Implement tasks unassign and contacts unassign (#102)

* Implement tasks unassign and contacts unassign

* Fix lint

src/main/java/seedu/address/logic/commands/contacts/UnassignCommand.java

@@ -0,0 +1,98 @@
+package seedu.address.logic.commands.contacts;
+
+import static java.util.Objects.requireNonNull;
+import static seedu.address.logic.parser.contacts.CliSyntax.PREFIX_CONTACT_ID;
+import static seedu.address.logic.parser.contacts.CliSyntax.PREFIX_TASK_ID;
+
+import java.util.HashSet;
+import java.util.List;
+import java.util.Set;
+
+import seedu.address.commons.core.EventsCenter;
+import seedu.address.commons.core.Messages;
+import seedu.address.commons.core.index.Index;
+import seedu.address.commons.events.ui.JumpToPersonListRequestEvent;
+import seedu.address.logic.CommandHistory;
+import seedu.address.logic.commands.Command;
+import seedu.address.logic.commands.CommandResult;
+import seedu.address.logic.commands.exceptions.CommandException;
+import seedu.address.model.Model;
+import seedu.address.model.person.Person;
+import seedu.address.model.person.PersonId;
+import seedu.address.model.task.Task;
+import seedu.address.model.task.TaskId;
+
+/**
+ * Unassigns a contact from a task. Both contact and task are identified by the index number used in the displayed
+ * person and task list respectively.
+ */
+public class UnassignCommand extends Command {
+
+    public static final String COMMAND_WORD = "unassign";
+
+    public static final String MESSAGE_USAGE = getCommandFormat(COMMAND_WORD)
+            + ": Unassigns a contact to a task. Both contact and task are identified by the index number used in the "
+            + "displayed person and task list respectively.\n"
+            + "Parameters: "
+            + PREFIX_CONTACT_ID + "CONTACT_INDEX "
+            + PREFIX_TASK_ID + "TASK_INDEX\n"
+            + "Example: " + getCommandFormat(COMMAND_WORD) + " "
+            + PREFIX_CONTACT_ID + "2 "
+            + PREFIX_TASK_ID + "4";
+
+    public static final String MESSAGE_ASSIGN_PERSON_SUCCESS = "Unassigned Person %1$s from Task %2$s";
+
+    private final Index targetContactIndex;
+    private final Index targetTaskIndex;
+
+    public UnassignCommand(Index targetContactIndex, Index targetTaskIndex) {
+        this.targetContactIndex = targetContactIndex;
+        this.targetTaskIndex = targetTaskIndex;
+    }
+
+    @Override
+    public CommandResult execute(Model model, CommandHistory history) throws CommandException {
+        requireNonNull(model);
+
+        List<Person> filteredPersonList = model.getFilteredPersonList();
+        if (targetContactIndex.getZeroBased() >= filteredPersonList.size()) {
+            throw new CommandException(Messages.MESSAGE_INVALID_PERSON_DISPLAYED_INDEX);
+        }
+
+        List<Task> filteredTaskList = model.getFilteredTaskList();
+        if (targetTaskIndex.getZeroBased() >= filteredTaskList.size()) {
+            throw new CommandException(Messages.MESSAGE_INVALID_TASK_DISPLAYED_INDEX);
+        }
+
+        Person personToEdit = filteredPersonList.get(targetContactIndex.getZeroBased());
+        Task taskToUnassign = filteredTaskList.get(targetTaskIndex.getZeroBased());
+
+        Set<TaskId> updatedTaskIds = new HashSet<>(personToEdit.getTaskIds());
+        updatedTaskIds.remove(taskToUnassign.getId());
+        Person editedPerson = new Person(personToEdit.getId(), personToEdit.getName(), personToEdit.getPhone(),
+                personToEdit.getEmail(), personToEdit.getAddress(), personToEdit.getTags(), updatedTaskIds);
+
+        Set<PersonId> updatedPersonIds = new HashSet<>(taskToUnassign.getPersonIds());
+        updatedPersonIds.remove(personToEdit.getId());
+        Task editedTask = new Task(taskToUnassign.getId(), taskToUnassign.getName(), taskToUnassign.getStartDateTime(),
+                taskToUnassign.getEndDateTime(), taskToUnassign.getTags(), updatedPersonIds);
+
+        model.updatePerson(personToEdit, editedPerson);
+        model.updateTask(taskToUnassign, editedTask);
+        model.commitAddressBook();
+
+        EventsCenter.getInstance().post(new JumpToPersonListRequestEvent(targetContactIndex));
+        return new CommandResult(String.format(MESSAGE_ASSIGN_PERSON_SUCCESS,
+                targetContactIndex.getOneBased(), targetTaskIndex.getOneBased()));
+
+    }
+
+    @Override
+    public boolean equals(Object other) {
+        return other == this // short circuit if same object
+                || (other instanceof UnassignCommand // instanceof handles nulls
+                && targetContactIndex.equals(((UnassignCommand) other).targetContactIndex) // state checks
+                && targetTaskIndex.equals(((UnassignCommand) other).targetTaskIndex)); // state checks
+    }
+}
+

