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 static java.util.logging.Logger.getLogger;
  21
  22 import java.io.BufferedReader;
  23 import java.io.IOException;
  24 import java.io.Reader;
  25 import java.net.MalformedURLException;
  26 import java.util.logging.Level;
  27 import java.util.logging.Logger;
  28 import java.util.regex.Matcher;
  29 import java.util.regex.Pattern;
  30
  31 import net.pterodactylus.sone.data.Album;
  32 import net.pterodactylus.sone.data.Post;
  33 import net.pterodactylus.sone.data.Sone;
  34 import net.pterodactylus.sone.data.impl.IdOnlySone;
  35 import net.pterodactylus.sone.database.AlbumProvider;
  36 import net.pterodactylus.sone.database.PostProvider;
  37 import net.pterodactylus.sone.database.SoneProvider;
  38 import net.pterodactylus.util.io.Closer;
  39
  40 import com.google.common.base.Optional;
  41
  42 import freenet.keys.FreenetURI;
  43
  44 /**
  45  * {@link Parser} implementation that can recognize Freenet URIs.
  46  *
  47  * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
  48  */
  49 public class SoneTextParser implements Parser<SoneTextParserContext> {
  50
  51         /** The logger. */
  52         private static final Logger logger = getLogger(SoneTextParser.class.getName());
  53
  54         /** Pattern to detect whitespace. */
  55         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]");
  56
  57         /**
  58          * Enumeration for all recognized link types.
  59          *
  60          * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
  61          */
  62         private enum LinkType {
  63
  64                 KSK("KSK@", true),
  65                 CHK("CHK@", true),
  66                 SSK("SSK@", true),
  67                 USK("USK@", true),
  68                 HTTP("http://", false),
  69                 HTTPS("https://", false),
  70                 SONE("sone://", false),
  71                 POST("post://", false),
  72                 ALBUM("album://", false);
  73
  74                 private final String scheme;
  75                 private final boolean freenetLink;
  76
  77                 LinkType(String scheme, boolean freenetLink) {
  78                         this.scheme = scheme;
  79                         this.freenetLink = freenetLink;
  80                 }
  81
  82                 /**
  83                  * Returns the scheme of this link type.
  84                  *
  85                  * @return The scheme of this link type
  86                  */
  87                 public String getScheme() {
  88                         return scheme;
  89                 }
  90
  91                 public boolean isFreenetLink() {
  92                         return freenetLink;
  93                 }
  94
  95         }
  96
  97         private final SoneProvider soneProvider;
  98         private final PostProvider postProvider;
  99         private final AlbumProvider albumProvider;
 100
 101         public SoneTextParser(SoneProvider soneProvider, PostProvider postProvider, AlbumProvider albumProvider) {
 102                 this.soneProvider = soneProvider;
 103                 this.postProvider = postProvider;
 104                 this.albumProvider = albumProvider;
 105         }
 106
 107         //
 108         // PART METHODS
 109         //
 110
 111         /**
 112          * {@inheritDoc}
 113          */
 114         @Override
 115         public Iterable<Part> parse(SoneTextParserContext context, Reader source) throws IOException {
 116                 PartContainer parts = new PartContainer();
 117                 BufferedReader bufferedReader = (source instanceof BufferedReader) ? (BufferedReader) source : new BufferedReader(source);
 118                 try {
 119                         String line;
 120                         boolean lastLineEmpty = true;
 121                         int emptyLines = 0;
 122                         while ((line = bufferedReader.readLine()) != null) {
 123                                 if (line.trim().length() == 0) {
 124                                         if (lastLineEmpty) {
 125                                                 continue;
 126                                         }
 127                                         parts.add(new PlainTextPart("\n"));
 128                                         ++emptyLines;
 129                                         lastLineEmpty = emptyLines == 2;
 130                                         continue;
 131                                 }
 132                                 emptyLines = 0;
 133                                 /*
 134                                  * lineComplete tracks whether the block you are parsing is the
 135                                  * first block of the line. this is important because sometimes
 136                                  * you have to add an additional line break.
