+ `;
+ $libraryList.append(itemHtml);
+ });
+
+ // --- Initialize Draggable on newly rendered library items ---
+ initializeDraggable();
+ // --- --- --- --- ---
+
+ }
+
+ /**
+ * Initializes draggable functionality on library items.
+ */
+ function initializeDraggable() {
+ $libraryList.find('.library-question-item').draggable({
+ connectToSortable: '#current-assessment-questions',
+ helper: 'clone',
+ revert: 'invalid',
+ start: function(event, ui) {
+ ui.helper.css('width', $(this).width()); // Maintain width during drag
+ ui.helper.addClass('dragging-helper'); // Optional: for styling the helper
+ },
+ stop: function(event, ui) {
+ ui.helper.removeClass('dragging-helper');
+ }
+ });
+ }
+
+
+ /**
+ * Helper to find question data in the currently rendered library list.
+ * Note: This is inefficient if the library is paginated. A better approach
+ * would be to store added question details in a separate object.
+ * @param {number} questionId
+ * @returns {object|null} Object with title, cost etc. or null if not found in current view.
+ */
+ function findQuestionDataInLibrary(questionId) {
+ const $item = $libraryList.find(`.library-question-item[data-question-id="${questionId}"]`);
+ if ($item.length) {
+ return {
+ id: questionId,
+ title: $item.find('strong').text(),
+ cost: $item.data('cost')
+ // Extract type if needed
+ };
+ }
+ return null; // Not found in the current library view
+ }
+
+
+ /**
+ * Updates the 'Add' buttons in the library list, disabling those for questions
+ * already present in the current assessment.
+ */
+ function updateLibraryButtons() {
+ $libraryList.find('.add-question-to-assessment').each(function() {
+ const $button = $(this);
+ const questionId = $button.data('question-id');
+ if (currentAssessmentQuestions.includes(questionId)) {
+ $button.prop('disabled', true).text('Added'); // TODO: Localize
+ } else {
+ $button.prop('disabled', false).text('Add'); // TODO: Localize
+ }
+ });
+ }
+
+ /**
+ * Saves the current assessment (title and question IDs) via AJAX.
+ */
+ function saveAssessment() {
+ console.log('Saving assessment...');
+ $saveSpinner.css('visibility', 'visible');
+ $saveButton.prop('disabled', true);
+ $saveStatus.empty().removeClass('success error');
+
+ const assessmentTitle = $assessmentTitleInput.val();
+ if (!assessmentTitle) {
+ alert('Assessment title cannot be empty.'); // TODO: Use a nicer notification
+ $saveSpinner.css('visibility', 'hidden');
+ $saveButton.prop('disabled', false);
+ return;
+ }
+
+ $.post(quiztechBuilderData.ajax_url, {
+ action: 'quiztech_save_assessment',
+ // nonce: quiztechBuilderData.save_nonce, // TODO: Implement nonce verification in PHP
+ assessment_id: currentAssessmentId, // Will be null for new assessments
+ title: assessmentTitle,
+ question_ids: currentAssessmentQuestions
+ })
+ .done(function(response) {
+ if (response.success && response.data.assessment_id) {
+ currentAssessmentId = response.data.assessment_id; // Store the ID after saving
+ $saveStatus.text(quiztechBuilderData.assessment_saved).addClass('success');
+ // Optionally redirect or update UI further
+ } else {
+ $saveStatus.text(response.data.message || quiztechBuilderData.error_generic).addClass('error');
+ }
+ })
+ .fail(function() {
+ $saveStatus.text(quiztechBuilderData.error_generic).addClass('error');
+ })
+ .always(function() {
+ $saveSpinner.css('visibility', 'hidden');
+ $saveButton.prop('disabled', false);
+ });
+ }
+
+
+ // --- Event Handlers ---
+
+ // Add question from library to current assessment (Handles manual click - less relevant with drag/drop but keep for now)
+ $libraryList.on('click', '.add-question-to-assessment', function() {
+ const $button = $(this);
+ const questionId = $button.data('question-id');
+ const $item = $button.closest('.library-question-item');
