/*
    * Copyright (c) 2002-2026 Gargoyle Software Inc.
    *
    * Licensed under the Apache License, Version 2.0 (the "License");
    * you may not use this file except in compliance with the License.
    * You may obtain a copy of the License at
    * https://www.apache.org/licenses/LICENSE-2.0
    *
    * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  package org.htmlunit.javascript.host.crypto;
  
  import java.util.Set;
  
  import org.htmlunit.corejs.javascript.Scriptable;
  import org.htmlunit.corejs.javascript.ScriptableObject;
  import org.htmlunit.corejs.javascript.VarScope;
  import org.htmlunit.javascript.JavaScriptEngine;
  
  /**
   * Internal helper representing AES key algorithm parameters.
   * Used by {@link SubtleCrypto} for AES key operations.
   *
   * @author Lai Quang Duong
   * @author Ronald Brill
   */
  final class AesKeyAlgorithm implements KeyAlgorithm {
  
      static final Set<String> SUPPORTED_NAMES = Set.of("AES-CBC", "AES-CTR", "AES-GCM", "AES-KW");
      static final Set<Integer> SUPPORTED_LENGTHS = Set.of(128, 192, 256);
  
      private final String name_;
      private final int length_;
  
      AesKeyAlgorithm(final String name, final int length) {
          if (!SUPPORTED_NAMES.contains(name)) {
              throw new UnsupportedOperationException("AES " + name);
          }
          name_ = name;
          length_ = length;
      }
  
      /**
       * Parses AES key algorithm parameters from a JS object.
       *
       * @param keyGenParams the JS algorithm parameters object
       * @return the parsed AesKeyAlgorithm
       */
      static AesKeyAlgorithm from(final Scriptable keyGenParams) {
          final String name = SubtleCrypto.resolveAlgorithmName(keyGenParams);
  
          final int length = (int) SubtleCrypto.getRequiredNumber(keyGenParams, "length");
          return new AesKeyAlgorithm(name, length);
      }
  
      static boolean isSupported(final String name) {
          return SUPPORTED_NAMES.contains(name);
      }
  
      @Override
      public String getName() {
          return name_;
      }
  
      int getLength() {
          return length_;
      }
  
      /**
       * Converts to a JS object matching the {@code AesKeyAlgorithm} dictionary:
       * {@code {name: "AES-GCM", length: 256}}.
       *
       * @param scope the JS scope for prototype/parent setup
       * @return the JS algorithm object
       */
      @Override
      public Scriptable toScriptableObject(final VarScope scope) {
          final Scriptable algorithm = JavaScriptEngine.newObject(scope);
          ScriptableObject.putProperty(algorithm, "name", getName());
          ScriptableObject.putProperty(algorithm, "length", getLength());
          return algorithm;
      }
  }