Add trigger for new comics.

diff --git a/src/main/java/net/pterodactylus/rhynodge/triggers/NewComicTrigger.java b/src/main/java/net/pterodactylus/rhynodge/triggers/NewComicTrigger.java
new file mode 100644 (file)
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+++ b/src/main/java/net/pterodactylus/rhynodge/triggers/NewComicTrigger.java
@@ -0,0 +1,128 @@
+/*
+ * rhynodge - NewComicTrigger.java - Copyright © 2013 David Roden
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package net.pterodactylus.rhynodge.triggers;
+
+import static com.google.common.base.Preconditions.*;
+
+import java.util.List;
+
+import net.pterodactylus.rhynodge.Reaction;
+import net.pterodactylus.rhynodge.State;
+import net.pterodactylus.rhynodge.Trigger;
+import net.pterodactylus.rhynodge.output.DefaultOutput;
+import net.pterodactylus.rhynodge.output.Output;
+import net.pterodactylus.rhynodge.states.ComicState;
+import net.pterodactylus.rhynodge.states.ComicState.Comic;
+
+import com.google.common.collect.Lists;
+import org.apache.commons.lang3.StringEscapeUtils;
+
+/**
+ * {@link Trigger} implementation that detects the presence of new {@link
+ * Comic}s in a {@link ComicState}.
+ *
+ * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
+ */
+public class NewComicTrigger implements Trigger {
+
+       /** The new comics. */
+       private final List<Comic> newComics = Lists.newArrayList();
+
+       @Override
+       public State mergeStates(State previousState, State currentState) {
+               checkArgument(previousState instanceof ComicState, "previous state must be a comic state");
+               checkArgument(currentState instanceof ComicState, "current state must be a comic state");
+
+               ComicState previousComicState = (ComicState) previousState;
+               ComicState currentComicState = (ComicState) currentState;
+
+               /* copy old state into new state. */
+               ComicState mergedComicState = new ComicState();
+               for (Comic comic : previousComicState) {
+                       mergedComicState.add(comic);
+               }
+
+               newComics.clear();
+               for (Comic comic : currentComicState) {
+                       if (!mergedComicState.comics().contains(comic)) {
+                               newComics.add(comic);
+                               mergedComicState.add(comic);
+                       }
+               }
+
+               return mergedComicState;
+       }
+
+       @Override
+       public boolean triggers() {
+               return !newComics.isEmpty();
+       }
+
+       @Override
+       public Output output(Reaction reaction) {
+               DefaultOutput output = new DefaultOutput(String.format("New Comic found for “%s!”", reaction.name()));
+
+               output.addText("text/plain", generatePlainText());
+               output.addText("text/html", generateHtmlText());
+
+               return output;
+       }
+
+       //
+       // PRIVATE METHODS
+       //
+
+       /**
+        * Generates a list of the new comics in plain text format.
+        *
+        * @return The list of new comics in plain text format
+        */
+       private String generatePlainText() {
+               StringBuilder text = new StringBuilder();
+
+               for (Comic newComic : newComics) {
+                       text.append("Comic Found: ").append(newComic.title()).append("\n\n");
+                       for (String imageUrl : newComic) {
+                               text.append("Image: ").append(imageUrl).append("\n");
+                       }
+                       text.append("\n\n");
+               }
+
+               return text.toString();
+       }
+
+       /**
+        * Generates a list of new comics in HTML format.
+        *
+        * @return The list of new comics in HTML format
+        */
+       private String generateHtmlText() {
+               StringBuilder html = new StringBuilder();
+               html.append("<body>");
+
+               for (Comic newComic : newComics) {
+                       html.append("<h1>").append(StringEscapeUtils.escapeHtml4(newComic.title())).append("</h1>\n");
+                       for (String imageUrl : newComic) {
+                               html.append("<div><img src=\"").append(StringEscapeUtils.escapeHtml4(imageUrl)).append("\"></div>\n");
+                       }
+               }
+
+               return html.append("</body>").toString();
+       }
+
+}