package cn.iocoder.yudao.module.hrm.service.attendance;

import cn.iocoder.yudao.framework.common.pojo.PageResult;
import cn.iocoder.yudao.framework.common.util.object.BeanUtils;
import cn.iocoder.yudao.framework.mybatis.core.query.LambdaQueryWrapperX;
import com.google.common.annotations.VisibleForTesting;
import cn.iocoder.yudao.module.hrm.controller.admin.attendance.vo.HrmAttendanceRulePageReqVO;
import cn.iocoder.yudao.module.hrm.controller.admin.attendance.vo.HrmAttendanceRuleSaveReqVO;
import cn.iocoder.yudao.module.hrm.dal.dataobject.attendance.HrmAttendanceRuleDO;
import cn.iocoder.yudao.module.hrm.dal.mysql.attendance.HrmAttendanceRuleMapper;
import jakarta.annotation.Resource;
import org.springframework.stereotype.Service;
import org.springframework.validation.annotation.Validated;

import java.math.BigDecimal;
import java.time.Duration;
import java.time.LocalDateTime;
import java.time.LocalTime;
import java.util.Comparator;
import java.util.List;

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

/**
 * 考勤规则配置 Service 实现类
 *
 * @author 超级管理员
 */
@Service
@Validated
public class HrmAttendanceRuleServiceImpl implements HrmAttendanceRuleService {

    /** 规则状态：0-启用 */
    private static final Integer ENABLED_STATUS = 0;

    @Resource
    private HrmAttendanceRuleMapper attendanceRuleMapper;

    @Override
    public Long createAttendanceRule(HrmAttendanceRuleSaveReqVO createReqVO) {
        // 校验规则名称是否重复
        validateAttendanceRuleNameUnique(null, createReqVO.getName());
        // 注：同一个部门允许配置多条规则（多班次），这里不再校验部门唯一
        HrmAttendanceRuleDO attendanceRule = BeanUtils.toBean(createReqVO, HrmAttendanceRuleDO.class);
        // 设置默认值
        if (attendanceRule.getLateAllowMinutes() == null) {
            attendanceRule.setLateAllowMinutes(0);
        }
        if (attendanceRule.getEarlyAllowMinutes() == null) {
            attendanceRule.setEarlyAllowMinutes(0);
        }
        if (attendanceRule.getOvertimeThreshold() == null) {
            attendanceRule.setOvertimeThreshold(BigDecimal.ONE);
        }
        if (attendanceRule.getStatus() == null) {
            attendanceRule.setStatus(0);
        }
        attendanceRuleMapper.insert(attendanceRule);
        return attendanceRule.getId();
    }

    @Override
    public void updateAttendanceRule(HrmAttendanceRuleSaveReqVO updateReqVO) {
        validateAttendanceRuleExists(updateReqVO.getId());
        // 校验规则名称是否重复
        validateAttendanceRuleNameUnique(updateReqVO.getId(), updateReqVO.getName());
        // 注：同一个部门允许配置多条规则（多班次），这里不再校验部门唯一
        HrmAttendanceRuleDO updateObj = BeanUtils.toBean(updateReqVO, HrmAttendanceRuleDO.class);
        attendanceRuleMapper.updateById(updateObj);
    }

    @Override
    public void deleteAttendanceRule(Long id) {
        validateAttendanceRuleExists(id);
        attendanceRuleMapper.deleteById(id);
    }

    private void validateAttendanceRuleExists(Long id) {
        if (attendanceRuleMapper.selectById(id) == null) {
            throw exception(ATTENDANCE_RULE_NOT_EXISTS);
        }
    }

    private void validateAttendanceRuleNameUnique(Long id, String name) {
        HrmAttendanceRuleDO rule = attendanceRuleMapper.selectOne(HrmAttendanceRuleDO::getName, name);
        if (rule == null) {
            return;
        }
        if (id == null) {
            throw exception(ATTENDANCE_RULE_NAME_EXISTS);
        }
        if (!rule.getId().equals(id)) {
            throw exception(ATTENDANCE_RULE_NAME_EXISTS);
        }
    }

    @Override
    public HrmAttendanceRuleDO getAttendanceRule(Long id) {
        return attendanceRuleMapper.selectById(id);
    }

    @Override
    public PageResult<HrmAttendanceRuleDO> getAttendanceRulePage(HrmAttendanceRulePageReqVO pageReqVO) {
        return attendanceRuleMapper.selectPage(pageReqVO);
    }