+
+ if (!currentAssessmentQuestions.includes(questionId)) {
+ // Clone the item, modify it, and append to the current list
+ const $clonedItem = $item.clone();
+ $clonedItem.removeClass('library-question-item').addClass('selected-question-item');
+ $clonedItem.find('.add-question-to-assessment').replaceWith(
+ `` // TODO: Localize
+ );
+
+ // Remove placeholder if it exists
+ $currentList.find('p').remove();
+
+ $currentList.append($clonedItem);
+
+ // Update state and UI
+ updateStateFromDOM();
+ updateTotalCost();
+ updateLibraryButtons();
+ }
+ });
+
+ // Remove question from current assessment
+ $currentList.on('click', '.remove-question-from-assessment', function() {
+ const $button = $(this);
+ const questionId = $button.data('question-id');
+ $button.closest('.selected-question-item').remove(); // Remove item from DOM
+
+ // Update state and UI
+ updateStateFromDOM();
+ updateTotalCost();
+ updateLibraryButtons(); // Re-enable the 'Add' button in the library
+
+ // Add placeholder if list becomes empty
+ if ($currentList.children().length === 0) {
+ $currentList.html('
' + 'No questions added yet.' + '
'); // TODO: Localize
+ }
+ });
+
+ // Save assessment button click
+ $saveButton.on('click', function(e) {
+ e.preventDefault();
+ saveAssessment();
+ });
+
+ // TODO: Add handlers for search/filter/pagination controls when implemented.
+ // --- Initialize Sortable ---
+ $currentList.sortable({
+ placeholder: "ui-state-highlight", // Class for placeholder styling
+ axis: 'y', // Allow vertical sorting only
+ update: function(event, ui) {
+ // This fires when sorting stops *within* the list OR when an item is received
+ console.log('Sortable Updated');
+ updateStateFromDOM();
+ updateTotalCost(); // Recalculate cost based on new order/items
+ },
+ receive: function(event, ui) {
+ // This fires specifically when a draggable is dropped onto the sortable
+ console.log('Sortable Received');
+ const questionId = ui.item.data('question-id');
+ const $originalItem = ui.item; // This is the helper clone that becomes the list item
+
+ // Check for duplicates based on the state *before* this item was potentially added by 'update'
+ const existingIds = $currentList.find('.selected-question-item').map(function() {
+ return $(this).data('question-id');
+ }).get();
+ let count = 0;
+ existingIds.forEach(id => { if (id === questionId) count++; });
+
+ if (count > 1) { // If the dropped item creates a duplicate
+ console.log('Duplicate detected, cancelling drop');
+ ui.sender.sortable('cancel'); // Cancel the drop/receive operation
+ $originalItem.remove(); // Remove the duplicate item that was briefly added
+ alert('This question is already in the assessment.'); // TODO: Nicer notification
+ return; // Stop further processing for this event
+ }
+
+ // Transform the received item (clone) into a selected item
+ $originalItem.removeClass('library-question-item dragging-helper').addClass('selected-question-item');
+ $originalItem.find('.add-question-to-assessment').replaceWith(
+ `` // TODO: Localize
+ );
+ $originalItem.css({ width: '', height: '' }); // Reset helper styles
+
+ // Remove placeholder if it exists
+ $currentList.find('p').remove();
+
+ // Update state and UI (update event will also fire, but good to be explicit)
+ updateStateFromDOM();
+ updateTotalCost();
+ updateLibraryButtons(); // Disable the 'Add' button in the library
+ }
+ }).disableSelection(); // Prevent text selection while dragging
+
+ // --- Initial Load ---
+ fetchLibraryQuestions(); // Load initial questions into the library (will also init draggable)
+ // renderCurrentAssessment(); // Don't render initially, sortable handles it
+
+ // Add placeholder initially if list is empty
+ if ($currentList.children().length === 0) {
+ $currentList.html('