/*
    * Copyright 2012 The Netty Project
    *
    * The Netty Project licenses this file to you 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 io.netty.handler.codec.compression;
  
  import io.netty.util.internal.PlatformDependent;
  import io.netty.util.internal.SystemPropertyUtil;
  import io.netty.util.internal.logging.InternalLogger;
  import io.netty.util.internal.logging.InternalLoggerFactory;
  
  /**
   * Creates a new {@link ZlibEncoder} and a new {@link ZlibDecoder}.
   */
  public final class ZlibCodecFactory {
      private static final InternalLogger logger = InternalLoggerFactory.getInstance(ZlibCodecFactory.class);
  
      private static final int DEFAULT_JDK_WINDOW_SIZE = 15;
      private static final int DEFAULT_JDK_MEM_LEVEL = 8;
  
      private static final boolean noJdkZlibDecoder;
      private static final boolean noJdkZlibEncoder;
  
      private static final boolean JZLIB_AVAILABLE;
  
      static {
          noJdkZlibDecoder = SystemPropertyUtil.getBoolean("io.netty.noJdkZlibDecoder", false);
          logger.debug("-Dio.netty.noJdkZlibDecoder: {}", noJdkZlibDecoder);
  
          noJdkZlibEncoder = SystemPropertyUtil.getBoolean("io.netty.noJdkZlibEncoder", false);
          logger.debug("-Dio.netty.noJdkZlibEncoder: {}", noJdkZlibEncoder);
  
          boolean jzlibAvailable;
          try {
              Class.forName("com.jcraft.jzlib.JZlib", false,
                  PlatformDependent.getClassLoader(ZlibCodecFactory.class));
              jzlibAvailable = true;
          } catch (ClassNotFoundException t) {
              jzlibAvailable = false;
              logger.debug(
                  "JZlib not in the classpath; the only window bits supported value will be " +
                      DEFAULT_JDK_WINDOW_SIZE);
          }
          JZLIB_AVAILABLE = jzlibAvailable;
      }
  
      /**
       * Returns {@code true} if specify a custom window size and mem level is supported.
       */
      public static boolean isSupportingWindowSizeAndMemLevel() {
          return JZLIB_AVAILABLE;
      }
  
      public static ZlibEncoder newZlibEncoder(int compressionLevel) {
          if (noJdkZlibEncoder) {
              return new JZlibEncoder(compressionLevel);
          } else {
              return new JdkZlibEncoder(compressionLevel);
          }
      }
  
      public static ZlibEncoder newZlibEncoder(ZlibWrapper wrapper) {
          if (noJdkZlibEncoder) {
              return new JZlibEncoder(wrapper);
          } else {
              return new JdkZlibEncoder(wrapper);
          }
      }
  
      public static ZlibEncoder newZlibEncoder(ZlibWrapper wrapper, int compressionLevel) {
          if (noJdkZlibEncoder) {
              return new JZlibEncoder(wrapper, compressionLevel);
          } else {
              return new JdkZlibEncoder(wrapper, compressionLevel);
          }
      }
  
      public static ZlibEncoder newZlibEncoder(ZlibWrapper wrapper, int compressionLevel, int windowBits, int memLevel) {
          if (noJdkZlibEncoder ||
                  windowBits != DEFAULT_JDK_WINDOW_SIZE || memLevel != DEFAULT_JDK_MEM_LEVEL) {
              return new JZlibEncoder(wrapper, compressionLevel, windowBits, memLevel);
          } else {
              return new JdkZlibEncoder(wrapper, compressionLevel);
          }
      }
  
      public static ZlibEncoder newZlibEncoder(byte[] dictionary) {
          if (noJdkZlibEncoder) {
             return new JZlibEncoder(dictionary);
         } else {
             return new JdkZlibEncoder(dictionary);
         }
     }
 
     public static ZlibEncoder newZlibEncoder(int compressionLevel, byte[] dictionary) {
         if (noJdkZlibEncoder) {
             return new JZlibEncoder(compressionLevel, dictionary);
         } else {
             return new JdkZlibEncoder(compressionLevel, dictionary);
         }
     }
 
     public static ZlibEncoder newZlibEncoder(int compressionLevel, int windowBits, int memLevel, byte[] dictionary) {
         if (noJdkZlibEncoder ||
                 windowBits != DEFAULT_JDK_WINDOW_SIZE || memLevel != DEFAULT_JDK_MEM_LEVEL) {
             return new JZlibEncoder(compressionLevel, windowBits, memLevel, dictionary);
         } else {
             return new JdkZlibEncoder(compressionLevel, dictionary);
         }
     }
 
     /**
      * Create a new decoder instance.
      *
      * @deprecated Use {@link ZlibCodecFactory#newZlibDecoder(int)}.
      */
     @Deprecated
     public static ZlibDecoder newZlibDecoder() {
         return newZlibDecoder(0);
     }
 
     /**
      * Create a new decoder instance with specified maximum buffer allocation.
      *
      * @param maxAllocation
      *           Maximum size of the decompression buffer. Must be >= 0.
      *           If zero, maximum size is not limited by decoder.
      */
     public static ZlibDecoder newZlibDecoder(int maxAllocation) {
         if (noJdkZlibDecoder) {
             return new JZlibDecoder(maxAllocation);
         } else {
             return new JdkZlibDecoder(true, maxAllocation);
         }
     }
 
     /**
      * Create a new decoder instance with the specified wrapper.
      *
      * @deprecated Use {@link ZlibCodecFactory#newZlibDecoder(ZlibWrapper, int)}.
      */
     @Deprecated
     public static ZlibDecoder newZlibDecoder(ZlibWrapper wrapper) {
         return newZlibDecoder(wrapper, 0);
     }
 
     /**
      * Create a new decoder instance with the specified wrapper and maximum buffer allocation.
      *
      * @param maxAllocation
      *          Maximum size of the decompression buffer. Must be >= 0.
      *          If zero, maximum size is not limited by decoder.
      */
     public static ZlibDecoder newZlibDecoder(ZlibWrapper wrapper, int maxAllocation) {
         if (noJdkZlibDecoder) {
             return new JZlibDecoder(wrapper, maxAllocation);
         } else {
             return new JdkZlibDecoder(wrapper, true, maxAllocation);
         }
     }
 
     /**
      * Create a new decoder instance with the specified preset dictionary. The wrapper
      * is always {@link ZlibWrapper#ZLIB} because it is the only format that
      * supports the preset dictionary.
      *
      * @deprecated Use {@link ZlibCodecFactory#newZlibDecoder(byte[], int)}.
      */
     @Deprecated
     public static ZlibDecoder newZlibDecoder(byte[] dictionary) {
         return newZlibDecoder(dictionary, 0);
     }
 
     /**
      * Create a new decoder instance with the specified preset dictionary and maximum buffer allocation.
      * The wrapper is always {@link ZlibWrapper#ZLIB} because it is the only format that
      * supports the preset dictionary.
      *
      * @param maxAllocation
      *          Maximum size of the decompression buffer. Must be >= 0.
      *          If zero, maximum size is not limited by decoder.
      */
     public static ZlibDecoder newZlibDecoder(byte[] dictionary, int maxAllocation) {
         if (noJdkZlibDecoder) {
             return new JZlibDecoder(dictionary, maxAllocation);
         } else {
             return new JdkZlibDecoder(dictionary, maxAllocation);
         }
     }
 
     private ZlibCodecFactory() {
         // Unused
     }
 }