1/*
2 * Copyright (c) 2018-2019, 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 android.annotation.TargetApi;
33import android.content.Context;
34import android.os.Build;
35import android.text.Spannable;
36import android.text.SpannableString;
37import android.text.SpannableStringBuilder;
38import android.text.style.ForegroundColorSpan;
39import android.util.LruCache;
40
41import androidx.annotation.ColorInt;
42
43import com.google.android.material.color.MaterialColors;
44
45import java.util.ArrayList;
46import java.util.Arrays;
47import java.util.Collection;
48import java.util.Collections;
49import java.util.HashMap;
50import java.util.HashSet;
51import java.util.List;
52import java.util.Map;
53import java.util.Set;
54import java.util.regex.Matcher;
55import java.util.regex.Pattern;
56
57import eu.siacs.conversations.R;
58import eu.siacs.conversations.xmpp.Jid;
59
60public class IrregularUnicodeDetector {
61
62 private static final Map<Character.UnicodeBlock, Character.UnicodeBlock> NORMALIZATION_MAP;
63 private static final LruCache<Jid, PatternTuple> CACHE = new LruCache<>(4096);
64 private static final List<String> AMBIGUOUS_CYRILLIC = Arrays.asList("а","г","е","ѕ","і","ј","ķ","ԛ","о","р","с","у","х");
65
66 static {
67 Map<Character.UnicodeBlock, Character.UnicodeBlock> temp = new HashMap<>();
68 temp.put(Character.UnicodeBlock.LATIN_1_SUPPLEMENT, Character.UnicodeBlock.BASIC_LATIN);
69 NORMALIZATION_MAP = Collections.unmodifiableMap(temp);
70 }
71
72 private static Character.UnicodeBlock normalize(Character.UnicodeBlock in) {
73 if (NORMALIZATION_MAP.containsKey(in)) {
74 return NORMALIZATION_MAP.get(in);
75 } else {
76 return in;
77 }
78 }
79
80 public static Spannable style(final Context context, Jid jid) {
81 return style(jid, MaterialColors.getColor(context, com.google.android.material.R.attr.colorError,"colorError not found"));
82 }
83
84 private static Spannable style(Jid jid, @ColorInt int color) {
85 PatternTuple patternTuple = find(jid);
86 SpannableStringBuilder builder = new SpannableStringBuilder();
87 if (jid.getEscapedLocal() != null && patternTuple.local != null) {
88 SpannableString local = new SpannableString(jid.getEscapedLocal());
89 colorize(local, patternTuple.local, color);
90 builder.append(local);
91 builder.append('@');
92 }
93 if (jid.getDomain() != null) {
94 String[] labels = jid.getDomain().toEscapedString().split("\\.");
95 for (int i = 0; i < labels.length; ++i) {
96 SpannableString spannableString = new SpannableString(labels[i]);
97 if (patternTuple.domain.size() > i) {
98 colorize(spannableString, patternTuple.domain.get(i), color);
99 }
100 if (i != 0) {
101 builder.append('.');
102 }
103 builder.append(spannableString);
104 }
105 }
106 if (builder.length() != 0 && jid.getResource() != null) {
107 builder.append('/');
108 builder.append(jid.getResource());
109 }
110 return builder;
111 }
112
113 private static void colorize(SpannableString spannableString, Pattern pattern, @ColorInt int color) {
114 Matcher matcher = pattern.matcher(spannableString);
115 while (matcher.find()) {
116 if (matcher.start() < matcher.end()) {
117 spannableString.setSpan(new ForegroundColorSpan(color), matcher.start(), matcher.end(), Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
118 }
119 }
120 }
121
122 private static Map<Character.UnicodeBlock, List<String>> mapCompat(String word) {
123 Map<Character.UnicodeBlock, List<String>> map = new HashMap<>();
124 final int length = word.length();
125 for (int offset = 0; offset < length; ) {
126 final int codePoint = word.codePointAt(offset);
127 offset += Character.charCount(codePoint);
128 if (!Character.isLetter(codePoint)) {
129 continue;
130 }
131 Character.UnicodeBlock block = normalize(Character.UnicodeBlock.of(codePoint));
132 List<String> codePoints;
133 if (map.containsKey(block)) {
134 codePoints = map.get(block);
135 } else {
136 codePoints = new ArrayList<>();
137 map.put(block, codePoints);
138 }
139 codePoints.add(String.copyValueOf(Character.toChars(codePoint)));
140 }
141 return map;
142 }
143
144 @TargetApi(Build.VERSION_CODES.N)
145 private static Map<Character.UnicodeScript, List<String>> map(String word) {
