/*
    * ====================================================================
    * 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 com.foxinmy.weixin4j.http.apache.mime;
  
  import java.io.File;
  import java.io.InputStream;
  import java.nio.charset.Charset;
  import java.util.ArrayList;
  import java.util.Collections;
  import java.util.List;
  import java.util.Random;
  
  import com.foxinmy.weixin4j.http.ContentType;
  import com.foxinmy.weixin4j.http.apache.content.ByteArrayBody;
  import com.foxinmy.weixin4j.http.apache.content.ContentBody;
  import com.foxinmy.weixin4j.http.apache.content.FileBody;
  import com.foxinmy.weixin4j.http.apache.content.InputStreamBody;
  import com.foxinmy.weixin4j.http.apache.content.StringBody;
  import com.foxinmy.weixin4j.util.NameValue;
  
  /**
   * Builder for multipart {@link HttpEntity}s.
   *
   * @since 4.3
   */
  public class MultipartEntityBuilder {
  
      /**
       * The pool of ASCII chars to be used for generating a multipart boundary.
       */
      private final static char[] MULTIPART_CHARS =
              "-_1234567890abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
                      .toCharArray();
  
      private final static String DEFAULT_SUBTYPE = "form-data";
  
      private ContentType contentType;
      private HttpMultipartMode mode = HttpMultipartMode.STRICT;
      private String boundary = null;
      private Charset charset = null;
      private List<FormBodyPart> bodyParts = null;
  
      public static MultipartEntityBuilder create() {
          return new MultipartEntityBuilder();
      }
  
      MultipartEntityBuilder() {
      }
  
      public MultipartEntityBuilder setMode(final HttpMultipartMode mode) {
          this.mode = mode;
          return this;
      }
  
      public MultipartEntityBuilder setLaxMode() {
          this.mode = HttpMultipartMode.BROWSER_COMPATIBLE;
          return this;
      }
  
      public MultipartEntityBuilder setStrictMode() {
          this.mode = HttpMultipartMode.STRICT;
          return this;
      }
  
      public MultipartEntityBuilder setBoundary(final String boundary) {
          this.boundary = boundary;
          return this;
      }
  
      /**
       * @since 4.4
       */
      public MultipartEntityBuilder setMimeSubtype(final String subType) {
          this.contentType = ContentType.create("multipart/" + subType);
         return this;
     }
 
     /**
      * @since 4.4
      *
      * @deprecated (4.5) Use {@link #setContentType(org.apache.http.entity.ContentType)}.
      */
     @Deprecated
     public MultipartEntityBuilder seContentType(final ContentType contentType) {
         return setContentType(contentType);
     }
 
     /**
      * @since 4.5
      */
     public MultipartEntityBuilder setContentType(final ContentType contentType) {
         this.contentType = contentType;
         return this;
     }
 
     public MultipartEntityBuilder setCharset(final Charset charset) {
         this.charset = charset;
         return this;
     }
 
     /**
      * @since 4.4
      */
     public MultipartEntityBuilder addPart(final FormBodyPart bodyPart) {
         if (bodyPart == null) {
             return this;
         }
         if (this.bodyParts == null) {
             this.bodyParts = new ArrayList<FormBodyPart>();
         }
         this.bodyParts.add(bodyPart);
         return this;
     }
 
     public MultipartEntityBuilder addPart(final String name, final ContentBody contentBody) {
         return addPart(FormBodyPartBuilder.create(name, contentBody).build());
     }
 
     public MultipartEntityBuilder addTextBody(
             final String name, final String text, final ContentType contentType) {
         return addPart(name, new StringBody(text, contentType));
     }
 
     public MultipartEntityBuilder addTextBody(
             final String name, final String text) {
         return addTextBody(name, text, ContentType.DEFAULT_TEXT);
     }
 
     public MultipartEntityBuilder addBinaryBody(
             final String name, final byte[] b, final ContentType contentType, final String filename) {
         return addPart(name, new ByteArrayBody(b, contentType, filename));
     }
 
     public MultipartEntityBuilder addBinaryBody(
             final String name, final byte[] b) {
         return addBinaryBody(name, b, ContentType.DEFAULT_BINARY, null);
     }
 
     public MultipartEntityBuilder addBinaryBody(
             final String name, final File file, final ContentType contentType, final String filename) {
         return addPart(name, new FileBody(file, contentType, filename));
     }
 
     public MultipartEntityBuilder addBinaryBody(
             final String name, final File file) {
         return addBinaryBody(name, file, ContentType.DEFAULT_BINARY, file != null ? file.getName() : null);
     }
 
     public MultipartEntityBuilder addBinaryBody(
             final String name, final InputStream stream, final ContentType contentType,
             final String filename) {
         return addPart(name, new InputStreamBody(stream, contentType, filename));
     }
 
     public MultipartEntityBuilder addBinaryBody(final String name, final InputStream stream) {
         return addBinaryBody(name, stream, ContentType.DEFAULT_BINARY, null);
     }
 
     private String generateBoundary() {
         final StringBuilder buffer = new StringBuilder();
         final Random rand = new Random();
         final int count = rand.nextInt(11) + 30; // a random size from 30 to 40
         for (int i = 0; i < count; i++) {
             buffer.append(MULTIPART_CHARS[rand.nextInt(MULTIPART_CHARS.length)]);
         }
         return buffer.toString();
     }
 
     public MultipartFormEntity buildEntity() {
         String boundaryCopy = boundary;
         if (boundaryCopy == null && contentType != null) {
             boundaryCopy = contentType.getParameter("boundary");
         }
         if (boundaryCopy == null) {
             boundaryCopy = generateBoundary();
         }
         Charset charsetCopy = charset;
         if (charsetCopy == null && contentType != null) {
             charsetCopy = contentType.getCharset();
         }
         final List<NameValue> paramsList = new ArrayList<NameValue>(2);
         paramsList.add(new NameValue("boundary", boundaryCopy));
         if (charsetCopy != null) {
             paramsList.add(new NameValue("charset", charsetCopy.name()));
         }
         final NameValue[] params = paramsList.toArray(new NameValue[paramsList.size()]);
         final ContentType contentTypeCopy = contentType != null ?
                 contentType.withParameters(params) :
                 ContentType.create("multipart/" + DEFAULT_SUBTYPE, params);
         final List<FormBodyPart> bodyPartsCopy = bodyParts != null ? new ArrayList<FormBodyPart>(bodyParts) :
                 Collections.<FormBodyPart>emptyList();
         final HttpMultipartMode modeCopy = mode != null ? mode : HttpMultipartMode.STRICT;
         final AbstractMultipartForm form;
         switch (modeCopy) {
             case BROWSER_COMPATIBLE:
                 form = new HttpBrowserCompatibleMultipart(charsetCopy, boundaryCopy, bodyPartsCopy);
                 break;
             case RFC6532:
                 form = new HttpRFC6532Multipart(charsetCopy, boundaryCopy, bodyPartsCopy);
                 break;
             default:
                 form = new HttpStrictMultipart(charsetCopy, boundaryCopy, bodyPartsCopy);
         }
         return new MultipartFormEntity(form, contentTypeCopy, form.getTotalLength());
     }
 }