src/main/java/net/pterodactylus/sone/text/SoneTextParser.java

   1 /*
   2  * Sone - SoneTextParser.java - Copyright © 2010–2013 David Roden
   3  *
   4  * This program is free software: you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation, either version 3 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  16  */
  17
  18 package net.pterodactylus.sone.text;
  19
  20 import java.io.BufferedReader;
  21 import java.io.IOException;
  22 import java.io.Reader;
  23 import java.net.MalformedURLException;
  24 import java.util.logging.Level;
  25 import java.util.logging.Logger;
  26 import java.util.regex.Matcher;
  27 import java.util.regex.Pattern;
  28
  29 import net.pterodactylus.sone.data.Post;
  30 import net.pterodactylus.sone.data.Sone;
  31 import net.pterodactylus.sone.data.impl.DefaultSone;
  32 import net.pterodactylus.sone.database.Database;
  33 import net.pterodactylus.util.io.Closer;
  34 import net.pterodactylus.util.logging.Logging;
  35
  36 import freenet.keys.FreenetURI;
  37
  38 import com.google.common.base.Optional;
  39
  40 /**
  41  * {@link Parser} implementation that can recognize Freenet URIs.
  42  *
  43  * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
  44  */
  45 public class SoneTextParser implements Parser<SoneTextParserContext> {
  46
  47         /** The logger. */
  48         private static final Logger logger = Logging.getLogger(SoneTextParser.class);
  49
  50         /** Pattern to detect whitespace. */
  51         private static final Pattern whitespacePattern = Pattern.compile("[\\u000a\u0020\u00a0\u1680\u180e\u2000\u2001\u2002\u2003\u2004\u2005\u2006\u2007\u2008\u2009\u200a\u200b\u200c\u200d\u202f\u205f\u2060\u2800\u3000]");
  52
  53         /**
  54          * Enumeration for all recognized link types.
  55          *
  56          * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
  57          */
  58         private enum LinkType {
  59
  60                 /** Link is a KSK. */
  61                 KSK("KSK@", true),
  62
  63                 /** Link is a CHK. */
  64                 CHK("CHK@", true),
  65
  66                 /** Link is an SSK. */
  67                 SSK("SSK@", true),
  68
  69                 /** Link is a USK. */
  70                 USK("USK@", true),
  71
  72                 /** Link is HTTP. */
  73                 HTTP("http://", false),
  74
  75                 /** Link is HTTPS. */
  76                 HTTPS("https://", false),
  77
  78                 /** Link is a Sone. */
  79                 SONE("sone://", false),
  80
  81                 /** Link is a post. */
  82                 POST("post://", false);
  83
  84                 /** The scheme identifying this link type. */
  85                 private final String scheme;
  86                 private final boolean freenetLink;
  87
  88                 /**
  89                  * Creates a new link type identified by the given scheme.
  90                  *
  91                  * @param scheme
  92                  *            The scheme of the link type
  93                  * @param freenetLink
  94                  */
  95                 private LinkType(String scheme, boolean freenetLink) {
  96                         this.scheme = scheme;
  97                         this.freenetLink = freenetLink;
  98                 }
  99
 100                 /**
 101                  * Returns the scheme of this link type.
 102                  *
 103                  * @return The scheme of this link type
 104                  */
 105                 public String getScheme() {
 106                         return scheme;
 107                 }
 108
 109                 public boolean isFreenetLink() {
 110                         return freenetLink;
 111                 }
 112
 113         }
 114
 115         private final Database database;
 116
 117         /**
 118          * Creates a new freenet link parser.
 119          *
 120          * @param database
 121          */
 122         public SoneTextParser(Database database) {
 123                 this.database = database;
 124         }
 125
 126         //
 127         // PART METHODS
 128         //
 129
 130         @Override
 131         public Iterable<Part> parse(SoneTextParserContext context, Reader source) throws IOException {
 132                 PartContainer parts = new PartContainer();
 133                 BufferedReader bufferedReader = (source instanceof BufferedReader) ? (BufferedReader) source : new BufferedReader(source);
 134                 try {
 135                         String line;
 136                         boolean lastLineEmpty = true;
 137                         int emptyLines = 0;
 138                         while ((line = bufferedReader.readLine()) != null) {
 139                                 if (line.trim().length() == 0) {
 140                                         if (lastLineEmpty) {
 141                                                 continue;
 142                                         }
 143                                         parts.add(new PlainTextPart("\n"));
 144                                         ++emptyLines;
 145                                         lastLineEmpty = emptyLines == 2;
 146                                         continue;
 147                                 }
 148                                 emptyLines = 0;
 149                                 /*
 150                                  * lineComplete tracks whether the block you are parsing is the
 151                                  * first block of the line. this is important because sometimes
 152                                  * you have to add an additional line break.
