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

   1 /*
   2  * Sone - FreenetLinkParser.java - Copyright © 2010 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.io.StringReader;
  24 import java.net.MalformedURLException;
  25 import java.util.logging.Level;
  26 import java.util.logging.Logger;
  27 import java.util.regex.Matcher;
  28 import java.util.regex.Pattern;
  29
  30 import net.pterodactylus.sone.core.Core;
  31 import net.pterodactylus.sone.data.Post;
  32 import net.pterodactylus.sone.data.Sone;
  33 import net.pterodactylus.sone.template.SoneAccessor;
  34 import net.pterodactylus.util.logging.Logging;
  35 import net.pterodactylus.util.template.TemplateContextFactory;
  36 import net.pterodactylus.util.template.TemplateParser;
  37 import freenet.keys.FreenetURI;
  38
  39 /**
  40  * {@link Parser} implementation that can recognize Freenet URIs.
  41  *
  42  * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
  43  */
  44 public class FreenetLinkParser implements Parser<FreenetLinkParserContext> {
  45
  46         /** The logger. */
  47         private static final Logger logger = Logging.getLogger(FreenetLinkParser.class);
  48
  49         /** Pattern to detect whitespace. */
  50         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]");
  51
  52         /**
  53          * Enumeration for all recognized link types.
  54          *
  55          * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
  56          */
  57         private enum LinkType {
  58
  59                 /** Link is a KSK. */
  60                 KSK,
  61
  62                 /** Link is a CHK. */
  63                 CHK,
  64
  65                 /** Link is an SSK. */
  66                 SSK,
  67
  68                 /** Link is a USK. */
  69                 USK,
  70
  71                 /** Link is HTTP. */
  72                 HTTP,
  73
  74                 /** Link is HTTPS. */
  75                 HTTPS,
  76
  77                 /** Link is a Sone. */
  78                 SONE,
  79
  80                 /** Link is a post. */
  81                 POST,
  82
  83         }
  84
  85         /** The core. */
  86         private final Core core;
  87
  88         /** The template factory. */
  89         private final TemplateContextFactory templateContextFactory;
  90
  91         /**
  92          * Creates a new freenet link parser.
  93          *
  94          * @param core
  95          *            The core
  96          * @param templateContextFactory
  97          *            The template context factory
  98          */
  99         public FreenetLinkParser(Core core, TemplateContextFactory templateContextFactory) {
 100                 this.core = core;
 101                 this.templateContextFactory = templateContextFactory;
 102         }
 103
 104         //
 105         // PART METHODS
 106         //
 107
 108         /**
 109          * {@inheritDoc}
 110          */
 111         @Override
 112         public Part parse(FreenetLinkParserContext context, Reader source) throws IOException {
 113                 PartContainer parts = new PartContainer();
 114                 BufferedReader bufferedReader = (source instanceof BufferedReader) ? (BufferedReader) source : new BufferedReader(source);
 115                 String line;
 116                 boolean lastLineEmpty = true;
 117                 int emptyLines = 0;
 118                 while ((line = bufferedReader.readLine()) != null) {
 119                         if (line.trim().length() == 0) {
 120                                 if (lastLineEmpty) {
 121                                         continue;
 122                                 }
 123                                 parts.add(createPlainTextPart("\n"));
 124                                 ++emptyLines;
 125                                 lastLineEmpty = emptyLines == 2;
 126                                 continue;
 127                         }
 128                         emptyLines = 0;
 129                         boolean lineComplete = true;
 130                         while (line.length() > 0) {
 131                                 int nextKsk = line.indexOf("KSK@");
 132                                 int nextChk = line.indexOf("CHK@");
 133                                 int nextSsk = line.indexOf("SSK@");
 134                                 int nextUsk = line.indexOf("USK@");
 135                                 int nextHttp = line.indexOf("http://");
 136                                 int nextHttps = line.indexOf("https://");
 137                                 int nextSone = line.indexOf("sone://");
 138                                 int nextPost = line.indexOf("post://");
 139                                 if ((nextKsk == -1) && (nextChk == -1) && (nextSsk == -1) && (nextUsk == -1) && (nextHttp == -1) && (nextHttps == -1) && (nextSone == -1) && (nextPost == -1)) {
 140                                         if (lineComplete && !lastLineEmpty) {
 141                                                 parts.add(createPlainTextPart("\n" + line));
 142                                         } else {
 143                                                 parts.add(createPlainTextPart(line));
 144                                         }
 145                                         break;
 146                                 }
 147                                 int next = Integer.MAX_VALUE;
 148                                 LinkType linkType = null;
 149                                 if ((nextKsk > -1) && (nextKsk < next)) {
 150                                         next = nextKsk;
 151                                         linkType = LinkType.KSK;
 152                                 }
 153                                 if ((nextChk > -1) && (nextChk < next)) {
 154                                         next = nextChk;
 155                                         linkType = LinkType.CHK;
 156                                 }
 157                                 if ((nextSsk > -1) && (nextSsk < next)) {
 158                                         next = nextSsk;
 159                                         linkType = LinkType.SSK;
 160                                 }
 161                                 if ((nextUsk > -1) && (nextUsk < next)) {
 162                                         next = nextUsk;
 163                                         linkType = LinkType.USK;
 164                                 }
 165                                 if ((nextHttp > -1) && (nextHttp < next)) {
 166                                         next = nextHttp;
 167                                         linkType = LinkType.HTTP;
 168                                 }
 169                                 if ((nextHttps > -1) && (nextHttps < next)) {
