package cn.iocoder.yudao.module.mes.service.safety;

import cn.iocoder.yudao.framework.common.pojo.PageResult;
import cn.iocoder.yudao.framework.common.util.object.BeanUtils;
import cn.iocoder.yudao.module.mes.controller.admin.safety.vo.risk.MesSafetyRiskPageReqVO;
import cn.iocoder.yudao.module.mes.controller.admin.safety.vo.risk.MesSafetyRiskSaveReqVO;
import cn.iocoder.yudao.module.mes.dal.dataobject.safety.MesSafetyRiskDO;
import cn.iocoder.yudao.module.mes.dal.mysql.safety.MesSafetyHazardMapper;
import cn.iocoder.yudao.module.mes.dal.mysql.safety.MesSafetyRiskMapper;
import jakarta.annotation.Resource;
import org.springframework.stereotype.Service;
import org.springframework.validation.annotation.Validated;

import java.math.BigDecimal;
import java.util.List;
import java.util.Objects;

import static cn.iocoder.yudao.framework.common.exception.util.ServiceExceptionUtil.exception;
import static cn.iocoder.yudao.module.mes.enums.ErrorCodeConstants.*;

/**
 * 安全生产 - 风险清单 Service 实现
 *
 * LEC 法（格雷厄姆-金尼法）：
 * D = L × E × C
 * 等级：D≥320 重大(1)；160≤D<320 较大(2)；70≤D<160 一般(3)；D<70 低(4)
 *
 * @author 超级管理员
 */
@Service
@Validated
public class MesSafetyRiskServiceImpl implements MesSafetyRiskService {

    /** 风险等级阈值 */
    private static final BigDecimal LEVEL_1_THRESHOLD = new BigDecimal("320");
    private static final BigDecimal LEVEL_2_THRESHOLD = new BigDecimal("160");
    private static final BigDecimal LEVEL_3_THRESHOLD = new BigDecimal("70");

    @Resource
    private MesSafetyRiskMapper riskMapper;

    @Resource
    private MesSafetyRiskUnitService riskUnitService;

    @Resource
    private MesSafetyHazardMapper hazardMapper;

    @Override
    public PageResult<MesSafetyRiskDO> getRiskPage(MesSafetyRiskPageReqVO pageReqVO) {
        return riskMapper.selectPage(pageReqVO);
    }

    @Override
    public MesSafetyRiskDO getRisk(Long id) {
        return riskMapper.selectById(id);
    }

    @Override
    public Long createRisk(MesSafetyRiskSaveReqVO createReqVO) {
        // 1. 风险单元必须存在
        riskUnitService.validateRiskUnitExists(createReqVO.getUnitId());
        // 2. 编码唯一
        validateCodeUnique(null, createReqVO.getCode());
        // 3. 转换并计算 LEC
        MesSafetyRiskDO risk = BeanUtils.toBean(createReqVO, MesSafetyRiskDO.class);
        applyLecEvaluation(risk);
        riskMapper.insert(risk);
        return risk.getId();
    }

    @Override
    public void updateRisk(MesSafetyRiskSaveReqVO updateReqVO) {
        validateRiskExists(updateReqVO.getId());
        riskUnitService.validateRiskUnitExists(updateReqVO.getUnitId());
        validateCodeUnique(updateReqVO.getId(), updateReqVO.getCode());
        MesSafetyRiskDO updateObj = BeanUtils.toBean(updateReqVO, MesSafetyRiskDO.class);
        applyLecEvaluation(updateObj);
        riskMapper.updateById(updateObj);
    }

    @Override
    public void deleteRisk(Long id) {
        validateRiskExists(id);
        // 已被隐患引用的风险不允许删除
        Long hazardCount = hazardMapper.selectCountByRiskId(id);
        if (hazardCount != null && hazardCount > 0) {
            throw exception(MES_SAFETY_HAZARD_HAS_REFERENCE);
        }
        riskMapper.deleteById(id);
    }

    @Override
    public List<MesSafetyRiskDO> getRiskListByUnitId(Long unitId) {
        return riskMapper.selectListByUnitId(unitId);
    }

    @Override
    public MesSafetyRiskDO validateRiskExists(Long id) {
        if (id == null) {
            throw exception(MES_SAFETY_RISK_NOT_EXISTS);
        }
        MesSafetyRiskDO risk = riskMapper.selectById(id);
        if (risk == null) {
            throw exception(MES_SAFETY_RISK_NOT_EXISTS);
        }
        return risk;
    }

    @Override
    public BigDecimal calculateRiskValue(BigDecimal likelihood, BigDecimal exposure, BigDecimal consequence) {
        if (likelihood == null || exposure == null || consequence == null) {
            return null;
        }
        if (likelihood.compareTo(BigDecimal.ZERO) <= 0
                || exposure.compareTo(BigDecimal.ZERO) <= 0
                || consequence.compareTo(BigDecimal.ZERO) <= 0) {
            throw exception(MES_SAFETY_RISK_LEC_INVALID);
        }
        // D = L × E × C，保留 2 位小数
        return likelihood.multiply(exposure).multiply(consequence)
                .setScale(2, java.math.RoundingMode.HALF_UP);
    }

    @Override
    public Integer calculateRiskLevel(BigDecimal riskValue) {
        if (riskValue == null) {
            return null;
        }
        if (riskValue.compareTo(LEVEL_1_THRESHOLD) >= 0) {
            return 1; // 重大风险
        }
        if (riskValue.compareTo(LEVEL_2_THRESHOLD) >= 0) {
            return 2; // 较大风险
        }
        if (riskValue.compareTo(LEVEL_3_THRESHOLD) >= 0) {
            return 3; // 一般风险
        }
        return 4;     // 低风险
    }

    /**
     * 计算并回填 D 值与风险等级
     */
    private void applyLecEvaluation(MesSafetyRiskDO risk) {
        // L/E/C 都为空时视为未评估，保持空值
        if (risk.getLikelihood() == null && risk.getExposure() == null && risk.getConsequence() == null) {
            risk.setRiskValue(null);
            risk.setRiskLevel(null);
            return;
        }
        BigDecimal riskValue = calculateRiskValue(risk.getLikelihood(), risk.getExposure(), risk.getConsequence());
        risk.setRiskValue(riskValue);
        risk.setRiskLevel(calculateRiskLevel(riskValue));
    }

    /**
     * 校验编码唯一（id 为空表示新增）
     */
    private void validateCodeUnique(Long id, String code) {
        MesSafetyRiskDO exists = riskMapper.selectByCode(code);
        if (exists == null) {
            return;
        }
        if (id == null || !Objects.equals(exists.getId(), id)) {
            throw exception(MES_SAFETY_RISK_CODE_DUPLICATE);
        }
    }

}