/*
 * Copyright 2000-2018 Vaadin Ltd.
 *
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not
 * use this file except in compliance with the License. You may obtain a copy of
 * the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations under
 * the License.
 */
package com.vaadin.client.ui.menubar;

import java.util.Iterator;
import java.util.Stack;

import com.google.gwt.core.client.GWT;
import com.google.gwt.dom.client.Element;
import com.google.gwt.user.client.Command;
import com.google.gwt.user.client.Timer;
import com.vaadin.client.ApplicationConnection;
import com.vaadin.client.Paintable;
import com.vaadin.client.TooltipInfo;
import com.vaadin.client.UIDL;
import com.vaadin.client.annotations.OnStateChange;
import com.vaadin.client.ui.AbstractComponentConnector;
import com.vaadin.client.ui.Icon;
import com.vaadin.client.ui.SimpleManagedLayout;
import com.vaadin.client.ui.VMenuBar;
import com.vaadin.shared.ui.ComponentStateUtil;
import com.vaadin.shared.ui.Connect;
import com.vaadin.shared.ui.menubar.MenuBarConstants;
import com.vaadin.shared.ui.menubar.MenuBarState;

@Connect(com.vaadin.ui.MenuBar.class)
public class MenuBarConnector extends AbstractComponentConnector
        implements Paintable, SimpleManagedLayout {

    /**
     * This method must be implemented to update the client-side component from
     * UIDL data received from server.
     *
     * This method is called when the page is loaded for the first time, and
     * every time UI changes in the component are received from the server.
     */
    @Override
    public void updateFromUIDL(UIDL uidl, ApplicationConnection client) {
        if (!isRealUpdate(uidl)) {
            return;
        }

        VMenuBar widget = getWidget();
        widget.htmlContentAllowed = uidl
                .hasAttribute(MenuBarConstants.HTML_CONTENT_ALLOWED);

        widget.openRootOnHover = uidl
                .getBooleanAttribute(MenuBarConstants.OPEN_ROOT_MENU_ON_HOWER);

        widget.enabled = isEnabled();

        // For future connections
        widget.client = client;
        widget.uidlId = uidl.getId();
        Timer timer = new Timer() {

            @Override
            public void run() {
                // Empty the menu every time it receives new information
                if (!widget.getItems().isEmpty()) {
                    widget.clearItems();
                }

                UIDL options = uidl.getChildUIDL(0);

                if (null != getState()
                        && !ComponentStateUtil.isUndefinedWidth(getState())) {
                    UIDL moreItemUIDL = options.getChildUIDL(0);
                    StringBuilder itemHTML = new StringBuilder();

                    if (moreItemUIDL.hasAttribute("icon")) {
                        Icon icon = client.getIcon(
                                moreItemUIDL.getStringAttribute("icon"));
                        if (icon != null) {
                            itemHTML.append(icon.getElement().getString());
                        }
                    }

                    String moreItemText = moreItemUIDL
                            .getStringAttribute("text");
                    if ("".equals(moreItemText)) {
                        moreItemText = "►";
                    }
                    itemHTML.append(moreItemText);

                    widget.moreItem = GWT.create(VMenuBar.CustomMenuItem.class);
                    widget.moreItem.setHTML(itemHTML.toString());
                    widget.moreItem.setCommand(VMenuBar.emptyCommand);

                    widget.collapsedRootItems = new VMenuBar(true, widget);
                    widget.moreItem.setSubMenu(widget.collapsedRootItems);
                    widget.moreItem.addStyleName(
                            widget.getStylePrimaryName() + "-more-menuitem");
                }

                UIDL uidlItems = uidl.getChildUIDL(1);
                Iterator<Object> itr = uidlItems.iterator();
                Stack<Iterator<Object>> iteratorStack = new Stack<>();
                Stack<VMenuBar> menuStack = new Stack<>();
                VMenuBar currentMenu = widget;

                while (itr.hasNext()) {
                    UIDL item = (UIDL) itr.next();
                    VMenuBar.CustomMenuItem currentItem = null;

                    final int itemId = item.getIntAttribute("id");

                    boolean itemHasCommand = item.hasAttribute("command");
                    boolean itemIsCheckable = item
                            .hasAttribute(MenuBarConstants.ATTRIBUTE_CHECKED);

