import {
  Alignment,
  BlockQuote,
  Bold,
  ClassicEditor,
  ClipboardPipeline,
  Essentials,
  FontBackgroundColor,
  FontColor,
  FontFamily,
  FontSize,
  Heading,
  HorizontalLine,
  Indent,
  IndentBlock,
  Italic,
  InputTextView,
  Plugin,
  Paragraph,
  Strikethrough,
  Subscript,
  Superscript,
  Underline
} from '/assets/js/vendor/ckeditor5/ckeditor5.js';
import { createTemplateSelectorLockController } from '/assets/js/slides/slide-form-template-lock.js';

(function () {
  var DEFAULT_FONT_SIZE = 32;

  var dataElement = document.getElementById('slide-editor-data');
  if (!dataElement) {
    return;
  }

  var slideEditorData = {};
  try {
    slideEditorData = JSON.parse(dataElement.getAttribute('data-json') || dataElement.textContent || '{}') || {};
  } catch (_error) {
    slideEditorData = {};
  }

  var templates = Array.isArray(slideEditorData.templates) ? slideEditorData.templates : [];
  var rssFeeds = Array.isArray(slideEditorData.rssFeeds) ? slideEditorData.rssFeeds : [];
  var apiSources = Array.isArray(slideEditorData.apiSources) ? slideEditorData.apiSources : [];
  var existingTemplateId = slideEditorData.existingTemplateId !== undefined ? slideEditorData.existingTemplateId : null;
  var existingContent = slideEditorData.existingContent || {};
  var templateSelect = document.getElementById('template-select');
  var templateFields = document.getElementById('template-fields');
  var slideForm = document.getElementById('slide-form');
  var slideEditorShell = document.querySelector('.slide-editor-shell');
  var slideEditorSidebar = document.querySelector('.slide-editor-sidebar');
  var slidePreviewMeta = document.getElementById('slide-preview-meta');
  var slidePreviewStage = document.getElementById('slide-preview-stage');
  var slidePreviewCanvas = document.getElementById('slide-preview-canvas');
  var slidePreviewBackground = document.getElementById('slide-preview-background');
  var slidePreviewEmpty = document.getElementById('slide-preview-empty');
  var slidePreviewOverlay = document.getElementById('slide-preview-overlay');
  var openPreviewPopupButton = document.getElementById('open-preview-popup');
  var editorInstances = new Map();
  var submitting = false;
  var previewRenderFrame = 0;
  var previewPopupWindow = null;
  var previewPopupRenderFrame = 0;
  var currentPreviewCanvasWidth = 0;
  var currentPreviewCanvasHeight = 0;
  var sidebarSyncFrame = 0;
  var sidebarTopOffset = 16;
  var templateSelectorLock = createTemplateSelectorLockController(templateSelect);

  class FontSizeInputUI extends Plugin {
    static get pluginName() {
      return 'FontSizeInputUI';
    }

    init() {
      var editor = this.editor;
      var fontSizeCommand = editor.commands.get('fontSize');
      var plugin = this;

      if (!fontSizeCommand) {
        return;
      }

      editor.ui.componentFactory.add('fontSizeInput', function (locale) {
        var view = new InputTextView(locale);

        view.extendTemplate({
          attributes: {
            class: ['ck-font-size-input']
          }
        });

        view.set({
          placeholder: 'Font size',
          ariaLabel: 'Font size'
        });

        function getCurrentFontSizeValue() {
          var value = fontSizeCommand.value;
          if (value === null || value === undefined || value === '') {
            return String(DEFAULT_FONT_SIZE);
          }

          var parsed = Math.round(Number(String(value).replace(/[^0-9.]/g, '')));
          return Number.isFinite(parsed) && parsed > 0 ? String(parsed) : '';
        }

        function syncValue() {
          if (view.element && document.activeElement === view.element) {
            return;
          }

          view.value = getCurrentFontSizeValue();
        }

        view.on('render', function () {
          if (!view.element) {
            return;
          }

          view.element.type = 'text';
          view.element.inputMode = 'numeric';
          view.element.autocomplete = 'off';
          view.element.spellcheck = false;
          view.element.style.width = '3.5em';
          syncValue();
        });

        function applyValue() {
          if (!view.element) {
            return;
          }

          var size = Math.max(1, Math.round(Number(view.element.value || 0)));
          if (!size) {
            return;
          }

          editor.execute('fontSize', { value: size + 'px' });
        }

        view.on('input', applyValue);
        view.on('blur', applyValue);

        view.on('keydown', function (_eventInfo, domEvent) {
          if (domEvent.key === 'Enter') {
            domEvent.preventDefault();
            if (view.element) {
              view.element.blur();
            }
          }
        });

        plugin.listenTo(editor.model.document.selection, 'change:range', syncValue);
        plugin.listenTo(fontSizeCommand, 'change:value', syncValue);

        syncValue();

        return view;
      });
    }
  }

  class ForcePlainTextPaste extends Plugin {
    static get pluginName() {
      return 'ForcePlainTextPaste';
    }

    static get requires() {
      return [ClipboardPipeline];
    }

    init() {
      var editor = this.editor;
      var clipboardPipeline = editor.plugins.get(ClipboardPipeline);

      this.listenTo(clipboardPipeline, 'inputTransformation', function (_event, data) {
        var plainText = data.dataTransfer.getData('text/plain');
        data.content = editor.data.processor.toView(plainTextToHtml(plainText));
      }, { priority: 'high' });
    }
  }

  function escapeHtml(value) {
    return String(value ?? '')
      .replace(/&/g, '&')
      .replace(/</g, '&lt;')
      .replace(/>/g, '&gt;')
      .replace(/"/g, '&quot;')
      .replace(/'/g, '&#39;');
  }

  function plainTextToHtml(value) {
    var lines = String(value ?? '').replace(/\r\n?/g, '\n').split('\n');
    var paragraphs = [];
    var currentParagraph = [];

    lines.forEach(function (line) {
      if (line === '') {
        if (currentParagraph.length) {
          paragraphs.push('<p>' + currentParagraph.join('<br />') + '</p>');
          currentParagraph = [];
        } else {
          paragraphs.push('<p></p>');
        }
        return;
      }

      currentParagraph.push(escapeHtml(line));
    });

    if (currentParagraph.length) {
      paragraphs.push('<p>' + currentParagraph.join('<br />') + '</p>');
    }

    return paragraphs.length ? paragraphs.join('') : '<p></p>';
  }

  function getTemplateById(id) {
    return templates.find(function (item) { return Number(item.id) === Number(id); }) || null;
  }

  function getCurrentRegionValue(region) {
    var current = existingContent[region.region_key];
    return current && current.value !== undefined ? current.value : '';
  }

  function normalizeEditorData(value) {
    return String(value || '');
  }

  function requestPreviewRender() {
    if (previewRenderFrame) {
      return;
    }

    previewRenderFrame = window.requestAnimationFrame(function () {
      previewRenderFrame = 0;
      renderPreview();
    });
  }

  function getTemplateFieldControls() {
    return templateFields ? templateFields.querySelectorAll('input, textarea, select') : [];
  }

  function sanitizePreviewHtml(html) {
    var output = String(html || '');
    output = output.replace(/<script[\s\S]*?<\/script>/gi, '');
    output = output.replace(/<style[\s\S]*?<\/style>/gi, '');
    return output.replace(/<[^>]+>/g, function (tag) {
      var match = tag.match(/^<\s*(\/?)\s*([a-z0-9]+)([\s\S]*?)(\/?)>$/i);
      if (!match) {
        return '';
      }
      var closing = Boolean(match[1]);
      var name = String(match[2] || '').toLowerCase();
      var attrText = String(match[3] || '');
      var selfClosing = Boolean(match[4]) || name === 'br' || name === 'hr';
      var allowed = ['a', 'b', 'blockquote', 'br', 'code', 'div', 'em', 'figure', 'figcaption', 'h1', 'h2', 'h3', 'h4', 'h5', 'h6', 'hr', 'i', 'li', 'ol', 'p', 'pre', 'span', 'strong', 'sub', 'sup', 'table', 'tbody', 'td', 'th', 'thead', 'tr', 'u', 'ul'];
      if (allowed.indexOf(name) === -1) {
        return '';
      }
      if (closing) {
        return '</' + name + '>';
      }
      if (selfClosing) {
        return '<' + name + sanitizeTagAttributes(name, attrText) + '>';
      }
      return '<' + name + sanitizeTagAttributes(name, attrText) + '>';
    });
  }

