make changes according to reviews

src/main/java/duke/Duke.java

@@ -1,5 +1,6 @@
 package duke;
 
+import duke.command.Command;
 import duke.data.TaskList;
 import duke.exception.DukeException;
 import duke.parser.Parser;
@@ -46,7 +47,9 @@ public TaskList getTaskList() {
 
     public String getResponse(String input) {
         try{
-            return parser.parse(input);
+            Command command = parser.parse(input);
+            return command.execute(this.taskList, this.ui, this.storage);
+
         } catch (DukeException e) {
             return e.getError();
         }

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

@@ -0,0 +1,30 @@
+package duke.command;
+
+import duke.data.TaskList;
+import duke.storage.Storage;
+import duke.ui.Ui;
+
+public class ByeCommand extends Command {
+    final static String cmd = "bye";
+    final static String usage = "exit app";
+    final static String format = "bye";
+
+    public ByeCommand() {}
+
+    @Override
+    public String execute(TaskList tasks, Ui ui, Storage storage) {
+        return ui.showBye();
+    }
+
+    public static String getCmd() {
+        return cmd;
+    }
+
+    public static String getUsage() {
+        return usage;
+    }
+
+    public static String getFormat() {
+        return format;
+    }
+}

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

@@ -1,50 +1,23 @@
 package duke.command;
 
+import duke.data.TaskList;
+import duke.exception.*;
+import duke.storage.Storage;
+import duke.ui.Ui;
+
+import java.time.LocalDateTime;
+import java.time.format.DateTimeFormatter;
+import java.time.format.DateTimeParseException;
+
 /**
  * Stores description of usage and format of command.
  */
-public class Command {
-    String cmd;
-    String fn;
-    String format;
+public abstract class Command {
 
     /**
      * Constructs Command object
-     *
-     * @param cmd command
-     * @param fn description of usage
-     * @param format format
-     */
-    public Command(String cmd, String fn, String format) {
-        this.cmd = cmd;
-        this.fn = fn;
-        this.format = format;
-    }
-
-    /**
-     * Returns command
-     *
-     * @return command
      */
-    public String getCmd() {
-        return this.cmd;
-    }
+    public Command() {}
 
-    /**
-     * Returns description of usage
-     *
-     * @return description of usage
-     */
-    public String getFn() {
-        return this.fn;
-    }
-
-    /**
-     * Returns format
-     *
-     * @return format
-     */
-    public String getFormat() {
-        return this.format;
-    }
+    public abstract String execute(TaskList tasks, Ui ui, Storage storage);
 }

src/main/java/duke/command/DeadlineCommand.java

@@ -0,0 +1,44 @@
+package duke.command;
+
+import duke.data.TaskList;
+import duke.storage.Storage;
+import duke.task.Deadline;
+import duke.ui.Ui;
+
+import java.time.LocalDateTime;
+
+public class DeadlineCommand extends Command {
+    final static String cmd = "deadline";
+    final static String usage = "add tasks that need to be done before a specific date & time";
+    final static String format = "deadline {task name} /by {yyyy-MM-dd HH:mm}";
+
+    private String name;
+    private LocalDateTime by;
+
+    public DeadlineCommand(String name, LocalDateTime by) {
+        this.name = name;
+        this.by = by;
+    }
+
+    public DeadlineCommand() {}
+
+    @Override
+    public String execute(TaskList tasks, Ui ui, Storage storage) {
+        Deadline deadline = new Deadline(name, by);
+        tasks.addTask(deadline);
+        storage.updateData(tasks);
+        return ui.showTaskAdded(deadline, tasks.getSize());
+    }
+
+    public static String getCmd() {
+        return cmd;
+    }
+
+    public static String getUsage() {
+        return usage;
+    }
+
+    public static String getFormat() {
+        return format;
+    }
+}

src/main/java/duke/command/DeleteCommand.java

@@ -0,0 +1,40 @@
+package duke.command;
+
+import duke.data.TaskList;
+import duke.storage.Storage;
+import duke.task.Task;
+import duke.ui.Ui;
+
+public class DeleteCommand extends Command {
+    final static String cmd = "delete";
+    final static String usage = "deletes specified task";
+    final static String format =  "delete {task number}";
+
+    private int taskNum;
+
+    public DeleteCommand(int taskNum) {
+        this.taskNum = taskNum;
+    }
+
+    public DeleteCommand() {}
+
+    @Override
+    public String execute(TaskList tasks, Ui ui, Storage storage) {
+        Task task = tasks.getTask(taskNum);
+        tasks.deleteTask(task);
+        storage.updateData(tasks);
+        return ui.showTaskDeleted(task, tasks.getSize());
+    }
+
+    public static String getCmd() {
+        return cmd;
+    }
+
+    public static String getUsage() {
+        return usage;
+    }
+
+    public static String getFormat() {
+        return format;
+    }
+}

