/*
    * GordianKnot: Security Suite
    * Copyright 2012-2026. Tony Washer
    *
    * 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
    *
    *   http://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 io.github.tonywasher.joceanus.gordianknot.impl.bc;
  
  import io.github.tonywasher.joceanus.gordianknot.api.base.GordianException;
  import io.github.tonywasher.joceanus.gordianknot.api.keypair.GordianKeyPair;
  import io.github.tonywasher.joceanus.gordianknot.api.keypair.GordianStateAwareKeyPair;
  import io.github.tonywasher.joceanus.gordianknot.api.keypair.spec.GordianKeyPairSpec;
  import io.github.tonywasher.joceanus.gordianknot.impl.core.exc.GordianDataException;
  import io.github.tonywasher.joceanus.gordianknot.impl.core.keypair.GordianCoreKeyPair;
  import io.github.tonywasher.joceanus.gordianknot.impl.core.keypair.GordianPrivateKey;
  import io.github.tonywasher.joceanus.gordianknot.impl.core.keypair.GordianPrivateKey.GordianStateAwarePrivateKey;
  import io.github.tonywasher.joceanus.gordianknot.impl.core.keypair.GordianPublicKey;
  import org.bouncycastle.crypto.params.AsymmetricKeyParameter;
  
  import java.util.Objects;
  
  /**
   * BouncyCastle Asymmetric KeyPair.
   */
  public class BouncyKeyPair
          extends GordianCoreKeyPair {
      /**
       * Constructor.
       *
       * @param pPublic the public key
       */
      protected BouncyKeyPair(final BouncyPublicKey<?> pPublic) {
          this(pPublic, null);
      }
  
      /**
       * Constructor.
       *
       * @param pPublic  the public key
       * @param pPrivate the private key
       */
      protected BouncyKeyPair(final BouncyPublicKey<?> pPublic,
                              final BouncyPrivateKey<?> pPrivate) {
          super(pPublic, pPrivate);
      }
  
      @Override
      public BouncyPublicKey<?> getPublicKey() {
          return (BouncyPublicKey<?>) super.getPublicKey();
      }
  
      @Override
      public BouncyPrivateKey<?> getPrivateKey() {
          return (BouncyPrivateKey<?>) super.getPrivateKey();
      }
  
      @Override
      public BouncyKeyPair getPublicOnly() {
          return new BouncyKeyPair(getPublicKey());
      }
  
      /**
       * Check for bouncyKeyPair.
       *
       * @param pKeyPair the keyPair to check
       * @throws GordianException on error
       */
      public static void checkKeyPair(final GordianKeyPair pKeyPair) throws GordianException {
          /* Check that it is a BouncyKeyPair */
          if (!(pKeyPair instanceof BouncyKeyPair)) {
              /* Reject keyPair */
              throw new GordianDataException("Invalid KeyPair");
          }
      }
  
      /**
       * Check for bouncyKeyPair.
       *
       * @param pKeyPair the keyPair to check
       * @param pSpec    the required keySpec
       * @throws GordianException on error
       */
      public static void checkKeyPair(final GordianKeyPair pKeyPair,
                                      final GordianKeyPairSpec pSpec) throws GordianException {
          /* Check the keyPair */
          checkKeyPair(pKeyPair);
  
          /* Check that it the correct key type */
          if (!pSpec.equals(pKeyPair.getKeyPairSpec())) {
             /* Reject keyPair */
             throw new GordianDataException("Invalid KeyPairType");
         }
     }
 
     /**
      * Bouncy PublicKey.
      *
      * @param <T> parameter type
      */
     public abstract static class BouncyPublicKey<T extends AsymmetricKeyParameter>
             extends GordianPublicKey {
         /**
          * Public Key details.
          */
         private final T theKey;
 
         /**
          * Constructor.
          *
          * @param pKeySpec the key spec
          * @param pKey     the key
          */
         protected BouncyPublicKey(final GordianKeyPairSpec pKeySpec,
                                   final T pKey) {
             super(pKeySpec);
             theKey = pKey;
         }
 
         /**
          * Obtain the public key.
          *
          * @return the key
          */
         public T getPublicKey() {
             return theKey;
         }
 
         /**
          * matchKey.
          *
          * @param pThat the key to match
          * @return true/false
          */
         protected abstract boolean matchKey(AsymmetricKeyParameter pThat);
 
         @Override
         public boolean equals(final Object pThat) {
             /* Handle the trivial cases */
             if (pThat == this) {
                 return true;
             }
             if (pThat == null) {
                 return false;
             }
 