src/main/java/seedu/address/logic/commands/tasks/UnassignCommand.java

@@ -0,0 +1,98 @@
+package seedu.address.logic.commands.tasks;
+
+import static java.util.Objects.requireNonNull;
+import static seedu.address.logic.parser.contacts.CliSyntax.PREFIX_CONTACT_ID;
+import static seedu.address.logic.parser.contacts.CliSyntax.PREFIX_TASK_ID;
+
+import java.util.HashSet;
+import java.util.List;
+import java.util.Set;
+
+import seedu.address.commons.core.EventsCenter;
+import seedu.address.commons.core.Messages;
+import seedu.address.commons.core.index.Index;
+import seedu.address.commons.events.ui.JumpToPersonListRequestEvent;
+import seedu.address.logic.CommandHistory;
+import seedu.address.logic.commands.Command;
+import seedu.address.logic.commands.CommandResult;
+import seedu.address.logic.commands.exceptions.CommandException;
+import seedu.address.model.Model;
+import seedu.address.model.person.Person;
+import seedu.address.model.person.PersonId;
+import seedu.address.model.task.Task;
+import seedu.address.model.task.TaskId;
+
+/**
+ * Unassigns a task from a contact. Both contact and task are identified by the index number used in the displayed
+ * person and task list respectively.
+ */
+public class UnassignCommand extends Command {
+
+    public static final String COMMAND_WORD = "unassign";
+
+    public static final String MESSAGE_USAGE = getCommandFormat(COMMAND_WORD)
+            + ": Unassigns a task from a contact. Both contact and task are identified by the index number used in the "
+            + "displayed person and task list respectively.\n"
+            + "Parameters: "
+            + PREFIX_CONTACT_ID + "CONTACT_INDEX "
+            + PREFIX_TASK_ID + "TASK_INDEX\n"
+            + "Example: " + getCommandFormat(COMMAND_WORD) + " "
+            + PREFIX_CONTACT_ID + "2 "
+            + PREFIX_TASK_ID + "4";
+
+    public static final String MESSAGE_ASSIGN_TASK_SUCCESS = "Unassigned Task %1$s from Person %2$s";
+
+    private final Index targetContactIndex;
+    private final Index targetTaskIndex;
+
+    public UnassignCommand(Index targetContactIndex, Index targetTaskIndex) {
+        this.targetContactIndex = targetContactIndex;
+        this.targetTaskIndex = targetTaskIndex;
+    }
+
+    @Override
+    public CommandResult execute(Model model, CommandHistory history) throws CommandException {
+        requireNonNull(model);
+
+        List<Person> filteredPersonList = model.getFilteredPersonList();
+        if (targetContactIndex.getZeroBased() >= filteredPersonList.size()) {
+            throw new CommandException(Messages.MESSAGE_INVALID_PERSON_DISPLAYED_INDEX);
+        }
+
+        List<Task> filteredTaskList = model.getFilteredTaskList();
+        if (targetTaskIndex.getZeroBased() >= filteredTaskList.size()) {
+            throw new CommandException(Messages.MESSAGE_INVALID_TASK_DISPLAYED_INDEX);
+        }
+
+        Person personToEdit = filteredPersonList.get(targetContactIndex.getZeroBased());
+        Task taskToUnassign = filteredTaskList.get(targetTaskIndex.getZeroBased());
+
+        Set<TaskId> updatedTaskIds = new HashSet<>(personToEdit.getTaskIds());
+        updatedTaskIds.remove(taskToUnassign.getId());
+        Person editedPerson = new Person(personToEdit.getId(), personToEdit.getName(), personToEdit.getPhone(),
+                personToEdit.getEmail(), personToEdit.getAddress(), personToEdit.getTags(), updatedTaskIds);
+
+        Set<PersonId> updatedPersonIds = new HashSet<>(taskToUnassign.getPersonIds());
+        updatedPersonIds.remove(personToEdit.getId());
+        Task editedTask = new Task(taskToUnassign.getId(), taskToUnassign.getName(), taskToUnassign.getStartDateTime(),
+                taskToUnassign.getEndDateTime(), taskToUnassign.getTags(), updatedPersonIds);
+
+        model.updatePerson(personToEdit, editedPerson);
+        model.updateTask(taskToUnassign, editedTask);
+        model.commitAddressBook();
+
+        EventsCenter.getInstance().post(new JumpToPersonListRequestEvent(targetContactIndex));
+        return new CommandResult(String.format(MESSAGE_ASSIGN_TASK_SUCCESS,
+                targetTaskIndex.getOneBased(), targetContactIndex.getOneBased()));
+
+    }
+
+    @Override
+    public boolean equals(Object other) {
+        return other == this // short circuit if same object
+                || (other instanceof UnassignCommand // instanceof handles nulls
+                && targetContactIndex.equals(((UnassignCommand) other).targetContactIndex) // state checks
+                && targetTaskIndex.equals(((UnassignCommand) other).targetTaskIndex)); // state checks
+    }
+}
+