src/main/java/duke/command/DoneCommand.java

@@ -0,0 +1,40 @@
+package duke.command;
+
+import duke.data.TaskList;
+import duke.storage.Storage;
+import duke.task.Task;
+import duke.ui.Ui;
+
+public class DoneCommand extends Command {
+    final static String cmd = "done";
+    final static String usage = "marks specified task as done";
+    final static String format =  "done {task number}";
+
+    private int taskNum;
+
+    public DoneCommand(int taskNum) {
+        this.taskNum = taskNum;
+    }
+
+    public DoneCommand() {}
+
+    @Override
+    public String execute(TaskList tasks, Ui ui, Storage storage) {
+        Task task = tasks.getTask(this.taskNum);
+        task.markAsDone();
+        storage.updateData(tasks);
+        return ui.showTaskDone(task);
+    }
+
+    public static String getCmd() {
+        return cmd;
+    }
+
+    public static String getUsage() {
+        return usage;
+    }
+
+    public static String getFormat() {
+        return format;
+    }
+}

src/main/java/duke/command/EventCommand.java

@@ -0,0 +1,44 @@
+package duke.command;
+
+import duke.data.TaskList;
+import duke.storage.Storage;
+import duke.task.Event;
+import duke.ui.Ui;
+
+import java.time.LocalDateTime;
+
+public class EventCommand extends Command {
+    final static String cmd = "event";
+    final static String usage = "add tasks that need that starts at a specific time";
+    final static String format = "event {task name} /by {yyyy-MM-dd HH:mm}";
+
+    private String name;
+    private LocalDateTime at;
+
+    public EventCommand(String name, LocalDateTime at) {
+        this.name = name;
+        this.at = at;
+    };
+
+    public EventCommand() {}
+
+    @Override
+    public String execute(TaskList tasks, Ui ui, Storage storage) {
+        Event event = new Event(name, at);
+        tasks.addTask(event);
+        storage.updateData(tasks);
+        return ui.showTaskAdded(event, tasks.getSize());
+    }
+
+    public static String getCmd() {
+        return cmd;
+    }
+
+    public static String getUsage() {
+        return usage;
+    }
+
+    public static String getFormat() {
+        return format;
+    }
+}

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

@@ -0,0 +1,37 @@
+package duke.command;
+
+import duke.data.TaskList;
+import duke.storage.Storage;
+import duke.ui.Ui;
+
+public class FindCommand extends Command {
+    final static String cmd = "find";
+    final static String usage = "find a task by searching for a keyword";
+    final static String format = "find {keyword}";
+
+    private String keyword;
+
+    public FindCommand(String keyword) {
+        this.keyword = keyword;
+    }
+
+    public FindCommand() {}
+
+    @Override
+    public String execute(TaskList tasks, Ui ui, Storage storage) {
+        TaskList t = tasks.matchTasks(keyword);
+        return ui.showTaskList(t, "find");
+    }
+
+    public static String getCmd() {
+        return cmd;
+    }
+
+    public static String getUsage() {
+        return usage;
+    }
+
+    public static String getFormat() {
+        return format;
+    }
+}

src/main/java/duke/command/HelpCommand.java

@@ -0,0 +1,30 @@
+package duke.command;
+
+import duke.data.TaskList;
+import duke.storage.Storage;
+import duke.ui.Ui;
+
+public class HelpCommand extends Command {
+    final static String cmd = "help";
+    final static String usage = "shows list of all commands & usages";
+    final static String format = "help";
+
+    public HelpCommand() {}
+
+    @Override
+    public String execute(TaskList tasks, Ui ui, Storage storage) {
+        return ui.showAfterHelp();
+    }
+
+    public static String getCmd() {
+        return cmd;
+    }
+
+    public static String getUsage() {
+        return usage;
+    }
+
+    public static String getFormat() {
+        return format;
+    }
+}

src/main/java/duke/command/InvalidCommand.java

@@ -0,0 +1,21 @@
+package duke.command;
+
+import duke.data.TaskList;
+import duke.exception.DukeException;
+import duke.exception.InvalidEntryException;
+import duke.storage.Storage;
+import duke.ui.Ui;
+
+public class InvalidCommand extends Command {
+
+    public InvalidCommand() {}
+
+    @Override
+    public String execute(TaskList tasks, Ui ui, Storage storage) {
+        try {
+            throw new InvalidEntryException("error");
+        } catch (DukeException e) {
+            return e.getError();
+        }
+    }
+}