Add BugUrlReplacer to clean up bare URLs

This transformation was suggested by Brian Campbell.

src/buglinky/BlipProcessor.java

@@ -30,9 +30,16 @@
 abstract class BlipProcessor {
 	private static final Logger LOG =
 		Logger.getLogger(BlipProcessor.class.getName());
+
+	/**
+	 * The accumulated difference between the original length of the
+	 * blip, and the length after text replacements have been performed.
+	 */
+	private int totalCorrection;
 
 	/**
-	 * Annotate the specified blip.
+	 * Apply this text processor to the specified blip.  This function
+	 * is not re-entrant.
 	 * 
 	 * @param blip The blip to process.
 	 */
@@ -42,11 +49,13 @@ public void processBlip(Blip blip) {
 		// Adapted from http://senikk.com/min-f%C3%B8rste-google-wave-robot,
 		// a robot which links to @names on Twitter.
 		TextView doc = blip.getDocument();
+		totalCorrection = 0; // Reset.
 		Matcher matcher = getCompiledPattern().matcher(doc.getText());
 		while (matcher.find()) {
 			LOG.fine("Found match to process: " + matcher.group());
-			Range range = new Range(matcher.start(), matcher.end());
-			processMatch(doc, range, matcher);
+			int start = matcher.start() + totalCorrection;
+			int end   = matcher.end()   + totalCorrection;
+			processMatch(doc, new Range(start, end), matcher);
 		}
 	}
 
@@ -98,6 +107,7 @@ private Pattern getCompiledPattern() {
 	 *              because of previous text replacements.
 	 * 
 	 * @see BlipProcessor#annotate(TextView, Range, String, String)
+	 * @see BlipProcessor#replace(TextView, Range, String)
 	 */
 	protected abstract void processMatch(TextView doc, Range range,
 			Matcher match);
@@ -129,5 +139,22 @@ protected void annotate(TextView doc, Range range, String name,
 
 		LOG.fine("Annotating with " + name + "=" + value);
 		doc.setAnnotation(range, name, value);
+	}
+
+	/**
+	 * Replace the specified range in the TextView with a new string, leaving
+	 * existing annotations alone.
+	 * 
+	 * @param doc   The TextView to containing the text to annotate.
+	 * @param range The range of text to replace.  This must fall entirely
+	 *              within the current match.
+	 * @param text  The replacement text.
+	 */
+	protected void replace(TextView doc, Range range, String text) {
+		doc.replace(range, text);
+
+		// Update our correction factor to account for this replacement.
+		int oldLength = range.getEnd() - range.getStart();
+		totalCorrection = (totalCorrection - oldLength) + text.length();
 	}	
 }

src/buglinky/BugLinkyServlet.java

@@ -15,6 +15,7 @@
 
 package buglinky;
 
+import java.util.ArrayList;
 import java.util.logging.Logger;
 
 import com.google.wave.api.AbstractRobotServlet;
@@ -68,7 +69,13 @@ private void addInstructionsToWave(RobotMessageBundle bundle) {
 
 	/** Dispatch events to the appropriate handler method. */
 	private void dispatchEvents(RobotMessageBundle bundle) {
-		BlipProcessor annotator = new BugLinkAnnotator(BUG_URL);
+		// We clean up URLs first, so that we can annotate the newly-created
+		// text in the second pass.
+		ArrayList<BlipProcessor> processors = new ArrayList<BlipProcessor>();
+		processors.add(new BugUrlReplacer(BUG_URL)); 
+		processors.add(new BugLinkAnnotator(BUG_URL)); 
+
+		// Process each event.
 		for (Event e : bundle.getEvents()) {
 			if (!e.getModifiedBy().equals(BOT_ADDRESS)) {
 				switch (e.getType()) {
@@ -78,7 +85,8 @@ private void dispatchEvents(RobotMessageBundle bundle) {
 				// BLIP_VERSION_CHANGED, we'll apply our links in real time.
 				case BLIP_SUBMITTED:
 				case BLIP_VERSION_CHANGED:
-					annotator.processBlip(e.getBlip());
+					for (BlipProcessor processor : processors)
+						processor.processBlip(e.getBlip());
 					break;
 
 				default:

src/buglinky/BugUrlReplacer.java

@@ -0,0 +1,32 @@
+package buglinky;
+
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+import com.google.wave.api.Range;
+import com.google.wave.api.TextView;
+
+/**
+ * Convert raw bug tracker URLs into text of the form "issue #NNN".
+ */
+class BugUrlReplacer extends BlipProcessor {
+	/** The URL to a bug, minus the actual bug number. */
+	private String bugUrl;
+
+	/** Create a BugUrlReplacer for the specified URL. */
+	public BugUrlReplacer(String bugUrl) {
+		super();
+		this.bugUrl = bugUrl;
+	}
+
+	@Override
+	protected String getPattern() {
+		return Pattern.quote(bugUrl) + "(\\d+)";
+	}
+
+	@Override
+	protected void processMatch(TextView doc, Range range, Matcher match) {
+		replace(doc, range, "issue #" + match.group(1));
+	}
+
+}