1/*
 2 * Copyright (c) 2017, Daniel Gultsch All rights reserved.
 3 *
 4 * Redistribution and use in source and binary forms, with or without modification,
 5 * are permitted provided that the following conditions are met:
 6 *
 7 * 1. Redistributions of source code must retain the above copyright notice, this
 8 * list of conditions and the following disclaimer.
 9 *
10 * 2. Redistributions in binary form must reproduce the above copyright notice,
11 * this list of conditions and the following disclaimer in the documentation and/or
12 * other materials provided with the distribution.
13 *
14 * 3. Neither the name of the copyright holder nor the names of its contributors
15 * may be used to endorse or promote products derived from this software without
16 * specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
20 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
21 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
22 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
23 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
24 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
25 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
27 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28 */
29
30package eu.siacs.conversations.utils;
31
32import java.net.MalformedURLException;
33import java.net.URL;
34import java.util.regex.Pattern;
35
36import eu.siacs.conversations.entities.Message;
37import eu.siacs.conversations.http.AesGcmURLStreamHandler;
38
39public class MessageUtils {
40
41	private static final Pattern LTR_RTL = Pattern.compile("(\\u200E[^\\u200F]*\\u200F){3,}");
42
43	private static final String EMPTY_STRING = "";
44
45	public static String prepareQuote(Message message) {
46		final StringBuilder builder = new StringBuilder();
47		final String body = message.getMergedBody().toString();
48		for (String line : body.split("\n")) {
49			if (line.length() <= 0) {
50				continue;
51			}
52			final char c = line.charAt(0);
53			if (c == '>' && UIHelper.isPositionFollowedByQuoteableCharacter(line, 0)
54					|| (c == '\u00bb' && !UIHelper.isPositionFollowedByQuote(line, 0))) {
55				continue;
56			}
57			if (builder.length() != 0) {
58				builder.append('\n');
59			}
60			builder.append(line.trim());
61		}
62		return builder.toString();
63	}
64
65	public static boolean treatAsDownloadable(final String body, final boolean oob) {
66		try {
67			final String[] lines = body.split("\n");
68			if (lines.length == 0) {
69				return false;
70			}
71			for (String line : lines) {
72				if (line.contains("\\s+")) {
73					return false;
74				}
75			}
76			final URL url = new URL(lines[0]);
77			final String ref = url.getRef();
78			final String protocol = url.getProtocol();
79			final boolean encrypted = ref != null && AesGcmURLStreamHandler.IV_KEY.matcher(ref).matches();
80			final boolean followedByDataUri = lines.length == 2 && lines[1].startsWith("data:");
81			final boolean validAesGcm = AesGcmURLStreamHandler.PROTOCOL_NAME.equalsIgnoreCase(protocol) && encrypted && (lines.length == 1 || followedByDataUri);
82			final boolean validOob = ("http".equalsIgnoreCase(protocol) || "https".equalsIgnoreCase(protocol)) && (oob || encrypted) && lines.length == 1;
83			return validAesGcm || validOob;
84		} catch (MalformedURLException e) {
85			return false;
86		}
87	}
88
89	public static String filterLtrRtl(String body) {
90		return LTR_RTL.matcher(body).replaceFirst(EMPTY_STRING);
91	}
92}