package nl.tudelft.cs05.frontend;

import com.vaadin.flow.component.button.Button;
import com.vaadin.flow.component.button.ButtonVariant;
import com.vaadin.flow.component.combobox.ComboBox;
import com.vaadin.flow.component.grid.Grid;
import com.vaadin.flow.component.html.Label;
import com.vaadin.flow.component.orderedlayout.HorizontalLayout;
import com.vaadin.flow.component.orderedlayout.VerticalLayout;
import com.vaadin.flow.data.renderer.ComponentRenderer;
import com.vaadin.flow.router.BeforeEnterEvent;
import com.vaadin.flow.router.BeforeEnterObserver;
import com.vaadin.flow.router.Route;
import nl.tudelft.cs05.Container;
import nl.tudelft.cs05.backend.attribute.Attribute;
import nl.tudelft.cs05.backend.attribute.AttributeService;
import nl.tudelft.cs05.backend.event.Event;
import nl.tudelft.cs05.backend.event.EventService;
import nl.tudelft.cs05.backend.feed.Feed;
import nl.tudelft.cs05.backend.feed.FeedService;
import nl.tudelft.cs05.backend.subscribe.Subscribe;
import nl.tudelft.cs05.backend.subscribe.SubscribeService;
import nl.tudelft.cs05.backend.user.UserService;
import nl.tudelft.cs05.helper.FileHelper;
import org.springframework.beans.factory.annotation.Autowired;

import java.io.BufferedReader;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.stream.Collectors;

/**
 * Displays the feeds to the user.
 */
@Route("feeds")
public class FeedView extends VerticalLayout implements BeforeEnterObserver {

    private final FeedService feedService;
    private final UserService userService;
    private final EventService eventService;
    private final AttributeService attributeService;
    private final SubscribeService subscribeService;
    private FileHelper fileHelper;
    private Grid<Feed> grid = new Grid<>(Feed.class, false);
    private Grid<Attribute> iocGrid = new Grid<>(Attribute.class, false);
    private ComboBox<String> comboBox = new ComboBox<>("Categories");
    private List<String> categoriesArray = new ArrayList<>();
    private List<String> namesArray = new ArrayList<>();

    /**
     * Creates a layout to which it adds the feeds and filter.
     *
     * @param feedService      The feed service which will provide the list with feeds.
     * @param eventService     The event service which will provide the list with events.
     * @param attributeService The attribute service which will provide the list with attributes.
     * @param userService      the user service which will provide the list of users.
     * @param subscribeService the subscribe service which will provide the list of subscribed feeds.
     */
    @Autowired
    public FeedView(UserService userService, FeedService feedService,
                    SubscribeService subscribeService, EventService eventService, AttributeService attributeService) {
        VerticalLayout layout = new VerticalLayout();
        this.feedService = feedService;
        this.eventService = eventService;
        this.attributeService = attributeService;
        this.userService = userService;
        this.subscribeService = subscribeService;
        this.fileHelper = new FileHelper();
        categorySuggestion();


        if (userService.isLoggedIn()) {
            setUpLayout(layout);
        }
    }

    private void setUpLayout(VerticalLayout layout) {
        grid.addColumn(Feed::getId).setHeader("ID").setFlexGrow(0).setWidth("5%");
        grid.addColumn(Feed::getName).setHeader("Name").setWidth("20%");
        grid.addColumn(Feed::getProvider).setHeader("Provider").setWidth("20%");
        grid.addColumn(Feed::getUrl).setHeader("URL").setWidth("30%");
        grid.setHeight("100%");
        grid.addComponentColumn(this::buildSubscribeButton);

        iocGrid.addColumn(Attribute::getId).setHeader("ID").setFlexGrow(0).setWidth("14%");
        iocGrid.addColumn(Attribute::getValue).setHeader("Value");
        grid.setItemDetailsRenderer(new ComponentRenderer<>(feed -> {
            VerticalLayout leftVerticalLayout = new VerticalLayout();
            VerticalLayout rightVerticalLayout = new VerticalLayout();

            HorizontalLayout horizontalLayout = new HorizontalLayout();


            if (eventService.findAll(feed.getEventId()).size() != 0) {
                Event event = eventService.findAll(feed.getEventId()).get(0);
                leftVerticalLayout.add(new Label("Date: " + event.getDate()));
                leftVerticalLayout.add(new Label("IoCs: " + event.getIocCount()));
                leftVerticalLayout.add(new Label("CreatorID: " + event.getUserId()));
            }
            leftVerticalLayout.add(new Label("EventID: " + feed.getEventId()));

            updateAttributes(feed.getEventId());
            rightVerticalLayout.add(iocGrid);
            horizontalLayout.add(leftVerticalLayout);
            horizontalLayout.add(rightVerticalLayout);
            return horizontalLayout;
        }));
        updateList();
        Container container = new Container();
        layout.add(comboBox, grid);
        layout.setHeightFull();
        container.setContent(layout);
        add(container);
    }


    /**
     * Builds the enable/disable button for a feed.
     *
     * @param feed is the feed.
     * @return the builded button.
     */
    private Button buildSubscribeButton(Feed feed) {
        Button button = new Button();

        if (subscribeService.isSubscribed(feed, userService.getAuthUser())) {
            button.addClickListener(onClick -> {
                Subscribe subscribe = subscribeService.findOneSubscribe(feed, userService.getAuthUser());
                subscribeService.delete(subscribe);
                updateList();
            });
            button.setText("Subscribed");
            button.addThemeVariants(ButtonVariant.LUMO_SUCCESS);
        } else {
            button.addClickListener(onClick -> {
                Subscribe subscribe = new Subscribe();
                subscribe.setUserID(userService.getAuthUser().getId());
                subscribe.setFeedID(feed.getId());
                subscribeService.save(subscribe);
                updateList();
            });
            button.setText("Not Subscribed");
            button.addThemeVariants(ButtonVariant.LUMO_ERROR);
        }

        return button;
    }

    /**
     * Creates a category filter which allows autosuggestion.
     */
    public void categorySuggestion() {
        comboBox.setAllowCustomValue(true);
        comboBox.setPlaceholder("filter by category...");
        BufferedReader in = fileHelper.readFile("/categories");
        categoriesArray = Arrays.asList(in.lines().collect(Collectors.joining()).split(","));

        comboBox.setItems(categoriesArray.stream().sorted());
        comboBox.setValue("All");
        comboBox.addValueChangeListener(e -> updateList());

    }

    /**
     * Updates the displayed feeds according to the given categories by the user.
     */
    protected void updateList() {
        if (comboBox.getValue() == null) {
            comboBox.setValue("");
        }
        List<Feed> feed = feedService.findAll(comboBox.getValue());
        grid.setItems(feed);
    }

    /**
     * Updates the displayed feeds according to the given categories by the user.
     */
    private void updateAttributes(int eventId) {
        List<Attribute> feed = attributeService.findAll(eventId);
        iocGrid.setItems(feed);
    }

    /**
     * Simple function to get the subscribe service.
     *
     * @return the service.
     */
    public SubscribeService getSubscribeService() {
        return subscribeService;
    }

    /**
     * Simple function to get the user service.
     *
     * @return the service.
     */
    public UserService getUserService() {
        return userService;
    }

    /**
     * Simple function to get the grid containing the feeds.
     *
     * @return the grid with feeds.
     */
    public Grid<Feed> getGrid() {
        return grid;
    }

    @Override
    public void beforeEnter(BeforeEnterEvent beforeEnterEvent) {
        if (!userService.isLoggedIn()) {
            beforeEnterEvent.rerouteTo(MainView.class);
        }
    }
}