doneit-web/src/app/utils/zod.ts

import { z } from 'zod';

/**
 * Regular expression to validate a data URL.
 * The pattern matches data URLs that start with `data:`, optionally followed by a media type,
 * optionally followed by an encoding (e.g., `base64`), and ending with base64 encoded data.
 */
export const zodDataUrlRegex = /^data:(?:[\w+\/-]+)?(?:[\w+\/-]+)?;base64,[\s\S]*$/;

/**
 * Zod schema for validating data URLs.
 * This schema ensures that the input string matches the format of a data URL.
 *
 * @example
 * const result = dataUrlSchema.safeParse('data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAUAAAAFCAYAAACNbyblAAAAHElEQVQI12P4//8/w38GIAXDCAAAAC0BEMAAW9R3AAAAAElFTkSuQmCC');
 * if (result.success) {
 *   console.log('Valid data URL:', result.data);
 * } else {
 *   console.error('Validation error:', result.error.errors);
 * }
 */
export const zodDataUrlSchema = z.string().refine(value => zodDataUrlRegex.test(value), {
  message: 'Invalid data URL',
});

/**
 * Validates if a string is a valid data URL.
 *
 * @param url - The string to validate as a data URL.
 * @returns {void} - Logs the result of the validation.
 *
 * @example
 * validateDataUrl('data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAUAAAAFCAYAAACNbyblAAAAHElEQVQI12P4//8/w38GIAXDCAAAAC0BEMAAW9R3AAAAAElFTkSuQmCC');
 * // Output: Valid data URL: data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAUAAAAFCAYAAACNbyblAAAAHElEQVQI12P4//8/w38GIAXDCAAAAC0BEMAAW9R3AAAAAElFTkSuQmCC
 * 
 * validateDataUrl('invalid-url');
 * // Output: Validation error: [ ... ]
 */
const validateDataUrl = (url: string) => {
  const result: any = zodDataUrlSchema.safeParse(url);
  if (result.success) {
    console.log('Valid data URL:', url);
  } else {
    console.error('Validation error:', result.error.errors);
  }
};

// Test the schema
validateDataUrl('data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAUAAAAFCAYAAACNbyblAAAAHElEQVQI12P4//8/w38GIAXDCAAAAC0BEMAAW9R3AAAAAElFTkSuQmCC');
validateDataUrl('invalid-url');