(function () {
    var root = document.documentElement;
    var storedMode = localStorage.getItem('neon-mode') || 'dark';
    var storedAccent = localStorage.getItem('neon-accent') || 'green';
    var modeButton = document.querySelector('[data-mode-toggle]');
    var accentButtons = document.querySelectorAll('[data-accent]');

    function labelAccent(accent) {
        return accent.charAt(0).toUpperCase() + accent.slice(1);
    }

    function applyMode(mode) {
        root.dataset.mode = mode;
        localStorage.setItem('neon-mode', mode);
        if (modeButton) {
            modeButton.textContent = 'Light';
            modeButton.setAttribute('aria-label', 'Light mode');
            modeButton.setAttribute('aria-pressed', mode === 'light' ? 'true' : 'false');
            modeButton.title = mode === 'light' ? 'Disable light mode' : 'Enable light mode';
        }
    }

    function applyAccent(accent) {
        root.dataset.accent = accent;
        localStorage.setItem('neon-accent', accent);
        accentButtons.forEach(function (button) {
            var selected = button.dataset.accent === accent;
            var name = labelAccent(button.dataset.accent || 'accent');
            button.setAttribute('aria-pressed', selected ? 'true' : 'false');
            button.setAttribute('aria-label', selected ? name + ' accent selected' : 'Use ' + name.toLowerCase() + ' accent');
            button.title = selected ? name + ' accent selected' : 'Use ' + name.toLowerCase() + ' accent';
        });
    }

    applyMode(storedMode);
    applyAccent(storedAccent);

    if (modeButton) {
        modeButton.addEventListener('click', function () {
            applyMode(root.dataset.mode === 'light' ? 'dark' : 'light');
        });
    }

    accentButtons.forEach(function (button) {
        button.addEventListener('click', function () {
            applyAccent(button.dataset.accent || 'green');
        });
    });

    function initLightbox() {
        var article = document.querySelector('.article .markdown');
        if (!article) {
            return;
        }

        var imageExtensions = /\.(avif|gif|jpe?g|png|webp|bmp|svg)(?:[?#].*)?$/i;
        var videoExtensions = /\.(m4v|mov|mp4|ogv|ogg|webm)(?:[?#].*)?$/i;
        var entries = [];
        var currentIndex = 0;
        var lastFocus = null;
        var lightbox = null;
        var mediaFrame = null;
        var titleNode = null;
        var countNode = null;
        var captionNode = null;
        var closeButton = null;

        function mediaTitle(element, fallback) {
            return element.getAttribute('alt') ||
                element.getAttribute('title') ||
                element.getAttribute('aria-label') ||
                fallback ||
                'Media';
        }

        function isVideoIframe(iframe, src) {
            return Boolean(iframe.closest('.shortcode-embed')) ||
                /(?:youtube\.com|youtu\.be|vimeo\.com|player\.vimeo|lone-embed\.php)/i.test(src) ||
                videoExtensions.test(src);
        }

        function addEntry(entry) {
            if (!entry.src) {
                return;
            }
            entries.push(entry);
        }

        article.querySelectorAll('img, video, iframe, a[href]').forEach(function (element) {
            var tag = element.tagName.toLowerCase();
            if (tag === 'img') {
                addEntry({
                    type: 'image',
                    src: element.currentSrc || element.src || element.getAttribute('src'),
                    title: mediaTitle(element, 'Image'),
                    trigger: element
                });
                return;
            }

            if (tag === 'video') {
                var source = element.currentSrc || element.getAttribute('src');
                var sourceElement = source ? null : element.querySelector('source[src]');
                if (!source && sourceElement) {
                    source = sourceElement.getAttribute('src');
                }
                addEntry({
                    type: 'video',
                    src: source,
                    poster: element.getAttribute('poster') || '',
                    title: mediaTitle(element, 'Video'),
                    trigger: element
                });
                return;
            }

            if (tag === 'iframe') {
                var iframeSrc = element.getAttribute('src') || '';
                if (isVideoIframe(element, iframeSrc)) {
                    addEntry({
                        type: 'iframe',
                        src: iframeSrc,
                        title: mediaTitle(element, 'Video'),
                        trigger: element
                    });
                }
                return;
            }

