Converting…'; hideError(); hideResult(); resetProgress(); progressWrap.classList.add('active'); try { /* ── STEP 1: Load PDF ── */ setProgress(5, 'Loading PDF with PDF.js…', 0); const arrayBuffer = await readFileAsArrayBuffer(selectedFile); const pdf = await pdfjsLib.getDocument({ data: arrayBuffer }).promise; const totalPages = pdf.numPages; setProgress(15, `PDF loaded — ${totalPages} pages found`, 0); steps[0].classList.remove('active'); steps[0].classList.add('done'); /* ── STEP 2: Extract text ── */ setProgress(20, 'Extracting text from pages…', 1); const pageTexts = []; for (let i = 1; i <= totalPages; i++) { const page = await pdf.getPage(i); const content = await page.getTextContent(); const pageText = content.items.map(item => item.str).join(' '); pageTexts.push(pageText.trim()); const pct = 20 + Math.round((i / totalPages) * 35); setProgress(pct, `Extracting page ${i} of ${totalPages}…`, 1); } steps[1].classList.remove('active'); steps[1].classList.add('done'); /* ── STEP 3: Structure chapters ── */ setProgress(58, 'Structuring chapters…', 2); const mode = chapterMode.value; const title = bookTitle.value.trim() || bookTitle.placeholder || 'Untitled'; const author = bookAuthor.value.trim() || 'Unknown Author'; const chapters = buildChapters(pageTexts, mode, title); const wordCount = pageTexts.join(' ').split(/\s+/).filter(Boolean).length; steps[2].classList.remove('active'); steps[2].classList.add('done'); /* ── STEP 4: Build EPUB ── */ setProgress(68, 'Building EPUB package…', 3); const zip = await buildEPUB(title, author, chapters, fontSizeSetting.value); steps[3].classList.remove('active'); steps[3].classList.add('done'); /* ── STEP 5: Generate blob ── */ setProgress(90, 'Generating download file…', 4); epubBlob = await zip.generateAsync({ type: 'blob', compression: 'DEFLATE', compressionOptions: { level: 6 } }); setProgress(100, 'Done!', 4); steps[4].classList.remove('active'); steps[4].classList.add('done'); /* ── Show result ── */ setTimeout(() => { progressWrap.classList.remove('active'); statPages.textContent = totalPages; statChapters.textContent = chapters.length; statWords.textContent = wordCount > 1000 ? (wordCount / 1000).toFixed(1) + 'k' : wordCount; resultSub.textContent = `${formatBytes(epubBlob.size)} · Valid EPUB 3`; resultPanel.classList.add('active'); }, 600); } catch (err) { console.error('Conversion error:', err); showError('Conversion failed: ' + (err.message || 'Unknown error. Please ensure the PDF contains extractable text.')); progressWrap.classList.remove('active'); } finally { isConverting = false; btnConvert.disabled = !selectedFile; btnConvert.innerHTML = ` Convert to EPUB`; } } /* ======================== CHAPTER BUILDER ======================== */ function buildChapters(pageTexts, mode, bookTitle) { if (mode === 'single') { return [{ title: bookTitle, content: pageTexts.join('\n\n') }]; } if (mode === 'page') { return pageTexts.map((text, i) => ({ title: `Page ${i + 1}`, content: text || '(Empty page)' })); } // mode === 'heading': detect headings const chapters = []; let current = { title: bookTitle, content: '' }; for (let pageText of pageTexts) { const lines = pageText.split(/\s{2,}|\n/).map(l => l.trim()).filter(Boolean); for (let line of lines) { if (isHeading(line) && current.content.trim().length > 30) { chapters.push(current); current = { title: toTitleCase(line), content: '' }; } else { current.content += (current.content ? ' ' : '') + line; } } current.content += '\n\n'; } if (current.content.trim()) chapters.push(current); if (chapters.length === 0) { return [{ title: bookTitle, content: pageTexts.join('\n\n') }]; } return chapters; } function isHeading(line) { if (!line || line.length < 2) return false; const trimmed = line.trim(); // All caps heading (2–80 chars, no period ending) if (trimmed === trimmed.toUpperCase() && trimmed.length >= 3 && trimmed.length <= 80 && !/\.$/.test(trimmed)) { return /[A-Z]/.test(trimmed); // at least one letter } // Short line: fewer than 8 words and doesn't end with period/comma const words = trimmed.split(/\s+/); if (words.length <= 6 && !/[,;:]$/.test(trimmed) && !/\.$/.test(trimmed) && trimmed.length >= 3) { // Bonus: starts with capital if (/^[A-Z0-9]/.test(trimmed)) return true; } // Chapter N pattern if (/^(chapter|section|part|unit)\s+[\divxlc]+/i.test(trimmed)) return true; return false; } function toTitleCase(str) { return str.toLowerCase().replace(/\b\w/g, c => c.toUpperCase()); } /* ======================== EPUB BUILDER ======================== */ async function buildEPUB(title, author, chapters, fontSize) { const zip = new JSZip(); const uid = 'urn:uuid:' + generateUUID(); const now = new Date().toISOString().replace(/\.\d{3}Z$/, 'Z'); /* ── mimetype (MUST be first, uncompressed) ── */ zip.file('mimetype', 'application/epub+zip', { compression: 'STORE' }); /* ── META-INF/container.xml ── */ zip.folder('META-INF').file('container.xml', ` `); const oebps = zip.folder('OEBPS'); const styles = oebps.folder('Styles'); const text = oebps.folder('Text'); /* ── Stylesheet ── */ styles.file('style.css', ` @charset "UTF-8"; body { font-family: Georgia, "Times New Roman", serif; font-size: ${fontSize}; line-height: 1.75; margin: 1.5em 2em; color: #1a1a1a; background: #fff; } h1, h2, h3, h4 { font-family: "Helvetica Neue", Arial, sans-serif; font-weight: 700; margin-top: 1.5em; margin-bottom: 0.5em; color: #111; page-break-after: avoid; } h1 { font-size: 1.6em; } h2 { font-size: 1.35em; border-bottom: 1px solid #ddd; padding-bottom: 0.2em; } h3 { font-size: 1.1em; } p { margin: 0 0 1em; text-align: justify; orphans: 2; widows: 2; } .chapter-title { font-size: 1.8em; font-weight: 800; margin-bottom: 1.5em; padding-bottom: 0.5em; border-bottom: 2px solid #333; page-break-before: always; } .chapter-title:first-child { page-break-before: avoid; } `); /* ── Cover page ── */ text.file('cover.xhtml', ` `); /* ── Chapter files ── */ const chapterManifestItems = []; const chapterSpineItems = []; const tocPoints = []; for (let i = 0; i < chapters.length; i++) { const ch = chapters[i]; const chId = `chapter${String(i + 1).padStart(3, '0')}`; const chFile = `${chId}.xhtml`; const chTitle = ch.title || `Chapter ${i + 1}`; // Format content: split by double newlines → paragraphs const paragraphs = ch.content .split(/\n\n+/) .map(p => p.replace(/\n/g, ' ').trim()) .filter(p => p.length > 0) .map(p => `

