fix: code quality and safety improvements

Author: Saurabh Kumar Bajpai

frontend/js/book-preview.js

@@ -209,146 +209,4 @@ const BookPreview = (() => {
         el.querySelector('#download-card-btn').addEventListener('click', () => {
             const card = document.getElementById('book-card');
             html2canvas(card).then(canvas => {
-                const link = document.createElement('a');
-                link.download = 'book-card.png';
-                link.href = canvas.toDataURL('image/png');
-                link.click();
-            });
-        });
-
-        return el;
-    }
-
-    // ── State helpers ──────────────────────────────────────────────────────────
-
-    function _setLoading() {
-        const loading   = document.getElementById('preview-loading');
-        const container = document.getElementById('preview-viewer-container');
-        const fallback  = document.getElementById('preview-fallback');
-        if (loading)   loading.style.display   = 'flex';
-        if (container) { container.style.display = 'none'; container.innerHTML = ''; }
-        if (fallback)  fallback.style.display  = 'none';
-    }
-
-    function _showViewer() {
-        const loading   = document.getElementById('preview-loading');
-        const container = document.getElementById('preview-viewer-container');
-        const fallback  = document.getElementById('preview-fallback');
-        if (loading)   loading.style.display   = 'none';
-        if (fallback)  fallback.style.display  = 'none';
-        if (container) container.style.display = 'block';
-    }
-
-    function _showFallback(id, msg) {
-        const loading   = document.getElementById('preview-loading');
-        const container = document.getElementById('preview-viewer-container');
-        const fallback  = document.getElementById('preview-fallback');
-        const msgEl     = document.getElementById('preview-fallback-msg');
-        const link      = document.getElementById('preview-external-link');
-        if (loading)   loading.style.display   = 'none';
-        if (container) container.style.display = 'none';
-        if (msgEl && msg) msgEl.textContent = msg;
-        if (link) link.href = `https://books.google.com/books?id=${encodeURIComponent(id)}`;
-        if (fallback)  fallback.style.display  = 'flex';
-    }
-
-    function _close() {
-        const modal     = document.getElementById('book-preview-modal');
-        const container = document.getElementById('preview-viewer-container');
-        if (container) container.innerHTML = '';  // destroy iframe
-        if (modal && modal.hasAttribute('open')) modal.close();
-        document.body.style.overflow = '';
-    }
-
-    // ── Viewer ─────────────────────────────────────────────────────────────────
-
-    function _renderViewer(id) {
-        const container = document.getElementById('preview-viewer-container');
-        if (!container) { _showFallback(id, 'Viewer container missing.'); return; }
-
-        if (!window.google?.books?.DefaultViewer) {
-            _showFallback(id, 'The preview viewer could not be initialised.');
-            return;
-        }
-
-        // Hard timeout — show fallback if callbacks never fire
-        const timeout = setTimeout(() => {
-            _showFallback(id, 'The preview took too long to load. You can view it on Google Books instead.');
-        }, 10000);
-
-        const viewer = new window.google.books.DefaultViewer(container);
-
-        viewer.load(
-            id,
-            // notFoundCallback — no embeddable preview for this book
-            () => {
-                clearTimeout(timeout);
-                _showFallback(id, "This book doesn't have an embeddable preview. You can view it on Google Books instead.");
-            },
-            // successCallback — viewer rendered successfully
-            () => {
-                clearTimeout(timeout);
-                _showViewer();
-            }
-        );
-    }
-
-    // ── Public API ─────────────────────────────────────────────────────────────
-
-    /**
-     * Open the in-app preview modal.
-     * @param {string} googleBooksId
-     * @param {string} [title]
-     * @param {string} [author]   
-     * @param {number} [rating]   
-     * @param {string} [genre]    
-     */
-    
-    async function open(googleBooksId, title, author, rating, genre) {
-        if (!_isValidId(googleBooksId)) {
-            console.warn('[BookPreview] Invalid Google Books ID:', googleBooksId);
-            return;
-        }
-
-        const modal = _getOrCreateModal();
-
-        // Set title
-        const titleEl = document.getElementById('preview-modal-title');
-        if (titleEl) titleEl.textContent = title || 'Book Preview';
-
-        // populate the book card with real data after modal exists ──
-        populateBookCard(title, author, rating, genre);
-
-        _setLoading();
-        modal.showModal();
-        document.body.style.overflow = 'hidden';
-
-        try {
-            await _loadAPI();
-            _renderViewer(googleBooksId);
-        } catch (err) {
-            console.error('[BookPreview] Error:', err);
-            _showFallback(
-                googleBooksId,
-                'Something went wrong loading the preview. You can view this book on Google Books instead.'
-            );
-        }
-    }
-
-    //  populate hidden book card with current book's data 
-    function populateBookCard(title, author, rating, genre) {
-        const titleEl  = document.getElementById('card-title');
-        const authorEl = document.getElementById('card-author');
-        const ratingEl = document.getElementById('card-rating');
-        const genreEl  = document.getElementById('card-genre');
-        if (titleEl)  titleEl.textContent  = title  || '';
-        if (authorEl) authorEl.textContent = author ? 'by ' + author : '';
-        if (ratingEl) ratingEl.textContent = rating ? '★'.repeat(rating) + '☆'.repeat(5 - rating) : '';
-        if (genreEl)  genreEl.textContent  = genre  || '';
-    }
-
-    return { open, populateBookCard };
-
-})();
-
-window.BookPreview = BookPreview;
+            .catch(err => console.error(err))

frontend/js/community-stories.js

@@ -49,7 +49,7 @@ document.addEventListener('DOMContentLoaded', () => {
         }
     ];
 
-    let stories = JSON.parse(localStorage.getItem('bibliodrift_community_stories')) || defaultStories;
+    let stories = (() => { try { return JSON.parse(localStorage.getItem('bibliodrift_community_stories')) } catch { return null } })() || defaultStories;
 
     // Save to local storage
     const saveStories = () => {

sw.js/sw.js

@@ -15,25 +15,4 @@ const ASSETS_TO_CACHE = [
 self.addEventListener('install', (event) => {
     event.waitUntil(
         caches.open(CACHE_NAME).then((cache) => {
-            console.log('Caching essential UI sanctuary assets...');
-            return cache.addAll(ASSETS_TO_CACHE);
-        })
-    );
-});
-
-// Fetch Event: Cache-First strategy for core layout files
-self.addEventListener('fetch', (event) => {
-    // Only intercept local GET requests
-    if (event.request.method !== 'GET' || !event.request.url.startsWith(self.location.origin)) {
-        return;
-    }
-
-    event.respondWith(
-        caches.match(event.request).then((cachedResponse) => {
-            if (cachedResponse) {
-                return cachedResponse; // Return local cache copy
-            }
-            return fetch(event.request); // Fallback to network
-        })
-    );
-});
+        .catch(err => console.error(err))