/*
    * ====================================================================
    * 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;
  
  import java.io.File;
  import java.io.InputStream;
  import java.io.Serializable;
  import java.util.Arrays;
  import java.util.List;
  
  import org.apache.hc.core5.http.ContentType;
  import org.apache.hc.core5.http.HttpEntity;
  import org.apache.hc.core5.http.NameValuePair;
  import org.apache.hc.core5.http.io.entity.AbstractHttpEntity;
  import org.apache.hc.core5.http.io.entity.ByteArrayEntity;
  import org.apache.hc.core5.http.io.entity.FileEntity;
  import org.apache.hc.core5.http.io.entity.InputStreamEntity;
  import org.apache.hc.core5.http.io.entity.SerializableEntity;
  import org.apache.hc.core5.http.io.entity.StringEntity;
  
  /**
   * Builder for {@link HttpEntity} instances.
   * <p>
   * Several setter methods of this builder are mutually exclusive. In case of multiple invocations
   * of the following methods only the last one will have effect:
   * </p>
   * <ul>
   *   <li>{@link #setText(String)}</li>
   *   <li>{@link #setBinary(byte[])}</li>
   *   <li>{@link #setStream(java.io.InputStream)}</li>
   *   <li>{@link #setSerializable(java.io.Serializable)}</li>
   *   <li>{@link #setParameters(java.util.List)}</li>
   *   <li>{@link #setParameters(NameValuePair...)}</li>
   *   <li>{@link #setFile(java.io.File)}</li>
   * </ul>
   *
   * @since 4.3
   */
  public class EntityBuilder {
  
      private String text;
      private byte[] binary;
      private InputStream stream;
      private List<NameValuePair> parameters;
      private Serializable serializable;
      private File file;
      private ContentType contentType;
      private String contentEncoding;
      private boolean chunked;
      private boolean gzipCompressed;
  
      EntityBuilder() {
          super();
      }
  
      public static EntityBuilder create() {
          return new EntityBuilder();
      }
  
      private void clearContent() {
          this.text = null;
          this.binary = null;
          this.stream = null;
          this.parameters = null;
          this.serializable = null;
          this.file = null;
      }
  
      /**
       * Returns entity content as a string if set using {@link #setText(String)} method.
       */
      public String getText() {
          return text;
      }
 
     /**
      * Sets entity content as a string. This method is mutually exclusive with
      * {@link #setBinary(byte[])},
      * {@link #setStream(java.io.InputStream)} ,
      * {@link #setSerializable(java.io.Serializable)} ,
      * {@link #setParameters(java.util.List)},
      * {@link #setParameters(NameValuePair...)}
      * {@link #setFile(java.io.File)} methods.
      */
     public EntityBuilder setText(final String text) {
         clearContent();
         this.text = text;
         return this;
     }
 
     /**
      * Returns entity content as a byte array if set using
      * {@link #setBinary(byte[])} method.
      */
     public byte[] getBinary() {
         return binary;
     }
 
     /**
      * Sets entity content as a byte array. This method is mutually exclusive with
      * {@link #setText(String)},
      * {@link #setStream(java.io.InputStream)} ,
      * {@link #setSerializable(java.io.Serializable)} ,
      * {@link #setParameters(java.util.List)},
      * {@link #setParameters(NameValuePair...)}
      * {@link #setFile(java.io.File)} methods.
      */
     public EntityBuilder setBinary(final byte[] binary) {
         clearContent();
         this.binary = binary;
         return this;
     }
 
     /**
      * Returns entity content as a {@link InputStream} if set using
      * {@link #setStream(java.io.InputStream)} method.
      */
     public InputStream getStream() {
         return stream;
     }
 
     /**
      * Sets entity content as a {@link InputStream}. This method is mutually exclusive with
      * {@link #setText(String)},
      * {@link #setBinary(byte[])},
      * {@link #setSerializable(java.io.Serializable)} ,
      * {@link #setParameters(java.util.List)},
      * {@link #setParameters(NameValuePair...)}
      * {@link #setFile(java.io.File)} methods.
      */
     public EntityBuilder setStream(final InputStream stream) {
         clearContent();
         this.stream = stream;
         return this;
     }
 
     /**
      * Returns entity content as a parameter list if set using
      * {@link #setParameters(java.util.List)} or
      * {@link #setParameters(NameValuePair...)} methods.
      */
     public List<NameValuePair> getParameters() {
         return parameters;
     }
 
     /**
      * Sets entity content as a parameter list. This method is mutually exclusive with
      * {@link #setText(String)},
      * {@link #setBinary(byte[])},
      * {@link #setStream(java.io.InputStream)} ,
      * {@link #setSerializable(java.io.Serializable)} ,
      * {@link #setFile(java.io.File)} methods.
      */
     public EntityBuilder setParameters(final List<NameValuePair> parameters) {
         clearContent();
         this.parameters = parameters;
         return this;
     }
 
