const TopMenuModule = (() => {

    const mainMenuItems = document.getElementById('main-menu')?.children ?? [];
    let infoList = document.getElementById('editor-info') ?? document.createElement("div");
    let infoElements = {};

    initMenu();

    function initMenu() {
        // for each button in main menu (starting at 1 to avoid logo), ending at length-1 to avoid
        // editor info
        for (let i = 1; i < mainMenuItems.length-1; i++) {

            //get the button that's in the list item
            const menuItem = mainMenuItems[i];
            const menuButton = menuItem.children[0];

            //when you click a main menu items button
            Events.on('click', menuButton, function (e) {
                // Close the already open menus
                closeMenu();
                // Select the item
                Util.select(e.target.parentElement);
                e.stopPropagation();
            });

            const subMenu = menuItem.children[1];
            const subMenuItems = subMenu.children;

            //when you click an item within a menu button
            for (var j = 0; j < subMenuItems.length; j++) {

                const currSubmenuItem = subMenuItems[j];
                const currSubmenuButton = currSubmenuItem.children[0];

                switch (currSubmenuButton.textContent) {
                    case 'New':
                        Events.on('click', currSubmenuButton, Dialogue.showDialogue, 'new-pixel');
                        break;
                    case 'Save project':
                        Events.on('click', currSubmenuButton, FileManager.openSaveProjectWindow);
                        break;
                    case 'Open':
                        Events.on('click', currSubmenuButton, FileManager.open);
                        break;
                    case 'Import':
                        Events.on('click', currSubmenuButton, FileManager.openImportImageWindow);
                        break;
                    case 'Export':
                        Events.on('click', currSubmenuButton, FileManager.openPixelExportWindow);
                        break;
                    case 'Exit':
                        //if a document exists, make sure they want to delete it
                        if (EditorState.documentCreated()) {
                            //ask user if they want to leave
                            if (confirm('Exiting will discard your current pixel. Are you sure you want to do that?'))
                                //skip onbeforeunload prompt
                                window.onbeforeunload = null;
                            else
                                e.preventDefault();
                        }
                        break;
                    case 'Paste':
                        Events.on('click', currSubmenuButton, function(e){
                            Events.emit("ctrl+v");
                            e.stopPropagation();
                        });
                        break;
                    case 'Copy':
                        Events.on('click', currSubmenuButton, function(e){
                            Events.emit("ctrl+c");
                            e.stopPropagation();
                        });
                        break;
                    case 'Cut':
                        Events.on('click', currSubmenuButton, function(e){
                            Events.emit("ctrl+x");
                            e.stopPropagation();
                        });
                        break;
                    case 'Cancel':
                        Events.on('click', currSubmenuButton, function(e){
                            Events.emit("esc-pressed");
                            e.stopPropagation();
                        });
                        break;
                    //Help Menu
                    case 'Settings':
                        Events.on('click', currSubmenuButton, Dialogue.showDialogue, 'settings');
                        break;
                    case 'Help':
                        Events.on('click', currSubmenuButton, Dialogue.showDialogue, 'help');
                        break;
                    case 'About':
                        Events.on('click', currSubmenuButton, Dialogue.showDialogue, 'about');
                        break;
                    case 'Changelog':
                        Events.on('click', currSubmenuButton, Dialogue.showDialogue, 'changelog');
                        break;
                }

                Events.on('click', currSubmenuButton, function() {TopMenuModule.closeMenu();});
            }
        }
    }

    function closeMenu () {
        //remove .selected class from all menu buttons
        for (var i = 0; i < mainMenuItems.length; i++) {
            Util.deselect(mainMenuItems[i]);
        }
    }

    function resetInfos() {
        infoList.innerHTML = "<ul></ul>";
    }

    function updateField(fieldId, value) {
        const elm = document.getElementById(fieldId);
        if(elm) {
            elm.value = value;
        } else {
            //console.warn('elm === ', elm);
        }
    }

    function addInfoElement(fieldId, field) {
        let liEl = document.createElement("li");

        infoElements[fieldId] = field;
        liEl.appendChild(field);

        infoList.firstChild.appendChild(liEl);
    }

    return {
        closeMenu,
        updateField,
        addInfoElement,
        resetInfos
    }
})();