package com.nju.edu.eval.service.serviceImpl;

import cn.seecoder.bok.common.QuestionType;
import com.nju.edu.eval.data.dao.ExamDao;
import com.nju.edu.eval.data.dao.SampleExamPaperDao;
import com.nju.edu.eval.data.dao.ScoreDao;
import com.nju.edu.eval.data.dao.UserDao;
import com.nju.edu.eval.data.entity.Exam;
import com.nju.edu.eval.data.entity.SampleExamPaper;
import com.nju.edu.eval.data.entity.Score;
import com.nju.edu.eval.data.entity.User;
import com.nju.edu.eval.exception.MyServiceException;
import com.nju.edu.eval.manager.QuestionManager;
import com.nju.edu.eval.model.vo.exam.*;
import com.nju.edu.eval.model.vo.question.QuestionAndScoreVO;
import com.nju.edu.eval.service.ExamService;
import com.nju.edu.eval.service.convertor.ExamConvertor;
import com.nju.edu.eval.util.InviteCodeUtil;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.domain.Page;
import org.springframework.data.domain.PageRequest;
import org.springframework.data.domain.Sort;
import org.springframework.stereotype.Service;

import java.util.*;
import java.util.stream.Collectors;

/**
 * @author mars
 */
@Service
public class ExamServiceImpl implements ExamService {
    private final ExamDao examDao;
    private final UserDao userDao;
    private final ScoreDao scoreDao;
    private final SampleExamPaperDao sampleExamPaperDao;
    private final QuestionManager questionManager;

    @Autowired
    public ExamServiceImpl(ExamDao examDao, UserDao userDao, ScoreDao scoreDao, QuestionManager questionManager, SampleExamPaperDao sampleExamPaperDao) {
        this.examDao = examDao;
        this.userDao = userDao;
        this.scoreDao = scoreDao;
        this.questionManager = questionManager;
        this.sampleExamPaperDao = sampleExamPaperDao;
    }

    @Override
    public NewExamVO createExam(CreateExamVO examVO, Integer creatorId) {
        User user = userDao.findById(creatorId).get();
        Exam exam = new Exam(examVO.getExamName(), examVO.getPosition(),
                                                      examVO.getSkills(), examVO.getStartTime(),
                                                      examVO.getEndTime(), examVO.getComment(), user);
        exam.setIsHidden(0);
        // 只有非公开的考试才需要邀请码
        if (!examVO.getIsPublic()) {
            exam.setIsPublic(0);
            exam.setInviteCode(InviteCodeUtil.produceInviteCode());
        } else {
            exam.setIsPublic(1);
        }

        if (examVO.getAntiCheating()) {
            exam.setAntiCheating(1);
        } else {
            exam.setAntiCheating(0);
        }
        examDao.save(exam);
//        List<CompleteQuestionVO> questionVOs = questionManager.getRecommendQuestions(examVO.getSkills(), examVO.getDifficulty());
        return new NewExamVO(exam.getId(), exam.getInviteCode(), exam.getDifficulty());
    }

    @Override
    public ExamListAndNumVO getExamList(int userId, int pageSize, int pageNum) {
//        Page<Exam> examEntities = examDao.findAll(PageRequest.of(pageNum, pageSize, Sort.by(Sort.Direction.DESC, "startTime")));
//        List<ExamVO> examVOList = examEntities.get()
//                .map(ExamConvertor::convertToVO).collect(Collectors.toList());
//        return new ExamListAndNumVO(examVOList, (int) examEntities.getTotalElements());
        List<Exam> exams = examDao.findByIsHidden(0);
        List<ExamVO> examVOList = exams.stream()
                .sorted(Comparator.comparing(Exam::getStartTime).reversed())
                .filter(exam -> exam.getIsHidden() == 0)
                .skip(pageSize * (pageNum - 1)).limit(pageSize)
                .map(ExamConvertor::convertToVO).collect(Collectors.toList());
        User user = userDao.findById(userId).orElse(null);
        List<Exam> currentUserExams = user.getExams();
        for (ExamVO examVO : examVOList) {
            Exam exam = examDao.findById(examVO.getExamId()).orElse(null);
            if (currentUserExams.contains(exam)) {
                examVO.setIsJoined(true);
            }
        }
        return new ExamListAndNumVO(examVOList, (int) exams.size());
    }

    @Override
    public List<ExamInfoVO> getExamListOfTimeRange(Date startTime, Date endTime) {
        List<Exam> examList = examDao.findAllByStartTimeBetweenOrderByStartTime(startTime, endTime);
        return examList.stream().map(ExamConvertor::convertToExamInfoVO).collect(Collectors.toList());
    }

    @Override
    public ExamVO getExamById(Integer id) {
        Exam exam = examDao.findById(id).orElse(null);
        return ExamConvertor.convertToVO(exam);
    }

    @Override
    public QuestionAndScoreVO getExamQuestionAndScoreById(Integer id) {
        Exam exam = examDao.findById(id).orElse(null);
        if (exam == null) {
            throw new MyServiceException("A0411", "没有对应的考试");
        }
        if (exam.getQuestionAndScore().size() == 0) {
            throw new MyServiceException("A0411", "该考试还未设置题目");
        }
        return new QuestionAndScoreVO(exam.getQuestionAndScore());
    }

    @Override
    public List<String> getCodeQuestionIdsByExamId(Integer id) {
        Exam exam = examDao.findById(id).orElse(null);
        if (exam == null) {
            throw new MyServiceException("A0411", "没有对应的考试");
        }
        Set<String> questionIds =  exam.getQuestionAndScore().keySet();
        return questionIds.stream()
                .filter(questionId -> questionManager.getQuestionById(questionId).get().getType() == QuestionType.CODE)
                .collect(Collectors.toList());
    }

