/*
 * Copyright (C) Sapphirecode - All Rights Reserved
 * This file is part of Auth-Server-Helper which is released under MIT.
 * See file 'LICENSE' for full license details.
 * Created by Timo Hocker <timo@scode.ovh>, December 2020
 */

import { debug } from './debug';

const logger = debug ('blacklist');

interface Signature {
  hash: string;
  iat: number;
}

class Blacklist {
  private _signatures: Signature[];

  public constructor () {
    this._signatures = [];
  }

  public clear (before: number = Number.POSITIVE_INFINITY): void {
    logger.extend ('clear') ('clearing blacklist');
    for (let i = this._signatures.length - 1; i >= 0; i--) {
      if (this._signatures[i].iat < before)
        this.remove_signature (i);
    }
  }

  public add_signature (hash: string): void {
    logger.extend ('add_signature') ('blacklisting signature %s', hash);
    this._signatures.push ({ iat: Date.now (), hash });
  }

  public remove_signature (signature: number | string): void {
    const log = logger.extend ('remove_signature');
    log ('removing signature from blacklist %s', signature);
    if (typeof signature === 'string') {
      log ('received string, searching through signatures');
      for (let i = this._signatures.length - 1; i >= 0; i--) {
        if (this._signatures[i].hash === signature)
          this._signatures.splice (i, 1);
      }
    }
    else {
      log ('received index, removing at index');
      this._signatures.splice (signature, 1);
    }
  }

  public is_valid (hash: string): boolean {
    const log = logger.extend ('is_valid');
    log ('checking signature for blacklist entry %s', hash);
    for (const sig of this._signatures) {
      if (sig.hash === hash) {
        log ('found matching blacklist entry');
        return false;
      }
    }

    log ('signature is not blacklisted');
    return true;
  }

  public export_blacklist (): Signature[] {
    logger.extend ('export_blacklist') ('exporting blacklist');
    return this._signatures;
  }

  public import_blacklist (data: Signature[]): void {
    logger.extend ('import_blacklist') (
      'importing %d blacklist entries',
      data.length
    );
    this._signatures.push (...data);
  }
}

const bl = (new Blacklist);

export { Blacklist };
export default bl;