package cn.iocoder.yudao.module.finance.service.statistics;

import cn.iocoder.yudao.module.erp.api.finance.ErpFinanceStatisticsApi;
import cn.iocoder.yudao.module.erp.api.finance.dto.ErpFinanceMonthlyStatisticsRespDTO;
import cn.iocoder.yudao.module.finance.controller.admin.statistics.vo.FinStatisticsOverviewRespVO;
import cn.iocoder.yudao.module.finance.controller.admin.statistics.vo.FinStatisticsReqVO;
import cn.iocoder.yudao.module.finance.controller.admin.statistics.vo.FinStatisticsTrendRespVO;
import cn.iocoder.yudao.module.finance.dal.dataobject.asset.FinFixedAssetDO;
import cn.iocoder.yudao.module.finance.dal.dataobject.asset.FinIntangibleAssetDO;
import cn.iocoder.yudao.module.finance.dal.mysql.subject.FinAccountSubjectMapper;
import cn.iocoder.yudao.module.finance.dal.mysql.voucher.FinVoucherMapper;
import cn.iocoder.yudao.module.finance.enums.FinVoucherStatusEnum;
import cn.iocoder.yudao.module.finance.service.asset.FinFixedAssetService;
import cn.iocoder.yudao.module.finance.service.asset.FinIntangibleAssetService;
import jakarta.annotation.Resource;
import org.springframework.stereotype.Service;
import org.springframework.validation.annotation.Validated;

import java.math.BigDecimal;
import java.time.LocalDate;
import java.time.LocalDateTime;
import java.time.YearMonth;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import java.util.function.Function;

import static cn.iocoder.yudao.framework.common.exception.util.ServiceExceptionUtil.exception;
import static cn.iocoder.yudao.framework.common.util.collection.CollectionUtils.convertMap;
import static cn.iocoder.yudao.module.finance.enums.ErrorCodeConstants.STATISTICS_PERIOD_INVALID;

/**
 * 财务报表 / 会计核算看板 Service 实现类
 *
 * @author 超级管理员
 */
@Service
@Validated
public class FinStatisticsServiceImpl implements FinStatisticsService {

    @Resource
    private ErpFinanceStatisticsApi erpFinanceStatisticsApi;
    @Resource
    private FinVoucherMapper voucherMapper;
    @Resource
    private FinAccountSubjectMapper accountSubjectMapper;
    @Resource
    private FinFixedAssetService fixedAssetService;
    @Resource
    private FinIntangibleAssetService intangibleAssetService;

    @Override
    public FinStatisticsOverviewRespVO getStatisticsOverview(FinStatisticsReqVO reqVO) {
        // 1. 期间
        LocalDate startDate = resolveStartDate(reqVO);
        LocalDate endDate = resolveEndDate(reqVO);
        validatePeriod(startDate, endDate);

        // 2. ERP 收支、购销金额
        List<ErpFinanceMonthlyStatisticsRespDTO> monthlyList = getErpMonthlyStatistics(startDate, endDate);
        BigDecimal receiptPrice = sumOf(monthlyList, ErpFinanceMonthlyStatisticsRespDTO::getReceiptPrice);
        BigDecimal paymentPrice = sumOf(monthlyList, ErpFinanceMonthlyStatisticsRespDTO::getPaymentPrice);
        BigDecimal saleOrderPrice = sumOf(monthlyList, ErpFinanceMonthlyStatisticsRespDTO::getSaleOrderPrice);
        BigDecimal purchaseOrderPrice = sumOf(monthlyList, ErpFinanceMonthlyStatisticsRespDTO::getPurchaseOrderPrice);

        // 3. 固定资产、无形资产（时点数，取全部资产）
        BigDecimal fixedAssetOriginalValue = BigDecimal.ZERO;
        BigDecimal fixedAssetAccumulatedDepreciation = BigDecimal.ZERO;
        BigDecimal fixedAssetNetValue = BigDecimal.ZERO;
        for (FinFixedAssetDO asset : fixedAssetService.getFixedAssetList()) {
            fixedAssetOriginalValue = fixedAssetOriginalValue.add(defaultIfNull(asset.getOriginalValue()));
            fixedAssetAccumulatedDepreciation = fixedAssetAccumulatedDepreciation
                    .add(defaultIfNull(asset.getAccumulatedDepreciation()));
            fixedAssetNetValue = fixedAssetNetValue.add(defaultIfNull(asset.getNetValue()));
        }
        BigDecimal intangibleAssetOriginalValue = BigDecimal.ZERO;
        BigDecimal intangibleAssetAccumulatedAmortization = BigDecimal.ZERO;
        BigDecimal intangibleAssetNetValue = BigDecimal.ZERO;
        for (FinIntangibleAssetDO asset : intangibleAssetService.getIntangibleAssetList()) {
            intangibleAssetOriginalValue = intangibleAssetOriginalValue.add(defaultIfNull(asset.getOriginalValue()));
            intangibleAssetAccumulatedAmortization = intangibleAssetAccumulatedAmortization
                    .add(defaultIfNull(asset.getAccumulatedAmortization()));
            intangibleAssetNetValue = intangibleAssetNetValue.add(defaultIfNull(asset.getNetValue()));
        }

