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

import cn.hutool.core.util.StrUtil;
import cn.iocoder.yudao.framework.common.pojo.PageResult;
import cn.iocoder.yudao.framework.common.util.object.BeanUtils;
import cn.iocoder.yudao.module.hrm.controller.admin.approval.vo.HrmResignationApplicationPageReqVO;
import cn.iocoder.yudao.module.hrm.controller.admin.approval.vo.HrmResignationApplicationRespVO;
import cn.iocoder.yudao.module.hrm.controller.admin.approval.vo.HrmResignationApplicationSaveReqVO;
import cn.iocoder.yudao.module.hrm.controller.admin.approval.vo.HrmResignationHandoverReqVO;
import cn.iocoder.yudao.module.hrm.dal.dataobject.approval.HrmResignationApplicationDO;
import cn.iocoder.yudao.module.hrm.dal.dataobject.employee.HrmEmployeeDO;
import cn.iocoder.yudao.module.hrm.dal.mysql.approval.HrmResignationApplicationMapper;
import cn.iocoder.yudao.module.hrm.dal.mysql.employee.HrmEmployeeMapper;
import cn.iocoder.yudao.module.hrm.dal.redis.HrmNoRedisDAO;
import cn.iocoder.yudao.module.hrm.enums.HrmAuditStatusEnum;
import cn.iocoder.yudao.module.hrm.enums.HrmResignationTypeEnum;
import cn.iocoder.yudao.module.hrm.service.handover.HrmUserHandoverService;
import cn.iocoder.yudao.module.system.api.approval.ApprovalConfigApi;
import cn.iocoder.yudao.module.system.api.dept.DeptApi;
import cn.iocoder.yudao.module.system.api.dept.dto.DeptRespDTO;
import cn.iocoder.yudao.module.system.api.storage.StorageAttachmentApi;
import cn.iocoder.yudao.module.system.api.user.AdminUserApi;
import cn.iocoder.yudao.module.system.api.user.dto.AdminUserRespDTO;
import jakarta.annotation.Resource;
import lombok.extern.slf4j.Slf4j;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;
import org.springframework.validation.annotation.Validated;

import java.time.LocalDate;
import java.util.Collections;
import java.util.List;
import java.util.Map;
import java.util.Objects;
import java.util.Set;
import java.util.stream.Collectors;
import java.util.stream.Stream;

import cn.iocoder.yudao.framework.security.core.util.SecurityFrameworkUtils;

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

/**
 * 离职申请 Service 实现类
 *
 * @author 超级管理员
 */
@Service
@Validated
@Slf4j
public class HrmResignationApplicationServiceImpl implements HrmResignationApplicationService {

    private static final Integer HANDOVER_STATUS_NOT_STARTED = 0;
    private static final Integer HANDOVER_STATUS_IN_PROGRESS = 10;
    private static final Integer HANDOVER_STATUS_COMPLETED = 20;

    /**
     * 离职申请审批的业务类型编码
     *
     * 与 system_approval_config.biz_type 对应，审批人在「系统管理 - 审批配置」中维护。
     */
    private static final String RESIGNATION_APPROVE_BIZ_TYPE = "hrm_resignation_approve";

    /**
     * 员工状态：离职
     */
    private static final Integer EMPLOYEE_STATUS_RESIGNED = 3;

    @Resource
    private HrmResignationApplicationMapper resignationApplicationMapper;
    @Resource
    private HrmNoRedisDAO noRedisDAO;
    @Resource
    private DeptApi deptApi;
    @Resource
    private AdminUserApi adminUserApi;
    @Resource
    private StorageAttachmentApi storageAttachmentApi;
    @Resource
    private ApprovalConfigApi approvalConfigApi;
    @Resource
    private HrmEmployeeMapper employeeMapper;
    @Resource
    private HrmUserHandoverService handoverService;

