/*
    * ====================================================================
    * 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.http.entity.mime;
  
  import org.apache.http.entity.mime.content.ContentBody;
  
  /**
   * FormBodyPart class represents a content body that can be used as a part of multipart encoded
   * entities. This class automatically populates the header with standard fields based on
   * the content description of the enclosed body.
   *
   * @since 4.0
   */
  public class FormBodyPart {
  
      private final String name;
      private final Header header;
  
      private final ContentBody body;
  
      public FormBodyPart(final String name, final ContentBody body) {
          super();
          if (name == null) {
              throw new IllegalArgumentException("Name may not be null");
          }
          if (body == null) {
              throw new IllegalArgumentException("Body may not be null");
          }
          this.name = name;
          this.body = body;
          this.header = new Header();
  
          generateContentDisp(body);
          generateContentType(body);
          generateTransferEncoding(body);
      }
  
      public String getName() {
          return this.name;
      }
  
      public ContentBody getBody() {
          return this.body;
      }
  
      public Header getHeader() {
          return this.header;
      }
  
      public void addField(final String name, final String value) {
          if (name == null) {
              throw new IllegalArgumentException("Field name may not be null");
          }
          this.header.addField(new MinimalField(name, value));
      }
  
      protected void generateContentDisp(final ContentBody body) {
          StringBuilder buffer = new StringBuilder();
          buffer.append("form-data; name=\"");
          buffer.append(getName());
          buffer.append("\"");
          if (body.getFilename() != null) {
              buffer.append("; filename=\"");
              buffer.append(body.getFilename());
              buffer.append("\"");
          }
          addField(MIME.CONTENT_DISPOSITION, buffer.toString());
      }
  
      protected void generateContentType(final ContentBody body) {
          StringBuilder buffer = new StringBuilder();
          buffer.append(body.getMimeType()); // MimeType cannot be null
          if (body.getCharset() != null) { // charset may legitimately be null
              buffer.append("; charset=");
             buffer.append(body.getCharset());
         }
         addField(MIME.CONTENT_TYPE, buffer.toString());
     }
 
     protected void generateTransferEncoding(final ContentBody body) {
         addField(MIME.CONTENT_TRANSFER_ENC, body.getTransferEncoding()); // TE cannot be null
     }
 
 }