                    String itemHTML = widget.buildItemHTML(item);

                    Command cmd = null;
                    if (!item.hasAttribute("separator")) {
                        if (itemHasCommand || itemIsCheckable) {
                            // Construct a command that fires onMenuClick(int)
                            // with the
                            // item's id-number
                            cmd = () -> widget.hostReference
                                    .onMenuClick(itemId);
                        }
                    }

                    currentItem = currentMenu.addItem(itemHTML, cmd);
                    currentItem.setId("" + itemId);
                    currentItem.updateFromUIDL(item, client);

                    String domId = getState().id;
                    if (domId != null && !domId.isEmpty()) {
                        currentItem.getElement().setId(domId+"-"+itemId);
                    }

                    if (item.getChildCount() > 0) {
                        menuStack.push(currentMenu);
                        iteratorStack.push(itr);
                        itr = item.iterator();
                        currentMenu = new VMenuBar(true, currentMenu);
                        client.getVTooltip()
                                .connectHandlersToWidget(currentMenu);
                        // this is the top-level style that also propagates to
                        // items -
                        // any item specific styles are set above in
                        // currentItem.updateFromUIDL(item, client)
                        if (ComponentStateUtil.hasStyles(getState())) {
                            for (String style : getState().styles) {
                                currentMenu.addStyleDependentName(style);
                            }
                        }
                        currentItem.setSubMenu(currentMenu);
                    }

                    while (!itr.hasNext() && !iteratorStack.empty()) {
                        boolean hasCheckableItem = false;
                        for (VMenuBar.CustomMenuItem menuItem : currentMenu
                                .getItems()) {
                            hasCheckableItem = hasCheckableItem
                                    || menuItem.isCheckable();
                        }
                        if (hasCheckableItem) {
                            currentMenu.addStyleDependentName("check-column");
                        } else {
                            currentMenu
                                    .removeStyleDependentName("check-column");
                        }

                        itr = iteratorStack.pop();
                        currentMenu = menuStack.pop();
                    }
                }
            }
        };
        getLayoutManager().setNeedsHorizontalLayout(MenuBarConnector.this);
        if (widget.mouseDownPressed) {
            timer.schedule(getState().delayMs);
            widget.mouseDownPressed = false;
        } else {
            timer.run();
        }
    }

    @Override
    public VMenuBar getWidget() {
        return (VMenuBar) super.getWidget();
    }

    @Override
    public MenuBarState getState() {
        return (MenuBarState) super.getState();
    }

    @Override
    public void layout() {
        getWidget().iLayout();
    }

    @Override
    public TooltipInfo getTooltipInfo(Element element) {
        TooltipInfo info = null;

        // Check content of widget to find tooltip for element
        if (element != getWidget().getElement()) {

            VMenuBar.CustomMenuItem item = getWidget()
                    .getMenuItemWithElement(element);
            if (item != null) {
                info = item.getTooltip();
            }
        }

        // Use default tooltip if nothing found from DOM three
        if (info == null) {
            info = super.getTooltipInfo(element);
        }

        return info;
    }

    @Override
    public boolean hasTooltip() {
        /*
         * Item tooltips are not processed until updateFromUIDL, so we can't be
         * sure that there are no tooltips during onStateChange when this method
         * is used.
         */
        return true;
    }

    @OnStateChange("enabled")
    void updateEnabled() {
        if (getState().enabled) {
            getWidget().getElement().removeAttribute("aria-disabled");
        } else {
            getWidget().getElement().setAttribute("aria-disabled", "true");
        }
    }

    @OnStateChange("tabIndex")
    void updateTabIndex() {
        getWidget().getElement().setAttribute("tabindex",
                String.valueOf(getState().tabIndex));
    }
}