Files
bentopdf/src/js/logic/add-watermark-page.ts
2025-12-11 19:34:14 +05:30

221 lines
9.8 KiB
TypeScript

import { createIcons, icons } from 'lucide';
import { showAlert, showLoader, hideLoader } from '../ui.js';
import { downloadFile, hexToRgb, formatBytes, readFileAsArrayBuffer } from '../utils/helpers.js';
import { PDFDocument as PDFLibDocument, rgb, degrees, StandardFonts } from 'pdf-lib';
interface PageState {
file: File | null;
pdfDoc: PDFLibDocument | null;
}
const pageState: PageState = { file: null, pdfDoc: null };
if (document.readyState === 'loading') {
document.addEventListener('DOMContentLoaded', initializePage);
} else {
initializePage();
}
function initializePage() {
createIcons({ icons });
const fileInput = document.getElementById('file-input') as HTMLInputElement;
const dropZone = document.getElementById('drop-zone');
const backBtn = document.getElementById('back-to-tools');
const processBtn = document.getElementById('process-btn');
if (fileInput) {
fileInput.addEventListener('change', handleFileUpload);
fileInput.addEventListener('click', () => { fileInput.value = ''; });
}
if (dropZone) {
dropZone.addEventListener('dragover', (e) => { e.preventDefault(); dropZone.classList.add('border-indigo-500'); });
dropZone.addEventListener('dragleave', () => { dropZone.classList.remove('border-indigo-500'); });
dropZone.addEventListener('drop', (e) => {
e.preventDefault();
dropZone.classList.remove('border-indigo-500');
if (e.dataTransfer?.files.length) handleFiles(e.dataTransfer.files);
});
}
if (backBtn) backBtn.addEventListener('click', () => { window.location.href = import.meta.env.BASE_URL; });
if (processBtn) processBtn.addEventListener('click', addWatermark);
setupWatermarkUI();
}
function handleFileUpload(e: Event) {
const input = e.target as HTMLInputElement;
if (input.files?.length) handleFiles(input.files);
}
async function handleFiles(files: FileList) {
const file = files[0];
if (!file || file.type !== 'application/pdf') {
showAlert('Invalid File', 'Please upload a valid PDF file.');
return;
}
showLoader('Loading PDF...');
try {
const arrayBuffer = await file.arrayBuffer();
pageState.pdfDoc = await PDFLibDocument.load(arrayBuffer);
pageState.file = file;
updateFileDisplay();
document.getElementById('options-panel')?.classList.remove('hidden');
} catch (error) {
console.error(error);
showAlert('Error', 'Failed to load PDF file.');
} finally {
hideLoader();
}
}
function updateFileDisplay() {
const fileDisplayArea = document.getElementById('file-display-area');
if (!fileDisplayArea || !pageState.file || !pageState.pdfDoc) return;
fileDisplayArea.innerHTML = '';
const fileDiv = document.createElement('div');
fileDiv.className = 'flex items-center justify-between bg-gray-700 p-3 rounded-lg';
const infoContainer = document.createElement('div');
infoContainer.className = 'flex flex-col flex-1 min-w-0';
const nameSpan = document.createElement('div');
nameSpan.className = 'truncate font-medium text-gray-200 text-sm mb-1';
nameSpan.textContent = pageState.file.name;
const metaSpan = document.createElement('div');
metaSpan.className = 'text-xs text-gray-400';
metaSpan.textContent = `${formatBytes(pageState.file.size)}${pageState.pdfDoc.getPageCount()} pages`;
infoContainer.append(nameSpan, metaSpan);
const removeBtn = document.createElement('button');
removeBtn.className = 'ml-4 text-red-400 hover:text-red-300 flex-shrink-0';
removeBtn.innerHTML = '<i data-lucide="trash-2" class="w-4 h-4"></i>';
removeBtn.onclick = resetState;
fileDiv.append(infoContainer, removeBtn);
fileDisplayArea.appendChild(fileDiv);
createIcons({ icons });
}
function resetState() {
pageState.file = null;
pageState.pdfDoc = null;
const fileDisplayArea = document.getElementById('file-display-area');
if (fileDisplayArea) fileDisplayArea.innerHTML = '';
document.getElementById('options-panel')?.classList.add('hidden');
const fileInput = document.getElementById('file-input') as HTMLInputElement;
if (fileInput) fileInput.value = '';
}
function setupWatermarkUI() {
const watermarkTypeRadios = document.querySelectorAll('input[name="watermark-type"]');
const textOptions = document.getElementById('text-watermark-options');
const imageOptions = document.getElementById('image-watermark-options');
watermarkTypeRadios.forEach((radio) => {
radio.addEventListener('change', (e) => {
