Implement find function (level 9)

src/main/java/Flash.java

@@ -31,25 +31,27 @@ public static void main(String[] args) {
                 if (command.equalsIgnoreCase("bye")) {
                     UI.displayByeMessage();
                     break;
-                } else if (command.equalsIgnoreCase("list")) {
+                } else if (command.equals("list")) {
                     UI.displayTasks(taskList.tasks);
-                } else if (command.equalsIgnoreCase("mark")) {
+                } else if (command.equals("mark")) {
                     taskList.markTask(input);
                     storage.save(taskList.tasks);
-                } else if (command.equalsIgnoreCase("unmark")) {
+                } else if (command.equals("unmark")) {
                     taskList.unMarkTask(input);
                     storage.save(taskList.tasks);
-                } else if (command.equalsIgnoreCase("todo")) {
+                } else if (command.equals("todo")) {
                     taskList.addTodo(input);
                     storage.save(taskList.tasks);
-                } else if (command.equalsIgnoreCase("deadline")) {
+                } else if (command.equals("deadline")) {
                     taskList.addDeadline(input);
                     storage.save(taskList.tasks);
-                } else if (command.equalsIgnoreCase("event")) {
+                } else if (command.equals("event")) {
                     taskList.addEvent(input);
-                } else if (command.equalsIgnoreCase("delete")) {
+                } else if (command.equals("delete")) {
                     taskList.deleteTask(input);
                     storage.save(taskList.tasks);
+                } else if (command.equals("find")) {
+                    taskList.listMatchedTasks(input);
                 } else {
                     throw new FlashException("Uh-oh! I don't know what that means.");
                 }

src/main/java/Parser.java

@@ -37,4 +37,9 @@ public static String[] parseEvent(String input) {
         String to = parts[2].trim();
         return new String[]{description, from, to};
     }
+
+    public static String parseKeyword(String input) {
+        String[] parts = input.split(" ", 2);
+        return parts[1];
+    }
 }

src/main/java/Storage.java

@@ -11,14 +11,27 @@
 import java.util.List;
 import java.util.ArrayList;
 
+/**
+ * Handles loading and saving tasks to a file.
+ */
 public class Storage {
     private String filePath;
 
+    /**
+     * Constructs a Storage object with the specified file path.
+     *
+     * @param filePath the path to the file where tasks are stored
+     */
     public Storage(String filePath) {
         this.filePath = filePath;
     }
 
-    // Method to load tasks from file
+    /**
+     * Loads tasks from the specified file.
+     *
+     * @return a list of tasks loaded from the file
+     * @throws FlashException if an error occurs during file operations or if the file format is corrupted
+     */
     public List<Task> load() throws FlashException {
         List<Task> tasks = new ArrayList<>();
         File file = new File(filePath);
@@ -69,7 +82,12 @@ public List<Task> load() throws FlashException {
         return tasks;
     }
 
-    // Method to save tasks to file
+    /**
+     * Saves the specified tasks to the file.
+     *
+     * @param tasks the list of tasks to save
+     * @throws FlashException if an error occurs during file operations
+     */
     public void save(List<Task> tasks) throws FlashException {
         try (FileWriter fw = new FileWriter(filePath)) {
             for (Task task : tasks) {

src/main/java/TaskList.java

@@ -90,4 +90,20 @@ public void markTask(String input) throws FlashException {
             throw new FlashException("Invalid task number. Please enter a valid task number.");
         }
     }
+
+    public void listMatchedTasks(String input) throws FlashException {
+        try{
+            String keyword = Parser.parseKeyword(input);
+            int index = 1;
+            List<Task> matchedTasks = new ArrayList<>();
+            for (Task task : this.tasks) {
+                if(task.getDescription().contains(keyword)) {
+                    matchedTasks.add(task);
+                }
+            }
+            UI.displayMatchedTasks(matchedTasks);
+        } catch (Exception e) {
+            throw new FlashException("Invalid Keyword");
+        }
+    }
 }

src/main/java/UI.java

@@ -6,6 +6,7 @@
 public class UI {
     public static void displayTasks(List<Task> tasks) {
         System.out.println("____________________________________________________________");
+        System.out.println("Here are the tasks in you list:");
         for(int i = 0; i < tasks.size(); i++) {
             System.out.println(i+1 + "." + tasks.get(i));
         }
@@ -62,4 +63,13 @@ static void displayByeMessage() {
         System.out.println("Bye. Hope to see you again soon!");
         System.out.println("____________________________________________________________");
     }
+
+    public static void displayMatchedTasks(List<Task> matchedTasks) {
+        System.out.println("____________________________________________________________");
+        System.out.println("Here are the matching tasks in you list:");
+        for(int i = 0; i < matchedTasks.size(); i++) {
+            System.out.println(i+1 + "." + matchedTasks.get(i));
+        }
+        System.out.println("____________________________________________________________");
+    }
 }

src/main/java/exception/FlashException.java

@@ -1,5 +1,10 @@
 package exception;
 
+/**
+ * Signals an error specific to the Flash application.
+ *
+ * @param message should provide details about the error.
+ */
 public class FlashException extends Exception {
     public FlashException(String message) {
         super(message);

src/main/java/task/Task.java

@@ -17,6 +17,10 @@ public String getIcon() {
         }
     }
 
+    public String getDescription() {
+        return this.description;
+    }
+
     public void markDone() {
         this.isDone = true;
     }