src/main/java/seedu/address/logic/parser/ContactsParser.java

@@ -16,12 +16,14 @@
 import seedu.address.logic.commands.contacts.FindCommand;
 import seedu.address.logic.commands.contacts.ListCommand;
 import seedu.address.logic.commands.contacts.SelectCommand;
+import seedu.address.logic.commands.contacts.UnassignCommand;
 import seedu.address.logic.parser.contacts.AddCommandParser;
 import seedu.address.logic.parser.contacts.AssignCommandParser;
 import seedu.address.logic.parser.contacts.DeleteCommandParser;
 import seedu.address.logic.parser.contacts.EditCommandParser;
 import seedu.address.logic.parser.contacts.FindCommandParser;
 import seedu.address.logic.parser.contacts.SelectCommandParser;
+import seedu.address.logic.parser.contacts.UnassignCommandParser;
 import seedu.address.logic.parser.exceptions.ParseException;
 
 /**
@@ -78,6 +80,9 @@ public Command parseCommand(String userInput) throws ParseException {
             case AssignCommand.COMMAND_WORD:
                 return new AssignCommandParser().parse(arguments);
 
+            case UnassignCommand.COMMAND_WORD:
+                return new UnassignCommandParser().parse(arguments);
+
             default:
                 throw new ParseException(MESSAGE_UNKNOWN_COMMAND);
             }

src/main/java/seedu/address/logic/parser/TasksParser.java

@@ -14,12 +14,14 @@
 import seedu.address.logic.commands.tasks.EditCommand;
 import seedu.address.logic.commands.tasks.FindCommand;
 import seedu.address.logic.commands.tasks.ListCommand;
+import seedu.address.logic.commands.tasks.UnassignCommand;
 import seedu.address.logic.parser.exceptions.ParseException;
 import seedu.address.logic.parser.tasks.AddCommandParser;
 import seedu.address.logic.parser.tasks.AssignCommandParser;
 import seedu.address.logic.parser.tasks.DeleteCommandParser;
 import seedu.address.logic.parser.tasks.EditCommandParser;
 import seedu.address.logic.parser.tasks.FindCommandParser;
+import seedu.address.logic.parser.tasks.UnassignCommandParser;
 
 /**
  * Parses user input.
@@ -69,6 +71,9 @@ public Command parseCommand(String userInput) throws ParseException {
             case AssignCommand.COMMAND_WORD:
                 return new AssignCommandParser().parse(arguments);
 
+            case UnassignCommand.COMMAND_WORD:
+                return new UnassignCommandParser().parse(arguments);
+
             default:
                 throw new ParseException(MESSAGE_UNKNOWN_COMMAND);
             }

