package ru.ulstu.activity.grant.service;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.data.domain.Page;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;
import org.springframework.validation.Errors;
import ru.ulstu.activity.common.service.ActivityService;
import ru.ulstu.activity.deadline.service.DeadlineService;
import ru.ulstu.activity.file.service.FileService;
import ru.ulstu.activity.grant.model.Grant;
import ru.ulstu.activity.grant.model.GrantDashboardDto;
import ru.ulstu.activity.grant.model.GrantDto;
import ru.ulstu.activity.grant.model.GrantListDto;
import ru.ulstu.activity.paper.model.Paper;
import ru.ulstu.activity.paper.model.PaperDto;
import ru.ulstu.activity.paper.service.PaperService;
import ru.ulstu.activity.ping.service.PingService;
import ru.ulstu.activity.project.service.ProjectService;
import ru.ulstu.activity.timeline.model.Event;
import ru.ulstu.activity.timeline.service.EventService;
import ru.ulstu.core.jpa.OffsetablePageRequest;
import ru.ulstu.core.model.response.PageableItems;
import ru.ulstu.core.util.DateUtils;
import ru.ulstu.user.model.User;
import ru.ulstu.user.service.UserService;

import java.io.IOException;
import java.text.ParseException;
import java.util.Arrays;
import java.util.Date;
import java.util.List;

import static java.util.stream.Collectors.toList;
import static ru.ulstu.activity.grant.model.Grant.GrantStatus.APPLICATION;
import static ru.ulstu.core.util.StreamApiUtils.convertPageable;

@Service
public class GrantService extends ActivityService<GrantListDto, Grant, GrantDto> {
    private final Logger log = LoggerFactory.getLogger(GrantService.class);

    private final GrantRepository grantRepository;
    private final ProjectService projectService;
    private final DeadlineService deadlineService;
    private final FileService fileService;
    private final UserService userService;
    private final PaperService paperService;
    private final EventService eventService;
    private final GrantNotificationService grantNotificationService;
    private final KiasService kiasService;
    private final PingService pingService;

    public GrantService(GrantRepository grantRepository,
                        FileService fileService,
                        DeadlineService deadlineService,
                        ProjectService projectService,
                        UserService userService,
                        PaperService paperService,
                        EventService eventService,
                        GrantNotificationService grantNotificationService,
                        KiasService kiasService,
                        PingService pingService) {
        super(grantRepository, grantNotificationService, pingService, eventService);
        this.grantRepository = grantRepository;
        this.kiasService = kiasService;
        this.fileService = fileService;
        this.deadlineService = deadlineService;
        this.projectService = projectService;
        this.userService = userService;
        this.paperService = paperService;
        this.eventService = eventService;
        this.grantNotificationService = grantNotificationService;
        this.pingService = pingService;
    }

    public GrantDto getExistGrantById(Integer id) {
        return new GrantDto(findById(id));
    }

    @Override
    public PageableItems<Grant> findAll(int offset, int count) {
        final Page<Grant> page = grantRepository.findAll(new OffsetablePageRequest(offset, count));
        return new PageableItems<>(page.getTotalElements(), page.getContent());
    }

    @Override
    protected GrantListDto getActivityListDto(Grant entity) {
        return new GrantListDto(entity);
    }

    @Override
    protected Grant getNewActivity() {
        return new Grant();
    }

    @Override
    protected GrantDto getNewActivityDto(Grant entity) {
        return new GrantDto(entity);
    }

    protected Grant copyFromDto(Grant grant, GrantDto grantDto) throws IOException {
        grant.setComment(grantDto.getComment());
        grant.setStatus(grantDto.getStatus() == null ? APPLICATION : grantDto.getStatus());
        grant.setTitle(grantDto.getTitle());
        grant.setDeadlines(deadlineService.saveOrCreate(grantDto.getDeadlines()));
        if (!grant.getFiles().isEmpty()) {
            grant.setFiles(fileService.saveOrCreate(grantDto.getFiles().stream()
                    .filter(f -> !f.isDeleted())
                    .collect(toList())));
        }
        grant.getAuthors().clear();
        if (grantDto.getMembers() != null && !grantDto.getMembers().isEmpty()) {
            grantDto.getMembers().forEach(memberDto -> grant.getAuthors().add(userService.findById(memberDto.getId())));
        }
        if (grantDto.getLeaderId() != null) {
            grant.setLeader(userService.findById(grantDto.getLeaderId()));
        }
        grant.getPapers().clear();
        if (grantDto.getPaperIds() != null && !grantDto.getPaperIds().isEmpty()) {
            grantDto.getPaperIds().forEach(paperIds -> grant.getPapers().add(paperService.findById(paperIds)));
        }
        return grant;
    }