    @Override
    public void updateQuestionsOfExam(Integer examId, QuestionScoreMapVO questionScoreMapVO) {
        Exam exam = examDao.findById(examId).orElse(null);
        if (exam == null) {
            throw new MyServiceException("A0411", "没有对应的考试");
        }
        Map<String, Double> questionScoreMap = questionScoreMapVO.getQuestionScoreMap();
//        for (Map.Entry<String, Double> entry : questionScoreMap.entrySet()) {
//            exam.getQuestionAndScore().put(entry.getKey(), entry.getValue());
//        }
        exam.setQuestionAndScore(questionScoreMap);
        examDao.save(exam);
    }

    @Override
    public Optional<Exam> extendExamTime(Integer examId, Date endTime) throws MyServiceException {
        Exam exam = examDao.findById(examId).orElse(null);
        if (exam != null) {
            if (endTime.before(exam.getStartTime()) || endTime.before(exam.getEndTime())) {
                throw new MyServiceException("A0420", "结束时间不能早于原先结束时间和开始时间");
            }
            exam.setEndTime(endTime);
            examDao.save(exam);
        } else {
            throw new MyServiceException("A0411", "没有对应的考试");
        }
        return Optional.of(exam);
    }

    @Override
    public ExamListAndNumVO getExamsByCurrentStudent(Integer id, int pageSize, int pageNum, int state) {
        User student = userDao.findById(id).orElse(null);
        if (student != null) {
            List<Exam> exams = student.getExams();

            return new ExamListAndNumVO(
                    exams.stream()
                            .sorted(Comparator.comparing(Exam::getStartTime).reversed())
                            .filter(exam -> state == 0 || exam.getState().ordinal() + 1 == state)
                            .filter(exam -> exam.getIsHidden() == 0)
                            .skip(pageSize * (pageNum - 1)).limit(pageSize)
                            .map(ExamConvertor::convertToJoinedVO).collect(Collectors.toList()),
                    //输出总个数，用于前端分页
                    (int) exams.stream().filter(exam -> state == 0 || exam.getState().ordinal() + 1 == state).filter(exam -> exam.getIsHidden() == 0).count());
        } else {
            throw new MyServiceException("A0201", "用户账号不存在");
        }
    }

    @Override
    public ExamListAndNumVO getExamsCreatedByCurrentTeacherOrHR(Integer id, int pageSize, int pageNum, int state) {
        User user = userDao.findById(id).orElse(null);
        if (user != null) {
            return new ExamListAndNumVO(examDao.findAllByCreator_Id(user.getId()).stream()
                    .filter(exam -> state == 0 || exam.getState().ordinal() + 1 == state)
                    .sorted(Comparator.comparing(Exam::getStartTime).reversed())
                    .skip(pageSize * (pageNum - 1)).limit(pageSize)
                    .map(ExamConvertor::convertToVO).collect(Collectors.toList()),
                    //输出总个数，用于前端分页
                    (int) examDao.findAllByCreator_Id(user.getId()).stream()
                            .filter(exam -> state == 0 || exam.getState().ordinal() + 1 == state).count());
        } else {
            throw new MyServiceException("A0201", "用户账号不存在");
        }
    }

    @Override
    public boolean takeExam(Integer userId, Integer examId, String inviteCodeInput) {
        User user = userDao.findById(userId).orElse(null);
        System.out.println(user.getExams());
        Exam exam = examDao.findById(examId).orElse(null);
        if (user.getExams().contains(exam)) {
            throw new MyServiceException("A0506", "已加入考试!");
        }
        if (user != null) {
            String correctInviteCode = exam.getInviteCode();
            if (exam.getIsPublic() == 1 || correctInviteCode.equals(inviteCodeInput)) {
//                List<Exam> examsOfUser = user.getExams();
//                // 更新用户参加的考试
//                examsOfUser.add(exam);
//                userDao.save(user);
                Score score = new Score(user, exam);
                scoreDao.save(score);
                return true;
            } else {
                throw new MyServiceException("A0210", "邀请码输入错误");
            }
        } else {
            throw new MyServiceException("A0201", "用户账号不存在");
        }
    }

    @Override
    public void setExamQuestionsBySampleExamPaper(int examId, int sampleExamPaperId) {
        Exam exam = examDao.findById(examId).orElse(null);
        SampleExamPaper sampleExamPaper = sampleExamPaperDao.findById(sampleExamPaperId).orElse(null);
        if (exam == null) {
            throw new MyServiceException("A0201", "无对应的考试");
        }
        if (sampleExamPaper == null) {
            throw new MyServiceException("A0201", "无对应样卷");
        }

        Map<String, Double> questionAndScore = new HashMap<>(sampleExamPaper.getQuestionAndScore());
        exam.setQuestionAndScore(questionAndScore);
        examDao.save(exam);
    }

    @Override
    public boolean updateExamName (Integer userId, Integer examId, String name){
        Exam exam = examDao.findById(examId).orElse(null);
        if (exam == null) {
            throw new MyServiceException("A0201", "无对应的考试");
        }

        exam.setExamName(name);
        examDao.save(exam);
        return true;
    }

    @Override
    public boolean setIsHidden (Integer userId, Integer examId, Integer hidden){
        Exam exam = examDao.findById(examId).orElse(null);
        if (exam == null) {
            throw new MyServiceException("A0201", "无对应的考试");
        }

        exam.setIsHidden(hidden);
        examDao.save(exam);
        return true;
    }

}