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

import cn.hutool.core.collection.CollUtil;
import cn.iocoder.yudao.module.bi.dal.dataobject.decision.BiKpiValueHistoryDO;
import cn.iocoder.yudao.module.bi.dal.mysql.decision.BiKpiDefinitionMapper;
import cn.iocoder.yudao.module.bi.dal.dataobject.decision.BiKpiDefinitionDO;
import cn.iocoder.yudao.module.bi.dal.mysql.decision.BiKpiValueHistoryMapper;
import jakarta.annotation.Resource;
import lombok.extern.slf4j.Slf4j;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.stereotype.Service;

import java.math.BigDecimal;
import java.math.RoundingMode;
import java.time.LocalDateTime;
import java.util.*;

/**
 * 决策支持 KPI 聚合 Service 实现
 *
 * 通过 JdbcTemplate 跨模块执行聚合 SQL
 *
 * @author 超级管理员
 */
@Slf4j
@Service
public class BiDecisionKpiServiceImpl implements BiDecisionKpiService {

    @Resource
    private BiKpiDefinitionMapper kpiMapper;

    @Resource
    private BiKpiValueHistoryMapper kpiValueHistoryMapper;

    @Resource
    private JdbcTemplate jdbcTemplate;

    @Override
    public Map<String, Object> getKpiOverview() {
        List<BiKpiDefinitionDO> kpis = kpiMapper.selectList();
        List<Map<String, Object>> items = new ArrayList<>();

        for (BiKpiDefinitionDO kpi : kpis) {
            Map<String, Object> item = new LinkedHashMap<>();
            item.put("code", kpi.getCode());
            item.put("name", kpi.getName());
            item.put("category", kpi.getCategory());
            item.put("unit", kpi.getUnit());
            item.put("chartType", kpi.getChartType());
            item.put("status", kpi.getStatus());

            // 执行查询获取当前值
            BigDecimal value = executeKpiSql(kpi.getQuerySql());
            item.put("value", value);

            // 判断预警状态
            String alertStatus = evaluateAlertStatus(kpi, value);
            item.put("alertStatus", alertStatus);

            items.add(item);
        }

        Map<String, Object> result = new LinkedHashMap<>();
        result.put("kpis", items);
        result.put("total", items.size());
        return result;
    }

    @Override
    public Map<String, Object> getKpiDetail(String kpiCode) {
        BiKpiDefinitionDO kpi = kpiMapper.selectOne(BiKpiDefinitionDO::getCode, kpiCode);
        if (kpi == null) {
            return Collections.emptyMap();
        }

        Map<String, Object> result = new LinkedHashMap<>();
        result.put("code", kpi.getCode());
        result.put("name", kpi.getName());
        result.put("unit", kpi.getUnit());
        result.put("category", kpi.getCategory());
        result.put("value", executeKpiSql(kpi.getQuerySql()));

        return result;
    }

    @Override
    public Map<String, Object> getKpiByCategory(String category) {
        List<BiKpiDefinitionDO> kpis = kpiMapper.selectList(
                BiKpiDefinitionDO::getCategory, category);
        List<Map<String, Object>> items = new ArrayList<>();

        for (BiKpiDefinitionDO kpi : kpis) {
            Map<String, Object> item = new LinkedHashMap<>();
            item.put("code", kpi.getCode());
            item.put("name", kpi.getName());
            item.put("unit", kpi.getUnit());
            item.put("value", executeKpiSql(kpi.getQuerySql()));
            items.add(item);
        }

        Map<String, Object> result = new LinkedHashMap<>();
        result.put("category", category);
        result.put("kpis", items);
        return result;
    }

    @Override
    public BigDecimal refreshKpi(String kpiCode) {
        BiKpiDefinitionDO kpi = kpiMapper.selectOne(BiKpiDefinitionDO::getCode, kpiCode);
        if (kpi == null) {
            return BigDecimal.ZERO;
        }
        return executeKpiSql(kpi.getQuerySql());
    }

    @Override
    public Map<String, Object> getKpiTrend(String kpiCode, LocalDateTime beginTime,
                                           LocalDateTime endTime, String periodType) {
        BiKpiDefinitionDO kpi = kpiMapper.selectOne(BiKpiDefinitionDO::getCode, kpiCode);
        Map<String, Object> result = new LinkedHashMap<>();
        result.put("kpiCode", kpiCode);
        result.put("kpiName", kpi != null ? kpi.getName() : kpiCode);
        result.put("category", kpi != null ? kpi.getCategory() : null);
        result.put("unit", kpi != null ? kpi.getUnit() : null);
        result.put("periodType", periodType != null ? periodType : "hour");

        if (kpi == null) {
            result.put("points", Collections.emptyList());
            return result;
        }

        LocalDateTime begin = beginTime != null ? beginTime :
                LocalDateTime.now().minusDays(30);
        LocalDateTime end = endTime != null ? endTime : LocalDateTime.now();
        List<BiKpiValueHistoryDO> history = kpiValueHistoryMapper
                .selectByKpiCodeAndTimeRange(kpiCode, begin, end);

