Merge branch-Level-9 with master

src/main/java/duke/Message.java

@@ -28,6 +28,7 @@ public class Message {
     public static final String FILE_NOT_FOUND = "The memory file cannot be found.";
     public static final String FILE_READ_ERROR = "There is an error when reading the memory file.";
     public static final String FILE_CREATE_ERROR = "There is an error when creating the memory file";
+    public static final String INVALID_FIND_TASK_FORMAT = "To find a task, please input this format: find {Keyword}";
 
     /**
      * Returns a String that describes that the task does not exist within the specified tasklist

src/main/java/duke/command/ByeCommand.java

@@ -31,4 +31,5 @@ public boolean isExit() {
     public void execute(TaskList tasks, Ui ui, Storage storage) throws DukeException {
         ui.showBye();
     }
+
 }

src/main/java/duke/command/Command.java

@@ -26,4 +26,5 @@ public abstract class Command {
      * @throws DukeException if an exception is thrown when the command is executed
      */
     public abstract void execute(TaskList tasks, Ui ui, Storage storage) throws DukeException;
+
 }

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

@@ -0,0 +1,27 @@
+package duke.command;
+
+import duke.DukeException;
+import duke.storage.Storage;
+import duke.task.TaskList;
+import duke.ui.Ui;
+
+public class FindCommand extends Command {
+
+    private String keyword;
+
+    public FindCommand(String keyword) {
+        this.keyword = keyword;
+    }
+
+    @Override
+    public boolean isExit() {
+        return false;
+    }
+
+    @Override
+    public void execute(TaskList tasks, Ui ui, Storage storage) throws DukeException {
+        String foundTasks = tasks.findTasks(this.keyword);
+        ui.showFound(foundTasks);
+    }
+
+}

src/main/java/duke/parser/Parser.java

@@ -28,8 +28,10 @@ public static Command parse(String fullCommand) throws DukeException {
             return addEvent(fullCommand);
         } else if (command.equals("todo")) {
             return addToDo(fullCommand);
-        } else if (command.equals("delete")){
+        } else if (command.equals("delete")) {
             return deleteTask(fullCommand);
+        } else if (command.equals("find")) {
+            return findTask(fullCommand);
         }
         throw new DukeException(Message.INVALID_USER_INPUT);
     }
@@ -51,9 +53,12 @@ private static AddCommand addDeadline(String input) throws DukeException {
             String description = stringArray[0].strip();
             String by = stringArray[1].strip();
             LocalDate deadlineDate = LocalDate.parse(by);
-            if (deadlineDate.isBefore(LocalDate.now()) || description.equals("")) {
+            if (deadlineDate.isBefore(LocalDate.now())) {
                 throw new DukeException(Message.INVALID_DATE_INPUT);
             }
+            if (description.equals("")) {
+                throw new DukeException(Message.INVALID_DEADLINE_INPUT);
+            }
             Deadline newDeadline = new Deadline(description, deadlineDate);
             return new AddCommand(newDeadline);
         } catch (ArrayIndexOutOfBoundsException e) {
@@ -108,4 +113,13 @@ private static DeleteCommand deleteTask(String command) throws DukeException {
         }
     }
 
+    private static FindCommand findTask(String command) throws DukeException {
+        String[] commandList = command.strip().split(" ");
+        try {
+            return new FindCommand(commandList[1]);
+        } catch (IndexOutOfBoundsException e) {
+            throw new DukeException(Message.INVALID_FIND_TASK_FORMAT);
+        }
+    }
+
 }

src/main/java/duke/task/Task.java

@@ -42,6 +42,15 @@ public void unmark() {
         this.isDone = false;
     }
 
+    /**
+     * Returns the description of the task
+     *
+     * @return task description
+     */
+    public String getDescription() {
+        return this.description;
+    }
+
     /**
      * Returns a string representation of this task
      *

src/main/java/duke/task/TaskList.java

@@ -85,7 +85,8 @@ public void unmarkTaskAtPos(int position) throws IndexOutOfBoundsException{
      *
      * @param position the index of the task in the list of tasks
      * @return the deleted task
-     * @throws IndexOutOfBoundsException the deleted task if given position > length of list of tasks or given position < 1
+     * @throws IndexOutOfBoundsException the deleted task if given position > length of list of tasks
+     * or given position < 1
      */
     public Task deleteTaskAtPos(int position) throws IndexOutOfBoundsException {
         Task deletedTask = getTask(position);
@@ -94,6 +95,33 @@ public Task deleteTaskAtPos(int position) throws IndexOutOfBoundsException {
         return deletedTask;
     }
 
+    /**
+     * Returns a string listing all the tasks found that include the keyword parameters given
+     * in their descriptions
+     *
+     * @param keyword the word used to find tasks that have this keyword in their descriptions
+     * @return a list of tasks containing the keyword
+     */
+    public String findTasks(String keyword) {
+        String foundTasks = "";
+        int taskCount = 1;
+        for (Task task : this.taskArray) {
+            String description = task.getDescription();
+            String[] words = description.split(" ");
+            for (String word : words) {
+                if (word.equals(keyword)) {
+                    if (taskCount == 1) {
+                         foundTasks += taskCount + ". " + task;
+                    } else {
+                        foundTasks += "\n" + taskCount + ". " + task;
+                    }
+                    taskCount++;
+                }
+            }
+        }
+        return foundTasks;
+    }
+
     /**
      * Returns the simple string representation of the list of tasks
      *

src/main/java/duke/ui/Ui.java

@@ -119,4 +119,8 @@ public void showDeleted(Task task) {
                 + "\nNow you have " + this.tasks.getCount() + " tasks in the list.");
     }
 
+    public void showFound(String foundTasks) {
+        showFullMessage("Here are the matching tasks in your list:\n" + foundTasks);
+    }
+
 }