src/main/java/seedu/address/logic/parser/contacts/UnassignCommandParser.java

@@ -0,0 +1,50 @@
+package seedu.address.logic.parser.contacts;
+
+import static seedu.address.commons.core.Messages.MESSAGE_INVALID_COMMAND_FORMAT;
+import static seedu.address.logic.parser.contacts.CliSyntax.PREFIX_CONTACT_ID;
+import static seedu.address.logic.parser.contacts.CliSyntax.PREFIX_TASK_ID;
+
+import java.util.stream.Stream;
+
+import seedu.address.commons.core.index.Index;
+import seedu.address.logic.commands.contacts.UnassignCommand;
+import seedu.address.logic.parser.ArgumentMultimap;
+import seedu.address.logic.parser.ArgumentTokenizer;
+import seedu.address.logic.parser.Parser;
+import seedu.address.logic.parser.Prefix;
+import seedu.address.logic.parser.exceptions.ParseException;
+
+/**
+ * Parses input arguments and creates a new UnassignCommand object
+ */
+public class UnassignCommandParser implements Parser<UnassignCommand> {
+
+    /**
+     * Parses the given {@code String} of arguments in the context of the UnassignCommand
+     * and returns an UnassignCommand object for execution.
+     * @throws ParseException if the user input does not conform the expected format
+     */
+    public UnassignCommand parse(String args) throws ParseException {
+        ArgumentMultimap argMultimap =
+                ArgumentTokenizer.tokenize(args, PREFIX_CONTACT_ID, PREFIX_TASK_ID);
+
+        if (!arePrefixesPresent(argMultimap, PREFIX_CONTACT_ID, PREFIX_TASK_ID)
+                || !argMultimap.getPreamble().isEmpty()) {
+            throw new ParseException(String.format(MESSAGE_INVALID_COMMAND_FORMAT, UnassignCommand.MESSAGE_USAGE),
+                    true);
+        }
+
+        Index contactIndex = ParserUtil.parseIndex(argMultimap.getValue(PREFIX_CONTACT_ID).get());
+        Index taskIndex = ParserUtil.parseIndex(argMultimap.getValue(PREFIX_TASK_ID).get());
+        return new UnassignCommand(contactIndex, taskIndex);
+    }
+
+    /**
+     * Returns true if none of the prefixes contains empty {@code Optional} values in the given
+     * {@code ArgumentMultimap}.
+     */
+    private static boolean arePrefixesPresent(ArgumentMultimap argumentMultimap, Prefix... prefixes) {
+        return Stream.of(prefixes).allMatch(prefix -> argumentMultimap.getValue(prefix).isPresent());
+    }
+}
+

src/main/java/seedu/address/logic/parser/tasks/UnassignCommandParser.java

@@ -0,0 +1,50 @@
+package seedu.address.logic.parser.tasks;
+
+import static seedu.address.commons.core.Messages.MESSAGE_INVALID_COMMAND_FORMAT;
+import static seedu.address.logic.parser.contacts.CliSyntax.PREFIX_CONTACT_ID;
+import static seedu.address.logic.parser.contacts.CliSyntax.PREFIX_TASK_ID;
+
+import java.util.stream.Stream;
+
+import seedu.address.commons.core.index.Index;
+import seedu.address.logic.commands.tasks.UnassignCommand;
+import seedu.address.logic.parser.ArgumentMultimap;
+import seedu.address.logic.parser.ArgumentTokenizer;
+import seedu.address.logic.parser.Parser;
+import seedu.address.logic.parser.Prefix;
+import seedu.address.logic.parser.exceptions.ParseException;
+
+/**
+ * Parses input arguments and creates a new UnassignCommand object
+ */
+public class UnassignCommandParser implements Parser<UnassignCommand> {
+
+    /**
+     * Parses the given {@code String} of arguments in the context of the UnassignCommand
+     * and returns an UnassignCommand object for execution.
+     * @throws ParseException if the user input does not conform the expected format
+     */
+    public UnassignCommand parse(String args) throws ParseException {
+        ArgumentMultimap argMultimap =
+                ArgumentTokenizer.tokenize(args, PREFIX_CONTACT_ID, PREFIX_TASK_ID);
+
+        if (!arePrefixesPresent(argMultimap, PREFIX_CONTACT_ID, PREFIX_TASK_ID)
+                || !argMultimap.getPreamble().isEmpty()) {
+            throw new ParseException(String.format(MESSAGE_INVALID_COMMAND_FORMAT, UnassignCommand.MESSAGE_USAGE),
+                    true);
+        }
+
+        Index contactIndex = ParserUtil.parseIndex(argMultimap.getValue(PREFIX_CONTACT_ID).get());
+        Index taskIndex = ParserUtil.parseIndex(argMultimap.getValue(PREFIX_TASK_ID).get());
+        return new UnassignCommand(contactIndex, taskIndex);
+    }
+
+    /**
+     * Returns true if none of the prefixes contains empty {@code Optional} values in the given
+     * {@code ArgumentMultimap}.
+     */
+    private static boolean arePrefixesPresent(ArgumentMultimap argumentMultimap, Prefix... prefixes) {
+        return Stream.of(prefixes).allMatch(prefix -> argumentMultimap.getValue(prefix).isPresent());
+    }
+}
+