  function sanitizeTagAttributes(tagName, attrText) {
    var allowedAttributes = {
      a: ['href', 'title', 'target', 'rel', 'class', 'style'],
      blockquote: ['class', 'style'],
      div: ['class', 'style'],
      figure: ['class', 'style'],
      figcaption: ['class', 'style'],
      h1: ['class', 'style'],
      h2: ['class', 'style'],
      h3: ['class', 'style'],
      h4: ['class', 'style'],
      h5: ['class', 'style'],
      h6: ['class', 'style'],
      li: ['class', 'style'],
      ol: ['class', 'style', 'start'],
      p: ['class', 'style'],
      pre: ['class', 'style'],
      span: ['class', 'style'],
      table: ['class', 'style'],
      td: ['class', 'style', 'colspan', 'rowspan'],
      th: ['class', 'style', 'colspan', 'rowspan', 'scope'],
      tr: ['class', 'style'],
      ul: ['class', 'style']
    };
    var allowed = allowedAttributes[tagName] || [];
    if (!allowed.length) {
      return '';
    }

    var attrs = [];
    attrText.replace(/([a-zA-Z0-9:-]+)(?:\s*=\s*("([^"]*)"|'([^']*)'|([^\s"'>/=`]+)))?/g, function (_full, key, _valuePart, doubleQuoted, singleQuoted, bareValue) {
      var lowerKey = String(key || '').toLowerCase();
      if (allowed.indexOf(lowerKey) === -1) {
        return '';
      }
      var value = doubleQuoted !== undefined ? doubleQuoted : singleQuoted !== undefined ? singleQuoted : bareValue !== undefined ? bareValue : '';
      if (lowerKey === 'href' && /^(?:\s*javascript:|\s*data:)/i.test(String(value || ''))) {
        return '';
      }
      if (lowerKey === 'style' && /(?:expression\s*\(|javascript:|url\s*\()/i.test(String(value || ''))) {
        return '';
      }
      if (lowerKey === 'target') {
        var targetValue = String(value || '').trim();
        if (targetValue === '_blank') {
          attrs.push(' target="_blank"');
          if (attrs.indexOf(' rel="noreferrer noopener"') === -1) {
            attrs.push(' rel="noreferrer noopener"');
          }
          return '';
        }
      }
      attrs.push(' ' + lowerKey + '="' + escapeHtml(value) + '"');
      return '';
    });

    return attrs.join('');
  }

  function renderPreviewListItem(item, tag) {
    if (item && typeof item === 'object') {
      var content = item.content !== undefined ? item.content : (item.text !== undefined ? item.text : item.value !== undefined ? item.value : '');
      var children = Array.isArray(item.items) ? item.items : Array.isArray(item.subItems) ? item.subItems : Array.isArray(item.children) ? item.children : [];
      var nested = children.length ? '<' + tag + ' style="list-style-type:' + (tag === 'ol' ? 'decimal' : 'disc') + ';padding-left:1.4em;">' + children.map(function (child) { return renderPreviewListItem(child, tag); }).join('') + '</' + tag + '>' : '';
      return '<li>' + sanitizePreviewHtml(content || '') + nested + '</li>';
    }
    return '<li>' + sanitizePreviewHtml(item || '') + '</li>';
  }

  function renderPreviewTable(data) {
    var rows = Array.isArray(data.content) ? data.content : Array.isArray(data.rows) ? data.rows : [];
    if (!rows.length) {
      return '';
    }
    var hasHeadings = Boolean(data.withHeadings);
    var body = rows.map(function (row, rowIndex) {
      var cells = Array.isArray(row) ? row : [];
      var cellTag = hasHeadings && rowIndex === 0 ? 'th' : 'td';
      var cellAttrs = cellTag === 'th' ? ' scope="col"' : '';
      return '<tr>' + cells.map(function (cell) {
        return '<' + cellTag + cellAttrs + '>' + sanitizePreviewHtml(cell || '') + '</' + cellTag + '>';
      }).join('') + '</tr>';
    }).join('');
    return '<table class="slide-preview-table">' + body + '</table>';
  }

  function renderPreviewBlock(block) {
    if (!block || !block.type || !block.data) {
      return '';
    }
    if (block.type === 'header') {
      var level = Math.max(1, Math.min(6, Number(block.data.level || 2)));
      return '<h' + level + '>' + sanitizePreviewHtml(block.data.text || '') + '</h' + level + '>';
    }
    if (block.type === 'list') {
      var tag = block.data.style === 'ordered' ? 'ol' : 'ul';
      var items = Array.isArray(block.data.items) ? block.data.items : [];
      return '<' + tag + ' style="list-style-type:' + (tag === 'ol' ? 'decimal' : 'disc') + ';padding-left:1.4em;">' + items.map(function (item) { return renderPreviewListItem(item, tag); }).join('') + '</' + tag + '>';
    }
    if (block.type === 'delimiter') {
      return '<hr />';
    }
    if (block.type === 'code') {
      return '<pre><code>' + sanitizePreviewHtml(block.data.code || '') + '</code></pre>';
    }
    if (block.type === 'table') {
      return renderPreviewTable(block.data);
    }
    if (block.type === 'paragraph') {
      return '<p>' + sanitizePreviewHtml(block.data.text || '') + '</p>';
    }
    return '';
  }

  function renderPreviewText(value) {
    var raw = String(value || '');
    if (!raw) {
      return '<div class="slide-preview-placeholder">Empty text</div>';
    }
    return sanitizePreviewHtml(raw);
  }

  function renderPreviewTextRegion(region, value, style, scale) {
    var fontFamily = style.font_family ? 'font-family:' + escapeHtml(style.font_family) + ';' : '';
    var color = style.font_color ? 'color:' + escapeHtml(style.font_color) + ';' : '';
    var fontSize = style.font_size ? 'font-size:' + Math.max(1, Math.round(Number(style.font_size))) + 'px;' : '';
    var width = Math.max(1, Math.round(Number(region && region.width ? region.width : 0) || 1));
    var height = Math.max(1, Math.round(Number(region && region.height ? region.height : 0) || 1));
    var wrapperStyle = 'width:' + width + 'px;height:' + height + 'px;overflow:hidden;' + fontFamily + fontSize + color;
    return '<div class="slide-preview-text-content" style="' + wrapperStyle + '">' + renderPreviewText(value) + '</div>';
  }

  function renderPreviewWebpageRegion(value) {
    var src = String(value || '').trim();
    if (!src) {
      return '<div class="slide-preview-placeholder">Webpage</div>';
    }
    return '<iframe class="slide-preview-webpage-frame" src="' + escapeHtml(src) + '" title="Webpage preview" loading="eager" referrerpolicy="no-referrer" scrolling="no"></iframe>';
  }

  function renderPreviewRtmpRegion(value, disableAudio) {
    var src = String(value || '').trim();
    var label = src ? 'RTMP' : 'RTMP stream';
    if (disableAudio) {
      label += ' (muted)';
    }
    return '<div class="slide-preview-placeholder">' + label + '</div>';
  }

  function renderPreviewHtmlRegion(value) {
    var html = String(value || '').trim();
    if (!html) {
      return '<div class="slide-preview-placeholder">HTML</div>';
    }
    return '<iframe class="slide-preview-html-frame" sandbox="" scrolling="no" srcdoc="<!doctype html><html><head><style>html,body{margin:0;width:100%;height:100%;overflow:hidden;background:transparent;}</style></head><body>' + escapeHtml(html) + '</body></html>" title="HTML preview" loading="eager"></iframe>';
  }

