Merge branch 'branch-Level-9'

src/main/java/data/tasks.txt

@@ -1 +1,2 @@
 T | 0 | borrow book
+D | 0 | return book | 06-06-2020 11:00

src/main/java/duke/Parser.java

@@ -19,7 +19,7 @@ public class Parser {
      * @throws DukeInvalidDateTimeException If date and time input is invalid.
      * @throws DukeInvalidCommandException If command is invalid.
      */
-    static Command parse(String fullCommand) throws DukeEmptyInputException, DukeInvalidDateTimeException, DukeInvalidCommandException {
+    static Command parse(String fullCommand) throws DukeEmptyInputException, DukeInvalidDateTimeException, DukeInvalidCommandException, DukeInvalidKeywordException {
         String[] commandArr = fullCommand.trim().split(" ", 2);
         switch(commandArr[0]) {
             case "bye":
@@ -30,6 +30,11 @@ static Command parse(String fullCommand) throws DukeEmptyInputException, DukeInv
                 return parseDone(Integer.parseInt(commandArr[1]));
             case "delete":
                 return parseDelete(Integer.parseInt(commandArr[1]));
+            case "find":
+                if(commandArr.length < 2) {
+                    throw new DukeInvalidKeywordException();
+                }
+                return parseFind(commandArr[1]);
             case "todo":
                 if(commandArr.length < 2) {
                     throw new DukeEmptyInputException("The description of a todo cannot be empty.");
@@ -84,6 +89,15 @@ static DeleteCommand parseDelete(int taskNo) {
         return new DeleteCommand(taskNo);
     }
 
+    /**
+     * Parses an FindCommand associated with a keyword.
+     * @param keyword Search keyword.
+     * @return Returns an FindCommand associated with the search keyword.
+     */
+    static FindCommand parseFind(String keyword) {
+        return new FindCommand(keyword);
+    }
+
     /**
      * Parses an AddCommand associated with a Todo.
      * @param description Description of the Todo.

src/main/java/duke/TaskList.java

@@ -87,6 +87,21 @@ public Task deleteTask(int taskNo) {
         return task;
     }
 
+    /**
+     * Finds the tasks related to keyword.
+     * @param keyword Keyword used to find the related tasks.
+     * @return Returns a list of related tasks.
+     */
+    public List<Task> findTasks(String keyword) {
+        List<Task> relatedTasks = new ArrayList<>();
+        for(Task task : this.tasks) {
+            if(task.description.contains(keyword)) {
+                relatedTasks.add(task);
+            }
+        }
+        return relatedTasks;
+    }
+
     /**
      * Retrieves a string describing the task size.
      * @return Returns the string.

src/main/java/duke/Ui.java

@@ -1,5 +1,6 @@
 package duke;
 
+import java.util.List;
 import java.util.Scanner;
 import duke.task.*;
 
@@ -50,12 +51,30 @@ public void list(TaskList taskList) {
         System.out.println("Here are the tasks in your list:");
         for (int i = 1; i <= taskList.size(); i++) {
             Task task = taskList.get(i - 1);
-            String message = String.valueOf(i) + ".";
+            String message = i + ".";
             message += task;
             System.out.println(message);
         }
     }
 
+    /**
+     * Parses the list of tasks and prints the search result.
+     * @param searchResult Search result for task list.
+     */
+    public void printSearchResult(List<Task> searchResult) {
+        if(searchResult.size() < 1) {
+            System.out.println("There are no matching results!");
+        } else {
+            System.out.println("Here are the matching tasks in your list:");
+            for (int i = 1; i <= searchResult.size(); i++) {
+                Task task = searchResult.get(i - 1);
+                String message = i + ".";
+                message += task;
+                System.out.println(message);
+            }
+        }
+    }
+
     /**
      * Read the user input.
      */

src/main/java/duke/command/FindCommand.java

@@ -0,0 +1,19 @@
+package duke.command;
+
+import duke.*;
+import duke.task.*;
+
+import java.util.List;
+
+public class FindCommand extends Command {
+    private String keyword;
+
+    public FindCommand(String keyword) {
+        this.keyword = keyword;
+    }
+
+    public void execute(TaskList taskList, Ui ui, Storage storage) {
+        List<Task> relatedTasks = taskList.findTasks(keyword);
+        ui.printSearchResult(relatedTasks);
+    }
+}

src/main/java/duke/exception/DukeInvalidKeywordException.java

@@ -0,0 +1,7 @@
+package duke.exception;
+
+public class DukeInvalidKeywordException extends DukeException{
+    public DukeInvalidKeywordException() {
+        super("Please enter a valid keyword!");
+    }
+}