             /* Make sure that the object is the same class */
             if (!(pThat instanceof BouncyPublicKey<?> myThat)) {
                 return false;
             }
 
             /* Check differences */
             return getKeySpec().equals(myThat.getKeySpec())
                     && matchKey(myThat.getPublicKey());
         }
 
         @Override
         public int hashCode() {
             return Objects.hash(getKeySpec().hashCode(), theKey);
         }
     }
 
     /**
      * Bouncy PrivateKey.
      *
      * @param <T> parameter type
      */
     public abstract static class BouncyPrivateKey<T extends AsymmetricKeyParameter>
             extends GordianPrivateKey {
         /**
          * Private Key details.
          */
         private final T theKey;
 
         /**
          * Constructor.
          *
          * @param pKeySpec the key spec
          * @param pKey     the key
          */
         protected BouncyPrivateKey(final GordianKeyPairSpec pKeySpec,
                                    final T pKey) {
             super(pKeySpec);
             theKey = pKey;
         }
 
         /**
          * Obtain the private key.
          *
          * @return the key
          */
         public T getPrivateKey() {
             return theKey;
         }
 
         /**
          * matchKey.
          *
          * @param pThat the key to match
          * @return true/false
          */
         protected abstract boolean matchKey(AsymmetricKeyParameter pThat);
 
         @Override
         public boolean equals(final Object pThat) {
             /* Handle the trivial cases */
             if (pThat == this) {
                 return true;
             }
             if (pThat == null) {
                 return false;
             }
 
             /* Make sure that the object is the same class */
             if (!(pThat instanceof BouncyPrivateKey<?> myThat)) {
                 return false;
             }
 
             /* Check differences */
             return getKeySpec().equals(myThat.getKeySpec())
                     && matchKey(myThat.getPrivateKey());
         }
 
         @Override
         public int hashCode() {
             return Objects.hash(getKeySpec(), theKey);
         }
     }
 
     /**
      * Bouncy StateAware PrivateKey.
      *
      * @param <T> parameter type
      */
     public abstract static class BouncyStateAwarePrivateKey<T extends AsymmetricKeyParameter>
             extends BouncyPrivateKey<T>
             implements GordianStateAwarePrivateKey {
         /**
          * The private key.
          */
         private final T thePrivateKey;
 
         /**
          * Constructor.
          *
          * @param pKeySpec the key spec
          * @param pKey     the key
          */
         protected BouncyStateAwarePrivateKey(final GordianKeyPairSpec pKeySpec,
                                              final T pKey) {
             super(pKeySpec, pKey);
             thePrivateKey = pKey;
         }
 
         @Override
         public T getPrivateKey() {
             return thePrivateKey;
         }
 
         @Override
         public abstract BouncyStateAwarePrivateKey<T> getKeyShard(int pNumUsages);
 
         @Override
         public boolean equals(final Object pThat) {
             /* Handle the trivial cases */
             if (pThat == this) {
                 return true;
             }
             if (pThat == null) {
                 return false;
             }
 
             /* Make sure that the object is the same class */
             if (!(pThat instanceof BouncyStateAwarePrivateKey<?> myThat)) {
                 return false;
             }
 
             /* Check differences */
             return getKeySpec().equals(myThat.getKeySpec())
                     && matchKey(myThat.getPrivateKey());
         }
 
         @Override
         public int hashCode() {
             return Objects.hash(getKeySpec(), thePrivateKey);
         }
     }
 
     /**
      * Bouncy StateAware KeyPair.
      */
     public static class BouncyStateAwareKeyPair
             extends BouncyKeyPair
             implements GordianStateAwareKeyPair {
         /**
          * Constructor.
          *
          * @param pPublic  the public key
          * @param pPrivate the private key
          */
         BouncyStateAwareKeyPair(final BouncyPublicKey<?> pPublic,
                                 final BouncyStateAwarePrivateKey<?> pPrivate) {
             super(pPublic, pPrivate);
         }
 
         @Override
         public BouncyStateAwarePrivateKey<?> getPrivateKey() {
             return (BouncyStateAwarePrivateKey<?>) super.getPrivateKey();
         }
 
         @Override
         public long getUsagesRemaining() {
             return getPrivateKey().getUsagesRemaining();
         }
 
         @Override
         public BouncyStateAwareKeyPair getKeyPairShard(final int pNumUsages) {
             return new BouncyStateAwareKeyPair(getPublicKey(), getPrivateKey().getKeyShard(pNumUsages));
         }
     }
 }