  function destroyEditors() {
    editorInstances.forEach(function (editor) {
      if (editor && typeof editor.destroy === 'function') {
        editor.destroy();
      }
    });
    editorInstances.clear();
  }

  function getEditorHiddenInput(regionId) {
    var card = templateFields.querySelector('[data-region-id="' + regionId + '"]');
    return card ? card.querySelector('input[type="hidden"][name="region_text_' + regionId + '"]') : null;
  }

  function getEditorFontSizeHiddenInput(regionId) {
    var card = templateFields.querySelector('[data-region-id="' + regionId + '"]');
    return card ? card.querySelector('input[name="region_font_size_' + regionId + '"]') : null;
  }

  function normalizeFontSizeValue(value) {
    var raw = String(value || '').trim().toLowerCase();
    if (/^\d+(?:\.\d+)?px$/.test(raw)) {
      return String(Math.max(1, Math.round(Number(raw.replace(/px$/, '')))));
    }
    if (/^\d+(?:\.\d+)?$/.test(raw)) {
      return String(Math.max(1, Math.round(Number(raw))));
    }
    return '';
  }

  function syncEditorFontSizeHidden(regionId, editor) {
    var fontSizeHidden = getEditorFontSizeHiddenInput(regionId);
    if (!fontSizeHidden || !editor) {
      return;
    }

    var fontSizeCommand = editor.commands.get('fontSize');
    fontSizeHidden.value = normalizeFontSizeValue(fontSizeCommand && fontSizeCommand.value) || String(DEFAULT_FONT_SIZE);
  }

  function getCurrentTextStyle(region) {
    var current = existingContent[region.region_key] || {};
    return {
      font_family: String(current.font_family || region.font_family || 'Arial').trim() || 'Arial',
      font_size: Math.max(8, Number(current.font_size || DEFAULT_FONT_SIZE)),
      font_color: String(current.font_color || region.font_color || '#000000').trim() || '#000000'
    };
  }

  function getRssFeedById(feedId) {
    var normalizedId = Number(feedId || 0);
    return rssFeeds.find(function (feed) {
      return Number(feed.id) === normalizedId;
    }) || null;
  }

  function getRssFieldList(feedId) {
    var feed = getRssFeedById(feedId);
    var sampleItem = feed && Array.isArray(feed.items) ? feed.items[0] : null;
    var sampleJson = sampleItem && sampleItem.itemJson && typeof sampleItem.itemJson === 'object' ? sampleItem.itemJson : null;

    function walkFields(value, prefix, output) {
      if (!value || typeof value !== 'object' || Array.isArray(value)) {
        return;
      }

      Object.keys(value).forEach(function (key) {
        if (key === 'rawXml') {
          return;
        }

        var nextPath = prefix ? prefix + '.' + key : key;
        var nextValue = value[key];
        if (nextValue && typeof nextValue === 'object' && !Array.isArray(nextValue)) {
          walkFields(nextValue, nextPath, output);
          return;
        }

        if (output.indexOf(nextPath) === -1) {
          output.push(nextPath);
        }
      });
    }

    var fields = [];
    walkFields(sampleJson, '', fields);
    return fields;
  }

  function updatePlaceholderChipList(card, fieldList, emptyLabel) {
    if (!card) {
      return;
    }

    var container = card.querySelector('[data-placeholder-chips]');
    if (!container) {
      return;
    }

    var chips = Array.isArray(fieldList) ? fieldList.map(function (field) {
      return '<span class="chip">{{' + escapeHtml(field) + '}}</span>';
    }).join('') : '';

    container.innerHTML = chips || '<span class="muted slide-image-file">' + escapeHtml(emptyLabel) + '</span>';
  }

  function updateRssPlaceholderChips(regionId, feedId) {
    var card = templateFields.querySelector('[data-region-id="' + regionId + '"]');
    updatePlaceholderChipList(card, getRssFieldList(feedId), 'No RSS fields available.');
  }

  function getCurrentRssConfig(region) {
    var current = existingContent[region.region_key] || {};
    var parsedItemNumber = Math.max(1, Number(current.item_number || 1));
    return {
      feed_id: current.feed_id === undefined || current.feed_id === null || current.feed_id === '' ? '' : Number(current.feed_id),
      item_number: Number.isFinite(parsedItemNumber) && parsedItemNumber > 0 ? parsedItemNumber : 1,
      value: current.value !== undefined ? current.value : ''
    };
  }

  function resolveRssPath(value, path) {
    var current = value;
    if (!path) {
      return current;
    }
    String(path).split('.').forEach(function (segment) {
      if (current === undefined || current === null) {
        current = '';
        return;
      }
      current = current[segment];
    });
    return current === undefined || current === null ? '' : current;
  }

  function normalizeRssVariableName(value) {
    var next = String(value || '').trim();
    return next || 'item';
  }

  function substituteRssVariables(html, item) {
    var source = String(html || '');
    return source.replace(/\{\{\s*([a-zA-Z0-9_]+)(?:\.([a-zA-Z0-9_.]+))?\s*\}\}/g, function (_match, tokenName, tokenPath) {
      if (!item || typeof item !== 'object') {
        return '';
      }
      var key = tokenName === 'item' && tokenPath ? tokenPath : tokenName;
      return escapeHtml(resolveRssPath(item, key || ''));
    });
  }

  function getRssItem(region, rssConfig) {
    var feed = getRssFeedById(rssConfig.feed_id);
    var items = feed && Array.isArray(feed.items) ? feed.items : [];
    var parsedItemNumber = Math.max(1, Number(rssConfig.item_number || 1));
    var index = Number.isFinite(parsedItemNumber) && parsedItemNumber > 0 ? parsedItemNumber - 1 : 0;
    return items[index] || null;
  }

  function getRssPreviewFallback(item) {
    if (!item || typeof item !== 'object') {
      return '<div class="slide-preview-placeholder">RSS item</div>';
    }

    var title = String(item.title || '').trim();
    var description = String(item.description || '').trim();
    var summary = [];
    if (title) {
      summary.push('<h3>' + escapeHtml(title) + '</h3>');
    }
    if (description) {
      summary.push('<p>' + sanitizePreviewHtml(description) + '</p>');
    }
    if (!summary.length) {
      return '<div class="slide-preview-placeholder">RSS item</div>';
    }
    return summary.join('');
  }

  function getApiSourceById(sourceId) {
    var normalizedId = Number(sourceId || 0);
    return apiSources.find(function (source) {
      return Number(source.id) === normalizedId;
    }) || null;
  }

  function getApiSourceItems(sourceId) {
    var source = getApiSourceById(sourceId);
    var responseJson = source && source.responseJson && typeof source.responseJson === 'object' ? source.responseJson : null;
    if (Array.isArray(responseJson)) {
      return responseJson;
    }
    if (responseJson && Array.isArray(responseJson.items)) {
      return responseJson.items;
    }
    if (responseJson && Array.isArray(responseJson.results)) {
      return responseJson.results;
    }
    if (responseJson && Array.isArray(responseJson.data)) {
      return responseJson.data;
    }
    return responseJson ? [responseJson] : [];
  }

  function getApiFieldList(sourceId) {
    var sampleItem = getApiSourceItems(sourceId)[0] || null;

    function walkFields(value, prefix, output) {
      if (!value || typeof value !== 'object' || Array.isArray(value)) {
        return;
      }

