/*
    * ====================================================================
    * 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.core5.http.support;
  
  import java.util.Iterator;
  
  import org.apache.hc.core5.http.Header;
  import org.apache.hc.core5.http.HttpMessage;
  import org.apache.hc.core5.http.ProtocolVersion;
  import org.apache.hc.core5.http.message.BasicHeader;
  import org.apache.hc.core5.http.message.HeaderGroup;
  
  /**
   * Abstract {@link HttpMessage} builder.
   *
   * @since 5.1
   */
  public abstract class AbstractMessageBuilder<T> {
  
      private ProtocolVersion version;
      private HeaderGroup headerGroup;
  
      protected AbstractMessageBuilder() {
      }
  
      protected void digest(final HttpMessage message) {
          if (message == null) {
              return;
          }
          setVersion(message.getVersion());
          setHeaders(message.headerIterator());
      }
  
      public ProtocolVersion getVersion() {
          return version;
      }
  
      public AbstractMessageBuilder<T> setVersion(final ProtocolVersion version) {
          this.version = version;
          return this;
      }
  
      public Header[] getHeaders() {
          return headerGroup != null ? headerGroup.getHeaders() : null;
      }
  
      public Header[] getHeaders(final String name) {
          return headerGroup != null ? headerGroup.getHeaders(name) : null;
      }
  
      public AbstractMessageBuilder<T> setHeaders(final Header... headers) {
          if (headerGroup == null) {
              headerGroup = new HeaderGroup();
          }
          headerGroup.setHeaders(headers);
          return this;
      }
  
      public AbstractMessageBuilder<T> setHeaders(final Iterator<Header> it) {
          if (headerGroup == null) {
              headerGroup = new HeaderGroup();
          } else {
              headerGroup.clear();
          }
          while (it.hasNext()) {
              headerGroup.addHeader(it.next());
          }
          return this;
      }
  
      public Header[] getFirstHeaders() {
          return headerGroup != null ? headerGroup.getHeaders() : null;
      }
  
     public Header getFirstHeader(final String name) {
         return headerGroup != null ? headerGroup.getFirstHeader(name) : null;
     }
 
     public Header getLastHeader(final String name) {
         return headerGroup != null ? headerGroup.getLastHeader(name) : null;
     }
 
     public AbstractMessageBuilder<T> addHeader(final Header header) {
         if (headerGroup == null) {
             headerGroup = new HeaderGroup();
         }
         headerGroup.addHeader(header);
         return this;
     }
 
     public AbstractMessageBuilder<T> addHeader(final String name, final String value) {
         if (headerGroup == null) {
             headerGroup = new HeaderGroup();
         }
         headerGroup.addHeader(new BasicHeader(name, value));
         return this;
     }
 
     public AbstractMessageBuilder<T> removeHeader(final Header header) {
         if (headerGroup == null) {
             headerGroup = new HeaderGroup();
         }
         headerGroup.removeHeader(header);
         return this;
     }
 
     public AbstractMessageBuilder<T> removeHeaders(final String name) {
         if (name == null || headerGroup == null) {
             return this;
         }
         for (final Iterator<Header> i = headerGroup.headerIterator(); i.hasNext(); ) {
             final Header header = i.next();
             if (name.equalsIgnoreCase(header.getName())) {
                 i.remove();
             }
         }
         return this;
     }
 
     public AbstractMessageBuilder<T> setHeader(final Header header) {
         if (headerGroup == null) {
             headerGroup = new HeaderGroup();
         }
         headerGroup.setHeader(header);
         return this;
     }
 
     public AbstractMessageBuilder<T> setHeader(final String name, final String value) {
         if (headerGroup == null) {
             headerGroup = new HeaderGroup();
         }
         headerGroup.setHeader(new BasicHeader(name, value));
         return this;
     }
 
     protected abstract T build();
 
 }