[W5] [T12-4] Jeremy Yiren Low

src/seedu/addressbook/Main.java

@@ -7,6 +7,7 @@
 import seedu.addressbook.commands.Command;
 import seedu.addressbook.commands.CommandResult;
 import seedu.addressbook.commands.ExitCommand;
+import seedu.addressbook.common.Messages;
 import seedu.addressbook.data.AddressBook;
 import seedu.addressbook.data.person.ReadOnlyPerson;
 import seedu.addressbook.parser.Parser;
@@ -32,6 +33,8 @@ public class Main {
     /** The list of person shown to the user most recently.  */
     private List<? extends ReadOnlyPerson> lastShownList = Collections.emptyList();
 
+    /** The previous command entered by user. */
+    private String PreviousUserCommand = Messages.HISTORY_EMPTY;
 
     public static void main(String... launchArgs) {
         new Main().run(launchArgs);
@@ -50,6 +53,7 @@ public void run(String[] launchArgs) {
      * @param launchArgs arguments supplied by the user at program launch
      *
      */
+
     private void start(String[] launchArgs) {
         try {
             this.ui = new TextUi();
@@ -83,9 +87,14 @@ private void runCommandLoopUntilExitCommand() {
         Command command;
         do {
             String userCommandText = ui.getUserCommand();
-            command = new Parser().parseCommand(userCommandText);
+            command = new Parser().parseCommand(userCommandText, PreviousUserCommand);
             CommandResult result = executeCommand(command);
             recordResult(result);
+            if(result.isExecuted){
+                PreviousUserCommand = userCommandText;
+            } else {
+                PreviousUserCommand = Messages.HISTORY_INVALID;
+            }
             ui.showResultToUser(result);
 
         } while (!ExitCommand.isExit(command));

src/seedu/addressbook/commands/AddCommand.java

@@ -66,9 +66,9 @@ public ReadOnlyPerson getPerson() {
     public CommandResult execute() {
         try {
             addressBook.addPerson(toAdd);
-            return new CommandResult(String.format(MESSAGE_SUCCESS, toAdd));
+            return new CommandResult(String.format(MESSAGE_SUCCESS, toAdd), true);
         } catch (UniquePersonList.DuplicatePersonException dpe) {
-            return new CommandResult(MESSAGE_DUPLICATE_PERSON);
+            return new CommandResult(MESSAGE_DUPLICATE_PERSON, false);
         }
     }
 

src/seedu/addressbook/commands/ClearCommand.java

@@ -14,6 +14,6 @@ public class ClearCommand extends Command {
     @Override
     public CommandResult execute() {
         addressBook.clear();
-        return new CommandResult(MESSAGE_SUCCESS);
+        return new CommandResult(MESSAGE_SUCCESS, true);
     }
 }

src/seedu/addressbook/commands/CommandResult.java

@@ -13,16 +13,21 @@ public class CommandResult {
     /** The feedback message to be shown to the user. Contains a description of the execution result */
     public final String feedbackToUser;
 
+    /** The feedback message to be shown to the user. Contains a description of the execution result */
+    public final boolean isExecuted;
+
     /** The list of persons that was produced by the command */
     private final List<? extends ReadOnlyPerson> relevantPersons;
 
-    public CommandResult(String feedbackToUser) {
+    public CommandResult(String feedbackToUser, boolean tag) {
         this.feedbackToUser = feedbackToUser;
+        isExecuted = tag;
         relevantPersons = null;
     }
 
-    public CommandResult(String feedbackToUser, List<? extends ReadOnlyPerson> relevantPersons) {
+    public CommandResult(String feedbackToUser, boolean tag, List<? extends ReadOnlyPerson> relevantPersons) {
         this.feedbackToUser = feedbackToUser;
+        isExecuted = tag;
         this.relevantPersons = relevantPersons;
     }
 

src/seedu/addressbook/commands/DeleteCommand.java

@@ -1,6 +1,7 @@
 package seedu.addressbook.commands;
 
 import seedu.addressbook.common.Messages;
+import seedu.addressbook.data.person.Person;
 import seedu.addressbook.data.person.ReadOnlyPerson;
 import seedu.addressbook.data.person.UniquePersonList.PersonNotFoundException;
 
