74 lines
2.4 KiB
TypeScript
74 lines
2.4 KiB
TypeScript
// ./utils/image-processor.ts
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import { logger } from './logger'; // Updated import path
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/**
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* Interface for image extraction result
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*/
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interface ImageInfo {
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base64Content: string;
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format: string;
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}
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/**
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* Interface for image format markers
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*/
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interface ImageMarker {
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prefix: string;
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format: string;
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}
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/**
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* Extracts base64 content and format from a data URL string.
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* E.g., "data:image/jpeg;base64,xxxxxxxxxxxxxxx"
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* @param {string} dataUrl The full data URL string.
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* @returns {ImageInfo|null} An object { base64Content: string, format: string } or null if not found.
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*/
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export function extractBase64Image(dataUrl: string): ImageInfo | null {
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if (typeof dataUrl !== 'string' || !dataUrl.startsWith('data:image/')) {
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return null;
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}
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const markers: ImageMarker[] = [
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{ prefix: "data:image/png;base64,", format: "png" },
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{ prefix: "data:image/jpeg;base64,", format: "jpeg" },
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{ prefix: "data:image/jpg;base64,", format: "jpg" },
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{ prefix: "data:image/gif;base64,", format: "gif" },
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{ prefix: "data:image/svg+xml;base64,", format: "svg" }, // svg+xml -> svg
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{ prefix: "data:image/webp;base64,", format: "webp" }
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];
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for (const marker of markers) {
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if (dataUrl.startsWith(marker.prefix)) {
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const base64Content = dataUrl.substring(marker.prefix.length);
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logger.debug(`Found image of format: ${marker.format}`);
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return { base64Content, format: marker.format };
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}
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}
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logger.warn("No known base64 image marker found in the provided data URL:", dataUrl.substring(0, 50) + "...");
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return null;
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}
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/**
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* Decodes a base64 string to a Uint8Array (Bun compatible).
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* Bun has optimized Buffer operations, which are compatible with Node's Buffer
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* @param {string} base64String The base64 encoded string (without the data URI prefix).
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* @returns {Uint8Array} The decoded binary data
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*/
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export function decodeBase64Image(base64String: string): Uint8Array {
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// Bun uses Node.js Buffer API and has highly optimized Buffer operations
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return Buffer.from(base64String, 'base64');
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}
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/**
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* Utility to convert a data URL directly to a binary buffer.
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* Helpful for working with file APIs in Bun.
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* @param {string} dataUrl The complete data URL
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* @returns {Uint8Array|null} The decoded image data or null if invalid
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*/
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export function dataUrlToBuffer(dataUrl: string): Uint8Array | null {
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const imageInfo = extractBase64Image(dataUrl);
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if (!imageInfo) return null;
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return decodeBase64Image(imageInfo.base64Content);
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} |