     /**
      * Sets entity content as a parameter list. This method is mutually exclusive with
      * {@link #setText(String)},
      * {@link #setBinary(byte[])},
      * {@link #setStream(java.io.InputStream)} ,
      * {@link #setSerializable(java.io.Serializable)} ,
      * {@link #setFile(java.io.File)} methods.
      */
     public EntityBuilder setParameters(final NameValuePair... parameters) {
         return setParameters(Arrays.asList(parameters));
     }
 
     /**
      * Returns entity content as a {@link Serializable} if set using
      * {@link #setSerializable(java.io.Serializable)} method.
      */
     public Serializable getSerializable() {
         return serializable;
     }
 
     /**
      * Sets entity content as a {@link Serializable}. This method is mutually exclusive with
      * {@link #setText(String)},
      * {@link #setBinary(byte[])},
      * {@link #setStream(java.io.InputStream)} ,
      * {@link #setParameters(java.util.List)},
      * {@link #setParameters(NameValuePair...)}
      * {@link #setFile(java.io.File)} methods.
      */
     public EntityBuilder setSerializable(final Serializable serializable) {
         clearContent();
         this.serializable = serializable;
         return this;
     }
 
     /**
      * Returns entity content as a {@link File} if set using
      * {@link #setFile(java.io.File)} method.
      */
     public File getFile() {
         return file;
     }
 
     /**
      * Sets entity content as a {@link File}. This method is mutually exclusive with
      * {@link #setText(String)},
      * {@link #setBinary(byte[])},
      * {@link #setStream(java.io.InputStream)} ,
      * {@link #setParameters(java.util.List)},
      * {@link #setParameters(NameValuePair...)}
      * {@link #setSerializable(java.io.Serializable)} methods.
      */
     public EntityBuilder setFile(final File file) {
         clearContent();
         this.file = file;
         return this;
     }
 
     /**
      * Returns {@link ContentType} of the entity, if set.
      */
     public ContentType getContentType() {
         return contentType;
     }
 
     /**
      * Sets {@link ContentType} of the entity.
      */
     public EntityBuilder setContentType(final ContentType contentType) {
         this.contentType = contentType;
         return this;
     }
 
     /**
      * Returns content encoding of the entity, if set.
      */
     public String getContentEncoding() {
         return contentEncoding;
     }
 
     /**
      * Sets content encoding of the entity.
      */
     public EntityBuilder setContentEncoding(final String contentEncoding) {
         this.contentEncoding = contentEncoding;
         return this;
     }
 
     /**
      * Returns {@code true} if entity is to be chunk coded, {@code false} otherwise.
      */
     public boolean isChunked() {
         return chunked;
     }
 
     /**
      * Makes entity chunk coded.
      */
     public EntityBuilder chunked() {
         this.chunked = true;
         return this;
     }
 
     /**
      * Returns {@code true} if entity is to be GZIP compressed, {@code false} otherwise.
      */
     public boolean isGzipCompressed() {
         return gzipCompressed;
     }
 
     /**
      * Makes entity GZIP compressed.
      */
     public EntityBuilder gzipCompressed() {
         this.gzipCompressed = true;
         return this;
     }
 
     private ContentType getContentOrDefault(final ContentType def) {
         return this.contentType != null ? this.contentType : def;
     }
 
     /**
      * Creates new instance of {@link HttpEntity} based on the current state.
      */
     public HttpEntity build() {
         final AbstractHttpEntity e;
         if (this.text != null) {
             e = new StringEntity(this.text, getContentOrDefault(ContentType.DEFAULT_TEXT), this.contentEncoding,
                 this.chunked);
         } else if (this.binary != null) {
             e = new ByteArrayEntity(this.binary, getContentOrDefault(ContentType.DEFAULT_BINARY),
                 this.contentEncoding, this.chunked);
         } else if (this.stream != null) {
             e = new InputStreamEntity(this.stream, -1, getContentOrDefault(ContentType.DEFAULT_BINARY),
                 this.contentEncoding);
         } else if (this.parameters != null) {
             e = new UrlEncodedFormEntity(this.parameters,
                     this.contentType != null ? this.contentType.getCharset() : null);
         } else if (this.serializable != null) {
             e = new SerializableEntity(this.serializable, ContentType.DEFAULT_BINARY, this.contentEncoding);
         } else if (this.file != null) {
             e = new FileEntity(this.file, getContentOrDefault(ContentType.DEFAULT_BINARY), this.contentEncoding);
         } else {
             throw new IllegalStateException("No entity set");
         }
         if (this.gzipCompressed) {
             return new GzipCompressingEntity(e);
         }
         return e;
     }
 
 }