@@ -29,13 +30,14 @@ public DeleteCommand(int targetVisibleIndex) {
     public CommandResult execute() {
         try {
             final ReadOnlyPerson target = getTargetPerson();
+            addressBook.sendToBin((Person)target);
             addressBook.removePerson(target);
-            return new CommandResult(String.format(MESSAGE_DELETE_PERSON_SUCCESS, target));
+            return new CommandResult(String.format(MESSAGE_DELETE_PERSON_SUCCESS, target), true);
 
         } catch (IndexOutOfBoundsException ie) {
-            return new CommandResult(Messages.MESSAGE_INVALID_PERSON_DISPLAYED_INDEX);
+            return new CommandResult(Messages.MESSAGE_INVALID_PERSON_DISPLAYED_INDEX, false);
         } catch (PersonNotFoundException pnfe) {
-            return new CommandResult(Messages.MESSAGE_PERSON_NOT_IN_ADDRESSBOOK);
+            return new CommandResult(Messages.MESSAGE_PERSON_NOT_IN_ADDRESSBOOK, false);
         }
     }
 

src/seedu/addressbook/commands/ExitCommand.java

@@ -13,7 +13,7 @@ public class ExitCommand extends Command {
 
     @Override
     public CommandResult execute() {
-        return new CommandResult(MESSAGE_EXIT_ACKNOWEDGEMENT);
+        return new CommandResult(MESSAGE_EXIT_ACKNOWEDGEMENT, true);
     }
 
     public static boolean isExit(Command command) {

src/seedu/addressbook/commands/FindCommand.java

@@ -37,7 +37,7 @@ public Set<String> getKeywords() {
     @Override
     public CommandResult execute() {
         final List<ReadOnlyPerson> personsFound = getPersonsWithNameContainingAnyKeyword(keywords);
-        return new CommandResult(getMessageForPersonListShownSummary(personsFound), personsFound);
+        return new CommandResult(getMessageForPersonListShownSummary(personsFound), true, personsFound);
     }
 
     /**

src/seedu/addressbook/commands/HelpCommand.java

@@ -19,10 +19,11 @@ public CommandResult execute() {
                 + "\n" + ClearCommand.MESSAGE_USAGE
                 + "\n" + FindCommand.MESSAGE_USAGE
                 + "\n" + ListCommand.MESSAGE_USAGE
+                + "\n" + UndoCommand.MESSAGE_USAGE
                 + "\n" + ViewCommand.MESSAGE_USAGE
                 + "\n" + ViewAllCommand.MESSAGE_USAGE
                 + "\n" + HelpCommand.MESSAGE_USAGE
                 + "\n" + ExitCommand.MESSAGE_USAGE
-        );
+        , true);
     }
 }

src/seedu/addressbook/commands/IncorrectCommand.java

@@ -14,7 +14,7 @@ public IncorrectCommand(String feedbackToUser) {
 
     @Override
     public CommandResult execute() {
-        return new CommandResult(feedbackToUser);
+        return new CommandResult(feedbackToUser, false);
     }
 
 }

src/seedu/addressbook/commands/ListCommand.java

@@ -20,6 +20,6 @@ public class ListCommand extends Command {
     @Override
     public CommandResult execute() {
         List<ReadOnlyPerson> allPersons = addressBook.getAllPersons().immutableListView();
-        return new CommandResult(getMessageForPersonListShownSummary(allPersons), allPersons);
+        return new CommandResult(getMessageForPersonListShownSummary(allPersons), true, allPersons);
     }
 }