    @Override
    public List<HrmAttendanceRuleDO> getAttendanceRuleList() {
        return attendanceRuleMapper.selectListByStatus(0);
    }

    @Override
    public HrmAttendanceRuleDO getAttendanceRuleByDeptId(Long deptId) {
        return getAttendanceRuleByDeptId(deptId, null);
    }

    @Override
    public HrmAttendanceRuleDO getAttendanceRuleByDeptId(Long deptId, LocalDateTime clockTime) {
        // 1. 先查找部门专属规则（同一个部门可以配置多条，用于多班次）
        List<HrmAttendanceRuleDO> deptRules = attendanceRuleMapper.selectList(new LambdaQueryWrapperX<HrmAttendanceRuleDO>()
                .eq(HrmAttendanceRuleDO::getDeptId, deptId)
                .eq(HrmAttendanceRuleDO::getStatus, ENABLED_STATUS));
        if (!deptRules.isEmpty()) {
            return matchRuleByClockTime(deptRules, clockTime);
        }
        // 2. 查找全局规则（deptId 为 null）
        List<HrmAttendanceRuleDO> globalRules = attendanceRuleMapper.selectList(new LambdaQueryWrapperX<HrmAttendanceRuleDO>()
                .isNull(HrmAttendanceRuleDO::getDeptId)
                .eq(HrmAttendanceRuleDO::getStatus, ENABLED_STATUS));
        if (!globalRules.isEmpty()) {
            return matchRuleByClockTime(globalRules, clockTime);
        }
        return null;
    }

    /**
     * 多条规则（同一个部门多班次）时，按打卡时间选班次：
     * 1. 打卡时间落在某个班次的 [上班时间, 下班时间] 内，就取这一条
     * 2. 都不在窗口内时，取班次时间窗口离打卡时间最近的一条
     * 3. 仍然并列时，按上班时间、编号排序，保证结果稳定（不会随数据库返回顺序漂移）
     * 打卡时间为空（不关心班次）时，取上班时间最早的一条。
     */
    @VisibleForTesting
    static HrmAttendanceRuleDO matchRuleByClockTime(List<HrmAttendanceRuleDO> rules, LocalDateTime clockTime) {
        if (rules.size() == 1) {
            return rules.get(0);
        }
        if (clockTime == null) {
            return rules.stream().min(Comparator
                            .comparing(HrmAttendanceRuleDO::getWorkStartTime,
                                    Comparator.nullsLast(Comparator.<LocalTime>naturalOrder()))
                            .thenComparing(HrmAttendanceRuleDO::getId))
                    .orElse(rules.get(0));
        }
        LocalTime time = clockTime.toLocalTime();
        return rules.stream().min(Comparator
                        .comparingLong((HrmAttendanceRuleDO rule) -> minutesToRuleWindow(rule, time))
                        .thenComparing(HrmAttendanceRuleDO::getWorkStartTime,
                                Comparator.nullsLast(Comparator.<LocalTime>naturalOrder()))
                        .thenComparing(HrmAttendanceRuleDO::getId))
                .orElse(rules.get(0));
    }

    /**
     * 打卡时间到规则班次窗口的距离（分钟）：落在窗口内为 0，班次时间未配置时记为最大。
     * 支持跨天班次（如 22:00-06:00，只要 end <= start 就按跨天处理）。
     */
    private static long minutesToRuleWindow(HrmAttendanceRuleDO rule, LocalTime time) {
        LocalTime start = rule.getWorkStartTime();
        LocalTime end = rule.getWorkEndTime();
        if (start == null || end == null) {
            return Long.MAX_VALUE;
        }
        boolean crossDay = !end.isAfter(start);
        boolean inWindow = crossDay
                ? !time.isBefore(start) || !time.isAfter(end)
                : !time.isBefore(start) && !time.isAfter(end);
        if (inWindow) {
            return 0;
        }
        return Math.min(minutesBetween(time, start), minutesBetween(time, end));
    }

    /** 两个时刻的分钟差，按一天 24 小时取最近的环回距离（23:50 与 00:10 只差 20 分钟） */
    private static long minutesBetween(LocalTime one, LocalTime other) {
        long minutes = Math.abs(Duration.between(one, other).toMinutes());
        return Math.min(minutes, 24 * 60 - minutes);
    }

}