Extract functions to detect long-enough links.
[Sone.git] / src / main / java / net / pterodactylus / sone / text / SoneTextParser.java
index 3085517..efb36c4 100644 (file)
 
 package net.pterodactylus.sone.text;
 
+import static com.google.common.base.Optional.absent;
+import static com.google.common.base.Optional.of;
+import static com.google.common.collect.FluentIterable.from;
+
 import java.io.BufferedReader;
 import java.io.IOException;
 import java.io.Reader;
 import java.net.MalformedURLException;
+import java.util.Comparator;
+import java.util.EnumMap;
+import java.util.Map.Entry;
 import java.util.logging.Level;
 import java.util.logging.Logger;
 import java.util.regex.Matcher;
@@ -33,9 +40,8 @@ import net.pterodactylus.sone.database.Database;
 import net.pterodactylus.util.io.Closer;
 import net.pterodactylus.util.logging.Logging;
 
-import freenet.keys.FreenetURI;
-
 import com.google.common.base.Optional;
+import freenet.keys.FreenetURI;
 
 /**
  * {@link Parser} implementation that can recognize Freenet URIs.
@@ -58,32 +64,33 @@ public class SoneTextParser implements Parser<SoneTextParserContext> {
        private enum LinkType {
 
                /** Link is a KSK. */
-               KSK("KSK@", true),
+               KSK("KSK@", true, false),
 
                /** Link is a CHK. */
-               CHK("CHK@", true),
+               CHK("CHK@", true, false),
 
                /** Link is an SSK. */
-               SSK("SSK@", true),
+               SSK("SSK@", true, false),
 
                /** Link is a USK. */
-               USK("USK@", true),
+               USK("USK@", true, false),
 
                /** Link is HTTP. */
-               HTTP("http://", false),
+               HTTP("http://", false, true),
 
                /** Link is HTTPS. */
-               HTTPS("https://", false),
+               HTTPS("https://", false, true),
 
                /** Link is a Sone. */
-               SONE("sone://", false),
+               SONE("sone://", false, false),
 
                /** Link is a post. */
-               POST("post://", false);
+               POST("post://", false, false);
 
                /** The scheme identifying this link type. */
                private final String scheme;
                private final boolean freenetLink;
+               private final boolean internetLink;
 
                /**
                 * Creates a new link type identified by the given scheme.
@@ -92,9 +99,10 @@ public class SoneTextParser implements Parser<SoneTextParserContext> {
                 *            The scheme of the link type
                 * @param freenetLink
                 */
-               private LinkType(String scheme, boolean freenetLink) {
+               private LinkType(String scheme, boolean freenetLink, boolean internetLink) {
                        this.scheme = scheme;
                        this.freenetLink = freenetLink;
+                       this.internetLink = internetLink;
                }
 
                /**
@@ -110,6 +118,10 @@ public class SoneTextParser implements Parser<SoneTextParserContext> {
                        return freenetLink;
                }
 
+               public boolean isInternetLink() {
+                       return internetLink;
+               }
+
        }
 
