content: /*
   * Solo - A small and beautiful blogging system written in Java.
   * Copyright (c) 2010-present, b3log.org
   *
   * Solo is licensed under Mulan PSL v2.
   * You can use this software according to the terms and conditions of the Mulan PSL v2.
   * You may obtain a copy of Mulan PSL v2 at:
   *         http://license.coscl.org.cn/MulanPSL2
   * THIS SOFTWARE IS PROVIDED ON AN "AS IS" BASIS, WITHOUT WARRANTIES OF ANY KIND, EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO NON-INFRINGEMENT, MERCHANTABILITY OR FIT FOR A PARTICULAR PURPOSE.
   * See the Mulan PSL v2 for more details.
   */
  package org.b3log.solo.util;
  
  import org.apache.commons.lang3.StringUtils;
  import org.apache.commons.lang3.time.DateFormatUtils;
  import org.apache.commons.lang3.time.DateUtils;
  import org.apache.logging.log4j.Level;
  import org.apache.logging.log4j.LogManager;
  import org.apache.logging.log4j.Logger;
  import org.jsoup.nodes.Document;
  import org.jsoup.nodes.Element;
  import org.jsoup.select.Elements;
  
  import java.util.ArrayList;
  import java.util.List;
  import java.util.concurrent.ThreadLocalRandom;
  
  /**
   * Image utilities.
   *
   * @author <a href="http://88250.b3log.org">Liang Ding</a>
   * @version 1.2.0.1, May 15, 2020
   * @since 2.7.0
   */
  public final class Images {
  
      /**
       * Logger.
       */
      private static final Logger LOGGER = LogManager.getLogger(Images.class);
  
      /**
       * Community file service URL.
       */
      public static String COMMUNITY_FILE_URL = "https://b3logfile.com";
  
      /**
       * Checks whether the specified URL has uploaded.
       *
       * @param url the specified URL
       * @return {@code true} if it has uploaded, returns {@code false} otherwise
       */
      public static boolean uploaded(final String url) {
          return StringUtils.startsWith(url, COMMUNITY_FILE_URL) || StringUtils.startsWith(url, "https://img.hacpai.com");
      }
  
      /**
       * Qiniu image processing.
       *
       * @param doc the specified doc
       */
      public static void qiniuImgProcessing(final Document doc) {
          final Elements imgs = doc.select("img");
          if (imgs.isEmpty()) {
              return;
          }
  
          for (final Element img : imgs) {
              String imgSrc = img.attr("src");
              if (!uploaded(imgSrc) ||
                      StringUtils.contains(imgSrc, ".gif") || StringUtils.containsIgnoreCase(imgSrc, "imageView") ||
                      StringUtils.containsIgnoreCase(imgSrc, "data:")) {
                  continue;
              }
  
              imgSrc += "?imageView2/2/w/1280/format/jpg/interlace/1/q/100";
              img.attr("src", imgSrc);
          }
      }
  
      /**
       * Returns image URL of Qiniu image processing style with the specified width and height.
       *
       * @param imageURL the specified image URL
       * @param width    the specified width
       * @param height   the specified height
       * @return image URL
       */
      public static String imageSize(final String imageURL, final int width, final int height) {
          if (StringUtils.containsIgnoreCase(imageURL, "imageView")) {
              return imageURL;
          }
  
          return imageURL + "?imageView2/1/w/" + width + "/h/" + height + "/interlace/1/q/100";
      }
  
      /**
       * Gets an image URL randomly. Sees https://github.com/88250/bing for more details.
       *
       * @return an image URL
       */
      public static String randImage() {
          try {
              final long min = DateUtils.parseDate("20171104", new String[]{"yyyyMMdd"}).getTime();
              final long max = System.currentTimeMillis();
              final long delta = max - min;
              final long time = ThreadLocalRandom.current().nextLong(0, delta) + min;
              return COMMUNITY_FILE_URL + "/bing/" + DateFormatUtils.format(time, "yyyyMMdd") + ".jpg";
          } catch (final Exception e) {
              LOGGER.log(Level.ERROR, "Generates random image URL failed", e);
              return COMMUNITY_FILE_URL + "/bing/20171104.jpg";
          }
      }
  
      /**
       * Gets image URLs randomly.
       *
       * @param n the specified size
       * @return image URLs
       */
      public static List<String> randomImages(final int n) {
          final List<String> ret = new ArrayList<>();
          int i = 0;
          while (i < n * 5) {
              final String url = randImage();
              if (!ret.contains(url)) {
                  ret.add(url);
              }
  
              if (ret.size() >= n) {
                  return ret;
              }
  
              i++;
          }
  
          return ret;
      }
  
      /**
       * Private constructor.
       */
      private Images() {
      }
  }
  