package ru.ulstu.paper.service;

import com.google.common.collect.ImmutableMap;
import org.springframework.stereotype.Service;
import ru.ulstu.core.util.DateUtils;
import ru.ulstu.paper.model.Paper;
import ru.ulstu.user.service.MailService;

import java.util.Date;
import java.util.List;
import java.util.Map;

@Service
public class PaperNotificationService {
    private final static int DAYS_TO_DEADLINE_NOTIFICATION = 7;

    private final MailService mailService;

    public PaperNotificationService(MailService mailService) {
        this.mailService = mailService;
    }

    public void sendDeadlineNotifications(List<Paper> papers, boolean isDeadlineBeforeWeek) {
        Date now = DateUtils.addDays(new Date(), DAYS_TO_DEADLINE_NOTIFICATION);
        papers
                .stream()
                .filter(paper -> needToSendDeadlineNotification(paper, now, isDeadlineBeforeWeek))
                .forEach(paper -> sendMessageDeadline(paper));
    }

    private boolean needToSendDeadlineNotification(Paper paper, Date compareDate, boolean isDeadlineBeforeWeek) {
        return (paper.getDeadlineDate() != null)
                && (compareDate.after(paper.getDeadlineDate()) && isDeadlineBeforeWeek
                || compareDate.before(paper.getDeadlineDate()) && !isDeadlineBeforeWeek)
                && paper.getDeadlineDate().after(new Date());
    }

    private void sendMessageDeadline(Paper paper) {
        paper.getAuthors().forEach(user -> {
            mailService.sendEmail(user.getEmail(), "Приближается срок сдачи статьи",
                    "Срок сдачи статьи " + paper.getTitle() + " " + paper.getDeadlineDate().toString());
        });
    }

    public void sendCreateNotification(Paper paper) {
        Map<String, Object> variables = ImmutableMap.of("paper", paper);
        paper.getAuthors().forEach(author -> {
            mailService.sendEmailFromTemplate(variables, author, "paperCreateNotification", "Создана статья");
        });
    }

    public void statusChangeNotification(Paper paper, Paper.PaperStatus oldStatus) {
        Map<String, Object> variables = ImmutableMap.of("paper", paper, "oldStatus", oldStatus);
        paper.getAuthors().forEach(author -> {
            mailService.sendEmailFromTemplate(variables, author, "paperStatusChangeNotification", "Изменился статус статьи");
        });
    }

    public void sendFailedNotification(Paper paper, Paper.PaperStatus oldStatus) {
        Map<String, Object> variables = ImmutableMap.of("paper", paper, "oldStatus", oldStatus);
        paper.getAuthors().forEach(author -> {
            mailService.sendEmailFromTemplate(variables, author, "paperFailedNotification", "Статья провалена");
        });
    }
}