[Bernard Wan De Yuan] iP

src/main/java/duke/Command/ExitCommand.java

@@ -1,6 +1,5 @@
 package duke.Command;
 
-import duke.Command.Command;
 import duke.Storage;
 import duke.TaskList;
 import duke.Ui;

src/main/java/duke/Command/FindCommand.java

@@ -0,0 +1,30 @@
+package duke.Command;
+
+import duke.*;
+
+import java.util.ArrayList;
+
+public class FindCommand extends Command{
+    String keyword;
+
+    public FindCommand(String keyword) {
+        this.keyword = keyword;
+    }
+
+    @Override
+    public void execute(TaskList tasks, Ui ui, Storage storage) throws DukeException {
+        ArrayList<Task> list = tasks.getList();
+        list.removeIf(task -> !task.getDescription().contains(this.keyword));
+        if (list.size() == 0) {
+            ui.print("No matching tasks found.");
+        } else {
+            ui.print(list.size() + " matching task(s):");
+            ui.print(new TaskList(list).allTasks());
+        }
+    }
+
+    @Override
+    public boolean isExit() {
+        return false;
+    }
+}

src/main/java/duke/DukeException.java

@@ -4,10 +4,4 @@ public class DukeException extends Exception{
     public DukeException(String errorMessage) {
         super(errorMessage);
     }
-
-    public class InvalidInputException extends DukeException {
-        public InvalidInputException(String errorMessage) {
-            super(errorMessage);
-        }
-    }
 }

src/main/java/duke/Parser.java

@@ -28,8 +28,15 @@ public static Command parse(String input) throws DukeException{
                 throw new DukeException("Sorry, please enter an integer after 'delete'. (e.g. delete 2)");
             }
             return new DeleteCommand(index);
-        }
-        else {
+        } else if (first_word.equals("find")){
+            String remaining;
+            try {
+                remaining = input.split(" ", 2)[1];
+            } catch (ArrayIndexOutOfBoundsException e) {
+                throw new DukeException("Sorry, please enter a keyword after 'find'.");
+            }
+            return new FindCommand(remaining);
+        } else {
             String remaining;
             try {
                 remaining = input.split(" ", 2)[1];

src/main/java/duke/TaskList.java

@@ -17,6 +17,15 @@ public void addTask(Task task) {
         list.add(task);
     }
 
+    /**
+     * Returns a copy of the list
+     * @return ArrayList copy containing all of the tasks
+     */
+    public ArrayList<Task> getList() {
+        ArrayList<Task> list = (ArrayList<Task>) this.list.clone();
+        return list;
+    }
+
     public Task getTask(int index) throws DukeException {
         Task task;
         try {

text-ui-test/EXPECTED.TXT

@@ -8,6 +8,9 @@ Added: [E][ ] project meeting (at: 3 December 2021)
 There are 3 tasks in the list
 Added: [D][ ] return book (by: 3 December 2021)
 There are 4 tasks in the list
+2 matching task(s):
+1. [T][ ] borrow book
+2. [D][ ] return book (by: 3 December 2021)
 Marked as done:
 return book (by: 3 December 2021)
 Sorry, I don't understand what that means. :(

text-ui-test/input.txt

@@ -2,6 +2,7 @@ todo borrow book
 event dinner with friends at 2021-12-03
 event project meeting at 2021-12-03
 deadline return book by 2021-12-03
+find book
 done 4
 smth blah blah
 todo