/*
    * 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.Map;
  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 EC key algorithm parameters.
   * Used by {@link SubtleCrypto} for ECDSA and ECDH key operations.
   *
   * @author Lai Quang Duong
   * @author Ronald Brill
   */
  final class EcKeyAlgorithm {
  
      static final Set<String> SUPPORTED_NAMES = Set.of("ECDSA", "ECDH");
  
      private static final Map<String, String> CURVE_TO_JCA = Map.of(
              "P-256", "secp256r1",
              "P-384", "secp384r1",
              "P-521", "secp521r1"
      );
  
      private final String name_;
      private final String namedCurve_;
  
      EcKeyAlgorithm(final String name, final String namedCurve) {
          if (!SUPPORTED_NAMES.contains(name)) {
              throw new UnsupportedOperationException("EC " + name);
          }
          name_ = name;
  
          if (!CURVE_TO_JCA.containsKey(namedCurve)) {
              throw new UnsupportedOperationException("EC curve " + namedCurve);
          }
          namedCurve_ = namedCurve;
      }
  
      /**
       * Parse EC key algorithm parameters from a JS object.
       *
       * @param keyGenParams the JS algorithm parameters object
       * @return the parsed EcKeyAlgorithm
       */
      static EcKeyAlgorithm from(final Scriptable keyGenParams) {
          final Object nameProp = ScriptableObject.getProperty(keyGenParams, "name");
          if (!(nameProp instanceof String name)) {
              throw new IllegalArgumentException("An invalid or illegal string was specified");
          }
  
          final Object curveProp = ScriptableObject.getProperty(keyGenParams, "namedCurve");
          if (!(curveProp instanceof String namedCurve)) {
              throw new IllegalArgumentException("An invalid or illegal string was specified");
          }
  
          return new EcKeyAlgorithm(name, namedCurve);
      }
  
      static boolean isSupported(final String name) {
          return SUPPORTED_NAMES.contains(name);
      }
  
      String getName() {
          return name_;
      }
  
      String getNamedCurve() {
          return namedCurve_;
      }
  
      /**
       * @return the JCA curve name (e.g. "secp256r1" for "P-256")
       */
      String getJavaCurveName() {
          return CURVE_TO_JCA.get(namedCurve_);
      }
  
      /**
       * Converts to a JS object matching the {@code EcKeyAlgorithm} dictionary:
       * {@code {name: "ECDSA", namedCurve: "P-256"}}
       *
      * @param scope the JS scope for prototype/parent setup
      * @return the JS algorithm object
      */
     Scriptable toScriptableObject(final VarScope scope) {
         final Scriptable algorithm = JavaScriptEngine.newObject(scope);
         ScriptableObject.putProperty(algorithm, "name", getName());
         ScriptableObject.putProperty(algorithm, "namedCurve", getNamedCurve());
         return algorithm;
     }
 }