            if (element.querySelector('img, video, iframe')) {
                return;
            }

            var href = element.getAttribute('href') || '';
            if (imageExtensions.test(href)) {
                addEntry({
                    type: 'image',
                    src: href,
                    title: mediaTitle(element, element.textContent.trim() || 'Image'),
                    trigger: element
                });
            } else if (videoExtensions.test(href)) {
                addEntry({
                    type: 'video',
                    src: href,
                    title: mediaTitle(element, element.textContent.trim() || 'Video'),
                    trigger: element
                });
            }
        });

        if (!entries.length) {
            return;
        }

        function buildLightbox() {
            lightbox = document.createElement('div');
            lightbox.className = 'tcms-lightbox';
            lightbox.hidden = true;
            lightbox.setAttribute('role', 'dialog');
            lightbox.setAttribute('aria-modal', 'true');
            lightbox.setAttribute('aria-labelledby', 'tcms-lightbox-title');
            lightbox.setAttribute('aria-describedby', 'tcms-lightbox-caption');

            lightbox.innerHTML = [
                '<button class="tcms-lightbox__backdrop" type="button" data-lightbox-close aria-label="Close media viewer"></button>',
                '<section class="tcms-lightbox__dialog" role="document">',
                '<header class="tcms-lightbox__bar">',
                '<strong class="tcms-lightbox__title" id="tcms-lightbox-title"></strong>',
                '<span class="tcms-lightbox__count" aria-live="polite"></span>',
                '<button class="tcms-lightbox__close" type="button" data-lightbox-close aria-label="Close">Close</button>',
                '</header>',
                '<div class="tcms-lightbox__stage">',
                '<button class="tcms-lightbox__nav tcms-lightbox__nav--previous" type="button" data-lightbox-previous aria-label="Previous media">Previous</button>',
                '<div class="tcms-lightbox__media"></div>',
                '<button class="tcms-lightbox__nav tcms-lightbox__nav--next" type="button" data-lightbox-next aria-label="Next media">Next</button>',
                '</div>',
                '<p class="tcms-lightbox__caption" id="tcms-lightbox-caption"></p>',
                '</section>'
            ].join('');

            document.body.appendChild(lightbox);
            mediaFrame = lightbox.querySelector('.tcms-lightbox__media');
            titleNode = lightbox.querySelector('.tcms-lightbox__title');
            countNode = lightbox.querySelector('.tcms-lightbox__count');
            captionNode = lightbox.querySelector('.tcms-lightbox__caption');
            closeButton = lightbox.querySelector('.tcms-lightbox__close');

            lightbox.querySelectorAll('[data-lightbox-close]').forEach(function (button) {
                button.addEventListener('click', closeLightbox);
            });
            lightbox.querySelector('[data-lightbox-previous]').addEventListener('click', function () {
                showLightboxItem(currentIndex - 1);
            });
            lightbox.querySelector('[data-lightbox-next]').addEventListener('click', function () {
                showLightboxItem(currentIndex + 1);
            });
        }

        function showLightboxItem(index) {
            if (!lightbox) {
                buildLightbox();
            }

            if (index < 0) {
                index = entries.length - 1;
            } else if (index >= entries.length) {
                index = 0;
            }
            currentIndex = index;

            var entry = entries[currentIndex];
            mediaFrame.textContent = '';
            titleNode.textContent = entry.title;
            countNode.textContent = (currentIndex + 1) + ' of ' + entries.length;
            countNode.setAttribute('aria-label', 'Media ' + (currentIndex + 1) + ' of ' + entries.length);
            captionNode.textContent = entry.title;

            if (entry.type === 'image') {
                var image = document.createElement('img');
                image.src = entry.src;
                image.alt = entry.title;
                image.addEventListener('click', function () {
                    if (entries.length > 1) {
                        showLightboxItem(currentIndex + 1);
                    }
                });
                mediaFrame.appendChild(image);
                return;
            }

            if (entry.type === 'video') {
                var video = document.createElement('video');
                video.src = entry.src;
                video.controls = true;
                video.playsInline = true;
                video.preload = 'metadata';
                video.setAttribute('aria-label', entry.title);
                if (entry.poster) {
                    video.poster = entry.poster;
                }
                mediaFrame.appendChild(video);
                return;
            }