 170                                         next = nextHttps;
 171                                         linkType = LinkType.HTTPS;
 172                                 }
 173                                 if ((nextSone > -1) && (nextSone < next)) {
 174                                         next = nextSone;
 175                                         linkType = LinkType.SONE;
 176                                 }
 177                                 if ((nextPost > -1) && (nextPost < next)) {
 178                                         next = nextPost;
 179                                         linkType = LinkType.POST;
 180                                 }
 181                                 if ((next >= 8) && (line.substring(next - 8, next).equals("freenet:"))) {
 182                                         next -= 8;
 183                                         line = line.substring(0, next) + line.substring(next + 8);
 184                                 }
 185                                 Matcher matcher = whitespacePattern.matcher(line);
 186                                 int nextSpace = matcher.find(next) ? matcher.start() : line.length();
 187                                 if (nextSpace > (next + 4)) {
 188                                         if (!lastLineEmpty && lineComplete) {
 189                                                 parts.add(createPlainTextPart("\n" + line.substring(0, next)));
 190                                         } else {
 191                                                 parts.add(createPlainTextPart(line.substring(0, next)));
 192                                         }
 193                                         String link = line.substring(next, nextSpace);
 194                                         String name = link;
 195                                         logger.log(Level.FINER, "Found link: %s", link);
 196                                         logger.log(Level.FINEST, "Next: %d, CHK: %d, SSK: %d, USK: %d", new Object[] { next, nextChk, nextSsk, nextUsk });
 197
 198                                         if ((linkType == LinkType.KSK) || (linkType == LinkType.CHK) || (linkType == LinkType.SSK) || (linkType == LinkType.USK)) {
 199                                                 FreenetURI uri;
 200                                                 if (name.indexOf('?') > -1) {
 201                                                         name = name.substring(0, name.indexOf('?'));
 202                                                 }
 203                                                 if (name.endsWith("/")) {
 204                                                         name = name.substring(0, name.length() - 1);
 205                                                 }
 206                                                 try {
 207                                                         uri = new FreenetURI(name);
 208                                                         name = uri.lastMetaString();
 209                                                         if (name == null) {
 210                                                                 name = uri.getDocName();
 211                                                         }
 212                                                         if (name == null) {
 213                                                                 name = link.substring(0, Math.min(9, link.length()));
 214                                                         }
 215                                                         boolean fromPostingSone = (context.getPostingSone() != null) && ((linkType == LinkType.SSK) || (linkType == LinkType.USK)) && link.substring(4, Math.min(link.length(), 47)).equals(context.getPostingSone().getId());
 216                                                         parts.add(fromPostingSone ? createTrustedFreenetLinkPart(link, name) : createFreenetLinkPart(link, name));
 217                                                 } catch (MalformedURLException mue1) {
 218                                                         /* not a valid link, insert as plain text. */
 219                                                         parts.add(createPlainTextPart(link));
 220                                                 } catch (NullPointerException npe1) {
 221                                                         /* FreenetURI sometimes throws these, too. */
 222                                                         parts.add(createPlainTextPart(link));
 223                                                 } catch (ArrayIndexOutOfBoundsException aioobe1) {
 224                                                         /* oh, and these, too. */
 225                                                         parts.add(createPlainTextPart(link));
 226                                                 }
 227                                         } else if ((linkType == LinkType.HTTP) || (linkType == LinkType.HTTPS)) {
 228                                                 name = link.substring(linkType == LinkType.HTTP ? 7 : 8);
 229                                                 int firstSlash = name.indexOf('/');
 230                                                 int lastSlash = name.lastIndexOf('/');
 231                                                 if ((lastSlash - firstSlash) > 3) {
 232                                                         name = name.substring(0, firstSlash + 1) + "…" + name.substring(lastSlash);
 233                                                 }
 234                                                 if (name.endsWith("/")) {
 235                                                         name = name.substring(0, name.length() - 1);
 236                                                 }
 237                                                 if (((name.indexOf('/') > -1) && (name.indexOf('.') < name.lastIndexOf('.', name.indexOf('/'))) || ((name.indexOf('/') == -1) && (name.indexOf('.') < name.lastIndexOf('.')))) && name.startsWith("www.")) {
 238                                                         name = name.substring(4);
 239                                                 }
 240                                                 if (name.indexOf('?') > -1) {
 241                                                         name = name.substring(0, name.indexOf('?'));
 242                                                 }
 243                                                 link = "?_CHECKED_HTTP_=" + link;
 244                                                 parts.add(createInternetLinkPart(link, name));
 245                                         } else if (linkType == LinkType.SONE) {
 246                                                 String soneId = link.substring(7);