 137                                  */
 138                                 boolean lineComplete = true;
 139                                 while (line.length() > 0) {
 140                                         Optional<NextLink> nextLink = NextLink.findNextLink(line);
 141                                         if (!nextLink.isPresent()) {
 142                                                 if (lineComplete && !lastLineEmpty) {
 143                                                         parts.add(new PlainTextPart("\n" + line));
 144                                                 } else {
 145                                                         parts.add(new PlainTextPart(line));
 146                                                 }
 147                                                 break;
 148                                         }
 149                                         LinkType linkType = nextLink.get().getLinkType();
 150                                         int next = nextLink.get().getPosition();
 151
 152                                         /* cut off “freenet:” from before keys. */
 153                                         if (linkType.isFreenetLink() && (next >= 8) && (line.substring(next - 8, next).equals("freenet:"))) {
 154                                                 next -= 8;
 155                                                 line = line.substring(0, next) + line.substring(next + 8);
 156                                         }
 157
 158                                         /* if there is text before the next item, write it out. */
 159                                         if (lineComplete && !lastLineEmpty) {
 160                                                 parts.add(new PlainTextPart("\n"));
 161                                         }
 162                                         if (next > 0) {
 163                                                 parts.add(new PlainTextPart(line.substring(0, next)));
 164                                                 line = line.substring(next);
 165                                         }
 166                                         lineComplete = false;
 167
 168                                         Matcher matcher = whitespacePattern.matcher(line);
 169                                         int nextSpace = matcher.find(0) ? matcher.start() : line.length();
 170                                         String link = line.substring(0, nextSpace);
 171                                         String name = link;
 172                                         logger.log(Level.FINER, String.format("Found link: %s", link));
 173
 174                                         /* if there is no text after the scheme, it’s not a link! */
 175                                         if (link.equals(linkType.getScheme())) {
 176                                                 parts.add(new PlainTextPart(linkType.getScheme()));
 177                                                 line = line.substring(linkType.getScheme().length());
 178                                                 continue;
 179                                         }
 180
 181                                         if (linkType == LinkType.SONE) {
 182                                                 if (line.length() >= (7 + 43)) {
 183                                                         String soneId = line.substring(7, 50);
 184                                                         Optional<Sone> sone = soneProvider.getSone(soneId);
 185                                                         if (!sone.isPresent()) {
 186                                                                 /*
 187                                                                  * don’t use create=true above, we don’t want
 188                                                                  * the empty shell.
 189                                                                  */
 190                                                                 sone = Optional.<Sone>of(new IdOnlySone(soneId));
 191                                                         }
 192                                                         parts.add(new SonePart(sone.get()));
 193                                                         line = line.substring(50);
 194                                                 } else {
 195                                                         parts.add(new PlainTextPart(line));
 196                                                         line = "";
 197                                                 }
 198                                                 continue;
 199                                         }
 200                                         if (linkType == LinkType.POST) {
 201                                                 Optional<Post> post = postProvider.getPost(link.substring(7));
 202                                                 if (post.isPresent()) {
 203                                                         parts.add(new PostPart(post.get(), link.substring(7).equals(post.get().getInternalId())));
 204                                                 } else {
 205                                                         parts.add(new PlainTextPart(link));
 206                                                 }
 207                                                 line = line.substring(link.length());
 208                                                 continue;
 209                                         }
 210                                         if (linkType == LinkType.ALBUM) {
 211                                                 Optional<Album> album = albumProvider.getAlbum(link.substring(linkType.getScheme().length()));
 212                                                 if (album.isPresent()) {
 213                                                         parts.add(new AlbumPart(album.get()));
 214                                                 } else {
 215                                                         parts.add(new PlainTextPart(link));
 216                                                 }
 217                                                 line = line.substring(link.length());
 218                                                 continue;
 219                                         }
 220
 221                                         if (linkType.isFreenetLink()) {
 222                                                 FreenetURI uri;
 223                                                 if (name.indexOf('?') > -1) {