src/seedu/addressbook/commands/UndoCommand.java

@@ -0,0 +1,47 @@
+package seedu.addressbook.commands;
+
+import seedu.addressbook.common.Messages;
+import seedu.addressbook.data.person.UniquePersonList;
+
+/**
+ * Clears the address book.
+ */
+public class UndoCommand extends Command {
+
+    public static final String COMMAND_WORD = "undo";
+    public static final String MESSAGE_USAGE = COMMAND_WORD + ": Reverts effect of previous command. "
+            + "Only applicable to add, delete commands.\n"
+            + "Example: " + COMMAND_WORD;
+
+    public static final String MESSAGE_SUCCESS = "Undo successful. Command reverted: ";
+    public static final String MESSAGE_INVALID = "Undo cannot be performed on this command: ";
+
+    private final String LAST_COMMAND;
+
+    public UndoCommand(String cmd){
+        this.LAST_COMMAND = cmd;
+    }
+
+    @Override
+    public CommandResult execute(){
+        String[] command = LAST_COMMAND.split(" ");
+        if(command[0].equals(AddCommand.COMMAND_WORD)){
+            try {
+              addressBook.removeLastPerson();
+            }
+            catch (UniquePersonList.PersonNotFoundException pnfe) {
+                return new CommandResult(Messages.MESSAGE_PERSON_NOT_IN_ADDRESSBOOK, true);
+            }
+            return new CommandResult(MESSAGE_SUCCESS + LAST_COMMAND, true);
+        } else if(command[0].equals(DeleteCommand.COMMAND_WORD)) {
+            try {
+                addressBook.addBackDeletedPerson();
+            } catch (UniquePersonList.DuplicatePersonException dpe){
+                return new CommandResult(AddCommand.MESSAGE_DUPLICATE_PERSON, false);
+            }
+            return new CommandResult(MESSAGE_SUCCESS + LAST_COMMAND, true);
+        } else {
+            return new CommandResult(MESSAGE_INVALID + LAST_COMMAND, true);
+        }
+    }
+}

src/seedu/addressbook/commands/ViewAllCommand.java

@@ -30,11 +30,11 @@ public CommandResult execute() {
         try {
             final ReadOnlyPerson target = getTargetPerson();
             if (!addressBook.containsPerson(target)) {
-                return new CommandResult(Messages.MESSAGE_PERSON_NOT_IN_ADDRESSBOOK);
+                return new CommandResult(Messages.MESSAGE_PERSON_NOT_IN_ADDRESSBOOK, true);
             }
-            return new CommandResult(String.format(MESSAGE_VIEW_PERSON_DETAILS, target.getAsTextShowAll()));
+            return new CommandResult(String.format(MESSAGE_VIEW_PERSON_DETAILS, target.getAsTextShowAll()), true);
         } catch (IndexOutOfBoundsException ie) {
-            return new CommandResult(Messages.MESSAGE_INVALID_PERSON_DISPLAYED_INDEX);
+            return new CommandResult(Messages.MESSAGE_INVALID_PERSON_DISPLAYED_INDEX, true);
         }
     }
 }

src/seedu/addressbook/commands/ViewCommand.java

@@ -30,11 +30,11 @@ public CommandResult execute() {
         try {
             final ReadOnlyPerson target = getTargetPerson();
             if (!addressBook.containsPerson(target)) {
-                return new CommandResult(Messages.MESSAGE_PERSON_NOT_IN_ADDRESSBOOK);
+                return new CommandResult(Messages.MESSAGE_PERSON_NOT_IN_ADDRESSBOOK, true);
             }
-            return new CommandResult(String.format(MESSAGE_VIEW_PERSON_DETAILS, target.getAsTextHidePrivate()));
+            return new CommandResult(String.format(MESSAGE_VIEW_PERSON_DETAILS, target.getAsTextHidePrivate()), true);
         } catch (IndexOutOfBoundsException ie) {
-            return new CommandResult(Messages.MESSAGE_INVALID_PERSON_DISPLAYED_INDEX);
+            return new CommandResult(Messages.MESSAGE_INVALID_PERSON_DISPLAYED_INDEX, true);
         }
     }
 

src/seedu/addressbook/common/Messages.java

@@ -15,4 +15,6 @@ public class Messages {
             "java seedu.addressbook.Main [STORAGE_FILE_PATH]";
     public static final String MESSAGE_WELCOME = "Welcome to your Address Book!";
     public static final String MESSAGE_USING_STORAGE_FILE = "Using storage file : %1$s";
+    public static final String HISTORY_EMPTY = "NO COMMAND HISTORY.";
+    public static final String HISTORY_INVALID = "PREVIOUS COMMAND IS INVALID. PLEASE ENTER NEW COMMAND.";
 }

src/seedu/addressbook/data/AddressBook.java

@@ -6,12 +6,16 @@
 import seedu.addressbook.data.person.UniquePersonList.DuplicatePersonException;
 import seedu.addressbook.data.person.UniquePersonList.PersonNotFoundException;
 
