/*
    * This file is part of Waarp Project (named also Waarp or GG).
    *
    *  Copyright (c) 2019, Waarp SAS, and individual contributors by the @author
    *  tags. See the COPYRIGHT.txt in the distribution for a full listing of
    * individual contributors.
    *
    *  All Waarp Project is free software: you can redistribute it and/or
    * modify it under the terms of the GNU General Public License as published by
   * the Free Software Foundation, either version 3 of the License, or (at your
   * option) any later version.
   *
   * Waarp is distributed in the hope that it will be useful, but WITHOUT ANY
   * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
   * A PARTICULAR PURPOSE. See the GNU General Public License for more details.
   *
   *  You should have received a copy of the GNU General Public License along with
   * Waarp . If not, see <http://www.gnu.org/licenses/>.
   */
  
  /*
   * 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 org.waarp.compress.zstdunsafe;
  
  import org.waarp.compress.MalformedInputException;
  
  import static org.waarp.compress.zstdunsafe.Constants.*;
  
  final class Util {
    private Util() {
    }
  
    public static int highestBit(final int value) {
      return 31 - Integer.numberOfLeadingZeros(value);
    }
  
    public static boolean isPowerOf2(final int value) {
      return (value & (value - 1)) == 0;
    }
  
    public static int mask(final int bits) {
      return (1 << bits) - 1;
    }
  
    public static void verify(final boolean condition, final long offset,
                              final String reason) {
      if (!condition) {
        throw new MalformedInputException(offset, reason);
      }
    }
  
    public static void checkArgument(final boolean condition,
                                     final String reason) {
      if (!condition) {
        throw new IllegalArgumentException(reason);
      }
    }
  
    public static void checkState(final boolean condition, final String reason) {
      if (!condition) {
        throw new IllegalStateException(reason);
      }
    }
  
    public static MalformedInputException fail(final long offset,
                                               final String reason) {
      throw new MalformedInputException(offset, reason);
    }
  
    public static int cycleLog(final int hashLog,
                               final CompressionParameters.Strategy strategy) {
      int cycleLog = hashLog;
      if (strategy == CompressionParameters.Strategy.BTLAZY2 ||
          strategy == CompressionParameters.Strategy.BTOPT ||
          strategy == CompressionParameters.Strategy.BTULTRA) {
        cycleLog = hashLog - 1;
      }
      return cycleLog;
    }
  
    public static void put24BitLittleEndian(final Object outputBase,
                                            final long outputAddress,
                                            final int value) {
      UnsafeUtil.UNSAFE.putShort(outputBase, outputAddress, (short) value);
      UnsafeUtil.UNSAFE.putByte(outputBase, outputAddress + SIZE_OF_SHORT,
                                (byte) (value >>> Short.SIZE));
    }
  
   // provides the minimum logSize to safely represent a distribution
   public static int minTableLog(final int inputSize, final int maxSymbolValue) {
     if (inputSize <= 1) {
       throw new IllegalArgumentException(
           "Not supported. RLE should be used instead"); // TODO
     }
 
     final int minBitsSrc = highestBit((inputSize - 1)) + 1;
     final int minBitsSymbols = highestBit(maxSymbolValue) + 2;
     return Math.min(minBitsSrc, minBitsSymbols);
   }
 }