 153                                  */
 154                                 boolean lineComplete = true;
 155                                 while (line.length() > 0) {
 156                                         int nextKsk = line.indexOf("KSK@");
 157                                         int nextChk = line.indexOf("CHK@");
 158                                         int nextSsk = line.indexOf("SSK@");
 159                                         int nextUsk = line.indexOf("USK@");
 160                                         int nextHttp = line.indexOf("http://");
 161                                         int nextHttps = line.indexOf("https://");
 162                                         int nextSone = line.indexOf("sone://");
 163                                         int nextPost = line.indexOf("post://");
 164                                         if ((nextKsk == -1) && (nextChk == -1) && (nextSsk == -1) && (nextUsk == -1) && (nextHttp == -1) && (nextHttps == -1) && (nextSone == -1) && (nextPost == -1)) {
 165                                                 if (lineComplete && !lastLineEmpty) {
 166                                                         parts.add(new PlainTextPart("\n" + line));
 167                                                 } else {
 168                                                         parts.add(new PlainTextPart(line));
 169                                                 }
 170                                                 break;
 171                                         }
 172                                         int next = Integer.MAX_VALUE;
 173                                         LinkType linkType = null;
 174                                         if ((nextKsk > -1) && (nextKsk < next)) {
 175                                                 next = nextKsk;
 176                                                 linkType = LinkType.KSK;
 177                                         }
 178                                         if ((nextChk > -1) && (nextChk < next)) {
 179                                                 next = nextChk;
 180                                                 linkType = LinkType.CHK;
 181                                         }
 182                                         if ((nextSsk > -1) && (nextSsk < next)) {
 183                                                 next = nextSsk;
 184                                                 linkType = LinkType.SSK;
 185                                         }
 186                                         if ((nextUsk > -1) && (nextUsk < next)) {
 187                                                 next = nextUsk;
 188                                                 linkType = LinkType.USK;
 189                                         }
 190                                         if ((nextHttp > -1) && (nextHttp < next)) {
 191                                                 next = nextHttp;
 192                                                 linkType = LinkType.HTTP;
 193                                         }
 194                                         if ((nextHttps > -1) && (nextHttps < next)) {
 195                                                 next = nextHttps;
 196                                                 linkType = LinkType.HTTPS;
 197                                         }
 198                                         if ((nextSone > -1) && (nextSone < next)) {
 199                                                 next = nextSone;
 200                                                 linkType = LinkType.SONE;
 201                                         }
 202                                         if ((nextPost > -1) && (nextPost < next)) {
 203                                                 next = nextPost;
 204                                                 linkType = LinkType.POST;
 205                                         }
 206
 207                                         /* cut off “freenet:” from before keys. */
 208                                         if (linkType.isFreenetLink() && (next >= 8) && (line.substring(next - 8, next).equals("freenet:"))) {
 209                                                 next -= 8;
 210                                                 line = line.substring(0, next) + line.substring(next + 8);
 211                                         }
 212
 213                                         /* if there is text before the next item, write it out. */
 214                                         if (lineComplete && !lastLineEmpty) {
 215                                                 parts.add(new PlainTextPart("\n"));
 216                                         }
 217                                         if (next > 0) {
 218                                                 parts.add(new PlainTextPart(line.substring(0, next)));
 219                                                 line = line.substring(next);
 220                                         }
 221                                         lineComplete = false;
 222
 223                                         Matcher matcher = whitespacePattern.matcher(line);
 224                                         int nextSpace = matcher.find(0) ? matcher.start() : line.length();
 225                                         String link = line.substring(0, nextSpace);
 226                                         String name = link;
 227                                         logger.log(Level.FINER, String.format("Found link: %s", link));
 228                                         logger.log(Level.FINEST, String.format("CHK: %d, SSK: %d, USK: %d", nextChk, nextSsk, nextUsk));
 229
 230                                         /* if there is no text after the scheme, it’s not a link! */
 231                                         if (link.equals(linkType.getScheme())) {
 232                                                 parts.add(new PlainTextPart(linkType.getScheme()));
 233                                                 line = line.substring(linkType.getScheme().length());
 234                                                 continue;
 235                                         }
 236
 237                                         if (linkType == LinkType.SONE) {
 238                                                 if (line.length() >= (7 + 43)) {
 239                                                         String soneId = line.substring(7, 50);
 240                                                         Optional<Sone> sone = database.getSone(soneId);
 241                                                         if (!sone.isPresent()) {
 242                                                                 /*
 243                                                                  * don’t use create=true above, we don’t want
 244                                                                  * the empty shell.