    @Override
    protected List<Event> getEvents(Grant entity) {
        return eventService.findByGrant(entity);
    }

    @Transactional
    public boolean delete(Integer grantId) {
        Grant grant = findById(grantId);
        if (grant != null) {
            grantRepository.delete(grant);
            return true;
        }
        return false;
    }

    public List<Grant.GrantStatus> getGrantStatuses() {
        return Arrays.asList(Grant.GrantStatus.values());
    }

    private boolean saveFromKias(GrantDto grantDto) throws IOException {
        grantDto.setTitle(grantDto.getTitle());
        if (checkUniqueName(grantDto.getTitle(), grantDto.getId())) {
            Grant grantFromDB = grantRepository.findByTitle(grantDto.getTitle()); //грант с таким же названием из бд
            if (checkSameDeadline(grantDto, grantFromDB.getId())) { //если дедайны тоже совпадают
                return false;
            } else { //иначе грант уже был в системе, но в другом году, поэтому надо создать
                create(grantDto);
                return true;
            }
        } else { //иначе такого гранта ещё нет, поэтому надо создать
            create(grantDto);
            return true;
        }
    }

    private void checkEmptyLeader(GrantDto grantDto, Errors errors) {
        if (grantDto.getLeaderId().equals(-1)) {
            errors.rejectValue("leaderId", "errorCode", "Укажите руководителя");
        }
    }

    private void checkEmptyDeadlines(GrantDto grantDto, Errors errors) {
        if (grantDto.getDeadlines().isEmpty()) {
            errors.rejectValue("deadlines", "errorCode", "Не может быть пусто");
        }
    }

    private boolean checkSameDeadline(GrantDto grantDto, Integer id) {
        Date date = DateUtils.clearTime(grantDto.getDeadlines().get(0).getDate()); //дата с сайта киас
        Date foundGrantDate = DateUtils.clearTime(deadlineService.findByGrantIdAndDate(id, date));
        return foundGrantDate != null && foundGrantDate.compareTo(date) == 0;
    }

    public List<PaperDto> getGrantPapers(List<Integer> paperIds) {
        return paperService.findAllSelect(paperIds);
    }

    public List<PaperDto> getAllUncompletedPapers() {
        return paperService.findAllNotCompleted();
    }

    private List<User> getCompletedPapersAuthors(Paper.PaperType type) {
        List<Paper> papers = paperService.findAllCompletedByType(type);
        return papers.stream()
                .filter(paper -> paper.getAuthors() != null)
                .flatMap(paper -> paper.getAuthors().stream())
                .collect(toList());
    }

    @Transactional
    public void createFromKias() throws IOException, ParseException {
        for (GrantDto grantDto : kiasService.getNewGrantsDto()) {
            if (saveFromKias(grantDto)) {
                log.debug("GrantScheduler.loadGrantsFromKias new grant was loaded");
            } else {
                log.debug("GrantScheduler.loadGrantsFromKias grant wasn't loaded, cause it's already exists");
            }
        }
    }

    public PageableItems<GrantDashboardDto> findAllActiveDto(int offset, int count) {
        return convertPageable(findAllActive(offset, count), GrantDashboardDto::new);
    }

    public PageableItems<Grant> findAllActive(int offset, int count) {
        Page<Grant> activeGrantsPage = grantRepository.findAllActive(new OffsetablePageRequest(offset, count));
        return new PageableItems<>(activeGrantsPage.getTotalElements(), activeGrantsPage.getContent());

    }

    public GrantDto findGrantById(Integer id) {
        return new GrantDto(findById(id));
    }

    public Grant findById(Integer id) {
        return grantRepository.getOne(id);
    }

    @Transactional
    public void ping(int grantId) {
        pingService.addPing(findById(grantId));
    }
}