 247                                                 Sone sone = core.getSone(soneId, false);
 248                                                 if (sone != null) {
 249                                                         parts.add(createInSoneLinkPart("viewSone.html?sone=" + soneId, SoneAccessor.getNiceName(sone)));
 250                                                 } else {
 251                                                         parts.add(createPlainTextPart(link));
 252                                                 }
 253                                         } else if (linkType == LinkType.POST) {
 254                                                 String postId = link.substring(7);
 255                                                 Post post = core.getPost(postId, false);
 256                                                 if (post != null) {
 257                                                         String postText = post.getText();
 258                                                         postText = postText.substring(0, Math.min(postText.length(), 20)) + "…";
 259                                                         Sone postSone = post.getSone();
 260                                                         parts.add(createInSoneLinkPart("viewPost.html?post=" + postId, postText, (postSone == null) ? postText : SoneAccessor.getNiceName(post.getSone())));
 261                                                 } else {
 262                                                         parts.add(createPlainTextPart(link));
 263                                                 }
 264                                         }
 265                                         line = line.substring(nextSpace);
 266                                 } else {
 267                                         if (!lastLineEmpty && lineComplete) {
 268                                                 parts.add(createPlainTextPart("\n" + line.substring(0, next + 4)));
 269                                         } else {
 270                                                 parts.add(createPlainTextPart(line.substring(0, next + 4)));
 271                                         }
 272                                         line = line.substring(next + 4);
 273                                 }
 274                                 lineComplete = false;
 275                         }
 276                         lastLineEmpty = false;
 277                 }
 278                 for (int partIndex = parts.size() - 1; partIndex >= 0; --partIndex) {
 279                         if (!parts.getPart(partIndex).toString().equals("\n")) {
 280                                 break;
 281                         }
 282                         parts.removePart(partIndex);
 283                 }
 284                 return parts;
 285         }
 286
 287         //
 288         // PRIVATE METHODS
 289         //
 290
 291         /**
 292          * Creates a new plain text part based on a template.
 293          *
 294          * @param text
 295          *            The text to display
 296          * @return The part that displays the given text
 297          */
 298         private Part createPlainTextPart(String text) {
 299                 return new TemplatePart(templateContextFactory, TemplateParser.parse(new StringReader("<% text|html>"))).set("text", text);
 300         }
 301
 302         /**
 303          * Creates a new part based on a template that links to a site within the
 304          * normal internet.
 305          *
 306          * @param link
 307          *            The target of the link
 308          * @param name
 309          *            The name of the link
 310          * @return The part that displays the link
 311          */
 312         private Part createInternetLinkPart(String link, String name) {
 313                 return new TemplatePart(templateContextFactory, TemplateParser.parse(new StringReader("<a class=\"internet\" href=\"/<% link|html>\" title=\"<% link|html>\"><% name|html></a>"))).set("link", link).set("name", name);
 314         }
 315
 316         /**
 317          * Creates a new part based on a template that links to a site within
 318          * freenet.
 319          *
 320          * @param link
 321          *            The target of the link
 322          * @param name
 323          *            The name of the link
 324          * @return The part that displays the link
 325          */
 326         private Part createFreenetLinkPart(String link, String name) {
 327                 return new TemplatePart(templateContextFactory, TemplateParser.parse(new StringReader("<a class=\"freenet\" href=\"/<% link|html>\" title=\"<% link|html>\"><% name|html></a>"))).set("link", link).set("name", name);
 328         }
 329
 330         /**
 331          * Creates a new part based on a template that links to a page in the
 332          * poster’s keyspace.
 333          *
 334          * @param link
 335          *            The target of the link
 336          * @param name
 337          *            The name of the link
 338          * @return The part that displays the link
 339          */
 340         private Part createTrustedFreenetLinkPart(String link, String name) {
 341                 return new TemplatePart(templateContextFactory, TemplateParser.parse(new StringReader("<a class=\"freenet-trusted\" href=\"/<% link|html>\" title=\"<% link|html>\"><% name|html></a>"))).set("link", link).set("name", name);
 342         }
 343
 344         /**
 345          * Creates a new part based on a template that links to a page in Sone.
 346          *
 347          * @param link
 348          *            The target of the link
 349          * @param name
 350          *            The name of the link
 351          * @return The part that displays the link
 352          */
 353         private Part createInSoneLinkPart(String link, String name) {
 354                 return createInSoneLinkPart(link, name, name);
 355         }
 356
 357         /**
 358          * Creates a new part based on a template that links to a page in Sone.
 359          *
 360          * @param link
 361          *            The target of the link
 362          * @param name
 363          *            The name of the link
 364          * @param title
 365          *            The title attribute of the link
 366          * @return The part that displays the link
 367          */
 368         private Part createInSoneLinkPart(String link, String name, String title) {
 369                 return new TemplatePart(templateContextFactory, TemplateParser.parse(new StringReader("<a class=\"in-sone\" href=\"<%link|html>\" title=\"<%title|html>\"><%name|html></a>"))).set("link", link).set("name", name).set("title", title);
 370         }
 371
 372 }