package com.gunshi.project.ss.service;


import com.baomidou.mybatisplus.core.conditions.query.LambdaQueryWrapper;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.gunshi.project.ss.common.mapper.StFlowRMapper;
import com.gunshi.project.ss.common.model.StFlowR;
import com.gunshi.project.ss.common.model.StStbprpB;
import com.gunshi.project.ss.entity.dto.StFlowDataCheckDto;
import com.gunshi.project.ss.entity.vo.StFlowLowerDataCheckVo;
import com.gunshi.project.ss.entity.vo.StFlowRListVo;
import com.gunshi.project.ss.entity.vo.StFlowRVo;
import com.gunshi.project.ss.mapper.StFlowRVoMapper;
import jakarta.servlet.http.HttpServletResponse;
import lombok.extern.slf4j.Slf4j;
import org.apache.poi.ss.usermodel.Row;
import org.apache.poi.ss.usermodel.Sheet;
import org.apache.poi.ss.usermodel.Workbook;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import java.io.IOException;
import java.math.BigDecimal;
import java.math.RoundingMode;
import java.net.URLEncoder;
import java.time.Duration;
import java.time.LocalDate;
import java.time.LocalDateTime;
import java.time.format.DateTimeFormatter;
import java.util.*;

@Service
@Slf4j
@Transactional(rollbackFor = Exception.class)
public class StFlowRService extends ServiceImpl<StFlowRMapper, StFlowR> {

    @Autowired
    private StFlowRVoMapper voMapper;

    @Autowired
    private StStbprpBService stStbprpBService;

    public StFlowR getNewDataByStcd(String stcd) {
        LambdaQueryWrapper<StFlowR> queryWrapper = new LambdaQueryWrapper<>();
        queryWrapper.eq(StFlowR::getStcd, stcd);
        queryWrapper.orderByDesc(StFlowR::getTm);
        queryWrapper.last("limit 1");
        return baseMapper.selectOne(queryWrapper);
    }

    public List<StFlowR> listNewData() {
        return this.baseMapper.listNewData();
    }

    public List<String> getStcdList() {
        return voMapper.listStcds();
    }

    public List<StFlowRVo> getDataByStcdAndTm(String stcd, Date tm) {
        return voMapper.getDataByStcdAndTm(stcd, tm);
    }

    public List<StFlowRListVo> listLatestData() {
        List<StFlowRListVo> res = new ArrayList<>();
        List<StStbprpB> flowStations = stStbprpBService.getFlowStations();
        LocalDateTime now = LocalDateTime.now();
        LocalDateTime lastDay = now.minusDays(1);

        for (StStbprpB flowStation : flowStations) {
            StFlowRListVo stFlowR = new StFlowRListVo();
            stFlowR.setStcd(flowStation.getStcd());
            stFlowR.setStnm(flowStation.getStnm());
            stFlowR.setLgtd(flowStation.getLgtd());
            stFlowR.setLttd(flowStation.getLttd());
            // 获取24小时内的所有流量数据
            List<StFlowR> list = lambdaQuery()
                    .eq(StFlowR::getStcd, flowStation.getStcd())
                    .ge(StFlowR::getTm, lastDay)
                    .le(StFlowR::getTm, now)
                    .orderByAsc(StFlowR::getTm) // 按时间升序排列，方便计算
                    .list();

            if(list.isEmpty()){
                res.add(stFlowR);
                continue;
            }

            // 设置最新时间点的数据
            StFlowR latestData = list.get(list.size() - 1);
            stFlowR.setTm(latestData.getTm());
            stFlowR.setQ(latestData.getQ());
            //判断状态
            LocalDateTime tm = latestData.getTm();
            Duration between = Duration.between(tm, now);
            if(between.toHours() > 24){
                stFlowR.setStatus(0);
            }else{
                stFlowR.setStatus(1);
            }
            // 计算统计值
            calculateTotalVolume(list, stFlowR);

            res.add(stFlowR);
        }
        return res;
    }

    // 替代的累计水量计算方法（使用梯形法，更精确）
    private void calculateTotalVolume(List<StFlowR> flowList, StFlowRListVo vo) {
        if (flowList == null || flowList.size() < 2) {
            vo.setTotal24V(BigDecimal.ZERO);
            return;
        }

        BigDecimal totalVolume = BigDecimal.ZERO;

        for (int i = 0; i < flowList.size() - 1; i++) {
            StFlowR current = flowList.get(i);
            StFlowR next = flowList.get(i + 1);

            if (current.getQ() != null && next.getQ() != null &&
                    current.getTm() != null && next.getTm() != null) {

                // 计算时间间隔（秒）
                long seconds = Duration.between(current.getTm(), next.getTm()).getSeconds();

                // 使用梯形法计算水量：(当前流量 + 下一流量) / 2 × 时间间隔
                BigDecimal avgQ = current.getQ().add(next.getQ())
                        .divide(BigDecimal.valueOf(2), 4, RoundingMode.HALF_UP);