        private final Database database;
@@ -153,15 +165,8 @@ public class SoneTextParser implements Parser<SoneTextParserContext> {
                                 */
                                boolean lineComplete = true;
                                while (line.length() > 0) {
-                                       int nextKsk = line.indexOf("KSK@");
-                                       int nextChk = line.indexOf("CHK@");
-                                       int nextSsk = line.indexOf("SSK@");
-                                       int nextUsk = line.indexOf("USK@");
-                                       int nextHttp = line.indexOf("http://");
-                                       int nextHttps = line.indexOf("https://");
-                                       int nextSone = line.indexOf("sone://");
-                                       int nextPost = line.indexOf("post://");
-                                       if ((nextKsk == -1) && (nextChk == -1) && (nextSsk == -1) && (nextUsk == -1) && (nextHttp == -1) && (nextHttps == -1) && (nextSone == -1) && (nextPost == -1)) {
+                                       Optional<NextLink> nextLink = findNextLink(line);
+                                       if (!nextLink.isPresent()) {
                                                if (lineComplete && !lastLineEmpty) {
                                                        parts.add(new PlainTextPart("\n" + line));
                                                } else {
@@ -169,40 +174,9 @@ public class SoneTextParser implements Parser<SoneTextParserContext> {
                                                }
                                                break;
                                        }
-                                       int next = Integer.MAX_VALUE;
-                                       LinkType linkType = null;
-                                       if ((nextKsk > -1) && (nextKsk < next)) {
-                                               next = nextKsk;
-                                               linkType = LinkType.KSK;
-                                       }
-                                       if ((nextChk > -1) && (nextChk < next)) {
-                                               next = nextChk;
-                                               linkType = LinkType.CHK;
-                                       }
-                                       if ((nextSsk > -1) && (nextSsk < next)) {
-                                               next = nextSsk;
-                                               linkType = LinkType.SSK;
-                                       }
-                                       if ((nextUsk > -1) && (nextUsk < next)) {
-                                               next = nextUsk;
-                                               linkType = LinkType.USK;
-                                       }
-                                       if ((nextHttp > -1) && (nextHttp < next)) {
-                                               next = nextHttp;
-                                               linkType = LinkType.HTTP;
-                                       }
-                                       if ((nextHttps > -1) && (nextHttps < next)) {
-                                               next = nextHttps;
-                                               linkType = LinkType.HTTPS;
-                                       }
-                                       if ((nextSone > -1) && (nextSone < next)) {
-                                               next = nextSone;
-                                               linkType = LinkType.SONE;
-                                       }
-                                       if ((nextPost > -1) && (nextPost < next)) {
-                                               next = nextPost;
-                                               linkType = LinkType.POST;
-                                       }
+
+                                       int next = nextLink.get().getNextIndex();
+                                       LinkType linkType = nextLink.get().getLinkType();
 
                                        /* cut off “freenet:” from before keys. */
                                        if (linkType.isFreenetLink() && (next >= 8) && (line.substring(next - 8, next).equals("freenet:"))) {
@@ -220,12 +194,10 @@ public class SoneTextParser implements Parser<SoneTextParserContext> {
                                        }
                                        lineComplete = false;
 
-                                       Matcher matcher = whitespacePattern.matcher(line);
-                                       int nextSpace = matcher.find(0) ? matcher.start() : line.length();
+                                       int nextSpace = findNextWhitespace(line);
                                        String link = line.substring(0, nextSpace);
                                        String name = link;
                                        logger.log(Level.FINER, String.format("Found link: %s", link));
-                                       logger.log(Level.FINEST, String.format("CHK: %d, SSK: %d, USK: %d", nextChk, nextSsk, nextUsk));
 
                                        /* if there is no text after the scheme, it’s not a link! */
                                        if (link.equals(linkType.getScheme())) {
@@ -235,7 +207,7 @@ public class SoneTextParser implements Parser<SoneTextParserContext> {
                                        }
 