      Object.keys(value).forEach(function (key) {
        var nextPath = prefix ? prefix + '.' + key : key;
        var nextValue = value[key];
        if (nextValue && typeof nextValue === 'object' && !Array.isArray(nextValue)) {
          walkFields(nextValue, nextPath, output);
          return;
        }

        if (output.indexOf(nextPath) === -1) {
          output.push(nextPath);
        }
      });
    }

    var fields = [];
    walkFields(sampleItem && typeof sampleItem === 'object' ? sampleItem : null, '', fields);
    return fields;
  }

  function updateApiPlaceholderChips(regionId, sourceId) {
    var card = templateFields.querySelector('[data-region-id="' + regionId + '"]');
    updatePlaceholderChipList(card, getApiFieldList(sourceId), 'No JSON fields available.');
  }

  function getCurrentApiConfig(region) {
    var current = existingContent[region.region_key] || {};
    var parsedItemNumber = Math.max(1, Number(current.item_number || 1));
    return {
      source_id: current.source_id === undefined || current.source_id === null || current.source_id === '' ? '' : Number(current.source_id),
      item_number: Number.isFinite(parsedItemNumber) && parsedItemNumber > 0 ? parsedItemNumber : 1,
      value: current.value !== undefined ? current.value : ''
    };
  }

  function resolveApiPath(value, path) {
    var current = value;
    if (!path) {
      return current;
    }
    String(path).split('.').forEach(function (segment) {
      if (current === undefined || current === null) {
        current = '';
        return;
      }
      current = current[segment];
    });
    return current === undefined || current === null ? '' : current;
  }

  function substituteApiVariables(html, item) {
    var source = String(html || '');
    return source.replace(/\{\{\s*([a-zA-Z0-9_]+)(?:\.([a-zA-Z0-9_.]+))?\s*\}\}/g, function (_match, tokenName, tokenPath) {
      if (!item || typeof item !== 'object') {
        return '';
      }
      var key = tokenName === 'item' && tokenPath ? tokenPath : tokenName;
      return escapeHtml(resolveApiPath(item, key || ''));
    });
  }

  function getApiItem(sourceId, itemNumber) {
    var items = getApiSourceItems(sourceId);
    var parsedItemNumber = Math.max(1, Number(itemNumber || 1));
    var index = Number.isFinite(parsedItemNumber) && parsedItemNumber > 0 ? parsedItemNumber - 1 : 0;
    return items[index] || null;
  }

  function getApiPreviewFallback(item) {
    if (!item || typeof item !== 'object') {
      return '<div class="slide-preview-placeholder">API item</div>';
    }

    var title = String(item.title || item.name || '').trim();
    var description = String(item.description || item.summary || item.text || '').trim();
    var summary = [];
    if (title) {
      summary.push('<h3>' + escapeHtml(title) + '</h3>');
    }
    if (description) {
      summary.push('<p>' + sanitizePreviewHtml(description) + '</p>');
    }
    if (!summary.length) {
      return '<div class="slide-preview-placeholder">API item</div>';
    }
    return summary.join('');
  }

  function getTextStyleFromCard(_card, region) {
    return getCurrentTextStyle(region);
  }

  function getSelectedTemplate() {
    return templates.find(function (item) { return Number(item.id) === Number(templateSelect.value); }) || null;
  }

  function clearImagePreviewUrls() {
    templateFields.querySelectorAll('input[type="file"][name^="region_image_"]').forEach(function (input) {
      if (input.dataset.previewUrl) {
        URL.revokeObjectURL(input.dataset.previewUrl);
        delete input.dataset.previewUrl;
      }
    });
  }

  function getRegionBox(region, canvasWidth, canvasHeight) {
    return {
      left: Math.max(0, Math.round(Number(region.x || 0))),
      top: Math.max(0, Math.round(Number(region.y || 0))),
      width: Math.max(1, Math.round(Number(region.width || 0) || 1)),
      height: Math.max(1, Math.round(Number(region.height || 0) || 1))
    };
  }

  function getPreviewCanvasDimensions(template) {
    return {
      width: Math.max(1, Number(template && template.canvas_size_width ? template.canvas_size_width : 1920)),
      height: Math.max(1, Number(template && template.canvas_size_height ? template.canvas_size_height : 1080))
    };
  }

  function buildPreviewPopupHtml() {
    return '<!doctype html>' +
      '<html>' +
      '<head>' +
      '<meta charset="utf-8" />' +
      '<meta name="viewport" content="width=device-width, initial-scale=1" />' +
      '<title>Slide preview</title>' +
      '<style>' +
      'html,body{margin:0;width:100%;height:100%;overflow:hidden;background:#111;color:#fff;font-family:Arial,sans-serif;}' +
      '#popup-preview-stage{position:relative;width:100%;height:100%;overflow:hidden;background:#111;}' +
      '#popup-preview-canvas{position:absolute;top:0;left:0;transform-origin:top left;will-change:transform;}' +
      '#popup-preview-canvas,#popup-preview-stage{box-sizing:border-box;}' +
      '.slide-preview-background,.slide-preview-overlay,.slide-preview-empty{position:absolute;inset:0;}' +
      '.slide-preview-background{width:100%;height:100%;object-fit:contain;display:block;z-index:1;}' +
      '.slide-preview-overlay{z-index:2;}' +
      '.slide-preview-empty{display:flex;align-items:center;justify-content:center;padding:1rem;text-align:center;color:rgba(255,255,255,0.75);z-index:0;}' +
      '.slide-preview-region{position:absolute;overflow:hidden;box-sizing:border-box;}' +
      '.slide-preview-image{width:100%;height:100%;object-fit:contain;display:block;}' +
      '.slide-preview-placeholder{width:100%;height:100%;display:flex;align-items:center;justify-content:center;color:rgba(255,255,255,0.65);background:rgba(255,255,255,0.06);font-size:0.9rem;}' +
      '</style>' +
      '</head>' +
      '<body>' +
      '<div id="popup-preview-stage">' +
        '<div id="popup-preview-canvas"></div>' +
      '</div>' +
      '</body>' +
      '</html>';
  }

  function syncPopupPreview() {
    if (!previewPopupWindow || previewPopupWindow.closed) {
      previewPopupWindow = null;
      return;
    }

    var popupDocument = previewPopupWindow.document;
    if (!popupDocument) {
      return;
    }

    var popupStage = popupDocument.getElementById('popup-preview-stage');
    var popupCanvas = popupDocument.getElementById('popup-preview-canvas');
    var template = getSelectedTemplate();

    if (!popupStage || !popupCanvas) {
      if (previewPopupRenderFrame) {
        cancelAnimationFrame(previewPopupRenderFrame);
      }
      previewPopupRenderFrame = requestAnimationFrame(syncPopupPreview);
      return;
    }

    if (!template) {
      popupStage.style.backgroundColor = '#111111';
      popupCanvas.style.width = '';
      popupCanvas.style.height = '';
      popupCanvas.style.transform = '';
      popupCanvas.innerHTML = slidePreviewCanvas.innerHTML;
      var popupEmpty = popupCanvas.querySelector('#slide-preview-empty');
      var popupOverlay = popupCanvas.querySelector('#slide-preview-overlay');
      var popupBackground = popupCanvas.querySelector('#slide-preview-background');
      if (popupBackground) {
        popupBackground.style.display = 'none';
      }
      if (popupEmpty) {
        popupEmpty.style.display = 'flex';
        popupEmpty.textContent = 'Select a template to preview the slide.';
      }
      if (popupOverlay) {
        popupOverlay.innerHTML = '';
      }
      return;
    }

    var canvasWidth = currentPreviewCanvasWidth || Math.max(1, Number(template.canvas_size_width || 1920));
    var canvasHeight = currentPreviewCanvasHeight || Math.max(1, Number(template.canvas_size_height || 1080));
    popupStage.style.backgroundColor = template.background_color || '#111111';
    popupCanvas.style.width = canvasWidth + 'px';
    popupCanvas.style.height = canvasHeight + 'px';
    popupCanvas.innerHTML = slidePreviewCanvas.innerHTML;
    var popupBackground = popupCanvas.querySelector('#slide-preview-background');
    var popupEmpty = popupCanvas.querySelector('#slide-preview-empty');
    var popupOverlay = popupCanvas.querySelector('#slide-preview-overlay');

    if (popupBackground) {
      popupBackground.style.display = template.background_image_path ? 'block' : 'none';
      popupBackground.src = template.background_image_path || '';
    }
    if (popupEmpty) {
      popupEmpty.style.display = 'none';
    }

    var stageRect = popupStage.getBoundingClientRect();
    if (!stageRect.width || !stageRect.height) {
      if (previewPopupRenderFrame) {
        cancelAnimationFrame(previewPopupRenderFrame);
      }
      previewPopupRenderFrame = requestAnimationFrame(syncPopupPreview);
      return;
    }

