74 lines
2.0 KiB
TypeScript
74 lines
2.0 KiB
TypeScript
import { FileExtensionImage, MimeTypeImage } from '$lib/enums';
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/**
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* Convert a WebP base64 data URL to a PNG data URL
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* @param base64UrlWebp - The WebP base64 data URL to convert
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* @param backgroundColor - Background color for the PNG (default: 'white')
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* @returns Promise resolving to PNG data URL
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*/
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export function webpBase64UrlToPngDataURL(
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base64UrlWebp: string,
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backgroundColor: string = 'white'
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): Promise<string> {
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return new Promise((resolve, reject) => {
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try {
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const img = new Image();
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img.onload = () => {
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const canvas = document.createElement('canvas');
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const ctx = canvas.getContext('2d');
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if (!ctx) {
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reject(new Error('Failed to get 2D canvas context.'));
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return;
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}
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const targetWidth = img.naturalWidth || 300;
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const targetHeight = img.naturalHeight || 300;
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canvas.width = targetWidth;
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canvas.height = targetHeight;
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if (backgroundColor) {
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ctx.fillStyle = backgroundColor;
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ctx.fillRect(0, 0, canvas.width, canvas.height);
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}
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ctx.drawImage(img, 0, 0, targetWidth, targetHeight);
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resolve(canvas.toDataURL(MimeTypeImage.PNG));
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};
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img.onerror = () => {
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reject(new Error('Failed to load WebP image. Ensure the WebP data is valid.'));
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};
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img.src = base64UrlWebp;
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} catch (error) {
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const message = error instanceof Error ? error.message : String(error);
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const errorMessage = `Error converting WebP to PNG: ${message}`;
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console.error(errorMessage, error);
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reject(new Error(errorMessage));
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}
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});
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}
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/**
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* Check if a file is a WebP based on its MIME type
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* @param file - The file to check
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* @returns True if the file is a WebP
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*/
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export function isWebpFile(file: File): boolean {
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return (
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file.type === MimeTypeImage.WEBP || file.name.toLowerCase().endsWith(FileExtensionImage.WEBP)
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);
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}
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/**
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* Check if a MIME type represents a WebP
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* @param mimeType - The MIME type to check
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* @returns True if the MIME type is image/webp
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*/
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export function isWebpMimeType(mimeType: string): boolean {
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return mimeType === MimeTypeImage.WEBP;
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}
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