${escapeXml(p)}

`) .join('\n'); const xhtml = `

${escapeXml(chTitle)}

${paragraphs || '

(No text content on this page)

'} `; text.file(chFile, xhtml); chapterManifestItems.push(` `); chapterSpineItems.push(` `); tocPoints.push({ id: chId, file: `Text/${chFile}`, title: chTitle, order: i + 2 }); } /* ── content.opf ── */ oebps.file('content.opf', ` ${escapeXml(author)} en ${uid} SnapToolSet PDF to EPUB Converter ${now} ${chapterManifestItems.join('\n')} ${chapterSpineItems.join('\n')} `); /* ── toc.ncx ── */ const ncxNavPoints = tocPoints.map(p => ` ${escapeXml(p.title)} `).join(''); oebps.file('toc.ncx', ` ${escapeXml(title)} Cover ${ncxNavPoints} `); /* ── nav.xhtml (EPUB 3 navigation) ── */ const navItems = tocPoints.map(p => `

${escapeXml(p.title)}

` ).join('\n'); oebps.file('nav.xhtml', ` `); return zip; } /* ======================== UTILITIES ======================== */ function readFileAsArrayBuffer(file) { return new Promise((resolve, reject) => { const reader = new FileReader(); reader.onload = e => resolve(e.target.result); reader.onerror = () => reject(new Error('Failed to read file')); reader.readAsArrayBuffer(file); }); } function escapeXml(str) { if (!str) return ''; return String(str) .replace(/&/g, '&') .replace(//g, '>') .replace(/"/g, '"') .replace(/'/g, '''); } function generateUUID() { return 'xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx'.replace(/[xy]/g, c => { const r = Math.random() * 16 | 0; const v = c === 'x' ? r : (r & 0x3 | 0x8); return v.toString(16); }); } /* ======================== DOWNLOAD ======================== */ btnDownload.addEventListener('click', () => { if (!epubBlob) return; const url = URL.createObjectURL(epubBlob); const a = document.createElement('a'); a.href = url; a.download = epubFilename; document.body.appendChild(a); a.click(); document.body.removeChild(a); setTimeout(() => URL.revokeObjectURL(url), 5000); }); /* ======================== RESET ======================== */ function resetTool() { selectedFile = null; epubBlob = null; fileInput.value = ''; bookTitle.value = ''; bookTitle.placeholder = 'Auto-detected from PDF'; bookAuthor.value = ''; filePreview.classList.remove('active'); btnConvert.disabled = true; hideError(); hideResult(); resetProgress(); } /* ======================== FAQ ACCORDION ======================== */ function toggleFaq(el) { const item = el.closest('.faq-item'); const wasOpen = item.classList.contains('open'); document.querySelectorAll('.faq-item.open').forEach(i => i.classList.remove('open')); if (!wasOpen) item.classList.add('open'); }