/*
    * ====================================================================
    * 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.entity.mime;
  
  import java.util.List;
  
  import org.apache.hc.core5.http.ContentType;
  import org.apache.hc.core5.http.NameValuePair;
  import org.apache.hc.core5.util.Args;
  import org.apache.hc.core5.util.Asserts;
  
  /**
   * Builder for individual {@link MultipartPart}s.
   *
   * @since 4.4
   */
  public class MultipartPartBuilder {
  
      private ContentBody body;
      private final Header header;
  
      public static MultipartPartBuilder create(final ContentBody body) {
          return new MultipartPartBuilder(body);
      }
  
      public static MultipartPartBuilder create() {
          return new MultipartPartBuilder();
      }
  
      MultipartPartBuilder(final ContentBody body) {
          this();
          this.body = body;
      }
  
      MultipartPartBuilder() {
          this.header = new Header();
      }
  
      public MultipartPartBuilder setBody(final ContentBody body) {
          this.body = body;
          return this;
      }
  
      public MultipartPartBuilder addHeader(final String name, final String value, final List<NameValuePair> parameters) {
          Args.notNull(name, "Header name");
          this.header.addField(new MimeField(name, value, parameters));
          return this;
      }
  
      public MultipartPartBuilder addHeader(final String name, final String value) {
          Args.notNull(name, "Header name");
          this.header.addField(new MimeField(name, value));
          return this;
      }
  
      public MultipartPartBuilder setHeader(final String name, final String value) {
          Args.notNull(name, "Header name");
          this.header.setField(new MimeField(name, value));
          return this;
      }
  
      public MultipartPartBuilder removeHeaders(final String name) {
          Args.notNull(name, "Header name");
          this.header.removeFields(name);
          return this;
      }
  
      public MultipartPart build() {
          Asserts.notNull(this.body, "Content body");
          final Header headerCopy = new Header();
          final List<MimeField> fields = this.header.getFields();
          for (final MimeField field: fields) {
              headerCopy.addField(field);
          }
         if (headerCopy.getField(MimeConsts.CONTENT_TYPE) == null) {
             final ContentType contentType;
             if (body instanceof AbstractContentBody) {
                 contentType = ((AbstractContentBody) body).getContentType();
             } else {
                 contentType = null;
             }
             if (contentType != null) {
                 headerCopy.addField(new MimeField(MimeConsts.CONTENT_TYPE, contentType.toString()));
             } else {
                 final StringBuilder buffer = new StringBuilder();
                 buffer.append(this.body.getMimeType()); // MimeType cannot be null
                 if (this.body.getCharset() != null) { // charset may legitimately be null
                     buffer.append("; charset=");
                     buffer.append(this.body.getCharset());
                 }
                 headerCopy.addField(new MimeField(MimeConsts.CONTENT_TYPE, buffer.toString()));
             }
         }
         return new MultipartPart(this.body, headerCopy);
     }
 }