    @Override
    @Transactional(rollbackFor = Exception.class)
    public Long createResignationApplication(HrmResignationApplicationSaveReqVO createReqVO) {
        Long userId = createReqVO.getUserId();
        if (userId == null) {
            userId = getCurrentUserId();
        }
        HrmResignationApplicationDO existing = resignationApplicationMapper.selectByUserIdAndStatusNot(userId,
                HrmAuditStatusEnum.CANCEL.getStatus());
        if (existing != null) {
            throw exception(RESIGNATION_APPLICATION_EXISTS);
        }
        String no = generateUniqueNo();
        AdminUserRespDTO user = adminUserApi.getUser(userId);
        if (user == null) {
            userId = getCurrentUserId();
            user = adminUserApi.getUser(userId);
        }
        HrmResignationApplicationDO application = BeanUtils.toBean(createReqVO, HrmResignationApplicationDO.class);
        application.setNo(no);
        application.setUserId(userId);
        application.setDeptId(createReqVO.getDeptId() != null ? createReqVO.getDeptId()
                : (user != null ? user.getDeptId() : null));
        application.setStatus(HrmAuditStatusEnum.DRAFT.getStatus());
        application.setHandoverStatus(HANDOVER_STATUS_NOT_STARTED);
        resignationApplicationMapper.insert(application);
        storageAttachmentApi.bindAttachments("file", "hrm_resignation_application",
                application.getId(), createReqVO.getBlobIds());
        return application.getId();
    }

    private Long getCurrentUserId() {
        return SecurityFrameworkUtils.getLoginUserId();
    }

    private String generateUniqueNo() {
        String no = noRedisDAO.generateResignationApplicationNo();
        if (resignationApplicationMapper.selectByNo(no) != null) {
            return generateUniqueNo();
        }
        return no;
    }

    @Override
    public void updateResignationApplication(HrmResignationApplicationSaveReqVO updateReqVO) {
        HrmResignationApplicationDO application = validateResignationApplicationExists(updateReqVO.getId());
        if (!Objects.equals(application.getStatus(), HrmAuditStatusEnum.DRAFT.getStatus())) {
            throw exception(RESIGNATION_APPLICATION_UPDATE_FAIL_NOT_DRAFT);
        }
        HrmResignationApplicationDO updateObj = BeanUtils.toBean(updateReqVO, HrmResignationApplicationDO.class);
        resignationApplicationMapper.updateById(updateObj);
        storageAttachmentApi.updateAttachments("file", "hrm_resignation_application", updateReqVO.getId(), updateReqVO.getBlobIds());
    }

    @Override
    public void deleteResignationApplication(Long id) {
        HrmResignationApplicationDO application = validateResignationApplicationExists(id);
        if (!Objects.equals(application.getStatus(), HrmAuditStatusEnum.DRAFT.getStatus())) {
            throw exception(RESIGNATION_APPLICATION_UPDATE_FAIL_NOT_DRAFT);
        }
        storageAttachmentApi.deleteAttachmentsByRecord("hrm_resignation_application", id);
        resignationApplicationMapper.deleteById(id);
    }

    private HrmResignationApplicationDO validateResignationApplicationExists(Long id) {
        HrmResignationApplicationDO application = resignationApplicationMapper.selectById(id);
        if (application == null) {
            throw exception(RESIGNATION_APPLICATION_NOT_EXISTS);
        }
        return application;
    }

    @Override
    public HrmResignationApplicationDO getResignationApplication(Long id) {
        return resignationApplicationMapper.selectById(id);
    }

    @Override
    public HrmResignationApplicationRespVO getResignationApplicationDetail(Long id) {
        HrmResignationApplicationDO application = getResignationApplication(id);
        if (application == null) {
            return null;
        }
        HrmResignationApplicationRespVO respVO = BeanUtils.toBean(application, HrmResignationApplicationRespVO.class);
        fillUserNames(respVO, application);
        if (application.getDeptId() != null) {
            DeptRespDTO dept = deptApi.getDept(application.getDeptId());
            if (dept != null) {
                respVO.setDeptName(dept.getName());
            }
        }
        respVO.setResignationTypeName(HrmResignationTypeEnum.getNameByStatus(application.getResignationType()));
        respVO.setHandoverStatusName(getHandoverStatusName(application.getHandoverStatus()));
        respVO.setStatusName(HrmAuditStatusEnum.getNameByStatus(application.getStatus()));
        respVO.setAttachmentList(storageAttachmentApi.listAttachments("hrm_resignation_application", id));
        return respVO;
    }