 245                                                                  */
 246                                                                 sone = Optional.<Sone>of(new DefaultSone(database, soneId, false, null));
 247                                                         }
 248                                                         parts.add(new SonePart(sone.get()));
 249                                                         line = line.substring(50);
 250                                                 } else {
 251                                                         parts.add(new PlainTextPart(line));
 252                                                         line = "";
 253                                                 }
 254                                                 continue;
 255                                         }
 256                                         if (linkType == LinkType.POST) {
 257                                                 if (line.length() >= (7 + 36)) {
 258                                                         String postId = line.substring(7, 43);
 259                                                         Optional<Post> post = database.getPost(postId);
 260                                                         if (post.isPresent()) {
 261                                                                 parts.add(new PostPart(post.get()));
 262                                                         } else {
 263                                                                 parts.add(new PlainTextPart(line.substring(0, 43)));
 264                                                         }
 265                                                         line = line.substring(43);
 266                                                 } else {
 267                                                         parts.add(new PlainTextPart(line));
 268                                                         line = "";
 269                                                 }
 270                                                 continue;
 271                                         }
 272
 273                                         if (linkType.isFreenetLink()) {
 274                                                 FreenetURI uri;
 275                                                 if (name.indexOf('?') > -1) {
 276                                                         name = name.substring(0, name.indexOf('?'));
 277                                                 }
 278                                                 if (name.endsWith("/")) {
 279                                                         name = name.substring(0, name.length() - 1);
 280                                                 }
 281                                                 try {
 282                                                         uri = new FreenetURI(name);
 283                                                         name = uri.lastMetaString();
 284                                                         if (name == null) {
 285                                                                 name = uri.getDocName();
 286                                                         }
 287                                                         if (name == null) {
 288                                                                 name = link.substring(0, Math.min(9, link.length()));
 289                                                         }
 290                                                         boolean fromPostingSone = ((linkType == LinkType.SSK) || (linkType == LinkType.USK)) && (context != null) && (context.getPostingSone() != null) && link.substring(4, Math.min(link.length(), 47)).equals(context.getPostingSone().getId());
 291                                                         parts.add(new FreenetLinkPart(link, name, fromPostingSone));
 292                                                 } catch (MalformedURLException mue1) {
 293                                                         /* not a valid link, insert as plain text. */
 294                                                         parts.add(new PlainTextPart(link));
 295                                                 } catch (NullPointerException npe1) {
 296                                                         /* FreenetURI sometimes throws these, too. */
 297                                                         parts.add(new PlainTextPart(link));
 298                                                 } catch (ArrayIndexOutOfBoundsException aioobe1) {
 299                                                         /* oh, and these, too. */
 300                                                         parts.add(new PlainTextPart(link));
 301                                                 }
 302                                         } else if ((linkType == LinkType.HTTP) || (linkType == LinkType.HTTPS)) {
 303                                                 name = link.substring(linkType == LinkType.HTTP ? 7 : 8);
 304                                                 int firstSlash = name.indexOf('/');
 305                                                 int lastSlash = name.lastIndexOf('/');
 306                                                 if ((lastSlash - firstSlash) > 3) {
 307                                                         name = name.substring(0, firstSlash + 1) + "…" + name.substring(lastSlash);
 308                                                 }
 309                                                 if (name.endsWith("/")) {
 310                                                         name = name.substring(0, name.length() - 1);
 311                                                 }
 312                                                 if (((name.indexOf('/') > -1) && (name.indexOf('.') < name.lastIndexOf('.', name.indexOf('/'))) || ((name.indexOf('/') == -1) && (name.indexOf('.') < name.lastIndexOf('.')))) && name.startsWith("www.")) {
 313                                                         name = name.substring(4);
 314                                                 }
 315                                                 if (name.indexOf('?') > -1) {
 316                                                         name = name.substring(0, name.indexOf('?'));
 317                                                 }
 318                                                 parts.add(new LinkPart(link, name));
 319                                         }
 320                                         line = line.substring(nextSpace);
 321                                 }
 322                                 lastLineEmpty = false;
 323                         }
 324                 } finally {
 325                         if (bufferedReader != source) {
 326                                 Closer.close(bufferedReader);
 327                         }
 328                 }
 329                 for (int partIndex = parts.size() - 1; partIndex >= 0; --partIndex) {
 330                         Part part = parts.getPart(partIndex);
 331                         if (!(part instanceof PlainTextPart) || !"\n".equals(part.getText())) {
 332                                 break;
 333                         }
 334                         parts.removePart(partIndex);
 335                 }
 336                 return parts;
 337         }
 338
 339 }