Add ability for the user to change the target save file

Add two new commands: showpath and setpath.

.gitignore

@@ -16,3 +16,4 @@ bin/
 /text-ui-test/ACTUAL.txt
 text-ui-test/EXPECTED-UNIX.TXT
 data/duke.txt
+*.txt

src/main/java/duke/CommandType.java

@@ -1,5 +1,6 @@
 package duke;
 
 public enum CommandType {
-    EXIT, LIST, ADD_TASK, COMPLETE_TASK, DELETE_TASK, FIND_TASK
+    EXIT, LIST, ADD_TASK, COMPLETE_TASK, DELETE_TASK, FIND_TASK,
+    SHOW_PATH, SET_PATH,
 }

src/main/java/duke/Duke.java

@@ -21,15 +21,10 @@ public Duke() {
      */
     public Duke(String filepath) {
         ui = new Ui();
-        storage = new Storage(filepath);
 
         try {
-            tasks = new TaskList(storage.load());
-            if (tasks.getSize() > 0) {
-                ui.printLoadTasks(tasks);
-            }
+            setStoragePath(filepath);
         } catch (DukeException e) {
-            ui.printErrorMessage(e.getMessage());
             tasks = new TaskList();
         }
     }
@@ -93,6 +88,10 @@ private String executeCommand(String userInput) throws DukeException {
             return deleteTask(Parser.parseTaskNum(userInput));
         case FIND_TASK:
             return findTask(Parser.parseSearchSubject(userInput));
+        case SHOW_PATH:
+            return ui.printCurrentStoragePath(storage);
+        case SET_PATH:
+            return setNewStoragePath(Parser.parseNewPath(userInput));
         default:
             throw new UnsupportedOperationException(); // Error
         }
@@ -126,4 +125,21 @@ private String deleteTask(int taskNum) {
     private String findTask(String subject) {
         return ui.printTasksWithSubject(tasks, subject);
     }
+
+    private void setStoragePath(String newPath) throws LoadingException {
+        Storage newStorage = new Storage(newPath);
+        TaskList newTasks = new TaskList(newStorage.load());
+
+        storage = newStorage;
+        tasks = newTasks;
+    }
+
+    private String setNewStoragePath(String newPath) {
+        try {
+            setStoragePath(newPath);
+            return ui.printNewStoragePath(storage, tasks);
+        } catch (DukeException e) {
+            return ui.printErrorMessage(e.getMessage());
+        }
+    }
 }

src/main/java/duke/Parser.java

@@ -39,6 +39,10 @@ public static CommandType parseCommandType(String userInput)
             return CommandType.DELETE_TASK;
         case "find":
             return CommandType.FIND_TASK;
+        case "showpath":
+            return CommandType.SHOW_PATH;
+        case "setpath":
+            return CommandType.SET_PATH;
         default:
             throw new UnsupportedOperationException();
         }
@@ -111,4 +115,10 @@ public static String parseSearchSubject(String userInput) {
         userInputScanner.next();
         return userInputScanner.nextLine().trim();
     }
+
+    public static String parseNewPath(String userInput) {
+        Scanner userInputScanner = new Scanner(userInput);
+        userInputScanner.next();
+        return userInputScanner.nextLine().trim();
+    }
 }

src/main/java/duke/Storage.java

@@ -111,4 +111,8 @@ public void saveTasks(TaskList tasks) {
             ex.printStackTrace();
         }
     }
+
+    public String getPath() {
+        return savePath.toString();
+    }
 }

src/main/java/duke/Ui.java

@@ -116,4 +116,13 @@ public String printLoadTasks(TaskList tasks) {
     public String printErrorMessage(String message) {
         return "Error: " + message + ".";
     }
+
+    public String printCurrentStoragePath(Storage storage) {
+        return "Current path is:\n" + storage.getPath();
+    }
+
+    public String printNewStoragePath(Storage storage, TaskList tasks) {
+        return "New path set:\n" + storage.getPath() + "\n\n"
+                + printLoadTasks(tasks);
+    }
 }