        // 4. 凭证统计
        Long voucherUnpostedCount = defaultIfNull(voucherMapper.selectCountByStatus(FinVoucherStatusEnum.UNPOSTED.getStatus()));
        Long voucherPostedCount = defaultIfNull(voucherMapper.selectCountByStatus(FinVoucherStatusEnum.POSTED.getStatus()));
        Long voucherCancelledCount = defaultIfNull(voucherMapper.selectCountByStatus(FinVoucherStatusEnum.CANCELLED.getStatus()));

        // 5. 组装
        return new FinStatisticsOverviewRespVO()
                .setStartDate(startDate).setEndDate(endDate)
                .setReceiptPrice(receiptPrice)
                .setPaymentPrice(paymentPrice)
                .setNetProfit(receiptPrice.subtract(paymentPrice))
                .setSaleOrderPrice(saleOrderPrice)
                .setPurchaseOrderPrice(purchaseOrderPrice)
                .setFixedAssetOriginalValue(fixedAssetOriginalValue)
                .setFixedAssetAccumulatedDepreciation(fixedAssetAccumulatedDepreciation)
                .setFixedAssetNetValue(fixedAssetNetValue)
                .setIntangibleAssetOriginalValue(intangibleAssetOriginalValue)
                .setIntangibleAssetAccumulatedAmortization(intangibleAssetAccumulatedAmortization)
                .setIntangibleAssetNetValue(intangibleAssetNetValue)
                .setTotalAssetNetValue(fixedAssetNetValue.add(intangibleAssetNetValue))
                .setSubjectCount(defaultIfNull(accountSubjectMapper.selectCount()))
                .setVoucherCount(voucherUnpostedCount + voucherPostedCount + voucherCancelledCount)
                .setVoucherUnpostedCount(voucherUnpostedCount)
                .setVoucherPostedCount(voucherPostedCount)
                .setVoucherCancelledCount(voucherCancelledCount);
    }

    @Override
    public List<FinStatisticsTrendRespVO> getStatisticsTrend(FinStatisticsReqVO reqVO) {
        // 1. 期间
        LocalDate startDate = resolveStartDate(reqVO);
        LocalDate endDate = resolveEndDate(reqVO);
        validatePeriod(startDate, endDate);

        // 2. ERP 月度数据转 Map，便于按月份补 0
        Map<String, ErpFinanceMonthlyStatisticsRespDTO> monthMap = convertMap(
                getErpMonthlyStatistics(startDate, endDate), ErpFinanceMonthlyStatisticsRespDTO::getMonth);

        // 3. 期间内逐月输出，没有数据的月份补 0
        List<FinStatisticsTrendRespVO> list = new ArrayList<>();
        YearMonth endMonth = YearMonth.from(endDate);
        for (YearMonth month = YearMonth.from(startDate); !month.isAfter(endMonth); month = month.plusMonths(1)) {
            ErpFinanceMonthlyStatisticsRespDTO dto = monthMap.get(month.toString());
            BigDecimal receiptPrice = dto == null ? BigDecimal.ZERO : defaultIfNull(dto.getReceiptPrice());
            BigDecimal paymentPrice = dto == null ? BigDecimal.ZERO : defaultIfNull(dto.getPaymentPrice());
            list.add(new FinStatisticsTrendRespVO()
                    .setMonth(month.toString())
                    .setReceiptPrice(receiptPrice)
                    .setPaymentPrice(paymentPrice)
                    .setNetProfit(receiptPrice.subtract(paymentPrice))
                    .setSaleOrderPrice(dto == null ? BigDecimal.ZERO : defaultIfNull(dto.getSaleOrderPrice()))
                    .setPurchaseOrderPrice(dto == null ? BigDecimal.ZERO : defaultIfNull(dto.getPurchaseOrderPrice())));
        }
        return list;
    }

    /**
     * 调用 ERP 模块 API 获取月度统计，并做兜底解包
     */
    private List<ErpFinanceMonthlyStatisticsRespDTO> getErpMonthlyStatistics(LocalDate startDate, LocalDate endDate) {
        List<ErpFinanceMonthlyStatisticsRespDTO> list = erpFinanceStatisticsApi
                .getMonthlyStatistics(startDate.atStartOfDay(), endDate.plusDays(1).atStartOfDay())
                .getCheckedData();
        return list == null ? List.of() : list;
    }

    private LocalDate resolveStartDate(FinStatisticsReqVO reqVO) {
        return reqVO.getStartMonth() != null ? reqVO.getStartMonth().atDay(1)
                : LocalDate.now().withDayOfYear(1);
    }

    private LocalDate resolveEndDate(FinStatisticsReqVO reqVO) {
        return reqVO.getEndMonth() != null ? reqVO.getEndMonth().atEndOfMonth()
                : LocalDate.now();
    }

    private void validatePeriod(LocalDate startDate, LocalDate endDate) {
        if (startDate.isAfter(endDate)) {
            throw exception(STATISTICS_PERIOD_INVALID, YearMonth.from(startDate), YearMonth.from(endDate));
        }
    }

    private static BigDecimal sumOf(List<ErpFinanceMonthlyStatisticsRespDTO> list,
                                   Function<ErpFinanceMonthlyStatisticsRespDTO, BigDecimal> getter) {
        return list.stream().map(getter).map(FinStatisticsServiceImpl::defaultIfNull)
                .reduce(BigDecimal.ZERO, BigDecimal::add);
    }

    private static BigDecimal defaultIfNull(BigDecimal amount) {
        return amount == null ? BigDecimal.ZERO : amount;
    }

    private static Long defaultIfNull(Long value) {
        return value == null ? 0L : value;
    }

}