feat: frontend file upload support

src/lib/utils/index.ts

@@ -127,3 +127,38 @@ export const findWordIndices = (text) => {
 
 	return matches;
 };
+
+export const calculateSHA256 = async (file) => {
+	console.log(file);
+	// Create a FileReader to read the file asynchronously
+	const reader = new FileReader();
+
+	// Define a promise to handle the file reading
+	const readFile = new Promise((resolve, reject) => {
+		reader.onload = () => resolve(reader.result);
+		reader.onerror = reject;
+	});
+
+	// Read the file as an ArrayBuffer
+	reader.readAsArrayBuffer(file);
+
+	try {
+		// Wait for the FileReader to finish reading the file
+		const buffer = await readFile;
+
+		// Convert the ArrayBuffer to a Uint8Array
+		const uint8Array = new Uint8Array(buffer);
+
+		// Calculate the SHA-256 hash using Web Crypto API
+		const hashBuffer = await crypto.subtle.digest('SHA-256', uint8Array);
+
+		// Convert the hash to a hexadecimal string
+		const hashArray = Array.from(new Uint8Array(hashBuffer));
+		const hashHex = hashArray.map((byte) => byte.toString(16).padStart(2, '0')).join('');
+
+		return `sha256:${hashHex}`;
+	} catch (error) {
+		console.error('Error calculating SHA-256 hash:', error);
+		throw error;
+	}
+};