package cn.iocoder.yudao.module.mes.service.wm.warning;

import cn.hutool.core.collection.CollUtil;
import cn.iocoder.yudao.framework.common.pojo.PageResult;
import cn.iocoder.yudao.framework.security.core.util.SecurityFrameworkUtils;
import cn.iocoder.yudao.framework.mybatis.core.query.LambdaQueryWrapperX;
import cn.iocoder.yudao.module.mes.controller.admin.wm.materialstock.vo.MesWmMaterialStockListReqVO;
import cn.iocoder.yudao.module.mes.controller.admin.wm.warning.vo.MesWmStockWarningHandleReqVO;
import cn.iocoder.yudao.module.mes.controller.admin.wm.warning.vo.MesWmStockWarningPageReqVO;
import cn.iocoder.yudao.module.mes.controller.admin.wm.warning.vo.MesWmStockWarningRespVO;
import cn.iocoder.yudao.module.mes.dal.dataobject.mdm.MesMdmItemDO;
import cn.iocoder.yudao.module.mes.dal.dataobject.wm.batch.MesWmBatchDO;
import cn.iocoder.yudao.module.mes.dal.dataobject.wm.materialstock.MesWmMaterialStockDO;
import cn.iocoder.yudao.module.mes.dal.dataobject.wm.warning.MesWmStockWarningDO;
import cn.iocoder.yudao.module.mes.dal.dataobject.wm.warehouse.MesWmWarehouseDO;
import cn.iocoder.yudao.module.mes.dal.mysql.wm.warning.MesWmStockWarningMapper;
import cn.iocoder.yudao.module.mes.enums.wm.MesWmStockStateEnum;
import cn.iocoder.yudao.module.mes.enums.wm.MesWmStockWarningTypeEnum;
import cn.iocoder.yudao.module.mes.service.mdm.MesMdmItemService;
import cn.iocoder.yudao.module.mes.service.wm.batch.MesWmBatchService;
import cn.iocoder.yudao.module.mes.service.wm.materialstock.MesWmMaterialStockService;
import cn.iocoder.yudao.module.mes.service.wm.warehouse.MesWmWarehouseService;
import jakarta.annotation.Resource;
import lombok.extern.slf4j.Slf4j;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;
import org.springframework.validation.annotation.Validated;

import java.math.BigDecimal;
import java.time.LocalDateTime;
import java.time.temporal.ChronoUnit;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import java.util.Set;

import static cn.iocoder.yudao.framework.common.exception.util.ServiceExceptionUtil.exception;
import static cn.iocoder.yudao.framework.common.util.collection.CollectionUtils.convertList;
import static cn.iocoder.yudao.framework.common.util.collection.CollectionUtils.convertSet;
import static cn.iocoder.yudao.module.mes.enums.ErrorCodeConstants.WM_STOCK_WARNING_NOT_EXISTS;

/**
 * MES 库存预警 Service 实现类
 * <p>
 * 低库存、临期、库龄三类预警。只针对合格库（正式库存），暂存库（待质检）与已出库不计入预警。
 */
@Service
@Validated
@Slf4j
public class MesWmStockWarningServiceImpl implements MesWmStockWarningService {

    /**
     * 未处理
     */
    private static final Integer STATUS_UNHANDLED = 10;
    /**
     * 已处理
     */
    private static final Integer STATUS_HANDLED = 20;
    /**
     * 库龄预警阈值（天）
     */
    private static final int AGING_DAYS = 365;

    @Resource
    private MesWmStockWarningMapper warningMapper;
    @Resource
    private MesWmMaterialStockService materialStockService;
    @Resource
    private MesMdmItemService mdmItemService;
    @Resource
    private MesWmWarehouseService warehouseService;
    @Resource
    private MesWmBatchService batchService;

