package cn.iocoder.yudao.module.bi.service.decision;

import cn.hutool.core.collection.CollUtil;
import cn.hutool.core.date.DateUtil;
import cn.iocoder.yudao.module.bi.controller.admin.decision.vo.DecisionForecastHistorySaveReqVO;
import cn.iocoder.yudao.module.bi.controller.admin.decision.vo.DecisionForecastWorkOrderCreateReqVO;
import cn.iocoder.yudao.module.bi.dal.dataobject.decision.BiForecastDataDO;
import cn.iocoder.yudao.module.bi.dal.dataobject.decision.BiKpiDefinitionDO;
import cn.iocoder.yudao.module.bi.dal.dataobject.decision.BiKpiValueHistoryDO;
import cn.iocoder.yudao.module.bi.dal.mysql.decision.BiForecastDataMapper;
import cn.iocoder.yudao.module.bi.dal.mysql.decision.BiKpiDefinitionMapper;
import cn.iocoder.yudao.module.bi.dal.mysql.decision.BiKpiValueHistoryMapper;
import cn.iocoder.yudao.module.mes.api.workorder.MesProWorkOrderApi;
import cn.iocoder.yudao.module.mes.api.workorder.dto.MesProWorkOrderCreateReqDTO;
import jakarta.annotation.Resource;
import lombok.extern.slf4j.Slf4j;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import java.math.BigDecimal;
import java.math.RoundingMode;
import java.time.LocalDateTime;
import java.util.ArrayList;
import java.util.List;

import static cn.iocoder.yudao.framework.common.exception.util.ServiceExceptionUtil.exception;
import static cn.iocoder.yudao.module.bi.enums.ErrorCodeConstants.BI_FORECAST_NO_HISTORY;
import static cn.iocoder.yudao.module.bi.enums.ErrorCodeConstants.BI_FORECAST_NOT_EXISTS;

/**
 * 负荷预测 Service 实现
 *
 * 本期使用简单移动平均占位，预留 ML 模型接口
 *
 * @author 超级管理员
 */
@Slf4j
@Service
public class BiForecastServiceImpl implements BiForecastService {

    /**
     * 工单来源类型：负荷预测（与字典 mes_pro_work_order_source_type 的 value=4 一致）
     */
    private static final Integer WORK_ORDER_SOURCE_TYPE_FORECAST = 4;

    @Resource
    private BiForecastDataMapper forecastDataMapper;
    @Resource
    private BiKpiDefinitionMapper kpiMapper;
    @Resource
    private BiKpiValueHistoryMapper kpiValueHistoryMapper;
    @Resource
    private MesProWorkOrderApi mesProWorkOrderApi;

    @Override
    public List<BiForecastDataDO> getForecastList(String forecastCode, LocalDateTime beginTime, LocalDateTime endTime) {
        return forecastDataMapper.selectListByCodeAndTimeRange(forecastCode, beginTime, endTime);
    }

    /**
     * 移动平均窗口大小
     */
    private static final int SMA_WINDOW = 12;

    @Override
    public Long createForecastHistory(DecisionForecastHistorySaveReqVO reqVO) {
        BiForecastDataDO data = BiForecastDataDO.builder()
                .forecastCode(reqVO.getForecastCode())
                .forecastName(reqVO.getForecastName())
                .pointTime(reqVO.getPointTime())
                .forecastValue(reqVO.getForecastValue())
                .actualValue(reqVO.getActualValue())
                .dimension(reqVO.getDimension())
                .dimensionValue(reqVO.getDimensionValue())
                .remark(reqVO.getRemark())
                .modelVersion("manual-history")
                .build();
        forecastDataMapper.insert(data);
        return data.getId();
    }

    @Override
    public void generateForecast(String forecastCode, LocalDateTime pointTime) {
        // 默认使用 SMA 模型
        generateForecast(forecastCode, "SMA", SMA_WINDOW, 7, pointTime);
    }

    @Override
    public void generateForecast(String forecastCode, String model, int window, int period,
                                 LocalDateTime pointTime) {
        // 基于同预测编码的历史预测数据做统计预测；无历史数据时不伪造零值
        List<BiForecastDataDO> history = forecastDataMapper.selectRecentByCode(forecastCode, SMA_WINDOW);
        if (CollUtil.isEmpty(history)) {
            throw exception(BI_FORECAST_NO_HISTORY);
        }
        List<BigDecimal> values = new ArrayList<>();
        for (BiForecastDataDO h : history) {
            if (h.getForecastValue() != null) {
                values.add(h.getForecastValue());
            }
        }
        BiForecastEngine.Forecast forecast = BiForecastEngine.forecast(model, values, window, period);
        if (forecast == null) {
            throw exception(BI_FORECAST_NO_HISTORY);
        }
        BiForecastDataDO data = BiForecastDataDO.builder()
                .forecastCode(forecastCode)
                .forecastName(history.get(0).getForecastName())
                .pointTime(pointTime)
                .forecastValue(forecast.value())
                .lowerBound(forecast.lowerBound())
                .upperBound(forecast.upperBound())
                .confidenceLevel(new BigDecimal("95.00"))
                .modelVersion("v2.0-" + model.toLowerCase())
                .build();
        forecastDataMapper.insert(data);
    }