    var scale = Math.min(stageRect.width / canvasWidth, stageRect.height / canvasHeight) || 1;
    popupCanvas.style.transform = 'translate3d(0, 0, 0) scale(' + scale + ')';
  }

  function openPreviewPopup() {
    if (previewPopupWindow && !previewPopupWindow.closed) {
      previewPopupWindow.focus();
      syncPopupPreview();
      return;
    }

    var popupWidth = 1280;
    var popupHeight = 900;
    var left = Math.max(0, Math.round((window.screen.width - popupWidth) / 2));
    var top = Math.max(0, Math.round((window.screen.height - popupHeight) / 2));
    var popupFeatures = [
      'popup=yes',
      'toolbar=no',
      'location=no',
      'menubar=no',
      'directories=no',
      'status=no',
      'scrollbars=yes',
      'resizable=yes',
      'width=' + popupWidth,
      'height=' + popupHeight,
      'left=' + left,
      'top=' + top
    ].join(',');

    previewPopupWindow = window.open('', 'slide-preview-popup', popupFeatures);
    if (!previewPopupWindow) {
      return;
    }

    previewPopupWindow.document.open();
    previewPopupWindow.document.write(buildPreviewPopupHtml());
    previewPopupWindow.document.close();
    previewPopupWindow.addEventListener('resize', syncPopupPreview);
    previewPopupWindow.focus();
    syncPopupPreview();
  }

  function syncSlideEditorSidebar() {
    sidebarSyncFrame = 0;

    if (!slideEditorShell || !slideEditorSidebar) {
      return;
    }

    if (window.matchMedia && window.matchMedia('(max-width: 1199.98px)').matches) {
      slideEditorSidebar.style.transform = '';
      return;
    }

    var shellRect = slideEditorShell.getBoundingClientRect();
    var sidebarHeight = slideEditorSidebar.offsetHeight;
    var shellTop = window.scrollY + shellRect.top;
    var shellBottom = shellTop + slideEditorShell.offsetHeight;
    var maxTranslate = Math.max(0, shellBottom - shellTop - sidebarHeight - sidebarTopOffset);
    var desiredTranslate = Math.max(0, Math.min(window.scrollY + sidebarTopOffset - shellTop, maxTranslate));

    slideEditorSidebar.style.transform = desiredTranslate ? 'translate3d(0, ' + desiredTranslate + 'px, 0)' : '';
  }

  function requestSidebarSync() {
    if (sidebarSyncFrame) {
      return;
    }

    sidebarSyncFrame = window.requestAnimationFrame(syncSlideEditorSidebar);
  }

  function renderPreview() {
    var template = getSelectedTemplate();
    if (!template) {
      slidePreviewMeta.textContent = '--';
      slidePreviewBackground.style.display = 'none';
      slidePreviewEmpty.style.display = 'flex';
      slidePreviewEmpty.textContent = 'Select a template to preview the slide.';
      slidePreviewCanvas.style.width = '';
      slidePreviewCanvas.style.height = '';
      slidePreviewOverlay.innerHTML = '';
      slidePreviewOverlay.style.width = '';
      slidePreviewOverlay.style.height = '';
      slidePreviewOverlay.style.transform = '';
      slidePreviewStage.style.aspectRatio = '16 / 9';
      slidePreviewStage.style.backgroundColor = '#111111';
      return;
    }

    var canvasSize = getPreviewCanvasDimensions(template);
    var canvasWidth = canvasSize.width;
    var canvasHeight = canvasSize.height;
    currentPreviewCanvasWidth = canvasWidth;
    currentPreviewCanvasHeight = canvasHeight;
    slidePreviewStage.style.aspectRatio = canvasWidth + ' / ' + canvasHeight;
    slidePreviewStage.style.backgroundColor = template.background_color || '#111111';
    slidePreviewMeta.textContent = canvasWidth + 'x' + canvasHeight;
    if (!(template.regions || []).length) {
      slidePreviewEmpty.style.display = 'flex';
      slidePreviewEmpty.textContent = 'This template has no regions.';
      slidePreviewBackground.style.display = template.background_image_path ? 'block' : 'none';
      slidePreviewBackground.src = template.background_image_path || '';
      slidePreviewCanvas.style.width = canvasWidth + 'px';
      slidePreviewCanvas.style.height = canvasHeight + 'px';
      slidePreviewCanvas.style.transform = '';
      slidePreviewOverlay.innerHTML = '';
      slidePreviewOverlay.style.width = '';
      slidePreviewOverlay.style.height = '';
      slidePreviewOverlay.style.transform = '';
      return;
    }

    slidePreviewEmpty.style.display = 'none';
    slidePreviewBackground.style.display = template.background_image_path ? 'block' : 'none';
    slidePreviewBackground.src = template.background_image_path || '';

    var stageRect = slidePreviewStage.getBoundingClientRect();
    if (!stageRect.width || !stageRect.height) {
      if (previewRenderFrame) {
        cancelAnimationFrame(previewRenderFrame);
      }
      previewRenderFrame = requestAnimationFrame(function () {
        previewRenderFrame = 0;
        renderPreview();
      });
      return;
    }
    var scale = Math.min(stageRect.width / canvasWidth, stageRect.height / canvasHeight) || 1;
    slidePreviewCanvas.style.width = canvasWidth + 'px';
    slidePreviewCanvas.style.height = canvasHeight + 'px';
    slidePreviewCanvas.style.transform = 'translate3d(0, 0, 0) scale(' + scale + ')';
    slidePreviewCanvas.style.transformOrigin = 'top left';
    var regions = template.regions || [];
    slidePreviewOverlay.innerHTML = regions.map(function (region) {
      var box = getRegionBox(region, canvasWidth, canvasHeight);
      var card = templateFields.querySelector('[data-region-id="' + region.id + '"]');
      var hiddenInput = card && card.querySelector('input[type="hidden"][name="region_text_' + region.id + '"]');
      var htmlInput = card && card.querySelector('textarea[name="region_html_' + region.id + '"]');
      var imageHidden = card && card.querySelector('input[type="hidden"][name="existing_region_image_' + region.id + '"]');
      var imageFileInput = card && card.querySelector('input[type="file"][name="region_image_' + region.id + '"]');
      var webpageInput = card && card.querySelector('input[type="url"][name="region_webpage_' + region.id + '"]');
      var rtmpInput = card && card.querySelector('input[type="url"][name="region_rtmp_' + region.id + '"]');
      var disableAudioInput = card && card.querySelector('input[type="checkbox"][name="region_disable_audio_' + region.id + '"]');
      var rssFeedInput = card && card.querySelector('select[name="region_rss_feed_id_' + region.id + '"]');
      var rssItemInput = card && card.querySelector('input[name="region_rss_item_number_' + region.id + '"]');
      var apiSourceInput = card && card.querySelector('select[name="region_api_source_id_' + region.id + '"]');
      var apiItemInput = card && card.querySelector('input[name="region_api_item_number_' + region.id + '"]');
      var existingRtmp = existingContent[region.region_key] || {};
      var existingRss = existingContent[region.region_key] || {};
      var existingApi = existingContent[region.region_key] || {};
      var value = region.region_type === 'image'
        ? ((imageFileInput && imageFileInput.dataset.previewUrl) ? imageFileInput.dataset.previewUrl : (imageHidden ? imageHidden.value : ''))
        : region.region_type === 'webpage'
          ? (webpageInput ? webpageInput.value : '')
          : region.region_type === 'rtmp'
            ? (rtmpInput ? rtmpInput.value : '')
          : region.region_type === 'rss'
            ? (hiddenInput ? hiddenInput.value : '')
          : region.region_type === 'api'
            ? (hiddenInput ? hiddenInput.value : '')
          : region.region_type === 'html'
            ? (htmlInput ? htmlInput.value : '')
          : (hiddenInput ? hiddenInput.value : '');
      var style = region.region_type === 'image'
        ? null
        : region.region_type === 'webpage'
          ? null
          : region.region_type === 'rtmp'
            ? null
          : region.region_type === 'html'
            ? null
          : getTextStyleFromCard(card, region);
      var content = region.region_type === 'image'
        ? (value ? '<img class="slide-preview-image" src="' + escapeHtml(value) + '" alt="" />' : '<div class="slide-preview-placeholder">Image</div>')
        : region.region_type === 'webpage'
          ? renderPreviewWebpageRegion(value)
          : region.region_type === 'rtmp'
            ? renderPreviewRtmpRegion(value, disableAudioInput ? disableAudioInput.checked : (existingRtmp.disable_audio === undefined ? true : Boolean(existingRtmp.disable_audio)))
          : region.region_type === 'rss'
            ? (function () {
              var item = getRssItem(region, {
                feed_id: rssFeedInput ? rssFeedInput.value : existingRss.feed_id,
                item_number: rssItemInput ? rssItemInput.value : existingRss.item_number
              });
              var rendered = substituteRssVariables(value, item);
              return renderPreviewTextRegion(region, rendered ? rendered : getRssPreviewFallback(item), style, scale);
            }())
          : region.region_type === 'api'
            ? (function () {
              var item = getApiItem(apiSourceInput ? apiSourceInput.value : existingApi.source_id, apiItemInput ? apiItemInput.value : existingApi.item_number);
              var rendered = substituteApiVariables(value, item);
              return renderPreviewTextRegion(region, rendered ? rendered : getApiPreviewFallback(item), style, scale);
            }())
          : region.region_type === 'html'
            ? renderPreviewHtmlRegion(value)
          : renderPreviewTextRegion(region, value, style, scale);
      var selected = region.region_type === 'image'
        ? ' slide-preview-image-region'
        : region.region_type === 'webpage'
          ? ' slide-preview-webpage-region'
          : region.region_type === 'rtmp'
            ? ' slide-preview-rtmp-region'
          : region.region_type === 'rss'
            ? ' slide-preview-rss-region'
          : region.region_type === 'api'
            ? ' slide-preview-api-region'
          : region.region_type === 'html'
            ? ' slide-preview-html-region'
          : ' slide-preview-text-region';
      return '<div class="slide-preview-region' + selected + '" style="left:' + box.left + 'px;top:' + box.top + 'px;width:' + box.width + 'px;height:' + box.height + 'px;">' + content + '</div>';
    }).join('');