    private void fillUserNames(HrmResignationApplicationRespVO respVO, HrmResignationApplicationDO application) {
        Set<Long> userIds = Stream.of(application.getUserId(), application.getHandoverUserId())
                .filter(Objects::nonNull).collect(Collectors.toSet());
        Map<Long, AdminUserRespDTO> userMap = adminUserApi.getUserMap(userIds);
        if (application.getUserId() != null && userMap.containsKey(application.getUserId())) {
            respVO.setUserName(userMap.get(application.getUserId()).getNickname());
        }
        if (application.getHandoverUserId() != null && userMap.containsKey(application.getHandoverUserId())) {
            respVO.setHandoverUserName(userMap.get(application.getHandoverUserId()).getNickname());
        }
    }

    private String getHandoverStatusName(Integer handoverStatus) {
        if (handoverStatus == null) {
            return "";
        }
        if (Objects.equals(handoverStatus, HANDOVER_STATUS_NOT_STARTED)) {
            return "未开始";
        }
        if (Objects.equals(handoverStatus, HANDOVER_STATUS_IN_PROGRESS)) {
            return "进行中";
        }
        if (Objects.equals(handoverStatus, HANDOVER_STATUS_COMPLETED)) {
            return "已完成";
        }
        return "";
    }

    @Override
    public PageResult<HrmResignationApplicationRespVO> getResignationApplicationPage(HrmResignationApplicationPageReqVO pageReqVO) {
        PageResult<HrmResignationApplicationDO> pageResult = resignationApplicationMapper.selectPage(pageReqVO);
        if (pageResult.getList().isEmpty()) {
            return new PageResult<>(Collections.emptyList(), pageResult.getTotal());
        }
        Set<Long> userIds = pageResult.getList().stream()
                .flatMap(app -> Stream.of(app.getUserId(), app.getHandoverUserId()))
                .filter(Objects::nonNull)
                .collect(Collectors.toSet());
        Map<Long, AdminUserRespDTO> userMap = adminUserApi.getUserMap(userIds);
        Set<Long> deptIds = pageResult.getList().stream()
                .map(HrmResignationApplicationDO::getDeptId)
                .filter(Objects::nonNull)
                .collect(Collectors.toSet());
        Map<Long, DeptRespDTO> deptMap = deptApi.getDeptMap(deptIds);
        List<HrmResignationApplicationRespVO> list = pageResult.getList().stream().map(app -> {
            HrmResignationApplicationRespVO vo = BeanUtils.toBean(app, HrmResignationApplicationRespVO.class);
            if (app.getUserId() != null && userMap.containsKey(app.getUserId())) {
                vo.setUserName(userMap.get(app.getUserId()).getNickname());
            }
            if (app.getHandoverUserId() != null && userMap.containsKey(app.getHandoverUserId())) {
                vo.setHandoverUserName(userMap.get(app.getHandoverUserId()).getNickname());
            }
            if (app.getDeptId() != null && deptMap.containsKey(app.getDeptId())) {
                vo.setDeptName(deptMap.get(app.getDeptId()).getName());
            }
            vo.setResignationTypeName(HrmResignationTypeEnum.getNameByStatus(app.getResignationType()));
            vo.setHandoverStatusName(getHandoverStatusName(app.getHandoverStatus()));
            vo.setStatusName(HrmAuditStatusEnum.getNameByStatus(app.getStatus()));
            return vo;
        }).collect(Collectors.toList());
        return new PageResult<>(list, pageResult.getTotal());
    }

    @Override
    @Transactional(rollbackFor = Exception.class)
    public void submitResignationApplication(Long id) {
        // 1. 校验存在 + 可提交状态（草稿 / 审核不通过）
        HrmResignationApplicationDO application = validateResignationApplicationExists(id);
        if (!Objects.equals(application.getStatus(), HrmAuditStatusEnum.DRAFT.getStatus())
                && !Objects.equals(application.getStatus(), HrmAuditStatusEnum.REJECT.getStatus())) {
            throw exception(RESIGNATION_APPLICATION_SUBMIT_FAIL_NOT_EDITABLE);
        }

        // 2. 校验审批配置已启用且配置了有效审批人（未配置时抛出带明确提示的业务异常）
        approvalConfigApi.validateApprovalEnabledAndGetApprovers(RESIGNATION_APPROVE_BIZ_TYPE);