+import java.util.Iterator;
+import java.util.Optional;
+
 /**
  * Represents the entire address book. Contains the data of the address book.
  */
 public class AddressBook {
 
     private final UniquePersonList allPersons;
+    private Optional<Person> deletedPerson = Optional.empty();
 
     /**
      * Creates an empty address book.
@@ -61,13 +65,35 @@ public void clear() {
         allPersons.clear();
     }
 
+    /**
+     * Clears the most recently added person from addressbook.
+     */
+    public void removeLastPerson() throws PersonNotFoundException {
+        Iterator<Person> itr = allPersons.iterator();
+        assert itr.hasNext();
+        Person p = itr.next();
+        while(itr.hasNext()){
+            p = itr.next();
+        }
+        this.removePerson(p);
+    }
+
     /**
      * Returns a new UniquePersonList of all persons in the address book at the time of the call.
      */
     public UniquePersonList getAllPersons() {
         return new UniquePersonList(allPersons);
     }
 
+    public void sendToBin(Person target) {
+        deletedPerson = Optional.of(target);
+    }
+
+    public void addBackDeletedPerson() throws DuplicatePersonException{
+        assert deletedPerson.isPresent();
+        allPersons.add(deletedPerson.get());
+    }
+
     @Override
     public boolean equals(Object other) {
         return other == this // short circuit if same object

src/seedu/addressbook/parser/Parser.java

@@ -3,25 +3,11 @@
 import static seedu.addressbook.common.Messages.MESSAGE_INVALID_COMMAND_FORMAT;
 import static seedu.addressbook.common.Messages.MESSAGE_INVALID_PERSON_DISPLAYED_INDEX;
 
-import java.util.Arrays;
-import java.util.Collection;
-import java.util.Collections;
-import java.util.HashSet;
-import java.util.Set;
+import java.util.*;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
-import seedu.addressbook.commands.AddCommand;
-import seedu.addressbook.commands.ClearCommand;
-import seedu.addressbook.commands.Command;
-import seedu.addressbook.commands.DeleteCommand;
-import seedu.addressbook.commands.ExitCommand;
-import seedu.addressbook.commands.FindCommand;
-import seedu.addressbook.commands.HelpCommand;
-import seedu.addressbook.commands.IncorrectCommand;
-import seedu.addressbook.commands.ListCommand;
-import seedu.addressbook.commands.ViewAllCommand;
-import seedu.addressbook.commands.ViewCommand;
+import seedu.addressbook.commands.*;
 import seedu.addressbook.data.exception.IllegalValueException;
 
 /**
@@ -62,12 +48,11 @@ public static class ParseException extends Exception {
      * @param userInput full user input string
      * @return the command based on the user input
      */
-    public Command parseCommand(String userInput) {
+    public Command parseCommand(String userInput, String previousInput) {
         final Matcher matcher = BASIC_COMMAND_FORMAT.matcher(userInput.trim());
         if (!matcher.matches()) {
             return new IncorrectCommand(String.format(MESSAGE_INVALID_COMMAND_FORMAT, HelpCommand.MESSAGE_USAGE));
         }
-
         final String commandWord = matcher.group("commandWord");
         final String arguments = matcher.group("arguments");
 
@@ -88,6 +73,9 @@ public Command parseCommand(String userInput) {
         case ListCommand.COMMAND_WORD:
             return new ListCommand();
 
+        case UndoCommand.COMMAND_WORD:
+                return new UndoCommand(previousInput.trim());
+
         case ViewCommand.COMMAND_WORD:
             return prepareView(arguments);
 
@@ -101,6 +89,7 @@ public Command parseCommand(String userInput) {
         default:
             return new HelpCommand();
         }
+
     }
 
     /**