/**
 * File navigation.js.
 *
 * Handles toggling the navigation menu for small screens and enables TAB key
 * navigation support for dropdown menus, including keyboard accessibility.
 */
(function () {
    const siteNavigation = document.getElementById('site-navigation');

    if (!siteNavigation) return;

    const button = siteNavigation.getElementsByTagName('button')[0];
    if (typeof button === 'undefined') return;

    const menu = siteNavigation.getElementsByTagName('ul')[0];
    if (typeof menu === 'undefined') {
        button.style.display = 'none';
        return;
    }

    if (!menu.classList.contains('nav-menu')) {
        menu.classList.add('nav-menu');
    }

    // Toggle menu open/close
    button.addEventListener('click', function () {
        siteNavigation.classList.toggle('toggled');
        const expanded = this.getAttribute('aria-expanded') === 'true' || false;
        this.setAttribute('aria-expanded', !expanded);

        // When menu opens, move focus to first link
        if (siteNavigation.classList.contains('toggled')) {
            trapFocus(siteNavigation);
            const firstLink = menu.querySelector('a');
            if (firstLink) firstLink.focus();
        } else {
            releaseFocusTrap();
        }
    });

    // Enter/Space toggles button
    button.addEventListener('keydown', function (e) {
        if (e.key === 'Enter' || e.key === ' ') {
            e.preventDefault();
            this.click();
        }
    });

    // Close menu when clicking outside
    document.addEventListener('click', function (event) {
        const isClickInside = siteNavigation.contains(event.target);
        if (!isClickInside) {
            siteNavigation.classList.remove('toggled');
            button.setAttribute('aria-expanded', 'false');
            releaseFocusTrap();
        }
    });

    // Submenu ARIA setup
    const links = menu.getElementsByTagName('a');
    const linksWithChildren = menu.querySelectorAll('.menu-item-has-children > a, .page_item_has_children > a');

    linksWithChildren.forEach(link => {
        link.setAttribute('aria-haspopup', 'true');
        link.setAttribute('aria-expanded', 'false');

        link.addEventListener('keydown', function (e) {
            if (e.key === 'Enter' || e.key === ' ') {
                e.preventDefault();
                const submenu = this.nextElementSibling;
                if (submenu && submenu.classList.contains('sub-menu')) {
                    const expanded = this.getAttribute('aria-expanded') === 'true' || false;
                    this.setAttribute('aria-expanded', !expanded);
                    submenu.classList.toggle('toggled');

                    // Close other submenus
                    const otherSubmenus = menu.querySelectorAll('.sub-menu.toggled');
                    otherSubmenus.forEach(otherSubmenu => {
                        if (otherSubmenu !== submenu) {
                            otherSubmenu.classList.remove('toggled');
                            const otherLink = otherSubmenu.previousElementSibling;
                            if (otherLink && otherLink.tagName === 'A') {
                                otherLink.setAttribute('aria-expanded', 'false');
                            }
                        }
                    });
                }
            }
        });
    });

    // Touch submenu icons
    function bsd_isMobileMenuContext() {
        return siteNavigation.classList.contains('toggled') || window.matchMedia('(max-width: 1024px)').matches;
    }

    const submenuIcons = menu.querySelectorAll('a > img.submenu-icon');
    submenuIcons.forEach(icon => {
        icon.addEventListener('click', function (e) {
            if (!bsd_isMobileMenuContext()) return;
            e.preventDefault();
            e.stopPropagation();

            const link = this.closest('a');
            const parentLi = link.closest('li.menu-item-has-children');
            const submenu = link.nextElementSibling;
            if (!submenu || !submenu.classList.contains('sub-menu')) return;

            const willOpen = !submenu.classList.contains('toggled');

            // Close siblings
            const siblingLis = parentLi && parentLi.parentElement ? parentLi.parentElement.children : [];
            Array.from(siblingLis).forEach(sib => {
                if (sib !== parentLi) {
                    const sibLink = sib.querySelector(':scope > a[aria-expanded]');
                    const sibSub = sib.querySelector(':scope > ul.sub-menu');
                    if (sibSub && sibSub.classList.contains('toggled')) {
                        sibSub.classList.remove('toggled');
                        sib.classList.remove('toggled');
                        if (sibLink) sibLink.setAttribute('aria-expanded', 'false');
                    }
                }
            });

            submenu.classList.toggle('toggled', willOpen);
            if (parentLi) parentLi.classList.toggle('toggled', willOpen);
            link.setAttribute('aria-expanded', willOpen ? 'true' : 'false');
            submenu.style.display = '';
        });
    });

    // Focus styling for keyboard users
    for (const link of links) {
        link.addEventListener('focus', bsd_toggleFocus, true);
        link.addEventListener('blur', bsd_toggleFocus, true);
    }
    for (const link of linksWithChildren) {
        link.addEventListener('touchstart', bsd_toggleFocus, false);
    }

    function bsd_toggleFocus(event) {
        if (event.type === 'focus' || event.type === 'blur') {
            let self = this;
            while (!self.classList.contains('nav-menu')) {
                if (self.tagName.toLowerCase() === 'li') {
                    self.classList.toggle('focus');
                }
                self = self.parentNode;
            }
        }
        if (event.type === 'touchstart') {
            const menuItem = this.parentNode;
            if (event.cancelable) event.preventDefault();
            for (const link of menuItem.parentNode.children) {
                if (menuItem !== link) link.classList.remove('focus');
            }
            menuItem.classList.toggle('focus');
        }
    }

    /**
     * 🔒 Focus Trap for Mobile Menu
     */
    let focusTrapHandler = null;

    function trapFocus(container) {
        const focusableSelectors = 'a[href], button:not([disabled]), input, select, textarea, [tabindex]:not([tabindex="-1"])';
        const focusableElements = container.querySelectorAll(focusableSelectors);
        if (!focusableElements.length) return;

        const firstEl = focusableElements[0];
        const lastEl = focusableElements[focusableElements.length - 1];

        focusTrapHandler = function (e) {
            if (e.key !== 'Tab') return;

            if (e.shiftKey) { // SHIFT + TAB
                if (document.activeElement === firstEl) {
                    e.preventDefault();
                    lastEl.focus();
                }
            } else { // TAB
                if (document.activeElement === lastEl) {
                    e.preventDefault();
                    firstEl.focus();
                }
            }
        };
        document.addEventListener('keydown', focusTrapHandler);
    }

    function releaseFocusTrap() {
        if (focusTrapHandler) {
            document.removeEventListener('keydown', focusTrapHandler);
            focusTrapHandler = null;
        }
    }

})();