Add suggestion for flags when invalid flag name was given :]

Core/src/main/java/com/intellectualcrafters/plot/commands/FlagCmd.java

@@ -12,6 +12,7 @@ import com.intellectualcrafters.plot.object.Plot;
 import com.intellectualcrafters.plot.object.PlotPlayer;
 import com.intellectualcrafters.plot.util.MainUtil;
 import com.intellectualcrafters.plot.util.Permissions;
+import com.intellectualcrafters.plot.util.StringComparison;
 import com.intellectualcrafters.plot.util.StringMan;
 import com.plotsquared.general.commands.CommandDeclaration;
 
@@ -63,7 +64,18 @@ public class FlagCmd extends SubCommand {
         if (args.length > 1) {
             flag = FlagManager.getFlag(args[1]);
             if (flag == null || flag.isReserved()) {
-                MainUtil.sendMessage(player, C.NOT_VALID_FLAG);
+                boolean suggested = false;
+                try {
+                    StringComparison<Flag<?>> stringComparison = new StringComparison<>(args[1], Flags.getFlags());
+                    String best = stringComparison.getBestMatch();
+                    if (best != null) {
+                        MainUtil.sendMessage(player, C.NOT_VALID_FLAG_SUGGESTED, best);
+                        suggested = true;
+                    }
+                } catch (final Exception ignored) { /* Happens sometimes because of mean code */ }
+                if (!suggested) {
+                    MainUtil.sendMessage(player, C.NOT_VALID_FLAG);
+                }
                 return false;
             }
         }

Core/src/main/java/com/intellectualcrafters/plot/config/C.java

@@ -553,6 +553,7 @@ public enum C {
     FLAG_TYPE("$2Type: %s", "Flag"),
     FLAG_DESC("$2Desc: %s", "Flag"),
     NOT_VALID_FLAG("$2That is not a valid flag", "Flag"),
+    NOT_VALID_FLAG_SUGGESTED("$2That is not a valid flag. Did you mean: $1%s", "Flag"),
     NOT_VALID_VALUE("$2Flag values must be alphanumerical", "Flag"),
     FLAG_NOT_IN_PLOT("$2The plot does not have that flag", "Flag"),
     FLAG_NOT_REMOVED("$2The flag could not be removed", "Flag"),

Core/src/main/java/com/intellectualcrafters/plot/flag/Flag.java

@@ -1,8 +1,9 @@
 package com.intellectualcrafters.plot.flag;
 
 import com.intellectualcrafters.plot.object.Plot;
+import com.intellectualcrafters.plot.util.StringComparison;
 
-public abstract class Flag<V> {
+public abstract class Flag<V> implements StringComparison.StringComparable {
 
     private final String name;
     private boolean reserved = false;
@@ -53,4 +54,9 @@ public abstract class Flag<V> {
     public boolean isSet(Plot plot) {
         return FlagManager.getPlotFlagRaw(plot, this) != null;
     }
+
+    @Override
+    public String getComparableString() {
+        return getName();
+    }
 }

Core/src/main/java/com/intellectualcrafters/plot/util/StringComparison.java

@@ -99,6 +99,9 @@ public class StringComparison<T> {
     }
 
     public String getString(T o) {
+        if (o instanceof StringComparable) {
+            return ((StringComparable) o).getComparableString();
+        }
         return o.toString();
     }
     
@@ -147,4 +150,8 @@ public class StringComparison<T> {
             this.best = best;
         }
     }
+
+    public interface StringComparable {
+        String getComparableString();
+    }
 }