Add chat filtering code

Java/bukkit/chat/filter/ChatFilter.java

@@ -0,0 +1,44 @@
+package network.walrus.ubiquitous.bukkit.chat.filter;
+
+import network.walrus.common.CommandSender;
+import network.walrus.ubiquitous.bukkit.UbiquitousPermissions;
+import org.bukkit.command.ConsoleCommandSender;
+import org.bukkit.entity.Player;
+
+/**
+ * Something which takes a {@link String} and manipulates it to fit certain specifications.
+ *
+ * @author Austin Mayes
+ */
+public abstract class ChatFilter {
+
+  private final String permission;
+
+  /**
+   * @param permission needed for players to bypass this filter
+   */
+  public ChatFilter(String permission) {
+    this.permission = permission;
+  }
+
+  /**
+   * Filter the specified string
+   *
+   * @param original to filter
+   * @return the filtered string
+   */
+  public abstract String filter(String original);
+
+  /**
+   * Determine if the given sender has the ability to bypass being affected by this filter.
+   *
+   * @param sender to check
+   * @return if the sender can bypass the filter
+   */
+  public boolean canBypass(CommandSender sender) {
+    return sender instanceof ConsoleCommandSender
+        || (sender instanceof Player
+        && (((Player) sender).hasPermission(UbiquitousPermissions.FILTER_BYPASS_ALL)
+        || ((Player) sender).hasPermission(this.permission)));
+  }
+}

Java/bukkit/chat/filter/IPFilter.java

@@ -0,0 +1,43 @@
+package network.walrus.ubiquitous.bukkit.chat.filter;
+
+import java.util.Set;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+import network.walrus.ubiquitous.bukkit.UbiquitousPermissions;
+
+/**
+ * Filter which removes domains and IPs from chat messages.
+ *
+ * @author Austin Mayes
+ */
+public class IPFilter extends ChatFilter {
+
+  private final Pattern URL_PATTERN =
+      Pattern.compile(
+          "(?:[a-z0-9](?:[a-z0-9-]{0,61}[a-z0-9])?\\.)+[a-z0-9][a-z0-9-]{0,61}[a-z0-9]");
+  private final Set<String> allowedDomains;
+
+  /**
+   * Constructor
+   * @param allowedDomains domains which are not filtered out
+   */
+  public IPFilter(Set<String> allowedDomains) {
+    super(UbiquitousPermissions.IP_FILTER_BYPASS);
+    this.allowedDomains = allowedDomains;
+  }
+
+  @Override
+  public String filter(String original) {
+    String res = original;
+    Matcher matcher = URL_PATTERN.matcher(original);
+    while (matcher.find()) {
+      String url = matcher.group();
+      for (String domain : allowedDomains) {
+        if (!url.toLowerCase().contains(domain)) {
+          res = original.replaceAll("(?i)" + Pattern.quote(url), "[REDACTED URL]");
+        }
+      }
+    }
+    return res;
+  }
+}

Java/bukkit/chat/filter/WordFilter.java

@@ -0,0 +1,56 @@
+package network.walrus.ubiquitous.bukkit.chat.filter;
+
+import java.util.Random;
+import java.util.Set;
+import java.util.regex.Pattern;
+import network.walrus.ubiquitous.bukkit.UbiquitousPermissions;
+
+/**
+ * Filter which replaces a set of words with a random replacement.
+ *
+ * @author Austin Mayes
+ */
+public class WordFilter extends ChatFilter {
+
+  private static final Random RANDOM = new Random();
+  private static final String[] REPLACEMENTS =
+      new String[]{
+          "Gardyloo",
+          "Taradiddle",
+          "Snickersnee",
+          "Collywobbles",
+          "Lollygag",
+          "Malarkey",
+          "Wabbit",
+          "Quire",
+          "Zoanthropy",
+          "Bumfuzzle",
+          "Gobbledygook",
+          "Dongle",
+          "Pronk",
+          "Abear",
+          "Oxter",
+          "Fartlek",
+          "Popple"
+      };
+  private final Set<String> words;
+
+  /**
+   * @param words to replace
+   */
+  public WordFilter(Set<String> words) {
+    super(UbiquitousPermissions.WORDS_FILTER_BYPASS);
+    this.words = words;
+  }
+
+  @Override
+  public String filter(String original) {
+    String res = original;
+    for (String word : words) {
+      res =
+          original.replaceAll(
+              "(?i)" + Pattern.quote(word), REPLACEMENTS[RANDOM.nextInt(REPLACEMENTS.length - 1)]);
+    }
+    return res;
+  }
+}