/*---------------------------------------------------------------------------------------------
 *  Copyright (c) Microsoft Corporation. All rights reserved.
 *  Licensed under the MIT License. See License.txt in the project root for license information.
 *--------------------------------------------------------------------------------------------*/

import CryptoOperations, { CryptoSuiteMap } from './CryptoOperations';
import IKeyStore from '../keyStore/IKeyStore';
import { SubtleCrypto } from 'webcrypto-core';

/**
 * Utility class to handle all CryptoSuite dependency injection
 */
export default class CryptoFactory {

  /**
   * The key encryptors
   */
  public keyEncrypters: CryptoSuiteMap;

  /**
   * The shared key encryptors
   */
  public sharedKeyEncrypters: CryptoSuiteMap;
  
  /**
   * The symmetric content encryptors
   */
  public symmetricEncrypter: CryptoSuiteMap;
  
  /**
   * The message signer
   */
  public messageSigners: CryptoSuiteMap;
  
  /**
   * The hmac operations
   */
  public messageAuthenticationCodeSigners: CryptoSuiteMap;
  
  /**
   * The digest operations
   */
  public messageDigests: CryptoSuiteMap;

  /**
   * Key store used by the CryptoFactory
   */
  public keyStore: IKeyStore;

  /**
   * Label for default algorithm
   */
  private readonly defaultAlgorithm = '*';

  /**
   * Constructs a new CryptoRegistry
   * @param keyStore used to store private keys
   * @param crypto The default subtle crypto for the environment used for dependency injection
   */
  constructor (keyStore: IKeyStore, crypto: SubtleCrypto) {
    this.keyStore = keyStore;
    this.keyEncrypters = <CryptoSuiteMap>{'*': crypto };
    this.sharedKeyEncrypters = <CryptoSuiteMap>{'*': crypto };
    this.symmetricEncrypter = <CryptoSuiteMap>{'*': crypto };
    this.messageSigners = <CryptoSuiteMap>{'*': crypto };
    this.messageAuthenticationCodeSigners = <CryptoSuiteMap>{'*': crypto };
    this.messageDigests = <CryptoSuiteMap>{'*': crypto };
  }

  /**
   * Gets the key encrypter object given the encryption algorithm's name
   * @param name The name of the algorithm
   * @returns The corresponding crypto API
   */
  public getKeyEncrypter (name: string): SubtleCrypto {
    if (this.keyEncrypters[name]) {
      return this.keyEncrypters[name];
    }
    return this.keyEncrypters[this.defaultAlgorithm];
  }

  /**
   * Gets the shared key encrypter object given the encryption algorithm's name
   * Used for DH algorithms
   * @param name The name of the algorithm
   * @returns The corresponding crypto API
   */
  getSharedKeyEncrypter (name: string): SubtleCrypto {
    if (this.sharedKeyEncrypters[name]) {
      return this.sharedKeyEncrypters[name];
    }
    return this.sharedKeyEncrypters[this.defaultAlgorithm];
  }

  /**
   * Gets the SymmetricEncrypter object given the symmetric encryption algorithm's name
   * @param name The name of the algorithm
   * @returns The corresponding crypto API
   */
  getSymmetricEncrypter (name: string): SubtleCrypto {
    if (this.symmetricEncrypter[name]) {
      return this.symmetricEncrypter[name];
    }
    return this.symmetricEncrypter[this.defaultAlgorithm];
  }
  
  /**
   * Gets the message signer object given the signing algorithm's name
   * @param name The name of the algorithm
   * @returns The corresponding crypto API
   */
  getMessageSigner (name: string): SubtleCrypto {
    if (this.messageSigners[name]) {
      return this.messageSigners[name];
    }
    return this.messageSigners[this.defaultAlgorithm];
  }

  /**
   * Gets the mac signer object given the signing algorithm's name
   * @param name The name of the algorithm
   * @returns The corresponding crypto API
   */
  getMessageAuthenticationCodeSigners (name: string): SubtleCrypto {
    if (this.messageAuthenticationCodeSigners[name]) {
      return this.messageAuthenticationCodeSigners[name];
    }
    return this.messageAuthenticationCodeSigners[this.defaultAlgorithm];
  }

  /**
   * Gets the message digest object given the digest algorithm's name
   * @param name The name of the algorithm
   * @returns The corresponding crypto API
   */
  getMessageDigest (name: string): SubtleCrypto {
    if (this.messageDigests[name]) {
      return this.messageDigests[name];
    }
    return this.messageDigests[this.defaultAlgorithm];
  }
}