package com.gkhy.exam.system.service.impl;

import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.gkhy.exam.common.api.CommonPage;
import com.gkhy.exam.common.constant.UserConstant;
import com.gkhy.exam.common.domain.entity.SysUser;
import com.gkhy.exam.common.enums.CodeTypeEnum;
import com.gkhy.exam.common.enums.QuestionAssignEnum;
import com.gkhy.exam.common.enums.QuestionTypeEnum;
import com.gkhy.exam.common.enums.UserTypeEnum;
import com.gkhy.exam.common.exception.ApiException;
import com.gkhy.exam.common.utils.PageUtils;
import com.gkhy.exam.common.utils.SecurityUtils;
import com.gkhy.exam.system.domain.ExExamPaper;
import com.gkhy.exam.system.domain.ExPaperQuestion;
import com.gkhy.exam.system.domain.ExQuestion;
import com.gkhy.exam.system.mapper.ExExamPaperMapper;
import com.gkhy.exam.system.mapper.ExPaperQuestionMapper;
import com.gkhy.exam.system.mapper.ExPaperStudentMapper;
import com.gkhy.exam.system.mapper.ExQuestionMapper;
import com.gkhy.exam.system.service.ExExamPaperService;
import com.gkhy.exam.system.utils.SequenceUtils;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import java.util.ArrayList;
import java.util.List;
import java.util.Objects;
import java.util.Random;
import java.util.stream.Collectors;

/**
 * <p>
 * 考卷(组卷)表 服务实现类
 * </p>
 *
 * @author kzy
 * @since 2024-06-05 15:07:36
 */
@Service
public class ExExamPaperServiceImpl extends ServiceImpl<ExExamPaperMapper, ExExamPaper> implements ExExamPaperService {
    @Autowired
    private ExPaperStudentMapper paperStudentMapper;

    @Autowired
    private ExPaperQuestionMapper paperQuestionMapper;
    @Autowired
    private ExQuestionMapper questionMapper;

    @Autowired
    private SequenceUtils sequenceUtils;

    @Override
    public CommonPage selectExamPaperList(ExExamPaper examPaper) {
        SysUser currentUser= SecurityUtils.getLoginUser().getUser();
        if(!Objects.equals(currentUser.getUserType(), UserTypeEnum.SYSTEM_USER.getCode())){
            examPaper.setCompanyId(currentUser.getCompanyId());
        }
        PageUtils.startPage();
        List<ExExamPaper> paperList=baseMapper.selectExamPaperList(examPaper);
        return CommonPage.restPage(paperList);
    }

    @Override
    public ExExamPaper selectExamPaperById(Long paperId) {
        ExExamPaper examPaper= baseMapper.selectExamPaperById(paperId);
        SysUser currentUser= SecurityUtils.getLoginUser().getUser();
        if(currentUser.getUserType().equals(UserTypeEnum.SYSTEM_USER.getCode())){
            return examPaper;
        }
        if(!examPaper.getCompanyId().equals(currentUser.getCompanyId())){
            throw new ApiException("无权限查看其它企业考卷信息");
        }
        return examPaper;
    }


    @Override
    @Transactional(rollbackFor = RuntimeException.class)
    public int insertExamPaper(ExExamPaper examPaper) {
        checkUserAllowed(examPaper);
        if(!checkNameUnique(examPaper)){
            throw new ApiException("试卷名称已存在");
        }
        //生成编码
        examPaper.setCode(sequenceUtils.getNextSequence(CodeTypeEnum.EXAM_PAPER.getCode()));
        examPaper.setCreateBy(SecurityUtils.getUsername());
        if(examPaper.getLimitTime()>0){
            examPaper.setLimit(1);
        }else{
            examPaper.setLimit(0);
        }
        int row=baseMapper.insert(examPaper);
        if(row<1){
            throw new ApiException("新增试卷失败");
        }
        //分配试题
        assignSingleQuestion(examPaper);
        assignMultiQuestion(examPaper);
        assignJudgeQuestion(examPaper);
        return row;
    }

    public void checkUserAllowed(ExExamPaper examPaper) {
        SysUser currentUser= SecurityUtils.getLoginUser().getUser();
        if(currentUser.getUserType().equals(UserTypeEnum.SYSTEM_USER.getCode())){
            throw new ApiException("系统用户不能创建、修改试卷");
        }
        if(currentUser.getUserType().equals(UserTypeEnum.STUDENT.getCode())){
            throw new ApiException("没有权限操作");
        }
        if(!currentUser.getCompanyId().equals(examPaper.getCompanyId())){
            throw new ApiException("没有权限操作其他企业试卷");
        }
    }

    //分配单选题
    public void assignSingleQuestion(ExExamPaper examPaper){
        List<ExPaperQuestion> paperQuestionList = getPaperQuestions(examPaper.getId(), examPaper.getSingleBankId(),
                examPaper.getSingleMethod(),examPaper.getSingleNum(), examPaper.getSingleScore(),QuestionTypeEnum.SINGLE);
        paperQuestionMapper.batchInsert(paperQuestionList);
    }

    //分配多选题
    public void assignMultiQuestion(ExExamPaper examPaper){
        List<ExPaperQuestion> paperQuestionList = getPaperQuestions(examPaper.getId(), examPaper.getMultiBankId(),
                examPaper.getMultiMethod(),examPaper.getMultiNum(), examPaper.getMultiScore(),QuestionTypeEnum.MULTI);
        paperQuestionMapper.batchInsert(paperQuestionList);
    }