 224                                                         name = name.substring(0, name.indexOf('?'));
 225                                                 }
 226                                                 if (name.endsWith("/")) {
 227                                                         name = name.substring(0, name.length() - 1);
 228                                                 }
 229                                                 try {
 230                                                         uri = new FreenetURI(name);
 231                                                         name = uri.lastMetaString();
 232                                                         if (name == null) {
 233                                                                 name = uri.getDocName();
 234                                                         }
 235                                                         if (name == null) {
 236                                                                 name = link.substring(0, Math.min(9, link.length()));
 237                                                         }
 238                                                         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());
 239                                                         parts.add(new FreenetLinkPart(link, name, fromPostingSone));
 240                                                 } catch (MalformedURLException mue1) {
 241                                                         /* not a valid link, insert as plain text. */
 242                                                         parts.add(new PlainTextPart(link));
 243                                                 } catch (NullPointerException npe1) {
 244                                                         /* FreenetURI sometimes throws these, too. */
 245                                                         parts.add(new PlainTextPart(link));
 246                                                 } catch (ArrayIndexOutOfBoundsException aioobe1) {
 247                                                         /* oh, and these, too. */
 248                                                         parts.add(new PlainTextPart(link));
 249                                                 }
 250                                         } else if ((linkType == LinkType.HTTP) || (linkType == LinkType.HTTPS)) {
 251                                                 name = link.substring(linkType == LinkType.HTTP ? 7 : 8);
 252                                                 int firstSlash = name.indexOf('/');
 253                                                 int lastSlash = name.lastIndexOf('/');
 254                                                 if ((lastSlash - firstSlash) > 3) {
 255                                                         name = name.substring(0, firstSlash + 1) + "…" + name.substring(lastSlash);
 256                                                 }
 257                                                 if (name.endsWith("/")) {
 258                                                         name = name.substring(0, name.length() - 1);
 259                                                 }
 260                                                 if (((name.indexOf('/') > -1) && (name.indexOf('.') < name.lastIndexOf('.', name.indexOf('/'))) || ((name.indexOf('/') == -1) && (name.indexOf('.') < name.lastIndexOf('.')))) && name.startsWith("www.")) {
 261                                                         name = name.substring(4);
 262                                                 }
 263                                                 if (name.indexOf('?') > -1) {
 264                                                         name = name.substring(0, name.indexOf('?'));
 265                                                 }
 266                                                 parts.add(new LinkPart(link, name));
 267                                         }
 268                                         line = line.substring(nextSpace);
 269                                 }
 270                                 lastLineEmpty = false;
 271                         }
 272                 } finally {
 273                         if (bufferedReader != source) {
 274                                 Closer.close(bufferedReader);
 275                         }
 276                 }
 277                 for (int partIndex = parts.size() - 1; partIndex >= 0; --partIndex) {
 278                         Part part = parts.getPart(partIndex);
 279                         if (!(part instanceof PlainTextPart) || !"\n".equals(part.getText())) {
 280                                 break;
 281                         }
 282                         parts.removePart(partIndex);
 283                 }
 284                 return parts;
 285         }
 286
 287         private static class NextLink {
 288
 289                 private final int position;
 290                 private final LinkType linkType;
 291
 292                 private NextLink(int position, LinkType linkType) {
 293                         this.position = position;
 294                         this.linkType = linkType;
 295                 }
 296
 297                 public int getPosition() {
 298                         return position;
 299                 }
 300
 301                 public LinkType getLinkType() {
 302                         return linkType;
 303                 }
 304
 305                 public static Optional<NextLink> findNextLink(String line) {
 306                         int earliestLinkPosition = Integer.MAX_VALUE;
 307                         LinkType linkType = null;
 308                         for (LinkType possibleLinkType : LinkType.values()) {
 309                                 int nextLinkPosition = line.indexOf(possibleLinkType.getScheme());
 310                                 if (nextLinkPosition > -1) {
 311                                         if (nextLinkPosition < earliestLinkPosition) {
 312                                                 earliestLinkPosition = nextLinkPosition;
 313                                                 linkType = possibleLinkType;
 314                                         }
 315                                 }
 316                         }
 317                         return earliestLinkPosition < Integer.MAX_VALUE ?
 318                                         Optional.of(new NextLink(earliestLinkPosition, linkType)) : Optional.<NextLink>absent();
 319                 }
 320
 321         }
 322
 323 }