        List<Map<String, Object>> points = new ArrayList<>();
        for (BiKpiValueHistoryDO h : history) {
            Map<String, Object> p = new LinkedHashMap<>();
            p.put("time", h.getSnapshotTime());
            p.put("value", h.getKpiValue());
            points.add(p);
        }
        result.put("points", points);
        return result;
    }

    @Override
    public Map<String, Object> getKpiCompare(String kpiCode) {
        BiKpiDefinitionDO kpi = kpiMapper.selectOne(BiKpiDefinitionDO::getCode, kpiCode);
        Map<String, Object> result = new LinkedHashMap<>();
        result.put("kpiCode", kpiCode);
        result.put("kpiName", kpi != null ? kpi.getName() : kpiCode);
        result.put("unit", kpi != null ? kpi.getUnit() : null);

        // 取最近 24 条快照（按时间倒序），最近一条为当前值
        List<BiKpiValueHistoryDO> recent = kpiValueHistoryMapper.selectRecentByKpiCode(kpiCode, 24);
        if (CollUtil.isEmpty(recent)) {
            result.put("currentValue", null);
            result.put("previousValue", null);
            result.put("changeRate", null);
            result.put("avgValue", null);
            result.put("maxValue", null);
            result.put("minValue", null);
            return result;
        }

        // recent 为倒序，第 0 条最新
        BiKpiValueHistoryDO current = recent.get(0);
        result.put("currentTime", current.getSnapshotTime());
        result.put("currentValue", current.getKpiValue());

        if (recent.size() > 1) {
            BiKpiValueHistoryDO previous = recent.get(1);
            result.put("previousTime", previous.getSnapshotTime());
            result.put("previousValue", previous.getKpiValue());
            result.put("changeRate", calcChangeRate(previous.getKpiValue(), current.getKpiValue()));
        } else {
            result.put("previousValue", null);
            result.put("changeRate", null);
        }

        // 近 24 期统计汇总
        BigDecimal sum = BigDecimal.ZERO;
        BigDecimal max = null;
        BigDecimal min = null;
        for (BiKpiValueHistoryDO h : recent) {
            if (h.getKpiValue() == null) {
                continue;
            }
            sum = sum.add(h.getKpiValue());
            max = max == null ? h.getKpiValue() : h.getKpiValue().max(max);
            min = min == null ? h.getKpiValue() : h.getKpiValue().min(min);
        }
        result.put("periodCount", recent.size());
        if (recent.size() > 0) {
            result.put("avgValue", sum.divide(BigDecimal.valueOf(recent.size()), 4, RoundingMode.HALF_UP));
        } else {
            result.put("avgValue", BigDecimal.ZERO);
        }
        result.put("maxValue", max);
        result.put("minValue", min);
        return result;
    }

    private BigDecimal calcChangeRate(BigDecimal previous, BigDecimal current) {
        if (previous == null || current == null || previous.compareTo(BigDecimal.ZERO) == 0) {
            return null;
        }
        return current.subtract(previous).divide(previous, 4, RoundingMode.HALF_UP)
                .multiply(new BigDecimal("100")).setScale(2, RoundingMode.HALF_UP);
    }

    /**
     * 执行 KPI 查询 SQL
     */
    private BigDecimal executeKpiSql(String querySql) {
        if (querySql == null || querySql.isBlank()) {
            return BigDecimal.ZERO;
        }
        try {
            List<Map<String, Object>> result = jdbcTemplate.queryForList(querySql);
            if (result.isEmpty()) {
                return BigDecimal.ZERO;
            }
            // 取第一行第一列的值
            Map<String, Object> row = result.get(0);
            Object value = row.values().iterator().next();
            if (value instanceof Number) {
                return BigDecimal.valueOf(((Number) value).doubleValue());
            }
            return BigDecimal.ZERO;
        } catch (Exception e) {
            log.error("[executeKpiSql][SQL执行失败] {}", querySql, e);
            return BigDecimal.ZERO;
        }
    }

    /**
     * 评估预警状态
     */
    private String evaluateAlertStatus(BiKpiDefinitionDO kpi, BigDecimal value) {
        if (kpi.getThresholdCritical() != null) {
            int cmp = value.compareTo(kpi.getThresholdCritical());
            boolean triggered = ">".equals(kpi.getComparisonOperator()) ? cmp > 0
                    : "<".equals(kpi.getComparisonOperator()) ? cmp < 0
                    : ">=".equals(kpi.getComparisonOperator()) ? cmp >= 0
                    : "<=".equals(kpi.getComparisonOperator()) ? cmp <= 0 : false;
            if (triggered) {
                return "critical";
            }
        }
        if (kpi.getThresholdWarn() != null) {
            int cmp = value.compareTo(kpi.getThresholdWarn());
            boolean triggered = ">".equals(kpi.getComparisonOperator()) ? cmp > 0
                    : "<".equals(kpi.getComparisonOperator()) ? cmp < 0
                    : ">=".equals(kpi.getComparisonOperator()) ? cmp >= 0
                    : "<=".equals(kpi.getComparisonOperator()) ? cmp <= 0 : false;
            if (triggered) {
                return "warn";
            }
        }
        return "normal";
    }

}