added reopen function

src/main/java/Enums/TaskType.java

@@ -2,5 +2,5 @@
 
 public enum TaskType {
     list, bye, find, done , delete, time, snooze, others, help, priority, reorder,
-    restore, add, subtask, update, sort, log, overdue, reschedule, completed, show, removeoverdue
+    restore, add, subtask, update, sort, log, overdue, reschedule, completed, show, removeoverdue, reopen
 }

src/main/java/Model_Classes/Leave.java

@@ -75,4 +75,12 @@ public String getAssignee() {
     public String toString() {
         return "[L] " + super.getDescription() + " (" + user + ")" + " (From: " + from + " To: " + to + ")";
     }
+
+    /**
+     * setter for user
+     * @param user name of user for the leave
+     */
+    public void setUser(String user) {
+        this.user = user;
+    }
 }

src/main/java/Operations/TaskCreator.java

@@ -468,35 +468,39 @@ public void updateTask(String input, Task oldTask) throws RoomShareException {
             }
         }
 
-        else if (input.contains("*")) {
+        if (input.contains("*")) {
             Priority priority = this.extractPriority(input);
             oldTask.setPriority(priority);
         }
 
-        else if (input.contains("@")) {
+        if (input.contains("@")) {
             String assignee = null;
             try {
                 assignee = this.extractAssignee(input);
             } catch (RoomShareException e) {
                 assignee = "everyone";
             }
             oldTask.setAssignee(assignee);
+            if (oldTask instanceof Leave) {
+                Leave oldLeave = (Leave) oldTask;
+                oldLeave.setUser(assignee);
+            }
         }
 
-        else if (input.contains("^") && oldTask instanceof Meeting) {
+        if (input.contains("^") && oldTask instanceof Meeting) {
             Pair<Integer, TimeUnit> durationAndUnit = this.extractDuration(input);
             int duration = durationAndUnit.getKey();
             TimeUnit unit = durationAndUnit.getValue();
             Meeting oldMeeting = (Meeting) oldTask;
             oldMeeting.setDuration(duration,unit);
         }
 
-        else if (input.contains("%")) {
+        if (input.contains("%")) {
             RecurrenceScheduleType recurrence = this.extractRecurrence(input);
             oldTask.setRecurrenceSchedule(recurrence);
         }
 
-        else if(input.contains("uncheck") && !(oldTask instanceof Leave)) {
+        if(input.contains("uncheck") && !(oldTask instanceof Leave)) {
             boolean checked = oldTask.getDone();
             oldTask.setDone(!checked);
         }

src/main/java/Operations/TaskList.java

@@ -492,4 +492,19 @@ public int[] listTagged(String user) throws RoomShareException{
         int[] done = {belongCount, doneCount};
         return done;
     }
+
+    /**
+     * sets the tasks which are done to an undone state.
+     * @param index index of task
+     * @param date date the new deadline of the task
+     * @throws RoomShareException when the task selected is a Leave
+     */
+    public void reopen(int index, Date date) throws RoomShareException {
+        tasks.get(index).setDate(date);
+        CheckAnomaly.checkDuplicate(tasks.get(index));
+        if (tasks.get(index) instanceof Meeting) {
+            CheckAnomaly.checkTimeClash(tasks.get(index));
+        }
+        tasks.get(index).setDone(false);
+    }
 }

src/main/java/Operations/Ui.java

@@ -337,4 +337,8 @@ public void showTaggedPercentage(String user) {
     public void showDeletedList() {
         System.out.println("Here are the tasks that you have deleted and are in temporary storage");
     }
+
+    public void showDoneList() {
+        System.out.println("These are the tasks that you have already done:");
+    }
 }

src/main/java/RoomShare.java

@@ -11,6 +11,7 @@
 
 import java.io.IOException;
 import java.util.ArrayList;
+import java.util.Date;
 
 /**
  * Main class of the RoomShare program.
@@ -430,6 +431,21 @@ public void run() throws RoomShareException, IOException, InterruptedException {
                 }
                 break;
 
+            case reopen:
+                Ui.clearScreen();
+                String userInput = parser.getCommandLine();
+                ui.showDoneList();
+                taskList.showCompleted();
+                try {
+                    int index = parser.getIndex(userInput);
+                    ArrayList<Date> date = taskCreator.extractDate(userInput);
+                    taskList.reopen(index,date.get(0));
+                } catch (RoomShareException e) {
+                    ui.showError(e);
+                }
+                listRoutine.list();
+                break;
+
             default:
                 Ui.clearScreen();
                 ui.startUp();