Update delete contact functionality

src/main/java/seedu/address/commons/exceptions/IllegalOperationException.java

@@ -0,0 +1,21 @@
+package seedu.address.commons.exceptions;
+
+/**
+ * Exception thrown when attempting to make illegal.
+ */
+public class IllegalOperationException extends Exception {
+    /**
+     * @param message that informs the user that it has attempted an illegal operation.
+     */
+    public IllegalOperationException(String message) {
+        super(message);
+    }
+
+    /**
+     * @param message that informs the user that it has attempted an illegal operation.
+     * @param cause of the main exception.
+     */
+    public IllegalOperationException(String message, Throwable cause) {
+        super(message, cause);
+    }
+}

src/main/java/seedu/address/logic/Messages.java

@@ -15,6 +15,7 @@ public class Messages {
     public static final String MESSAGE_UNKNOWN_COMMAND = "Unknown command";
     public static final String MESSAGE_INVALID_COMMAND_FORMAT = "Invalid command format! \n%1$s";
     public static final String MESSAGE_INVALID_CONTACT_DISPLAYED_INDEX = "The contact index provided is invalid";
+    public static final String MESSAGE_NO_SUCH_CONTACT = "No such contact";
     public static final String MESSAGE_CONTACTS_LISTED_OVERVIEW = "%1$d contacts listed!";
     public static final String MESSAGE_DUPLICATE_FIELDS =
                 "Multiple values specified for the following single-valued field(s): ";

src/main/java/seedu/address/logic/commands/DeleteCommand.java

@@ -3,16 +3,18 @@
 import static java.util.Objects.requireNonNull;
 
 import java.util.List;
+import java.util.function.Function;
 
 import seedu.address.commons.core.index.Index;
 import seedu.address.commons.util.ToStringBuilder;
 import seedu.address.logic.Messages;
 import seedu.address.logic.commands.exceptions.CommandException;
 import seedu.address.model.Model;
 import seedu.address.model.person.Contact;
+import seedu.address.model.person.Id;
 
 /**
- * Deletes a contact identified using it's displayed index from the address book.
+ * Deletes a contact identified using its displayed index or its contact id from the address book.
  */
 public class DeleteCommand extends Command {
 
@@ -25,22 +27,75 @@ public class DeleteCommand extends Command {
 
     public static final String MESSAGE_DELETE_CONTACT_SUCCESS = "Deleted Contact: %1$s";
 
-    private final Index targetIndex;
+    private final Object selector; // TODO: This is very sus but this will only be used for equals comparison
 
+    private final Function<Model, Contact> contactFunction;
+
+    private final CommandException commandException;
+
+    /**
+     * @param targetIndex of the contact to be deleted
+     */
     public DeleteCommand(Index targetIndex) {
-        this.targetIndex = targetIndex;
+        this.selector = targetIndex;
+        this.contactFunction = (Model model) -> {
+            List<Contact> lastShownList = model.getFilteredContactList();
+
+            if (targetIndex.getZeroBased() >= lastShownList.size()) {
+                return null;
+            }
+
+            return lastShownList.get(targetIndex.getZeroBased());
+        };
+        this.commandException = new CommandException(Messages.MESSAGE_INVALID_CONTACT_DISPLAYED_INDEX);
+    }
+
+    /**
+     * @param targetId of the contact to be deleted
+     */
+    public DeleteCommand(Id targetId) {
+        this.selector = targetId;
+        this.contactFunction = (Model model) -> model.getContactById(targetId);
+        this.commandException = new CommandException(Messages.MESSAGE_NO_SUCH_CONTACT);
+    }
+
+    /**
+     * Creates an executable DeleteCommand based on whether to delete recursively.
+     *
+     * @param targetIndex of the contact to delete in the current list
+     * @param shouldDeleteChildren specifies if child contacts should be deleted
+     */
+    public static DeleteCommand selectIndex(Index targetIndex, boolean shouldDeleteChildren) {
+        // TODO: Add documentation to DG
+        requireNonNull(targetIndex);
+        if (shouldDeleteChildren) {
+            return new DeleteWithChildrenCommand(targetIndex);
+        }
+        return new DeleteCommand(targetIndex);
+    }
+
+    /**
+     * Creates an executable DeleteCommand based on whether to delete recursively.
+     *
+     * @param id of the contact to delete in the current list
+     * @param shouldDeleteChildren specifies if child contacts should be deleted
+     */
+    public static DeleteCommand selectId(Id id, boolean shouldDeleteChildren) {
+        // TODO: Add documentation to DG
+        requireNonNull(id);
+        if (shouldDeleteChildren) {
+            return new DeleteWithChildrenCommand(id);
+        }
+        return new DeleteCommand(id);
     }
 