146 Map<Character.UnicodeScript, List<String>> map = new HashMap<>();
147 final int length = word.length();
148 for (int offset = 0; offset < length; ) {
149 final int codePoint = word.codePointAt(offset);
150 Character.UnicodeScript script = Character.UnicodeScript.of(codePoint);
151 if (script != Character.UnicodeScript.COMMON) {
152 List<String> codePoints;
153 if (map.containsKey(script)) {
154 codePoints = map.get(script);
155 } else {
156 codePoints = new ArrayList<>();
157 map.put(script, codePoints);
158 }
159 codePoints.add(String.copyValueOf(Character.toChars(codePoint)));
160 }
161 offset += Character.charCount(codePoint);
162 }
163 return map;
164 }
165
166 private static Set<String> eliminateFirstAndGetCodePointsCompat(Map<Character.UnicodeBlock, List<String>> map) {
167 return eliminateFirstAndGetCodePoints(map, Character.UnicodeBlock.BASIC_LATIN);
168 }
169
170 @TargetApi(Build.VERSION_CODES.N)
171 private static Set<String> eliminateFirstAndGetCodePoints(Map<Character.UnicodeScript, List<String>> map) {
172 return eliminateFirstAndGetCodePoints(map, Character.UnicodeScript.COMMON);
173 }
174
175 private static <T> Set<String> eliminateFirstAndGetCodePoints(Map<T, List<String>> map, T defaultPick) {
176 T pick = defaultPick;
177 int size = 0;
178 for (Map.Entry<T, List<String>> entry : map.entrySet()) {
179 if (entry.getValue().size() > size) {
180 size = entry.getValue().size();
181 pick = entry.getKey();
182 }
183 }
184 map.remove(pick);
185 Set<String> all = new HashSet<>();
186 for (List<String> codePoints : map.values()) {
187 all.addAll(codePoints);
188 }
189 return all;
190 }
191
192 private static Set<String> findIrregularCodePoints(String word) {
193 Set<String> codePoints;
194 if (Build.VERSION.SDK_INT < Build.VERSION_CODES.N) {
195 final Map<Character.UnicodeBlock, List<String>> map = mapCompat(word);
196 final Set<String> set = asSet(map);
197 if (containsOnlyAmbiguousCyrillic(set)) {
198 return set;
199 }
200 codePoints = eliminateFirstAndGetCodePointsCompat(map);
201 } else {
202 final Map<Character.UnicodeScript, List<String>> map = map(word);
203 final Set<String> set = asSet(map);
204 if (containsOnlyAmbiguousCyrillic(set)) {
205 return set;
206 }
207 codePoints = eliminateFirstAndGetCodePoints(map);
208 }
209 return codePoints;
210 }
211
212 private static Set<String> asSet(Map<?, List<String>> map) {
213 final Set<String> flat = new HashSet<>();
214 for(List<String> value : map.values()) {
215 flat.addAll(value);
216 }
217 return flat;
218 }
219
220
221 private static boolean containsOnlyAmbiguousCyrillic(Collection<String> codePoints) {
222 for (String codePoint : codePoints) {
223 if (!AMBIGUOUS_CYRILLIC.contains(codePoint)) {
224 return false;
225 }
226 }
227 return true;
228 }
229
230 private static PatternTuple find(Jid jid) {
231 synchronized (CACHE) {
232 PatternTuple pattern = CACHE.get(jid);
233 if (pattern != null) {
234 return pattern;
235 }
236 pattern = PatternTuple.of(jid);
237 CACHE.put(jid, pattern);
238 return pattern;
239 }
240 }
241
242 private static Pattern create(Set<String> codePoints) {
243 final StringBuilder pattern = new StringBuilder();
244 for (String codePoint : codePoints) {
245 if (pattern.length() != 0) {
246 pattern.append('|');
247 }
248 pattern.append(Pattern.quote(codePoint));
249 }
250 return Pattern.compile(pattern.toString());
251 }
252
253 private static class PatternTuple {
254 private final Pattern local;
255 private final List<Pattern> domain;
256
257 private PatternTuple(Pattern local, List<Pattern> domain) {
258 this.local = local;
259 this.domain = domain;
260 }
261
262 private static PatternTuple of(Jid jid) {
263 final Pattern localPattern;
264 if (jid.getEscapedLocal() != null) {
265 localPattern = create(findIrregularCodePoints(jid.getEscapedLocal()));
266 } else {
267 localPattern = null;
268 }
269 String domain = jid.getDomain().toEscapedString();
270 final List<Pattern> domainPatterns = new ArrayList<>();
271 if (domain != null) {
272 for (String label : domain.split("\\.")) {
273 domainPatterns.add(create(findIrregularCodePoints(label)));
274 }
275 }
276 return new PatternTuple(localPattern, domainPatterns);
277 }
278 }
279}