    syncPopupPreview();
  }

  function renderTextRegion(region) {
    var current = getCurrentRegionValue(region);
    return '' +
      '<div class="card card-outline card-secondary admin-form-card template-field-card mb-3" data-region-id="' + region.id + '">' +
        '<div class="card-header template-field-head">' +
          '<strong>' + escapeHtml(region.label) + '</strong>' +
          '<div class="template-field-actions">' +
            '<button type="button" class="btn btn-sm btn-outline-secondary template-editor-toggle" data-toggle-editor-height="' + region.id + '">Expand</button>' +
            '<span class="chip">Text</span>' +
          '</div>' +
        '</div>' +
        '<div class="card-body p-3 d-grid gap-3">' +
          '<div class="ckeditor-holder" data-region-id="' + region.id + '">' +
            '<textarea class="ckeditor-source" rows="10">' + escapeHtml(current) + '</textarea>' +
          '</div>' +
          '<input type="hidden" name="region_font_size_' + region.id + '" value="' + escapeHtml(getCurrentTextStyle(region).font_size) + '" />' +
          '<input type="hidden" name="region_text_' + region.id + '" value="' + escapeHtml(current) + '" />' +
        '</div>' +
      '</div>';
  }

  function renderRssRegion(region) {
    var current = existingContent[region.region_key] || {};
    var config = getCurrentRssConfig(region);
    var fieldList = getRssFieldList(config.feed_id);
    var placeholderChips = fieldList.map(function (field) {
      return '<span class="chip">{{' + escapeHtml(field) + '}}</span>';
    }).join('');
    var feedOptions = rssFeeds.map(function (feed) {
      var selected = Number(feed.id) === Number(config.feed_id) ? ' selected' : '';
      return '<option value="' + escapeHtml(feed.id) + '"' + selected + '>' + escapeHtml(feed.name || ('Feed ' + feed.id)) + '</option>';
    }).join('');
    return '' +
      '<div class="card card-outline card-secondary admin-form-card template-field-card mb-3" data-region-id="' + region.id + '">' +
        '<div class="card-header template-field-head">' +
          '<strong>' + escapeHtml(region.label) + '</strong>' +
          '<div class="template-field-actions">' +
            '<button type="button" class="btn btn-sm btn-outline-secondary template-editor-toggle" data-toggle-editor-height="' + region.id + '">Expand</button>' +
            '<span class="chip">RSS</span>' +
          '</div>' +
        '</div>' +
        '<div class="card-body p-3 d-grid gap-3">' +
          '<div class="ckeditor-holder" data-region-id="' + region.id + '">' +
            '<textarea class="ckeditor-source" rows="10">' + escapeHtml(current.value !== undefined ? current.value : '') + '</textarea>' +
          '</div>' +
          '<div class="row g-3 align-items-end">' +
            '<div class="col-12 col-md-8">' +
              '<label class="form-label" for="region_rss_feed_id_' + region.id + '">RSS feed</label>' +
                '<select name="region_rss_feed_id_' + region.id + '" class="form-select">' +
                  '<option value="">Select a feed</option>' +
                  feedOptions +
                '</select>' +
            '</div>' +
            '<div class="col-6 col-md-4">' +
              '<label class="form-label" for="region_rss_item_number_' + region.id + '">Entry number</label>' +
                '<input type="number" min="1" step="1" name="region_rss_item_number_' + region.id + '" class="form-control" value="' + escapeHtml(config.item_number) + '" />' +
            '</div>' +
          '</div>' +
          '<input type="hidden" name="region_font_size_' + region.id + '" value="' + escapeHtml(getCurrentTextStyle(region).font_size) + '" />' +
          '<input type="hidden" name="region_text_' + region.id + '" value="' + escapeHtml(current.value !== undefined ? current.value : '') + '" />' +
          '<div class="muted slide-image-file">Use placeholders like {{title}} or {{link}}. Available placeholders:</div>' +
          '<div class="d-flex flex-wrap gap-2" data-placeholder-chips>' + (placeholderChips || '<span class="muted slide-image-file">No RSS fields available.</span>') + '</div>' +
        '</div>' +
      '</div>';
  }

    function renderApiRegion(region) {
      var current = existingContent[region.region_key] || {};
      var config = getCurrentApiConfig(region);
      var fieldList = getApiFieldList(config.source_id);
      var placeholderChips = fieldList.map(function (field) {
        return '<span class="chip">{{' + escapeHtml(field) + '}}</span>';
      }).join('');
      var sourceOptions = apiSources.map(function (source) {
        var selected = Number(source.id) === Number(config.source_id) ? ' selected' : '';
        return '<option value="' + escapeHtml(source.id) + '"' + selected + '>' + escapeHtml(source.name || ('Source ' + source.id)) + '</option>';
      }).join('');
      return '' +
        '<div class="card card-outline card-secondary admin-form-card template-field-card mb-3" data-region-id="' + region.id + '">' +
          '<div class="card-header template-field-head">' +
            '<strong>' + escapeHtml(region.label) + '</strong>' +
            '<div class="template-field-actions">' +
              '<button type="button" class="btn btn-sm btn-outline-secondary template-editor-toggle" data-toggle-editor-height="' + region.id + '">Expand</button>' +
              '<span class="chip">API</span>' +
            '</div>' +
          '</div>' +
          '<div class="card-body p-3 d-grid gap-3">' +
            '<div class="ckeditor-holder" data-region-id="' + region.id + '">' +
              '<textarea class="ckeditor-source" rows="10">' + escapeHtml(current.value !== undefined ? current.value : '') + '</textarea>' +
            '</div>' +
            '<div class="row g-3 align-items-end">' +
              '<div class="col-12 col-md-8">' +
                '<label class="form-label" for="region_api_source_id_' + region.id + '">API source</label>' +
                  '<select name="region_api_source_id_' + region.id + '" class="form-select">' +
                    '<option value="">Select a source</option>' +
                    sourceOptions +
                  '</select>' +
              '</div>' +
              '<div class="col-6 col-md-4">' +
                '<label class="form-label" for="region_api_item_number_' + region.id + '">Item number</label>' +
                  '<input type="number" min="1" step="1" name="region_api_item_number_' + region.id + '" class="form-control" value="' + escapeHtml(config.item_number) + '" />' +
              '</div>' +
            '</div>' +
            '<input type="hidden" name="region_font_size_' + region.id + '" value="' + escapeHtml(getCurrentTextStyle(region).font_size) + '" />' +
            '<input type="hidden" name="region_text_' + region.id + '" value="' + escapeHtml(current.value !== undefined ? current.value : '') + '" />' +
            '<div class="muted slide-image-file">Use placeholders like {{title}} or {{description}}. Available placeholders:</div>' +
            '<div class="d-flex flex-wrap gap-2" data-placeholder-chips>' + (placeholderChips || '<span class="muted slide-image-file">No JSON fields available.</span>') + '</div>' +
          '</div>' +
        '</div>';
    }