     @Override
     public CommandResult execute(Model model) throws CommandException {
         requireNonNull(model);
-        List<Contact> lastShownList = model.getFilteredContactList();
-
-        if (targetIndex.getZeroBased() >= lastShownList.size()) {
-            throw new CommandException(Messages.MESSAGE_INVALID_CONTACT_DISPLAYED_INDEX);
+        Contact contactToDelete = this.contactFunction.apply(model);
+        if (contactToDelete == null) {
+            throw commandException;
         }
-
-        Contact contactToDelete = lastShownList.get(targetIndex.getZeroBased());
         model.deleteContact(contactToDelete);
         return new CommandResult(String.format(MESSAGE_DELETE_CONTACT_SUCCESS, Messages.format(contactToDelete)));
     }
@@ -57,13 +112,23 @@ public boolean equals(Object other) {
         }
 
         DeleteCommand otherDeleteCommand = (DeleteCommand) other;
-        return targetIndex.equals(otherDeleteCommand.targetIndex);
+        return selector.equals(otherDeleteCommand.selector);
     }
 
     @Override
     public String toString() {
+        // TODO: replace this toString method with sth better than targetIndex
+        // To not replace yet until we do the tests
         return new ToStringBuilder(this)
-                .add("targetIndex", targetIndex)
+                .add("targetIndex", selector)
                 .toString();
     }
+
+    /**
+     * Gives the contact that the DeleteCommand is going to delete if a model is given.
+     * If such a contact does not exist, gives null.
+     */
+    protected Contact getContact(Model model) {
+        return contactFunction.apply(model);
+    }
 }

src/main/java/seedu/address/logic/commands/DeleteWithChildrenCommand.java

@@ -0,0 +1,56 @@
+package seedu.address.logic.commands;
+
+import static java.util.Objects.requireNonNull;
+
+import java.util.Arrays;
+
+import seedu.address.commons.core.index.Index;
+import seedu.address.logic.Messages;
+import seedu.address.logic.commands.exceptions.CommandException;
+import seedu.address.model.Model;
+import seedu.address.model.person.Contact;
+import seedu.address.model.person.Id;
+
+/**
+ * Deletes a contact and also deletes its child contacts.
+ */
+public class DeleteWithChildrenCommand extends DeleteCommand {
+
+    public static final String MESSAGE_DELETE_CONTACT_SUCCESS = DeleteCommand.MESSAGE_DELETE_CONTACT_SUCCESS + " with"
+            + ":\n%2$s";
+
+
+    /**
+     * @param targetIndex of the contact to be deleted in the current contact list
+     */
+    public DeleteWithChildrenCommand(Index targetIndex) {
+        // TODO add documentation in DG
+        super(targetIndex);
+    }
+
+    public DeleteWithChildrenCommand(Id targetId) {
+        super(targetId);
+    }
+
+    @Override
+    public CommandResult execute(Model model) throws CommandException {
+        requireNonNull(model);
+        Contact contactToDelete = super.getContact(model);
+        super.execute(model);
+        // At this point if the contact is null, the superclass would have thrown exception.
+        // Superclass would have also deleted the contact from the list.
+        assert contactToDelete != null;
+        Contact[] childContacts = contactToDelete.getChildren();
+        Arrays.stream(childContacts).forEach(contact -> {
+            model.deleteContact(contactToDelete);
+        });
+        return new CommandResult(String.format(
+                MESSAGE_DELETE_CONTACT_SUCCESS,
+                Messages.format(contactToDelete),
+                Arrays.stream(childContacts)
+                        .map(c -> Messages.format(c) + "\n")
+                        .reduce((c1, c2) -> c1 + c2)
+                        .orElse("No other contacts found") // I can't find a better method.
+        ));
+    }
+}

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

@@ -17,8 +17,7 @@ public class CliSyntax {
     public static final Flag FLAG_STATUS = new Flag("stat");
     public static final Flag FLAG_POSITION = new Flag("pos");
     public static final Flag FLAG_ID = new Flag("id");
+    public static final Flag FLAG_RECURSIVE = new Flag("recursive");
     public static final Flag FLAG_ORGANIZATION_ID = new Flag("oid");
 
