/*
    * 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.api.keyset;
  
  import io.github.tonywasher.joceanus.gordianknot.api.base.GordianLength;
  import io.github.tonywasher.joceanus.gordianknot.api.key.GordianKeyLengths;
  
  import java.util.Objects;
  
  /**
   * KeySet Specification.
   */
  public class GordianKeySetSpec {
      /**
       * Minimum Cipher Steps.
       */
      public static final Integer MINIMUM_CIPHER_STEPS = 3;
  
      /**
       * Maximum Cipher Steps.
       */
      public static final Integer MAXIMUM_CIPHER_STEPS = 6;
  
      /**
       * Default Cipher Steps.
       */
      public static final Integer DEFAULT_CIPHER_STEPS = 4;
  
      /**
       * Default KeyLength.
       */
      public static final GordianLength DEFAULT_KEYLEN = GordianLength.LEN_256;
  
      /**
       * KeyLength.
       */
      private final GordianLength theKeyLength;
  
      /**
       * Number of CipherSteps.
       */
      private final int theCipherSteps;
  
      /**
       * Is the Spec valid?.
       */
      private final boolean isValid;
  
      /**
       * Constructor.
       */
      public GordianKeySetSpec() {
          this(DEFAULT_KEYLEN);
      }
  
      /**
       * Constructor.
       *
       * @param pKeyLen the keyLength.
       */
      public GordianKeySetSpec(final GordianLength pKeyLen) {
          this(pKeyLen, DEFAULT_CIPHER_STEPS);
      }
  
      /**
       * Constructor.
       *
       * @param pKeyLen   the keyLength.
       * @param pNumSteps the number of cipherSteps
       */
      public GordianKeySetSpec(final GordianLength pKeyLen,
                               final int pNumSteps) {
          theKeyLength = pKeyLen;
          theCipherSteps = pNumSteps;
          isValid = validateKeySetSpec();
      }
  
      /**
       * Is the Spec valid?
       *
       * @return true/false
       */
      public boolean isValid() {
          return isValid;
      }
 
     /**
      * Obtain the keyLength.
      *
      * @return the keyLength
      */
     public GordianLength getKeyLength() {
         return theKeyLength;
     }
 
     /**
      * Obtain the number of Cipher Steps.
      *
      * @return the # of cipher steps
      */
     public int getCipherSteps() {
         return theCipherSteps;
     }
 
     /**
      * Validate the Parameters.
      *
      * @return valid true/false
      */
     private boolean validateKeySetSpec() {
         /* Check keyLength */
         if (theKeyLength == null
                 || !GordianKeyLengths.isSupportedLength(theKeyLength)) {
             return false;
         }
 
         /* Check cipher steps is in range */
         return !(theCipherSteps < MINIMUM_CIPHER_STEPS
                 || theCipherSteps > MAXIMUM_CIPHER_STEPS);
     }
 
     @Override
     public boolean equals(final Object pThat) {
         /* Handle the trivial cases */
         if (this == pThat) {
             return true;
         }
         if (pThat == null) {
             return false;
         }
 
         /* Check Length and cipherSteps */
         return pThat instanceof GordianKeySetSpec myThat
                 && theKeyLength == myThat.getKeyLength()
                 && theCipherSteps == myThat.getCipherSteps();
     }
 
     @Override
     public int hashCode() {
         return Objects.hash(theKeyLength, theCipherSteps);
     }
 
     @Override
     public String toString() {
         return "KeySet" + theKeyLength + "-" + theCipherSteps;
     }
 }