content: /*
   * Copyright 2007 ZXing authors
   *
   * Licensed 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.
   */
  
  package com.ailiwean.core.zxing.core.client.result;
  
  
  import com.ailiwean.core.zxing.core.Result;
  
  import java.util.regex.Matcher;
  import java.util.regex.Pattern;
  
  /**
   * Tries to parse results that are a URI of some kind.
   * 
   * @author Sean Owen
   */
  public final class URIResultParser extends ResultParser {
  
    private static final Pattern ALLOWED_URI_CHARS_PATTERN =
        Pattern.compile("[-._~:/?#\\[\\]@!$&'()*+,;=%A-Za-z0-9]+");
    private static final Pattern USER_IN_HOST = Pattern.compile(":/*([^/@]+)@[^/]+");
    // See http://www.ietf.org/rfc/rfc2396.txt
    private static final Pattern URL_WITH_PROTOCOL_PATTERN = Pattern.compile("[a-zA-Z][a-zA-Z0-9+-.]+:");
    private static final Pattern URL_WITHOUT_PROTOCOL_PATTERN = Pattern.compile(
        "([a-zA-Z0-9\\-]+\\.){1,6}[a-zA-Z]{2,}" + // host name elements; allow up to say 6 domain elements
        "(:\\d{1,5})?" + // maybe port
        "(/|\\?|$)"); // query, path or nothing
  
    @Override
    public URIParsedResult parse(Result result) {
      String rawText = getMassagedText(result);
      // We specifically handle the odd "URL" scheme here for simplicity and add "URI" for fun
      // Assume anything starting this way really means to be a URI
      if (rawText.startsWith("URL:") || rawText.startsWith("URI:")) {
        return new URIParsedResult(rawText.substring(4).trim(), null);
      }
      rawText = rawText.trim();
      if (!isBasicallyValidURI(rawText) || isPossiblyMaliciousURI(rawText)) {
        return null;
      }
      return new URIParsedResult(rawText, null);
    }
  
    /**
     * @return true if the URI contains suspicious patterns that may suggest it intends to
     *  mislead the user about its true nature. At the moment this looks for the presence
     *  of user/password syntax in the host/authority portion of a URI which may be used
     *  in attempts to make the URI's host appear to be other than it is. Example:
     *  http://yourbank.com@phisher.com  This URI connects to phisher.com but may appear
     *  to connect to yourbank.com at first glance.
     */
    static boolean isPossiblyMaliciousURI(String uri) {
      return !ALLOWED_URI_CHARS_PATTERN.matcher(uri).matches() || USER_IN_HOST.matcher(uri).find();
    }
  
    static boolean isBasicallyValidURI(String uri) {
      if (uri.contains(" ")) {
        // Quick hack check for a common case
        return false;
      }
      Matcher m = URL_WITH_PROTOCOL_PATTERN.matcher(uri);
      if (m.find() && m.start() == 0) { // match at start only
        return true;
      }
      m = URL_WITHOUT_PROTOCOL_PATTERN.matcher(uri);
      return m.find() && m.start() == 0;
    }
  
  }