    @Override
    public int generateKpiForecast(String kpiCode, String model, int window, int period,
                                   int periods, int intervalMinutes) {
        // 1. 校验 KPI 定义
        BiKpiDefinitionDO kpi = kpiMapper.selectOne(BiKpiDefinitionDO::getCode, kpiCode);
        if (kpi == null) {
            throw exception(BI_FORECAST_NOT_EXISTS);
        }
        // 2. 取 KPI 历史快照（升序），无数据不预测
        List<BiKpiValueHistoryDO> historyList = kpiValueHistoryMapper.selectByKpiCodeAndTimeRange(
                kpiCode, LocalDateTime.now().minusMonths(6), LocalDateTime.now());
        if (CollUtil.isEmpty(historyList)) {
            throw exception(BI_FORECAST_NO_HISTORY);
        }
        List<BigDecimal> history = new ArrayList<>();
        LocalDateTime lastSnapshotTime = null;
        for (BiKpiValueHistoryDO h : historyList) {
            if (h.getKpiValue() != null) {
                history.add(h.getKpiValue());
                lastSnapshotTime = h.getSnapshotTime();
            }
        }
        if (history.isEmpty()) {
            throw exception(BI_FORECAST_NO_HISTORY);
        }
        // 3. 逐期滚动预测
        int targetPeriods = periods > 0 ? Math.min(periods, 90) : 30;
        int stepMinutes = intervalMinutes > 0 ? intervalMinutes : 360;
        int count = 0;
        LocalDateTime nextTime = lastSnapshotTime;
        for (int i = 0; i < targetPeriods; i++) {
            BiForecastEngine.Forecast f = BiForecastEngine.forecast(model, history, window, period);
            if (f == null) {
                break;
            }
            nextTime = nextTime.plusMinutes(stepMinutes);
            BiForecastDataDO data = BiForecastDataDO.builder()
                    .forecastCode(kpiCode)
                    .forecastName(kpi.getName() + " 预测")
                    .pointTime(nextTime)
                    .forecastValue(f.value())
                    .lowerBound(f.lowerBound())
                    .upperBound(f.upperBound())
                    .confidenceLevel(new BigDecimal("95.00"))
                    .modelVersion("v2.0-" + (model == null ? "sma" : model.toLowerCase()))
                    .dimension("kpi")
                    .dimensionValue(kpiCode)
                    .build();
            forecastDataMapper.insert(data);
            count++;
            // 将预测值追加进历史，供下一期滚动
            history.add(f.value());
            if (history.size() > 200) {
                history.remove(0);
            }
        }
        return count;
    }

    @Override
    @Transactional(rollbackFor = Exception.class)
    public Long createWorkOrderFromForecast(DecisionForecastWorkOrderCreateReqVO reqVO) {
        // 1. 校验预测数据存在
        BiForecastDataDO forecast = forecastDataMapper.selectById(reqVO.getForecastId());
        if (forecast == null) {
            throw exception(BI_FORECAST_NOT_EXISTS);
        }
        // 2. 组装工单 DTO 并调用 MES API 创建（无产品工单，跳 BOM）
        MesProWorkOrderCreateReqDTO dto = new MesProWorkOrderCreateReqDTO();
        dto.setCode(generateWorkOrderCode());
        dto.setName(reqVO.getWorkOrderName() != null
                ? reqVO.getWorkOrderName()
                : ("负荷预测-" + forecast.getForecastName()));
        dto.setType(reqVO.getWorkOrderType());
        dto.setOrderSourceType(WORK_ORDER_SOURCE_TYPE_FORECAST);
        dto.setOrderSourceCode(forecast.getForecastCode());
        dto.setRequestDate(reqVO.getRequestDate());
        dto.setQuantity(reqVO.getQuantity());
        dto.setRemark(reqVO.getRemark());
        return mesProWorkOrderApi.createWorkOrder(dto);
    }

    private String generateWorkOrderCode() {
        return "GZ" + DateUtil.format(LocalDateTime.now(), "yyyyMMddHHmmss")
                + String.format("%03d", (int) (Math.random() * 1000));
    }

}