    //分配判断题
    public void assignJudgeQuestion(ExExamPaper examPaper){
        List<ExPaperQuestion> paperQuestionList = getPaperQuestions(examPaper.getId(), examPaper.getJudgeBankId(),
                examPaper.getJudgeMethod(),examPaper.getJudgeNum(), examPaper.getJudgeScore(),QuestionTypeEnum.JUDGE);
        paperQuestionMapper.batchInsert(paperQuestionList);
    }

    private List<ExPaperQuestion> getPaperQuestions(Long paperId,Long bankId,Integer questionMethod,Integer questionCount,Integer questionScore, QuestionTypeEnum questionTypeEnum) {
        SysUser currentUser=SecurityUtils.getLoginUser().getUser();
        Integer totalQuestionCount=questionMapper.selectCountByBankId(currentUser.getCompanyId(), bankId, questionTypeEnum.getCode());
        if(totalQuestionCount< questionCount){
            throw new ApiException(String.format("所选题库<%s>数量不足，无法分配",questionTypeEnum.getInfo()));
        }
        List<ExQuestion> questions=new ArrayList<>();
        if(Objects.equals(questionMethod, QuestionAssignEnum.RANDOM.getCode())){//随机分配
            questions=questionMapper.selectRandomQuestion(currentUser.getCompanyId(), bankId,questionTypeEnum.getCode(), questionCount);
        }else{//顺序分配
            int totalPage=questionCount/questionMethod;//不能整除，忽略最后一页
            Random random=new Random();
            int startIndex=random.nextInt(totalPage)+1;
            questions=questionMapper.selectQuestionWithLimit(currentUser.getCompanyId(), bankId,questionTypeEnum.getCode(),startIndex, questionCount);
        }
        List<ExPaperQuestion> paperQuestionList=questions.stream().map(item -> {
            ExPaperQuestion exPaperQuestion=new ExPaperQuestion();
            exPaperQuestion.setPaperId(paperId);
            exPaperQuestion.setQuestionId(item.getId());
            exPaperQuestion.setScore(questionScore);
            return exPaperQuestion;
        }).collect(Collectors.toList());
        return paperQuestionList;
    }


    @Override
    public int updateExamPaper(ExExamPaper examPaper) {
        checkUserAllowed(examPaper);
        if(!checkNameUnique(examPaper)){
            throw new ApiException("试卷名称已存在");
        }
        //校验考卷下是否有学员
        if(checkPaperHasStudent(examPaper.getId())){
            throw new ApiException("该试卷下已分配学员，不能编辑");
        }
        examPaper.setCode(null);//编号不能修改
        if(examPaper.getLimitTime()>0){
            examPaper.setLimit(1);
        }else{
            examPaper.setLimit(0);
        }
        int row=baseMapper.updateById(examPaper);
        if(row<1){
            throw new ApiException("更新试卷失败");
        }
        //重新分配题
        if(examPaper.getSingleRebuild()==1){
            deletePaperQuestion(examPaper.getId(),QuestionTypeEnum.SINGLE);
            assignSingleQuestion(examPaper);
        }
        if(examPaper.getMultiRebuild()==1) {
           deletePaperQuestion(examPaper.getId(),QuestionTypeEnum.MULTI);
           assignMultiQuestion(examPaper);
        }
        if(examPaper.getJudgeRebuild()==1) {
           deletePaperQuestion(examPaper.getId(),QuestionTypeEnum.JUDGE);
           assignJudgeQuestion(examPaper);
        }
        return row;
    }

    public void deletePaperQuestion(Long paperId,QuestionTypeEnum questionTypeEnum){
        paperQuestionMapper.deletePaperQuestion(paperId,questionTypeEnum!=null?questionTypeEnum.getCode():null);
    }

    @Override
    public int deleteExamPaperById(Long paperId) {
        checkUserAllowed(baseMapper.selectById(paperId));
        //查询该试卷分配的学员人数
        if(checkPaperHasStudent(paperId)){
            throw new ApiException("该试卷下已分配学员，不能删除");
        }
        int row=baseMapper.deletePaperById(paperId);
        if(row<1){
            throw new ApiException("删除试卷失败");
        }
        //删除考卷试题
     //   paperQuestionMapper.deletebyPapaerId(paperId);
        return row;
    }

    public Boolean checkPaperHasStudent(Long paperId){
        //查询该试卷分配的学员人数
        int studentCount=paperStudentMapper.countByPaperId(paperId);
        if(studentCount>0){
            return true;
        }
        return false;
    }

    @Override
    public boolean checkNameUnique(ExExamPaper examPaper) {
        Long paperId=examPaper.getId()==null?-1L:examPaper.getId();
        ExExamPaper paper= baseMapper.checkNameUnique(examPaper.getName());
        if(paper!=null&&paper.getId().longValue()!=paperId.longValue()){
            return UserConstant.NOT_UNIQUE;
        }
        return UserConstant.UNIQUE;
    }

    @Override
    public int changeExamPaperStatus(Long paperId, Integer status) {
        checkUserAllowed(baseMapper.selectById(paperId));
        return baseMapper.updateById(new ExExamPaper().setId(paperId).setStatus(status).setUpdateBy(SecurityUtils.getUsername()));
    }
}