package nju.seec.helper.service.impl;

import com.google.common.collect.Lists;
import nju.seec.helper.api.dataanalysis.dto.EventDTO;
import nju.seec.helper.api.dataanalysis.EventApi;
import nju.seec.helper.dao.*;
import nju.seec.helper.entity.*;
import nju.seec.helper.enums.UserRole;
import nju.seec.helper.service.EventService;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import java.time.LocalDateTime;
import java.util.List;
import java.util.Objects;

/**
 * @author cst
 */
@Service
public class EventServiceImpl implements EventService {
    private final CourseDAO courseDAO;
    private final ChooseDAO chooseDAO;
    private final UserDAO userDAO;
    private final CommentDAO commentDAO;
    private final QuizStudentAnswerDAO quizStudentAnswerDAO;

    private final EventApi eventApi;

    public EventServiceImpl(CourseDAO courseDAO, ChooseDAO chooseDAO, UserDAO userDAO, CommentDAO commentDAO, QuizStudentAnswerDAO quizStudentAnswerDAO, EventApi eventApi) {
        this.courseDAO = courseDAO;
        this.chooseDAO = chooseDAO;
        this.userDAO = userDAO;
        this.commentDAO = commentDAO;
        this.quizStudentAnswerDAO = quizStudentAnswerDAO;
        this.eventApi = eventApi;
    }

    @Transactional(readOnly = true)
    @Override
    public List<EventDTO> getAllEvents() {
        List<EventDTO> eventDTOS = Lists.newArrayList();
        List<Course> courses = courseDAO.findAll();
        courses.forEach(course -> {
            List<Choose> chooses = chooseDAO.findByCourseId(course.getId());
            chooses.forEach(
                    choose -> {
                        User student = userDAO.findUserById(choose.getStudentId());
                        if (student.getPid() != null) {
                            eventDTOS.add(eventApi.createParticipateClassEventDTO(String.valueOf(Objects.requireNonNull(student).getPid()), LocalDateTime.now(), course));
                        }
                    }
            );
        });
        List<Comment> comments = commentDAO.findAll();
        comments.forEach(comment -> {
            User user = comment.getUser();
            if (user.getPid() != null && user.getRole() == UserRole.STUDENT) {
                eventDTOS.add(eventApi.createInitPostEventDTO(String.valueOf(user.getPid()), comment.getCreateAt(), comment.getTitle()));
            }
        });
        List<QuizStudentAnswer> quizStudentAnswers = quizStudentAnswerDAO.findAll();
        quizStudentAnswers.forEach(quizStudentAnswer -> {
            User student = quizStudentAnswer.getStudent();
            if (student.getPid() != null) {
                Quiz quiz = quizStudentAnswer.getQuiz();
                eventDTOS.add(eventApi.createCompleteQuizEventDTO(String.valueOf(student.getPid()), quizStudentAnswer.getSubmitAt(), quiz));
            }
        });
        return eventDTOS;
    }
}