  function renderWebpageRegion(region) {
    var current = getCurrentRegionValue(region);
    return '' +
        '<div class="card card-outline card-secondary admin-form-card template-field-card mb-3" data-region-id="' + region.id + '">' +
          '<div class="card-header template-field-head">' +
            '<strong>' + escapeHtml(region.label) + '</strong>' +
            '<span class="chip">Webpage</span>' +
          '</div>' +
          '<div class="card-body p-3 d-grid gap-3">' +
            '<label style="display:block;">Webpage URL' +
              '<input type="url" name="region_webpage_' + region.id + '" class="form-control" value="' + escapeHtml(current) + '" placeholder="https://example.com" />' +
            '</label>' +
            '<div class="muted slide-image-file">The webpage will be loaded in an iframe.</div>' +
          '</div>' +
        '</div>';
  }

  function renderRtmpRegion(region) {
    var current = existingContent[region.region_key] || {};
    var url = String(current.value || '').trim();
    var disableAudio = current.disable_audio === undefined ? true : Boolean(current.disable_audio);
    return '' +
        '<div class="card card-outline card-secondary admin-form-card template-field-card mb-3" data-region-id="' + region.id + '">' +
          '<div class="card-header template-field-head">' +
            '<strong>' + escapeHtml(region.label) + '</strong>' +
            '<span class="chip">RTMP</span>' +
          '</div>' +
          '<div class="card-body p-3 d-grid gap-3">' +
            '<label style="display:block;">RTMP URL' +
              '<input type="url" name="region_rtmp_' + region.id + '" class="form-control" value="' + escapeHtml(url) + '" placeholder="rtmp://example.com/live/stream" />' +
            '</label>' +
            '<label class="form-check m-0">' +
              '<input class="form-check-input" type="checkbox" name="region_disable_audio_' + region.id + '" value="1"' + (disableAudio ? ' checked' : '') + ' />' +
              '<span class="form-check-label">Disable audio</span>' +
            '</label>' +
            '<div class="muted slide-image-file">Player controls stay hidden and the stream is not interactive.</div>' +
          '</div>' +
        '</div>';
  }

  function renderHtmlRegion(region) {
    var current = getCurrentRegionValue(region);
    return '' +
        '<div class="card card-outline card-secondary admin-form-card template-field-card mb-3" data-region-id="' + region.id + '">' +
          '<div class="card-header template-field-head">' +
            '<strong>' + escapeHtml(region.label) + '</strong>' +
            '<span class="chip">HTML</span>' +
          '</div>' +
          '<div class="card-body p-3 d-grid gap-3">' +
            '<label style="display:block;">HTML content' +
              '<textarea name="region_html_' + region.id + '" class="form-control" rows="10" placeholder="<div>Hello</div>">' + escapeHtml(current) + '</textarea>' +
            '</label>' +
            '<div class="muted slide-image-file">HTML is rendered in a sandboxed iframe preview.</div>' +
          '</div>' +
        '</div>';
  }

  function renderImageRegion(region) {
    var current = getCurrentRegionValue(region);
    return '' +
      '<div class="card card-outline card-secondary admin-form-card template-field-card mb-3" data-region-id="' + region.id + '">' +
        '<div class="card-header template-field-head">' +
          '<strong>' + escapeHtml(region.label) + '</strong>' +
          '<span class="chip">Image</span>' +
        '</div>' +
        '<div class="card-body p-3 d-grid gap-3">' +
          '<label style="display:block;">Image file' +
            '<input type="file" name="region_image_' + region.id + '" class="form-control" accept="image/*" />' +
          '</label>' +
          '<input type="hidden" name="existing_region_image_' + region.id + '" value="' + escapeHtml(current) + '" />' +
          (current
            ? '<div class="muted slide-image-file">Current: <a href="' + escapeHtml(current) + '" target="_blank" rel="noreferrer">' + escapeHtml(current) + '</a></div>'
            : '<div class="muted slide-image-file">No image selected.</div>') +
        '</div>' +
      '</div>';
  }

  function renderTemplate() {
    templateSelectorLock.reset();
    clearImagePreviewUrls();
    destroyEditors();
    var template = getTemplateById(templateSelect.value);
    if (!template) {
      templateFields.innerHTML = '';
      requestPreviewRender();
      return;
    }

    templateFields.innerHTML = template.regions.length ? template.regions.map(function (region) {
      if (region.region_type === 'image') {
        return renderImageRegion(region);
      }
      if (region.region_type === 'webpage') {
        return renderWebpageRegion(region);
      }
      if (region.region_type === 'rtmp') {
        return renderRtmpRegion(region);
      }
      if (region.region_type === 'rss') {
        return renderRssRegion(region);
      }
      if (region.region_type === 'api') {
        return renderApiRegion(region);
      }
      if (region.region_type === 'html') {
        return renderHtmlRegion(region);
      }
      return renderTextRegion(region);
    }).join('') : '<div class="muted">This template has no regions.</div>';

    templateFields.querySelectorAll('.ckeditor-holder').forEach(function (holder) {
      var regionId = holder.getAttribute('data-region-id');
      var source = holder.querySelector('.ckeditor-source');
      var hidden = getEditorHiddenInput(regionId);
      var editorConfig = {
        licenseKey: 'GPL',
        placeholder: 'Write content...',
        toolbar: {
          items: [
            'undo',
            'redo',
            '|',
            'fontSizeInput',
            'fontFamily',
            'fontColor',
            'fontBackgroundColor',
            '|',
            'bold',
            'italic',
            'underline',
            'strikethrough',
            'subscript',
            'superscript',
            '|',
            'horizontalLine',
            'blockQuote',
            '|',
            'alignment',
            '|',
            'outdent',
            'indent'
          ],
          shouldNotGroupWhenFull: false
        },
        plugins: [
          Alignment,
          BlockQuote,
          Bold,
          Essentials,
          ForcePlainTextPaste,
          FontBackgroundColor,
          FontColor,
          FontFamily,
          FontSize,
          FontSizeInputUI,
          HorizontalLine,
          Indent,
          IndentBlock,
          Italic,
          Paragraph,
          Strikethrough,
          Subscript,
          Superscript,
          Underline
        ],
        fontFamily: {
          supportAllValues: true
        },
        fontSize: {
          options: [20, 24, 28, 32, 36, 40, 44],
          supportAllValues: true
        },
        initialData: normalizeEditorData((source && source.value) || (hidden ? hidden.value : ''))
      };