            var iframe = document.createElement('iframe');
            iframe.src = entry.src;
            iframe.title = entry.title;
            iframe.loading = 'lazy';
            iframe.allow = 'accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share';
            iframe.allowFullscreen = true;
            mediaFrame.appendChild(iframe);
        }

        function openLightbox(index) {
            if (!lightbox) {
                buildLightbox();
            }
            lastFocus = document.activeElement;
            lightbox.hidden = false;
            document.body.classList.add('tcms-lightbox-open');
            showLightboxItem(index);
            closeButton.focus();
        }

        function closeLightbox() {
            if (!lightbox || lightbox.hidden) {
                return;
            }
            lightbox.hidden = true;
            mediaFrame.textContent = '';
            document.body.classList.remove('tcms-lightbox-open');
            if (lastFocus && document.contains(lastFocus) && typeof lastFocus.focus === 'function') {
                lastFocus.focus();
            }
        }

        function trapLightboxFocus(event) {
            var focusable;
            var first;
            var last;

            if (!lightbox || lightbox.hidden || event.key !== 'Tab') {
                return;
            }

            focusable = Array.prototype.slice.call(lightbox.querySelectorAll([
                'button:not([disabled])',
                'a[href]',
                'iframe',
                'video[controls]',
                '[tabindex]:not([tabindex="-1"])'
            ].join(','))).filter(function (element) {
                return !element.hidden && element.offsetParent !== null;
            });

            if (!focusable.length) {
                event.preventDefault();
                closeButton.focus();
                return;
            }

            first = focusable[0];
            last = focusable[focusable.length - 1];
            if (event.shiftKey && document.activeElement === first) {
                event.preventDefault();
                last.focus();
            } else if (!event.shiftKey && document.activeElement === last) {
                event.preventDefault();
                first.focus();
            }
        }

        function openFromEvent(event, index) {
            event.preventDefault();
            event.stopPropagation();
            openLightbox(index);
        }

        entries.forEach(function (entry, index) {
            var trigger = entry.trigger;
            var tag = trigger.tagName.toLowerCase();
            var button;

            if (tag === 'img' || tag === 'a') {
                trigger.classList.add('tcms-lightboxable');
                trigger.setAttribute('data-lightbox-index', String(index));
                if (tag === 'img' && !trigger.hasAttribute('tabindex')) {
                    trigger.setAttribute('tabindex', '0');
                }
                if (tag === 'img') {
                    trigger.setAttribute('role', 'button');
                    trigger.setAttribute('aria-label', 'Open image viewer for ' + entry.title);
                }
                trigger.setAttribute('aria-haspopup', 'dialog');
                trigger.addEventListener('click', function (event) {
                    openFromEvent(event, index);
                });
                trigger.addEventListener('keydown', function (event) {
                    if (event.key === 'Enter' || event.key === ' ') {
                        openFromEvent(event, index);
                    }
                });
                return;
            }

            button = document.createElement('button');
            button.className = 'tcms-lightbox-trigger';
            button.type = 'button';
            button.textContent = 'View';
            button.setAttribute('aria-haspopup', 'dialog');
            button.setAttribute('aria-label', 'Open media viewer for ' + entry.title);
            button.addEventListener('click', function (event) {
                openFromEvent(event, index);
            });

            if (tag === 'iframe' && trigger.parentElement && trigger.parentElement.classList.contains('shortcode-embed')) {
                trigger.parentElement.classList.add('tcms-lightbox-host');
                trigger.parentElement.appendChild(button);
                return;
            }

            trigger.insertAdjacentElement('afterend', button);
        });

        document.addEventListener('keydown', function (event) {
            if (!lightbox || lightbox.hidden) {
                return;
            }
            if (event.key === 'Escape') {
                closeLightbox();
            } else if (event.key === 'ArrowRight') {
                showLightboxItem(currentIndex + 1);
            } else if (event.key === 'ArrowLeft') {
                showLightboxItem(currentIndex - 1);
            }
            trapLightboxFocus(event);
        });
    }

    initLightbox();
}());