- Implemented DualEventCommand class for handling expert inputs for event commands

Author: Cheezeblokz

src/main/java/seedu/duke/calendar/command/DualEventCommand.java

@@ -0,0 +1,32 @@
+//@@author wendelinwemhoener-reused
+
+package seedu.duke.calendar.command;
+
+import seedu.duke.calendar.EventList;
+
+import java.util.Scanner;
+
+public abstract class DualEventCommand extends EventCommand {
+    protected int beginnerCommandLength;
+    protected int expertCommandLength;
+    protected String input;
+    protected String syntaxString;
+
+    protected abstract void executeBeginnerMode(Scanner scanner, EventList eventList);
+
+    protected abstract void executeExpertMode(Scanner scanner,
+                                              EventList eventList);
+
+    public void execute(Scanner scanner, EventList eventList) {
+        String[] commandParts = input.split(" ");
+
+        if (commandParts.length == beginnerCommandLength) {
+            executeBeginnerMode(scanner, eventList);
+        } else if (commandParts.length == expertCommandLength) {
+            executeExpertMode(scanner, eventList);
+        } else {
+            System.out.println("    Invalid syntax! The syntax is '" + syntaxString + "'");
+            System.out.println("    Please try again.");
+        }
+    }
+}