (!StringUtils.hasText(value)) return LocalDateTime.now();
        String normalized = value.replace("-", "").replace(":", "").replace(" ", "");
        try {
            return LocalDateTime.parse(normalized, TIME_FORMAT);
        } catch (DateTimeParseException exception) {
            return LocalDateTime.now();
        }
    }

    private boolean isSuccess(String status) {
        return "S".equalsIgnoreCase(status) || "SUCCESS".equalsIgnoreCase(status)
                || "SUCCEEDED".equalsIgnoreCase(status) || "00000100".equalsIgnoreCase(status);
    }

    private String first(JSONObject body, String... keys) {
        if (body == null) return null;
        for (String key : keys) {
            String value = body.getString(key);
            if (StringUtils.hasText(value)) return value;
        }
        JSONObject data = body.getJSONObject("data");
        if (data != null) return first(data, keys);
        return null;
    }
}