import { describe, expect, it } from 'vitest';
import { CryptoError } from './cryptoError.js';
import { decodeMetadata, encodeMetadata, META_LENGTH } from './metadata.js';

describe('metadata', () => {
  describe('encodeMetadata', () => {
    it('should encode metadata object into a base64 string', () => {
      const metadata = {
        iv: Buffer.from('1234567890123456'),
        tag: Buffer.from('1234567890123456'),
        file: 'example.txt',
        ext: 'txt',
        version: '1.0'
      };
      const encoded = encodeMetadata(metadata);
      expect(encoded).toMatch(/^[A-Za-z0-9+/!]+={0,2}$/);
      expect(encoded.length).toBe(META_LENGTH);
    });

    it('should use random bytes for padding', () => {
      const metadata = {
        iv: Buffer.from('1234567890123456'),
        tag: Buffer.from('1234567890123456'),
        file: 'example.txt',
        ext: 'txt',
        version: '1.0'
      };
      const encoded1 = encodeMetadata(metadata);
      const encoded2 = encodeMetadata(metadata);
      expect(encoded1).not.toBe(encoded2);

      const end = encoded1.slice(encoded1.indexOf('!'));
      expect(encoded2.endsWith(end)).toBe(true);
    });
  });

  describe('decodeMetadata', () => {
    it('should decode valid encoded metadata string to Metadata object', () => {
      const metadata = {
        iv: Buffer.from('1234567890123456'),
        tag: Buffer.from('1234567890123456'),
        file: 'example.txt',
        ext: 'txt',
        version: '1.0'
      };
      const encodedMetadata = encodeMetadata(metadata);

      const result = decodeMetadata(encodedMetadata);
      expect(result).toEqual(metadata);
    });

    it('should throw CryptoError when encoded metadata string has incorrect length', () => {
      const invalidEncodedMetadata = 'shortString';
      expect(() => decodeMetadata(invalidEncodedMetadata)).toThrow(CryptoError);
      expect(() => decodeMetadata(invalidEncodedMetadata)).toThrow(
        'Invalid metadata length'
      );
    });

    it('should throw CryptoError for invalid JSON structure in metadata', () => {
      const encodedMetadata =
        '6eUO0B22yCQ8GI7kzYGH47PTIUWUuqQ75+peaNEEeayNP+ELbcezC9uw6WtlravqdaQXjmI4vciKVQMUNCxZE5ocVpa/9op178Df/ZVDCs8n48xsxtFebd07vb8QmBxaebVXqKnRwX08HGnTTenE4ggTmvReYmDrAv7HhybT0yFDTNlnOOm1l6kSD9qMIeMLpoBDXzasrA7PcYxz3L3ERBQF338G5E9UcRvKivTBh8VIhhP!aW52YWxpZEpTT04=';
      expect(() => decodeMetadata(encodedMetadata)).toThrow(CryptoError);
      expect(() => decodeMetadata(encodedMetadata)).toThrow('Invalid metadata');
    });
  });
});