Performs some necessary work required for the edit command

Adds an implementation for the edit tab completer
Adds an enum representing a paid sign property
Adds an enum representing a paid sign condition property
Adds aliases to all commands

src/main/java/net/knarcraft/paidsigns/utility/TabCompleteHelper.java

@@ -1,16 +1,24 @@
 package net.knarcraft.paidsigns.utility;
 
 import net.knarcraft.paidsigns.PaidSigns;
+import org.bukkit.Bukkit;
+import org.bukkit.permissions.Permission;
 
 import java.util.ArrayList;
+import java.util.HashMap;
 import java.util.List;
+import java.util.Map;
 import java.util.Set;
+import java.util.StringJoiner;
 
 /**
  * A helper class for providing common tab complete options
  */
 public final class TabCompleteHelper {
 
+    private static List<String> plugins;
+    private static Map<String, List<String>> permissions;
+
     private TabCompleteHelper() {
 
     }
@@ -122,4 +130,65 @@ public final class TabCompleteHelper {
         return conditionStrings;
     }
 
+    /**
+     * Gets the tab complete value for the permission typed
+     *
+     * @param typedNode <p>The full permission node typed by the player</p>
+     * @return <p>All known valid auto-complete options</p>
+     */
+    public static List<String> tabCompletePermission(String typedNode) {
+        if (plugins == null) {
+            loadAvailablePermissions();
+        }
+        List<String> output;
+        if (typedNode.contains(".")) {
+            List<String> matchingPermissions = permissions.get(typedNode.substring(0, typedNode.lastIndexOf(".")));
+            if (matchingPermissions == null) {
+                output = new ArrayList<>();
+            } else {
+                //Filter by the typed text
+                output = TabCompleteHelper.filterMatchingStartsWith(matchingPermissions, typedNode);
+            }
+        } else {
+            output = plugins;
+        }
+
+        //Add previous permissions in the comma-separated lists as a prefix
+        return output;
+    }
+
+    /**
+     * Loads all permissions available from bukkit plugins
+     */
+    private static void loadAvailablePermissions() {
+        plugins = new ArrayList<>();
+        permissions = new HashMap<>();
+
+        for (Permission permission : Bukkit.getPluginManager().getPermissions()) {
+            loadPermission(permission.getName());
+        }
+    }
+
+    /**
+     * Loads a given permission into the proper lists and maps
+     *
+     * @param permissionName <p>The permission to load</p>
+     */
+    private static void loadPermission(String permissionName) {
+        String[] permissionParts = permissionName.split("\\.");
+        if (permissionParts.length == 1 && !plugins.contains(permissionParts[0])) {
+            plugins.add(permissionParts[0]);
+        } else if (permissionParts.length > 1) {
+            StringJoiner pathJoiner = new StringJoiner(".");
+            for (int j = 0; j < permissionParts.length - 1; j++) {
+                pathJoiner.add(permissionParts[j]);
+            }
+            String path = pathJoiner.toString();
+            List<String> permissionList = permissions.computeIfAbsent(path, k -> new ArrayList<>());
+            permissionList.add(permissionName);
+
+            loadPermission(path);
+        }
+    }
+
 }