package ru.ulstu.conference.service;

import org.apache.commons.lang3.StringUtils;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;
import ru.ulstu.conference.model.Conference;
import ru.ulstu.conference.model.ConferenceDto;
import ru.ulstu.conference.model.ConferenceFilterDto;
import ru.ulstu.conference.model.ConferenceUser;
import ru.ulstu.conference.repository.ConferenceRepository;
import ru.ulstu.deadline.service.DeadlineService;
import ru.ulstu.paper.model.Paper;
import ru.ulstu.paper.service.PaperService;
import ru.ulstu.user.model.User;
import ru.ulstu.user.service.UserService;

import java.io.IOException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;

import static org.springframework.util.ObjectUtils.isEmpty;
import static ru.ulstu.core.util.StreamApiUtils.convert;

@Service
public class ConferenceService {
    private final static int MAX_DISPLAY_SIZE = 40;

    private final ConferenceRepository conferenceRepository;
    private final ConferenceUserService conferenceUserService;
    private final DeadlineService deadlineService;
    private final PaperService paperService;
    private final UserService userService;

    public ConferenceService(ConferenceRepository conferenceRepository,
                             ConferenceUserService conferenceUserService,
                             DeadlineService deadlineService,
                             PaperService paperService,
                             UserService userService) {
        this.conferenceRepository = conferenceRepository;
        this.conferenceUserService = conferenceUserService;
        this.deadlineService = deadlineService;
        this.paperService = paperService;
        this.userService = userService;
    }

    public ConferenceDto getExistConferenceById(Integer id) {
        ConferenceDto conferenceDto = findOneDto(id);
        conferenceDto.setNotSelectedPapers(getNotSelectPapers(conferenceDto.getPaperIds()));
        conferenceDto.setDisabledTakePart(isCurrentUserParticipant(conferenceDto.getUsers()));
        return conferenceDto;
    }

    public ConferenceDto getNewConference() {
        ConferenceDto conferenceDto = new ConferenceDto();
        conferenceDto.setNotSelectedPapers(getNotSelectPapers(new ArrayList<Integer>()));
        return conferenceDto;
    }


    public List<Conference> findAll() {
        return conferenceRepository.findAll();
    }

    public List<ConferenceDto> findAllDto() {
        List<ConferenceDto> conferences = convert(findAll(), ConferenceDto::new);
        conferences.forEach(conferenceDto -> conferenceDto.setTitle(StringUtils.abbreviate(conferenceDto.getTitle(), MAX_DISPLAY_SIZE)));
        return conferences;
    }

    public ConferenceDto findOneDto(Integer id) {
        return new ConferenceDto(conferenceRepository.findOne(id));
    }

    public void save(ConferenceDto conferenceDto) throws IOException {
        if (isEmpty(conferenceDto.getId())) {
            create(conferenceDto);
        } else {
            update(conferenceDto);
        }
    }

    @Transactional
    public Integer create(ConferenceDto conferenceDto) throws IOException {
        Conference newConference = copyFromDto(new Conference(), conferenceDto);
        newConference = conferenceRepository.save(newConference);
        return newConference.getId();
    }

    @Transactional
    public Integer update(ConferenceDto conferenceDto) throws IOException {
        Conference conference = conferenceRepository.findOne(conferenceDto.getId());
        conferenceRepository.save(copyFromDto(conference, conferenceDto));
        conferenceDto.getRemovedDeadlineIds().forEach(deadlineService::remove);
        return conference.getId();
    }

    @Transactional
    public void delete(Integer conferenceId) {
        if (conferenceRepository.exists(conferenceId)) {
            conferenceRepository.delete(conferenceId);
        }
    }

    public void removeDeadline(ConferenceDto conferenceDto, Integer deadlineIndex) throws IOException {
        if (conferenceDto.getDeadlines().get(deadlineIndex).getId() != null) {
            conferenceDto.getRemovedDeadlineIds().add(conferenceDto.getDeadlines().get(deadlineIndex).getId());
        }
        conferenceDto.getDeadlines().remove((int) deadlineIndex);
    }

    public void removePaper(ConferenceDto conferenceDto, Integer paperIndex) throws IOException {
        Paper removedPaper = conferenceDto.getPapers().remove((int) paperIndex);
        conferenceDto.getNotSelectedPapers().add(removedPaper);
    }

    public void takePart(ConferenceDto conferenceDto) throws IOException {
        conferenceDto.getUsers().add(new ConferenceUser(userService.getCurrentUser()));
        conferenceDto.setDisabledTakePart(true);
    }

    public List<Paper> getNotSelectPapers(List<Integer> paperIds) {
        return paperService.findAllNotSelect(paperIds);
    }

    public List<User> getAllUsers() {
        return userService.findAll();
    }

    public List<ConferenceUser.Participation> getAllParticipations() {
        return Arrays.asList(ConferenceUser.Participation.values());
    }

    public List<ConferenceUser.Deposit> getAllDeposit() {
        return Arrays.asList(ConferenceUser.Deposit.values());
    }

    private Conference copyFromDto(Conference conference, ConferenceDto conferenceDto) throws IOException {
        conference.setTitle(conferenceDto.getTitle());
        conference.setDescription(conferenceDto.getDescription());
        conference.setUrl(conferenceDto.getUrl());
        conference.setPing(0);
        conference.setBeginDate(conferenceDto.getBeginDate());
        conference.setEndDate(conferenceDto.getEndDate());
        conference.setPapers(conferenceDto.getPapers());
        conference.setDeadlines(deadlineService.saveOrCreate(conferenceDto.getDeadlines()));
        conference.setUsers(conferenceUserService.saveOrCreate(conferenceDto.getUsers()));
        if (conferenceDto.getPaperIds() != null && !conferenceDto.getPaperIds().isEmpty()) {
            conferenceDto.getPaperIds().forEach(paperId ->
                    conference.getPapers().add(paperService.findEntityById(paperId)));
        }
        return conference;
    }


    public boolean isCurrentUserParticipant(List<ConferenceUser> conferenceUsers) {
        return conferenceUsers.stream().anyMatch(participant -> participant.getUser().equals(userService.getCurrentUser()));
    }

    public List<ConferenceDto> filter(ConferenceFilterDto conferenceFilterDto) {
        return convert(conferenceRepository.filter(
                conferenceFilterDto.getFilterUserId() == null ? null : userService.findById(conferenceFilterDto.getFilterUserId()),
                conferenceFilterDto.getYear()), ConferenceDto::new);

    }
}