      ClassicEditor.create(source || holder, editorConfig).then(function (editor) {
        editorInstances.set(regionId, editor);
        var fontSizeCommand = editor.commands.get('fontSize');
        if (hidden) {
          hidden.value = editor.getData();
        }
        syncEditorFontSizeHidden(regionId, editor);
        if (fontSizeCommand) {
          fontSizeCommand.on('change:value', function () {
            syncEditorFontSizeHidden(regionId, editor);
          });
        }
        editor.model.document.on('change:data', function () {
          var instance = editorInstances.get(regionId);
          if (instance !== editor) {
            return;
          }
          if (hidden) {
            hidden.value = editor.getData();
          }
          templateSelectorLock.markEdited();
          requestPreviewRender();
        });
        requestPreviewRender();
      }).catch(function (error) {
        console.error('Failed to initialize CKEditor.', error);
      });
    });

    templateFields.querySelectorAll('[data-toggle-editor-height]').forEach(function (button) {
      button.addEventListener('click', function () {
        var regionId = button.getAttribute('data-toggle-editor-height');
        var card = templateFields.querySelector('[data-region-id="' + regionId + '"]');
        if (!card) {
          return;
        }

        var expanded = card.classList.toggle('is-expanded');
        button.textContent = expanded ? 'Collapse' : 'Expand';
      });
    });

    templateFields.querySelectorAll('input[type="file"][name^="region_image_"]').forEach(function (input) {
      input.addEventListener('change', function () {
        if (input.dataset.previewUrl) {
          URL.revokeObjectURL(input.dataset.previewUrl);
          delete input.dataset.previewUrl;
        }
        if (input.files && input.files.length) {
          input.dataset.previewUrl = URL.createObjectURL(input.files[0]);
        }
        templateSelectorLock.markEdited();
        requestPreviewRender();
      });
    });
    templateFields.querySelectorAll('select[name^="region_rss_feed_id_"], input[name^="region_rss_item_number_"], select[name^="region_api_source_id_"], input[name^="region_api_item_number_"]').forEach(function (input) {
      input.addEventListener('input', function () {
        var regionId = input.name.replace(/^region_(?:rss_feed_id|rss_item_number|api_source_id|api_item_number)_/, '');
        if (input.name.indexOf('region_rss_') === 0) {
          var rssFeed = input.name.indexOf('region_rss_feed_id_') === 0 ? input.value : (templateFields.querySelector('select[name="region_rss_feed_id_' + regionId + '"]') || {}).value;
          updateRssPlaceholderChips(regionId, rssFeed);
        }
        if (input.name.indexOf('region_api_') === 0) {
          var apiSource = input.name.indexOf('region_api_source_id_') === 0 ? input.value : (templateFields.querySelector('select[name="region_api_source_id_' + regionId + '"]') || {}).value;
          updateApiPlaceholderChips(regionId, apiSource);
        }
        templateSelectorLock.markEdited();
        requestPreviewRender();
      });
      input.addEventListener('change', function () {
        var regionId = input.name.replace(/^region_(?:rss_feed_id|rss_item_number|api_source_id|api_item_number)_/, '');
        if (input.name.indexOf('region_rss_') === 0) {
          var rssFeed = input.name.indexOf('region_rss_feed_id_') === 0 ? input.value : (templateFields.querySelector('select[name="region_rss_feed_id_' + regionId + '"]') || {}).value;
          updateRssPlaceholderChips(regionId, rssFeed);
        }
        if (input.name.indexOf('region_api_') === 0) {
          var apiSource = input.name.indexOf('region_api_source_id_') === 0 ? input.value : (templateFields.querySelector('select[name="region_api_source_id_' + regionId + '"]') || {}).value;
          updateApiPlaceholderChips(regionId, apiSource);
        }
        templateSelectorLock.markEdited();
        requestPreviewRender();
      });
    });

    if (existingTemplateId) {
      templateSelectorLock.arm();
      templateSelectorLock.markEdited();
      requestPreviewRender();
      return;
    }

    window.requestAnimationFrame(function () {
      templateSelectorLock.arm();
    });
    requestPreviewRender();
  }

  slideForm.addEventListener('submit', async function (event) {
    if (submitting) {
      return;
    }
    event.preventDefault();
    var slideFormUrl = new URL(slideForm.action, window.location.href);
    var isCreateForm = slideFormUrl.pathname === '/slides';
    var submitterValue = event.submitter && event.submitter.name === 'save_action'
      ? String(event.submitter.value || '').trim().toLowerCase()
      : '';
    var saves = Array.prototype.map.call(templateFields.querySelectorAll('.ckeditor-holder'), function (holder) {
      var regionId = holder.getAttribute('data-region-id');
      var editor = editorInstances.get(regionId);
      var hidden = getEditorHiddenInput(regionId);
      if (!editor || !hidden) {
        return Promise.resolve();
      }
      syncEditorFontSizeHidden(regionId, editor);
      hidden.value = editor.getData();
      return Promise.resolve();
    });
    submitting = true;
    try {
      await Promise.all(saves);
      var formData = new FormData(slideForm);
      if (event.submitter && event.submitter.name) {
        formData.set(event.submitter.name, event.submitter.value || '');
      }
      var response = await fetch(slideForm.action, {
        method: (slideForm.method || 'POST').toUpperCase(),
        headers: {
          'X-Requested-With': 'XMLHttpRequest',
          'Accept': 'text/html, application/json, text/plain, */*'
        },
        body: formData,
        credentials: 'same-origin'
      });

      if (!response.ok) {
        throw new Error(await response.text() || 'Unable to save slide.');
      }

      if (submitterValue === 'close' || submitterValue === 'new') {
        var redirectUrl = submitterValue === 'close'
          ? String(slideForm.dataset.asyncSaveCloseUrl || response.url || slideForm.action)
          : String(slideForm.dataset.asyncSaveNewUrl || response.url || slideForm.action);
        window.location.replace(redirectUrl);
        return;
      }

      if (isCreateForm) {
        try {
          if (response.url) {
            window.location.replace(response.url);
            return;
          }
        } catch (_error) {
          // Fall through and show a toast if the redirect URL cannot be resolved.
        }
        slideForm.dataset.dirty = 'false';
        showToast('Saved slide.', 'success');
        return;
      }

      var responseText = await response.text();
      var savedMessage = '';
      try {
        var doc = new DOMParser().parseFromString(responseText || '', 'text/html');
        var toastBody = doc.querySelector('.toast-body');
        if (toastBody && toastBody.textContent) {
          savedMessage = toastBody.textContent.trim();
        }
      } catch (_error) {
        savedMessage = '';
      }

      showToast(savedMessage || 'Saved slide.', 'success');
      slideForm.dataset.dirty = 'false';
    } catch (error) {
      if (typeof showToast === 'function') {
        var variant = Number(error && error.status) >= 400 && Number(error && error.status) < 500 ? 'warning' : 'danger';
        showToast(error && error.message ? error.message : 'Unable to save slide.', variant);
      } else {
        window.alert(error && error.message ? error.message : 'Unable to save slide.');
      }
    } finally {
      submitting = false;
    }
  });

  slideForm.addEventListener('input', function () {
    slideForm.dataset.dirty = 'true';
  }, true);

  slideForm.addEventListener('change', function () {
    slideForm.dataset.dirty = 'true';
  }, true);

  if (openPreviewPopupButton) {
    openPreviewPopupButton.addEventListener('click', function () {
      openPreviewPopup();
    });
  }

  templateSelect.addEventListener('change', renderTemplate);
  templateFields.addEventListener('change', function () {
    templateSelectorLock.markEdited();
    requestPreviewRender();
  });
  templateFields.addEventListener('input', function () {
    templateSelectorLock.markEdited();
    requestPreviewRender();
  });
  if (existingTemplateId) {
    templateSelect.value = String(existingTemplateId);
  }
  renderTemplate();
  if (window.ResizeObserver && slidePreviewStage) {
    var previewResizeObserver = new ResizeObserver(function () {
      requestPreviewRender();
    });
    previewResizeObserver.observe(slidePreviewStage);
  }
  requestSidebarSync();
  window.addEventListener('scroll', requestSidebarSync, { passive: true });
  window.addEventListener('resize', requestPreviewRender);
  window.addEventListener('resize', requestSidebarSync);
  window.addEventListener('beforeunload', function () {
    if (previewPopupWindow && !previewPopupWindow.closed) {
      previewPopupWindow.close();
    }
  });
})();