package us.codecraft.webmagic.utils;
   
   import org.apache.commons.lang3.StringUtils;
   import us.codecraft.webmagic.Request;
   
   import java.net.MalformedURLException;
   import java.net.URL;
   import java.nio.charset.Charset;
   import java.util.ArrayList;
  import java.util.Collection;
  import java.util.List;
  import java.util.regex.Matcher;
  import java.util.regex.Pattern;
  
  /**
   * url and html utils.
   *
   * @author code4crafter@gmail.com <br>
   * @since 0.1.0
   */
  public class UrlUtils {
  
      /**
       * canonicalizeUrl
       * <br>
       * Borrowed from Jsoup.
       *
       * @param url url
       * @param refer refer
       * @return canonicalizeUrl
       */
      public static String canonicalizeUrl(String url, String refer) {
          URL base;
          try {
              try {
                  base = new URL(refer);
              } catch (MalformedURLException e) {
                  // the base is unsuitable, but the attribute may be abs on its own, so try that
                  URL abs = new URL(refer);
                  return abs.toExternalForm();
              }
              // workaround: java resolves '//path/file + ?foo' to '//path/?foo', not '//path/file?foo' as desired
              if (url.startsWith("?"))
                  url = base.getPath() + url;
              URL abs = new URL(base, url);
              return abs.toExternalForm();
          } catch (MalformedURLException e) {
              return "";
          }
      }
  
      /**
       *
       * @param url url
       * @return new url
       * @deprecated
       */
      public static String encodeIllegalCharacterInUrl(String url) {
          return url.replace(" ", "%20");
      }
  
      public static String fixIllegalCharacterInUrl(String url) {
          //TODO more charator support
          return url.replace(" ", "%20").replaceAll("#+", "#");
      }
  
      public static String getHost(String url) {
          String host = url;
          int i = StringUtils.ordinalIndexOf(url, "/", 3);
          if (i > 0) {
              host = StringUtils.substring(url, 0, i);
          }
          return host;
      }
  
      private static Pattern patternForProtocal = Pattern.compile("[\\w]+://");
  
      public static String removeProtocol(String url) {
          return patternForProtocal.matcher(url).replaceAll("");
      }
  
      public static String getDomain(String url) {
          String domain = removeProtocol(url);
          int i = StringUtils.indexOf(domain, "/", 1);
          if (i > 0) {
              domain = StringUtils.substring(domain, 0, i);
          }
          return removePort(domain);
      }
  
      public static String removePort(String domain) {
          int portIndex = domain.indexOf(":");
          if (portIndex != -1) {
              return domain.substring(0, portIndex);
          }else {
              return domain;
          }
      }
  
     public static List<Request> convertToRequests(Collection<String> urls) {
         List<Request> requestList = new ArrayList<Request>(urls.size());
         for (String url : urls) {
             requestList.add(new Request(url));
         }
         return requestList;
     }
 
     public static List<String> convertToUrls(Collection<Request> requests) {
         List<String> urlList = new ArrayList<String>(requests.size());
         for (Request request : requests) {
             urlList.add(request.getUrl());
         }
         return urlList;
     }
 
     private static final Pattern patternForCharset = Pattern.compile("charset\\s*=\\s*['\"]*([^\\s;'\"]*)", Pattern.CASE_INSENSITIVE);
 
     public static String getCharset(String contentType) {
         Matcher matcher = patternForCharset.matcher(contentType);
         if (matcher.find()) {
             String charset = matcher.group(1);
             if (Charset.isSupported(charset)) {
                 return charset;
             }
         }
         return null;
     }
 
 }