                // 水量 = 平均流量(m³/s) × 时间(秒)
                BigDecimal volume = avgQ.multiply(BigDecimal.valueOf(seconds));

                totalVolume = totalVolume.add(volume);
            }
        }

        // 转换为万立方米（1万立方米 = 10000立方米）
        totalVolume = totalVolume.divide(BigDecimal.valueOf(10000), 4, RoundingMode.HALF_UP);
        vo.setTotal24V(totalVolume);
    }

    public List<StFlowRListVo> upperDataCheck(StFlowDataCheckDto dto) {
        List<StFlowRListVo> res = new ArrayList<>();
        List<StFlowR> list = lambdaQuery()
                .eq(StFlowR::getStcd, dto.getStcd())
                .ge(StFlowR::getTm, dto.getDateTimeRangeSo().getStart())
                .le(StFlowR::getTm, dto.getDateTimeRangeSo().getEnd())
                .orderByDesc(StFlowR::getTm)
                .list();
        if(list.isEmpty()){
            return res;
        }
        if(dto.getType() == 0){
            for (StFlowR stFlowR : list) {
                StFlowRListVo stFlowRListVo = new StFlowRListVo();
                stFlowRListVo.setStcd(stFlowR.getStcd());
                stFlowRListVo.setQ(stFlowR.getQ());
                stFlowRListVo.setTm(stFlowR.getTm());
                res.add(stFlowRListVo);
            }
        }else{
            // 使用Map按日期分组
            Map<LocalDate, List<StFlowR>> dailyMap = new LinkedHashMap<>();

            for (StFlowR flow : list) {
                LocalDate date = flow.getTm().toLocalDate();
                dailyMap.computeIfAbsent(date, k -> new ArrayList<>()).add(flow);
            }

            // 计算每天的平均流量
            for (Map.Entry<LocalDate, List<StFlowR>> entry : dailyMap.entrySet()) {
                LocalDate date = entry.getKey();
                List<StFlowR> dayList = entry.getValue();

                if (!dayList.isEmpty()) {
                    StFlowR sample = dayList.get(0);
                    BigDecimal totalQ = BigDecimal.ZERO;
                    int count = 0;

                    // 计算当日流量总和
                    for (StFlowR flow : dayList) {
                        if (flow.getQ() != null) {
                            totalQ = totalQ.add(flow.getQ());
                            count++;
                        }
                    }

                    // 创建结果对象
                    StFlowRListVo vo = new StFlowRListVo();
                    vo.setStcd(sample.getStcd());

                    // 计算平均值并保留2位小数
                    if (count > 0) {
                        BigDecimal avgQ = totalQ.divide(BigDecimal.valueOf(count), 2, RoundingMode.HALF_UP);
                        vo.setQ(avgQ);
                    }

                    // 设置时间为当天的开始时间（00:00:00）
                    vo.setTm(date.atStartOfDay());
                    res.add(vo);
                }
            }
        }
        return res;
    }

    public StFlowLowerDataCheckVo lowerDataCheckVoR(StFlowDataCheckDto dto) {
        return null;
    }

    public List<StFlowR> getByStcd(StFlowDataCheckDto dto) {
        StStbprpB one = stStbprpBService.lambdaQuery()
                .eq(StStbprpB::getStcd, dto.getStcd()).one();
        if(one == null){
            throw new IllegalArgumentException("对不起，该站点不存在");
        }
        LambdaQueryWrapper<StFlowR> queryWrapper = new LambdaQueryWrapper<>();
        queryWrapper.eq(StFlowR::getStcd, dto.getStcd());
        queryWrapper.ge(StFlowR::getTm, dto.getDateTimeRangeSo().getStart());
        queryWrapper.le(StFlowR::getTm, dto.getDateTimeRangeSo().getEnd());
        queryWrapper.orderByDesc(StFlowR::getTm);
        List<StFlowR> stFlowRS = this.baseMapper.selectList(queryWrapper);
        stFlowRS.stream().forEach(o -> o.setStnm(one.getStnm()));
        return stFlowRS;
    }
    public void export(StFlowDataCheckDto dto, HttpServletResponse response) {
        // 1. 获取数据
        List<StFlowR> dataList = getByStcd(dto);

        // 2. 创建Excel工作簿
        try (Workbook workbook = new XSSFWorkbook()) {
            Sheet sheet = workbook.createSheet("流量数据");

            // 3. 创建标题行
            Row headerRow = sheet.createRow(0);
            headerRow.createCell(0).setCellValue("站点名称");
            headerRow.createCell(1).setCellValue("时间");
            headerRow.createCell(2).setCellValue("瞬时流量(m³/s)");

            // 4. 填充数据
            DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss");

            for (int i = 0; i < dataList.size(); i++) {
                StFlowR flowData = dataList.get(i);
                Row row = sheet.createRow(i + 1);

                // 站点名称
                row.createCell(0).setCellValue(flowData.getStnm() != null ? flowData.getStnm() : "");

                // 时间
                String timeStr = "";
                if (flowData.getTm() != null) {
                    timeStr = flowData.getTm().format(formatter);
                }
                row.createCell(1).setCellValue(timeStr);

                // 流量
                if (flowData.getQ() != null) {
                    row.createCell(2).setCellValue(flowData.getQ().doubleValue());
                } else {
                    row.createCell(2).setCellValue("");
                }
            }

            // 5. 自动调整列宽
            for (int i = 0; i < 3; i++) {
                sheet.autoSizeColumn(i);
            }

            // 6. 设置响应头
            String fileName = "流量数据_" + System.currentTimeMillis() + ".xlsx";
            response.setContentType("application/vnd.openxmlformats-officedocument.spreadsheetml.sheet");
            response.setHeader("Content-Disposition", "attachment;filename=" + URLEncoder.encode(fileName, "UTF-8"));

            // 7. 写入响应流
            workbook.write(response.getOutputStream());

        } catch (IOException e) {
            throw new RuntimeException("导出Excel失败", e);
        }
    }
}