import { Buffer } from 'buffer';
import { gunzipSync, gzipSync } from 'zlib';
import { RevocationStatusList } from './revocationStatusList.js';
import { STATUS_LIST } from '../config.js';
import BitArray from './BitArray.js';
import InvalidCredentialIndexException from './exceptions/invalidCredentialIndexException.js';

export class RevocationStatusListArray implements RevocationStatusList {
  private encodedList: BitArray;

  constructor(bitArray?: BitArray) {
    this.encodedList =
      bitArray ?? new BitArray(STATUS_LIST.MAX_CREDENTIAL_ID / 8);
  }

  static fromEncoded(encodedList: string): RevocationStatusListArray {
    const decodedFromBase64 = Buffer.from(encodedList, 'base64');
    const uncompressedData = gunzipSync(decodedFromBase64);
    return new RevocationStatusListArray(new BitArray(uncompressedData));
  }

  encoded(): string {
    const compressedData = Buffer.from(gzipSync(this.encodedList.toArray()));
    return compressedData.toString('base64');
  }

  revokeCredential(credentialId: number): void {
    this.checkCredentialId(credentialId);
    this.encodedList.set(credentialId);
  }

  checkCredentialId(credentialId: number): void {
    if (credentialId > STATUS_LIST.MAX_CREDENTIAL_ID || credentialId < 0)
      throw new InvalidCredentialIndexException(credentialId.toString());
  }

  isRevoked(credentialId: number): boolean {
    return this.encodedList.get(credentialId) === 1;
  }
}