/*
    * ====================================================================
    * Licensed to the Apache Software Foundation (ASF) under one
    * or more contributor license agreements.  See the NOTICE file
    * distributed with this work for additional information
    * regarding copyright ownership.  The ASF 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
   *
   *   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.
   * ====================================================================
   *
   * This software consists of voluntary contributions made by many
   * individuals on behalf of the Apache Software Foundation.  For more
   * information on the Apache Software Foundation, please see
   * <http://www.apache.org/>.
   *
   */
  
  package org.apache.hc.client5.http.impl;
  
  import java.nio.ByteBuffer;
  
  import org.apache.hc.core5.annotation.Internal;
  import org.apache.hc.core5.util.Args;
  import org.slf4j.Logger;
  
  @Internal
  public class Wire {
  
      private static final int MAX_STRING_BUILDER_SIZE = 2048;
  
      private static final ThreadLocal<StringBuilder> THREAD_LOCAL = new ThreadLocal<>();
  
      /**
       * Returns a {@code StringBuilder} that this Layout implementation can use to write the formatted log event to.
       *
       * @return a {@code StringBuilder}
       */
      private static StringBuilder getStringBuilder() {
          StringBuilder result = THREAD_LOCAL.get();
          if (result == null) {
              result = new StringBuilder(MAX_STRING_BUILDER_SIZE);
              THREAD_LOCAL.set(result);
          }
          trimToMaxSize(result, MAX_STRING_BUILDER_SIZE);
          result.setLength(0);
          return result;
      }
  
      /**
       * Ensures that the char[] array of the specified StringBuilder does not exceed the specified number of characters.
       * This method is useful to ensure that excessively long char[] arrays are not kept in memory forever.
       *
       * @param stringBuilder the StringBuilder to check
       * @param maxSize the maximum number of characters the StringBuilder is allowed to have
       */
      private static void trimToMaxSize(final StringBuilder stringBuilder, final int maxSize) {
          if (stringBuilder != null && stringBuilder.capacity() > maxSize) {
              stringBuilder.setLength(maxSize);
              stringBuilder.trimToSize();
          }
      }
  
      private final Logger log;
      private final String id;
  
      public Wire(final Logger log, final String id) {
          super();
          this.log = log;
          this.id = id;
      }
  
      private void wire(final String header, final byte[] b, final int pos, final int off) {
          final StringBuilder buffer = getStringBuilder();
          for (int i = 0; i < off; i++) {
              final int ch = b[pos + i];
              if (ch == 13) {
                  buffer.append("[\\r]");
              } else if (ch == 10) {
                  buffer.append("[\\n]\"");
                  buffer.insert(0, "\"");
                  buffer.insert(0, header);
                  log.debug("{} {}", this.id, buffer);
                  buffer.setLength(0);
              } else if ((ch < 32) || (ch >= 127)) {
                  buffer.append("[0x");
                  buffer.append(Integer.toHexString(ch));
                  buffer.append("]");
              } else {
                  buffer.append((char) ch);
             }
         }
         if (buffer.length() > 0) {
             buffer.append('\"');
             buffer.insert(0, '\"');
             buffer.insert(0, header);
             log.debug("{} {}", this.id, buffer);
         }
     }
 
 
     public boolean isEnabled() {
         return log.isDebugEnabled();
     }
 
     public void output(final byte[] b, final int pos, final int off) {
         Args.notNull(b, "Output");
         wire(">> ", b, pos, off);
     }
 
     public void input(final byte[] b, final int pos, final int off) {
         Args.notNull(b, "Input");
         wire("<< ", b, pos, off);
     }
 
     public void output(final byte[] b) {
         Args.notNull(b, "Output");
         output(b, 0, b.length);
     }
 
     public void input(final byte[] b) {
         Args.notNull(b, "Input");
         input(b, 0, b.length);
     }
 
     public void output(final int b) {
         output(new byte[] {(byte) b});
     }
 
     public void input(final int b) {
         input(new byte[] {(byte) b});
     }
 
     public void output(final String s) {
         Args.notNull(s, "Output");
         output(s.getBytes());
     }
 
     public void input(final String s) {
         Args.notNull(s, "Input");
         input(s.getBytes());
     }
 
     public void output(final ByteBuffer b) {
         Args.notNull(b, "Output");
         if (b.hasArray()) {
             output(b.array(), b.arrayOffset() + b.position(), b.remaining());
         } else {
             final byte[] tmp = new byte[b.remaining()];
             b.get(tmp);
             output(tmp);
         }
     }
 
     public void input(final ByteBuffer b) {
         Args.notNull(b, "Input");
         if (b.hasArray()) {
             input(b.array(), b.arrayOffset() + b.position(), b.remaining());
         } else {
             final byte[] tmp = new byte[b.remaining()];
             b.get(tmp);
             input(tmp);
         }
     }
 
 }