        // 3. 状态置为审批中，并清空上一轮审核结果，避免残留「审核不通过」的原因
        resignationApplicationMapper.submitAndResetAuditInfo(id, HrmAuditStatusEnum.PROCESS.getStatus());
    }

    @Override
    public Set<Long> getResignationApplicationApproverUserIds() {
        return approvalConfigApi.getApproverUserIds(RESIGNATION_APPROVE_BIZ_TYPE);
    }

    @Override
    @Transactional(rollbackFor = Exception.class)
    public void auditResignationApplication(Long id, Boolean pass, String reviewRemark) {
        // 1. 校验存在
        HrmResignationApplicationDO application = validateResignationApplicationExists(id);
        // 2. 校验处于审批中状态
        if (!Objects.equals(application.getStatus(), HrmAuditStatusEnum.PROCESS.getStatus())) {
            throw exception(RESIGNATION_APPLICATION_AUDIT_FAIL_NOT_PROCESS);
        }
        // 3. 校验当前登录用户是该业务类型的审批人（或签：任一人均可审核）
        Long userId = getLoginUserId();
        approvalConfigApi.validateApprover(RESIGNATION_APPROVE_BIZ_TYPE, userId);
        // 4. 审核不通过：必须填写原因，状态置为审核不通过，退回提交人修改后可重新提交
        if (!Boolean.TRUE.equals(pass)) {
            if (StrUtil.isBlank(reviewRemark)) {
                throw exception(RESIGNATION_APPLICATION_AUDIT_REJECT_REASON_REQUIRED);
            }
            resignationApplicationMapper.auditResignationApplication(id, HrmAuditStatusEnum.REJECT.getStatus(),
                    userId, getUserNickname(userId), reviewRemark);
            return;
        }
        // 5. 审核通过：记录审核人与审核意见，状态置为审核通过
        resignationApplicationMapper.auditResignationApplication(id, HrmAuditStatusEnum.APPROVE.getStatus(),
                userId, getUserNickname(userId), reviewRemark);

        // 6. 审核通过后置业务逻辑：回写员工主档（状态=离职，离职日期 = 实际离职日期或预计离职日期）
        writeBackEmployee(application);
    }

    /**
     * 审核通过后回写员工主档
     *
     * @param application 离职申请
     */
    private void writeBackEmployee(HrmResignationApplicationDO application) {
        HrmEmployeeDO employee = employeeMapper.selectByUserId(application.getUserId());
        if (employee == null) {
            log.warn("[writeBackEmployee] 离职申请({}) 用户({}) 未找到员工档案，跳过回写", application.getId(), application.getUserId());
            return;
        }
        LocalDate leaveDate = application.getActualDate() != null
                ? application.getActualDate() : application.getExpectedDate();
        employeeMapper.updateById(HrmEmployeeDO.builder()
                .id(employee.getId())
                .employeeStatus(EMPLOYEE_STATUS_RESIGNED)
                .leaveDate(leaveDate)
                .build());
    }

    /**
     * 获取用户昵称
     *
     * @param userId 用户编号
     * @return 昵称，用户不存在时返回 null
     */
    private String getUserNickname(Long userId) {
        if (userId == null) {
            return null;
        }
        AdminUserRespDTO user = adminUserApi.getUser(userId);
        return user == null ? null : user.getNickname();
    }

    @Override
    @Transactional(rollbackFor = Exception.class)
    public void updateHandoverStatus(HrmResignationHandoverReqVO reqVO) {
        HrmResignationApplicationDO application = validateResignationApplicationExists(reqVO.getId());
        resignationApplicationMapper.updateById(HrmResignationApplicationDO.builder()
                .id(reqVO.getId())
                .handoverStatus(reqVO.getHandoverStatus())
                .build());
        // 交接完成时，创建用户数据交接映射
        if (Objects.equals(reqVO.getHandoverStatus(), HANDOVER_STATUS_COMPLETED)
                && application.getHandoverUserId() != null) {
            handoverService.createHandover(
                    application.getUserId(),
                    application.getHandoverUserId(),
                    application.getId());
        }
    }

}