yet-another-cad-viewer/frontend/tools/b64.ts

export function b64UrlEncode(data: Uint8Array): string {
    const base64 = btoa(String.fromCharCode(...data));
    return base64.replace(/\+/g, '-').replace(/\//g, '_').replace(/=+$/, '');
}

export function b64UrlDecode(encoded: string): Uint8Array {
    // Replace URL-safe characters with standard base64 characters
    let base64 = encoded.replace(/-/g, '+').replace(/_/g, '/');
    // Add padding if necessary
    const padding = base64.length % 4;
    if (padding) {
        base64 += '='.repeat(4 - padding);
    }
    // Decode the base64 string to a byte array
    const binaryString = atob(base64);
    const byteArray = new Uint8Array(binaryString.length);
    for (let i = 0; i < binaryString.length; i++) {
        byteArray[i] = binaryString.charCodeAt(i);
    }
    return byteArray;
}