                                        if (linkType == LinkType.SONE) {
-                                               if (line.length() >= (7 + 43)) {
+                                               if (lineIsLongEnoughToContainASoneLink(line)) {
                                                        String soneId = line.substring(7, 50);
                                                        Optional<Sone> sone = database.getSone(soneId);
                                                        if (!sone.isPresent()) {
@@ -254,7 +226,7 @@ public class SoneTextParser implements Parser<SoneTextParserContext> {
                                                continue;
                                        }
                                        if (linkType == LinkType.POST) {
-                                               if (line.length() >= (7 + 36)) {
+                                               if (lineIsLongEnoughToContainAPostLink(line)) {
                                                        String postId = line.substring(7, 43);
                                                        Optional<Post> post = database.getPost(postId);
                                                        if (post.isPresent()) {
@@ -287,7 +259,7 @@ public class SoneTextParser implements Parser<SoneTextParserContext> {
                                                        if (name == null) {
                                                                name = link.substring(0, Math.min(9, link.length()));
                                                        }
-                                                       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());
+                                                       boolean fromPostingSone = ((linkType == LinkType.SSK) || (linkType == LinkType.USK)) && linkMatchesPostingSone(context, link);
                                                        parts.add(new FreenetLinkPart(link, name, fromPostingSone));
                                                } catch (MalformedURLException mue1) {
                                                        /* not a valid link, insert as plain text. */
@@ -299,8 +271,8 @@ public class SoneTextParser implements Parser<SoneTextParserContext> {
                                                        /* oh, and these, too. */
                                                        parts.add(new PlainTextPart(link));
                                                }
-                                       } else if ((linkType == LinkType.HTTP) || (linkType == LinkType.HTTPS)) {
-                                               name = link.substring(linkType == LinkType.HTTP ? 7 : 8);
+                                       } else if (linkType.isInternetLink()) {
+                                               name = link.substring(linkType.getScheme().length());
                                                int firstSlash = name.indexOf('/');
                                                int lastSlash = name.lastIndexOf('/');
                                                if ((lastSlash - firstSlash) > 3) {
@@ -326,14 +298,84 @@ public class SoneTextParser implements Parser<SoneTextParserContext> {
                                Closer.close(bufferedReader);
                        }
                }
+               removeTrailingWhitespaceParts(parts);
+               return parts;
+       }
+
+       private void removeTrailingWhitespaceParts(PartContainer parts) {
                for (int partIndex = parts.size() - 1; partIndex >= 0; --partIndex) {
                        Part part = parts.getPart(partIndex);
-                       if (!(part instanceof PlainTextPart) || !"\n".equals(((PlainTextPart) part).getText())) {
+                       if (!(part instanceof PlainTextPart) || !"\n".equals(part.getText())) {
                                break;
                        }
                        parts.removePart(partIndex);
                }
-               return parts;
+       }
+
+       private boolean linkMatchesPostingSone(SoneTextParserContext context, String link) {
+               return (context != null) && (context.getPostingSone() != null) && link.substring(4, Math.min(link.length(), 47)).equals(context.getPostingSone().getId());
+       }
+
+       private boolean lineIsLongEnoughToContainAPostLink(String line) {
+               return line.length() >= (7 + 36);
+       }
+
+       private boolean lineIsLongEnoughToContainASoneLink(String line) {
+               return line.length() >= (7 + 43);
+       }
+
+       private int findNextWhitespace(String line) {
+               Matcher matcher = whitespacePattern.matcher(line);
+               return matcher.find(0) ? matcher.start() : line.length();
+       }
+
+       private Optional<NextLink> findNextLink(String line) {
+               EnumMap<LinkType, Integer> linkTypeIndexes = new EnumMap<LinkType, Integer>(LinkType.class);
+               for (LinkType linkType : LinkType.values()) {
+                       int index = line.indexOf(linkType.getScheme());
+                       if (index != -1) {
+                               linkTypeIndexes.put(linkType, index);
+                       }
+               }
+               if (linkTypeIndexes.isEmpty()) {
+                       return absent();
+               }
+               Entry<LinkType, Integer> smallestEntry = from(linkTypeIndexes.entrySet()).toSortedList(locateSmallestIndex()).get(0);
+               return of(new NextLink(smallestEntry.getValue(), smallestEntry.getKey()));
+       }
+
+       private Comparator<Entry<LinkType, Integer>> locateSmallestIndex() {
+               return new Comparator<Entry<LinkType, Integer>>() {
+                       @Override
+                       public int compare(Entry<LinkType, Integer> leftEntry, Entry<LinkType, Integer> rightEntry) {
+                               return leftEntry.getValue() - rightEntry.getValue();
+                       }
+               };
+       }
+
+       /**
+        * Container for position and type of the next link in a line.
+        *
+        * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
+        */
+       private static class NextLink {
+
+               private final int nextIndex;
+               private final LinkType linkType;
+
+               private NextLink(int nextIndex, LinkType linkType) {
+                       this.nextIndex = nextIndex;
+                       this.linkType = linkType;
+               }
+
+               private int getNextIndex() {
+                       return nextIndex;
+               }
+
+               private LinkType getLinkType() {
+                       return linkType;
+               }
+
        }
 
 }