    @Override
    public PageResult<MesWmStockWarningRespVO> getWarningPage(MesWmStockWarningPageReqVO pageReqVO) {
        PageResult<MesWmStockWarningDO> pageResult = warningMapper.selectPage(pageReqVO);
        Map<Long, MesMdmItemDO> itemMap = mdmItemService.getItemMap(
                convertSet(pageResult.getList(), MesWmStockWarningDO::getItemId));
        return new PageResult<>(convertList(pageResult.getList(),
                warning -> toRespVO(warning, itemMap.get(warning.getItemId()))), pageResult.getTotal());
    }

    @Override
    public List<MesWmStockWarningRespVO> getCurrentWarnings() {
        List<MesWmStockWarningDO> warnings = computeCurrentWarnings();
        if (CollUtil.isEmpty(warnings)) {
            return List.of();
        }
        Map<Long, MesMdmItemDO> itemMap = mdmItemService.getItemMap(
                convertSet(warnings, MesWmStockWarningDO::getItemId));
        return convertList(warnings, warning -> toRespVO(warning, itemMap.get(warning.getItemId())));
    }

    @Override
    @Transactional(rollbackFor = Exception.class)
    public int persistCurrentWarnings() {
        // 1. 实时计算当前预警
        List<MesWmStockWarningDO> current = computeCurrentWarnings();
        // 2. 删除旧的未处理预警（已处理记录作为历史保留）
        warningMapper.delete(new LambdaQueryWrapperX<MesWmStockWarningDO>()
                .eq(MesWmStockWarningDO::getStatus, STATUS_UNHANDLED));
        // 3. 写入当前预警
        if (CollUtil.isNotEmpty(current)) {
            current.forEach(warningMapper::insert);
        }
        log.info("[persistCurrentWarnings][库存预警落库 {} 条]", current.size());
        return current.size();
    }

    @Override
    public void handle(MesWmStockWarningHandleReqVO reqVO) {
        MesWmStockWarningDO warning = warningMapper.selectById(reqVO.getId());
        if (warning == null) {
            throw exception(WM_STOCK_WARNING_NOT_EXISTS);
        }
        warningMapper.updateById(new MesWmStockWarningDO()
                .setId(warning.getId())
                .setStatus(STATUS_HANDLED)
                .setHandleUserId(SecurityFrameworkUtils.getLoginUserId())
                .setHandleTime(LocalDateTime.now())
                .setHandleRemark(reqVO.getHandleRemark()));
    }

    // ==================== 私有方法 ====================

    /**
     * 实时计算当前预警（低库存 / 临期 / 库龄），针对合格库存
     */
    private List<MesWmStockWarningDO> computeCurrentWarnings() {
        List<MesWmStockWarningDO> result = new ArrayList<>();
        // 仅扫描合格库（正式库存）
        List<MesWmMaterialStockDO> stocks = materialStockService.getMaterialStockList(
                new MesWmMaterialStockListReqVO().setStockState(MesWmStockStateEnum.QUALIFIED.getState()));
        if (CollUtil.isEmpty(stocks)) {
            return result;
        }
        LocalDateTime now = LocalDateTime.now();
        Set<Long> itemIds = convertSet(stocks, MesWmMaterialStockDO::getItemId);
        Map<Long, MesMdmItemDO> itemMap = mdmItemService.getItemMap(itemIds);
        Set<Long> warehouseIds = convertSet(stocks, MesWmMaterialStockDO::getWarehouseId);
        Map<Long, MesWmWarehouseDO> warehouseMap = warehouseService.getWarehouseMap(warehouseIds);

        for (MesWmMaterialStockDO stock : stocks) {
            MesMdmItemDO item = itemMap.get(stock.getItemId());
            MesWmWarehouseDO warehouse = warehouseMap.get(stock.getWarehouseId());
            if (item == null) {
                continue;
            }
            MesWmBatchDO batch = stock.getBatchId() != null ? batchService.getBatch(stock.getBatchId()) : null;
            BigDecimal quantity = stock.getQuantity() != null ? stock.getQuantity() : BigDecimal.ZERO;