const target = e.target as HTMLInputElement;
if (target.value === 'text') {
textOptions?.classList.remove('hidden');
imageOptions?.classList.add('hidden');
} else {
textOptions?.classList.add('hidden');
imageOptions?.classList.remove('hidden');
}
});
});
const opacitySliderText = document.getElementById('opacity-text') as HTMLInputElement;
const opacityValueText = document.getElementById('opacity-value-text');
const angleSliderText = document.getElementById('angle-text') as HTMLInputElement;
const angleValueText = document.getElementById('angle-value-text');
opacitySliderText?.addEventListener('input', () => { if (opacityValueText) opacityValueText.textContent = opacitySliderText.value; });
angleSliderText?.addEventListener('input', () => { if (angleValueText) angleValueText.textContent = angleSliderText.value; });
const opacitySliderImage = document.getElementById('opacity-image') as HTMLInputElement;
const opacityValueImage = document.getElementById('opacity-value-image');
const angleSliderImage = document.getElementById('angle-image') as HTMLInputElement;
const angleValueImage = document.getElementById('angle-value-image');
opacitySliderImage?.addEventListener('input', () => { if (opacityValueImage) opacityValueImage.textContent = opacitySliderImage.value; });
angleSliderImage?.addEventListener('input', () => { if (angleValueImage) angleValueImage.textContent = angleSliderImage.value; });
}
async function addWatermark() {
if (!pageState.pdfDoc) {
showAlert('Error', 'Please upload a PDF file first.');
return;
}
const watermarkType = (document.querySelector('input[name="watermark-type"]:checked') as HTMLInputElement)?.value || 'text';
showLoader('Adding watermark...');
try {
const pages = pageState.pdfDoc.getPages();
let watermarkAsset: any = null;
if (watermarkType === 'text') {
watermarkAsset = await pageState.pdfDoc.embedFont(StandardFonts.Helvetica);
} else {
const imageFile = (document.getElementById('image-watermark-input') as HTMLInputElement).files?.[0];
if (!imageFile) throw new Error('Please select an image file for the watermark.');
const imageBytes = await readFileAsArrayBuffer(imageFile);
if (imageFile.type === 'image/png') {
watermarkAsset = await pageState.pdfDoc.embedPng(imageBytes as ArrayBuffer);
} else if (imageFile.type === 'image/jpeg') {
watermarkAsset = await pageState.pdfDoc.embedJpg(imageBytes as ArrayBuffer);
} else {
throw new Error('Unsupported Image. Please use a PNG or JPG for the watermark.');
}
}
for (const page of pages) {
const { width, height } = page.getSize();
if (watermarkType === 'text') {
const text = (document.getElementById('watermark-text') as HTMLInputElement).value;
if (!text.trim()) throw new Error('Please enter text for the watermark.');
const fontSize = parseInt((document.getElementById('font-size') as HTMLInputElement).value) || 72;
const angle = parseInt((document.getElementById('angle-text') as HTMLInputElement).value) || 0;
const opacity = parseFloat((document.getElementById('opacity-text') as HTMLInputElement).value) || 0.3;
const colorHex = (document.getElementById('text-color') as HTMLInputElement).value;
const textColor = hexToRgb(colorHex);
const textWidth = watermarkAsset.widthOfTextAtSize(text, fontSize);
page.drawText(text, {
x: (width - textWidth) / 2,
y: height / 2,
font: watermarkAsset,
size: fontSize,
color: rgb(textColor.r, textColor.g, textColor.b),
opacity: opacity,
rotate: degrees(angle),
});
} else {
const angle = parseInt((document.getElementById('angle-image') as HTMLInputElement).value) || 0;
const opacity = parseFloat((document.getElementById('opacity-image') as HTMLInputElement).value) || 0.3;
const scale = 0.5;
const imgWidth = watermarkAsset.width * scale;
const imgHeight = watermarkAsset.height * scale;
page.drawImage(watermarkAsset, {
x: (width - imgWidth) / 2,
y: (height - imgHeight) / 2,
width: imgWidth,
height: imgHeight,
opacity: opacity,
rotate: degrees(angle),
});
}
}
const newPdfBytes = await pageState.pdfDoc.save();
downloadFile(new Blob([new Uint8Array(newPdfBytes)], { type: 'application/pdf' }), 'watermarked.pdf');
showAlert('Success', 'Watermark added successfully!', 'success', () => { resetState(); });
} catch (e: any) {
console.error(e);
showAlert('Error', e.message || 'Could not add the watermark.');
} finally {
hideLoader();
}
}