Add unarchive feature

data/archive.txt

@@ -1,2 +1,4 @@
 T | 0 | helloworld
-T | 0 | helloworld
+T | 0 | helloworld
+E | 0 | valentine with girlfriend | 14-02-2020 21:00
+E | 0 | drunk with friends | 13-02-2020 23:59

data/tasks.txt

@@ -1,3 +1,9 @@
+T | 0 | helloworld
+T | 0 | helloworld
 E | 0 | drunk with friends | 13-02-2020 23:59
 E | 0 | valentine with girlfriend | 14-02-2020 21:00
-D | 0 | CS2103 Duke Project | 14-02-2020 23:59
+T | 0 | dddskpfs
+T | 0 | duar
+T | 0 | tod
+T | 0 | todododod
+T | 0 | dododododo

src/main/java/duke/command/UnarchiveCommand.java

@@ -52,7 +52,7 @@ public String execute(TaskList taskList, Storage storage, ArchiveList archiveLis
         Task task = archiveList.getTask(this.index);
         archiveList.deleteArchivedTask(this.index, storage);
         taskList.addTask(task, storage);
-        return "Done! I have successfully unarchived: " + task;
+        return "Done! I have successfully unarchived:\n" + task;
     }
 
     /**

src/main/java/duke/util/Keyword.java

@@ -32,11 +32,12 @@ public enum Keyword {
      * <li>ARCHIVE_LIST</li>
      * <li>ARCHIVE_ADD</li>
      * <li>ARCHIVE_DELETE</li>
+     * <li>UNARCHIVE</li>
      * <li>NOTE_LIST</li>
      * <li>NOTE_ADD</li>
      * <li>NOTE_DELETE</li>
      */
 
     LIST, DONE, TODO, DEADLINE, EVENT, DELETE, FIND, BYE, REMINDER, ARCHIVE_LIST, ARCHIVE_ADD, ARCHIVE_DELETE,
-    NOTE_LIST, NOTE_ADD, NOTE_DELETE;
+    UNARCHIVE, NOTE_LIST, NOTE_ADD, NOTE_DELETE;
 }

src/main/java/duke/util/Parser.java

@@ -14,6 +14,7 @@
 import duke.command.NoteAddCommand;
 import duke.command.NoteDeleteCommand;
 import duke.command.NoteListCommand;
+import duke.command.UnarchiveCommand;
 import duke.exception.DukeInvalidArgumentFormatException;
 import duke.exception.DukeInvalidDateFormatException;
 import duke.exception.DukeUnknownKeywordException;
@@ -54,6 +55,7 @@ public class Parser {
             put("archive-list", Keyword.ARCHIVE_LIST);
             put("archive-add", Keyword.ARCHIVE_ADD);
             put("archive-delete", Keyword.ARCHIVE_DELETE);
+            put("unarchive", Keyword.UNARCHIVE);
             put("note-list", Keyword.NOTE_LIST);
             put("note-add", Keyword.NOTE_ADD);
             put("note-delete", Keyword.NOTE_DELETE);
@@ -157,6 +159,9 @@ private Command validateCommand(Keyword keyword, String details, IList<Task> tas
         case ARCHIVE_DELETE:
             command = checkValidArchiveDeleteArgument(details, archiveList);
             break;
+        case UNARCHIVE:
+            command = checkValidUnarchiveArgument(details, archiveList);
+            break;
         case NOTE_LIST:
             command = checkValidNoteListArgument(details);
             break;
@@ -418,6 +423,29 @@ private ArchiveDeleteCommand checkValidArchiveDeleteArgument(String details, ILi
         return new ArchiveDeleteCommand(index);
     }
 
+    /**
+     * Verifies that the command entered by the client is a valid unarchive command.
+     * @param details The details of the command.
+     * @param taskList The list of the archives.
+     * @return The UnarchiveCommand instance of the corresponding input.
+     */
+
+    private UnarchiveCommand checkValidUnarchiveArgument(String details, IList<Task> taskList) throws
+            DukeInvalidArgumentFormatException {
+        int index = -1;
+        try {
+            index = Integer.parseInt(details);
+        } catch (NumberFormatException e) {
+            throw new DukeInvalidArgumentFormatException("☹ OOPS!!! "
+                    + "The argument for 'archive-delete' command requires a number.");
+        }
+
+        if (index <= 0 || index > taskList.size()) {
+            throw new DukeInvalidArgumentFormatException("☹ OOPS!!! The index given is out of bound.");
+        }
+        return new UnarchiveCommand(index);
+    }
+
     /**
      * Verifies that the command entered by the client is a valid
      * note-add command.

src/main/resources/view/DialogBox.fxml

@@ -5,8 +5,9 @@
 <?import javafx.scene.image.ImageView?>
 <?import javafx.scene.layout.HBox?>
 
-<fx:root alignment="TOP_RIGHT" maxHeight="1.7976931348623157E308" maxWidth="1.7976931348623157E308" prefWidth="400.0"
-         type="javafx.scene.layout.HBox" xmlns="http://javafx.com/javafx/11.0.1" xmlns:fx="http://javafx.com/fxml/1">
+<fx:root alignment="TOP_RIGHT" maxHeight="1.7976931348623157E308" maxWidth="1.7976931348623157E308" minHeight="-Infinity"
+         prefWidth="400.0"  type="javafx.scene.layout.HBox" xmlns="http://javafx.com/javafx/11.0.1"
+         xmlns:fx="http://javafx.com/fxml/1">
     <children>
         <Label fx:id="dialog" style="-fx-background-color: #bfff00;" wrapText="true">
          <padding>