            // 1. 低库存：在库数量 <= 最低库存
            if (item.getMinStock() != null && quantity.compareTo(item.getMinStock()) <= 0) {
                result.add(buildWarning(stock, item, warehouse, MesWmStockWarningTypeEnum.LOW_STOCK,
                        item.getMinStock(), quantity, batch != null ? batch.getExpireDate() : null));
            }
            // 2. 临期：批次有有效期，且剩余天数 <= 物料配置的有效期天数
            if (item.getExpiryDay() != null && batch != null && batch.getExpireDate() != null) {
                long remainDays = ChronoUnit.DAYS.between(now.toLocalDate(), batch.getExpireDate().toLocalDate());
                if (remainDays <= item.getExpiryDay()) {
                    result.add(buildWarning(stock, item, warehouse, MesWmStockWarningTypeEnum.EXPIRING,
                            BigDecimal.valueOf(item.getExpiryDay()), BigDecimal.valueOf(Math.max(remainDays, 0)),
                            batch.getExpireDate()));
                }
            }
            // 3. 库龄：入库时间超过阈值
            if (stock.getReceiptTime() != null) {
                long ageDays = ChronoUnit.DAYS.between(stock.getReceiptTime().toLocalDate(), now.toLocalDate());
                if (ageDays >= AGING_DAYS) {
                    result.add(buildWarning(stock, item, warehouse, MesWmStockWarningTypeEnum.AGING,
                            BigDecimal.valueOf(AGING_DAYS), BigDecimal.valueOf(ageDays), null));
                }
            }
        }
        return result;
    }

    private MesWmStockWarningDO buildWarning(MesWmMaterialStockDO stock, MesMdmItemDO item, MesWmWarehouseDO warehouse,
                                             MesWmStockWarningTypeEnum type, BigDecimal threshold, BigDecimal current,
                                             LocalDateTime expireDate) {
        return MesWmStockWarningDO.builder()
                .itemId(item.getId()).itemCode(item.getCode())
                .batchId(stock.getBatchId()).batchCode(stock.getBatchCode())
                .warehouseId(stock.getWarehouseId())
                .warehouseName(warehouse != null ? warehouse.getName() : null)
                .warningType(type.getType()).thresholdValue(threshold).currentValue(current)
                .expireDate(expireDate).receiptTime(stock.getReceiptTime())
                .status(STATUS_UNHANDLED)
                .build();
    }

    private MesWmStockWarningRespVO toRespVO(MesWmStockWarningDO warning, MesMdmItemDO item) {
        MesWmStockWarningRespVO vo = new MesWmStockWarningRespVO();
        vo.setId(warning.getId());
        vo.setItemId(warning.getItemId());
        vo.setItemCode(warning.getItemCode());
        vo.setItemName(item != null ? item.getName() : null);
        vo.setBatchId(warning.getBatchId());
        vo.setBatchCode(warning.getBatchCode());
        vo.setWarehouseId(warning.getWarehouseId());
        vo.setWarehouseName(warning.getWarehouseName());
        vo.setWarningType(warning.getWarningType());
        vo.setWarningTypeName(warningTypeName(warning.getWarningType()));
        vo.setThresholdValue(warning.getThresholdValue());
        vo.setCurrentValue(warning.getCurrentValue());
        vo.setExpireDate(warning.getExpireDate());
        vo.setReceiptTime(warning.getReceiptTime());
        vo.setStatus(warning.getStatus());
        vo.setStatusName(statusName(warning.getStatus()));
        vo.setHandleUserId(warning.getHandleUserId());
        vo.setHandleTime(warning.getHandleTime());
        vo.setHandleRemark(warning.getHandleRemark());
        return vo;
    }

    private String warningTypeName(Integer type) {
        if (type == null) {
            return "";
        }
        for (MesWmStockWarningTypeEnum e : MesWmStockWarningTypeEnum.values()) {
            if (e.getType().equals(type)) {
                return e.getName();
            }
        }
        return String.valueOf(type);
    }

    private String statusName(Integer status) {
        if (status == null) {
            return "";
        }
        return status.equals(STATUS_HANDLED) ? "已处理" : "未处理";
    }

}