-
-
 }

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

@@ -1,10 +1,13 @@
 package seedu.address.logic.parser;
 
 import static seedu.address.logic.Messages.MESSAGE_INVALID_COMMAND_FORMAT;
+import static seedu.address.logic.parser.CliSyntax.FLAG_ID;
+import static seedu.address.logic.parser.CliSyntax.FLAG_RECURSIVE;
 
 import seedu.address.commons.core.index.Index;
 import seedu.address.logic.commands.DeleteCommand;
 import seedu.address.logic.parser.exceptions.ParseException;
+import seedu.address.model.person.Id;
 
 /**
  * Parses input arguments and creates a new DeleteCommand object
@@ -17,13 +20,45 @@ public class DeleteCommandParser implements Parser<DeleteCommand> {
      * @throws ParseException if the user input does not conform the expected format
      */
     public DeleteCommand parse(String args) throws ParseException {
+        ArgumentMultimap argumentMultimap =
+                ArgumentTokenizer.tokenize(args,
+                        FLAG_ID, FLAG_RECURSIVE);
+
+        boolean hasIndex = !argumentMultimap.getPreamble().isEmpty();
+        boolean hasId = argumentMultimap.getValue(FLAG_ID).isPresent();
+        boolean isRecursive = argumentMultimap.getValue(FLAG_RECURSIVE).isPresent();
+
+        if (hasIndex) {
+            return parseDeleteIndexCommand(argumentMultimap.getPreamble(), isRecursive);
+        }
+
+        if (hasId) {
+            return parseDeleteIdCommand(argumentMultimap.getValue(FLAG_ID).get(), isRecursive);
+        }
+        throw new ParseException(
+                String.format(MESSAGE_INVALID_COMMAND_FORMAT, DeleteCommand.MESSAGE_USAGE));
+    }
+
+    private static DeleteCommand parseDeleteIdCommand(String idString, boolean isRecursive) throws ParseException {
+        Id id;
         try {
-            Index index = ParserUtil.parseIndex(args);
-            return new DeleteCommand(index);
+            // We are guaranteed that there is something by
+            id = ParserUtil.parseId(idString);
+            return DeleteCommand.selectId(id, isRecursive);
         } catch (ParseException pe) {
             throw new ParseException(
                     String.format(MESSAGE_INVALID_COMMAND_FORMAT, DeleteCommand.MESSAGE_USAGE), pe);
         }
     }
 
+    private static DeleteCommand parseDeleteIndexCommand(String indexStr, boolean isRecursive) throws ParseException {
+        Index index;
+        try {
+            index = ParserUtil.parseIndex(indexStr);
+            return DeleteCommand.selectIndex(index, isRecursive);
+        } catch (ParseException pe) {
+            throw new ParseException(
+                    String.format(MESSAGE_INVALID_COMMAND_FORMAT, DeleteCommand.MESSAGE_USAGE), pe);
+        }
+    }
 }

src/main/java/seedu/address/model/AddressBook.java

@@ -7,6 +7,7 @@
 import javafx.collections.ObservableList;
 import seedu.address.commons.util.ToStringBuilder;
 import seedu.address.model.person.Contact;
+import seedu.address.model.person.Id;
 import seedu.address.model.person.UniqueContactList;
 
 /**
@@ -94,6 +95,21 @@ public void removeContact(Contact key) {
         contacts.remove(key);
     }
 
+    /**
+     * Gives a contact which id matches the given id.
+     * Gives null if a contact with such id does not exist.
+     * Given id must not be null.
+     */
+    public Contact getContactById(Id id) {
+        requireNonNull(id);
+        for (Contact c: contacts) {
+            if (id.equals(c.getId())) {
+                return c;
+            }
+        }
+        return null;
+    }
+
     //// util methods
 
     @Override

src/main/java/seedu/address/model/Model.java

@@ -6,6 +6,7 @@
 import javafx.collections.ObservableList;
 import seedu.address.commons.core.GuiSettings;
 import seedu.address.model.person.Contact;
+import seedu.address.model.person.Id;
 
 /**
  * The API of the Model component.
@@ -76,6 +77,13 @@ public interface Model {
      */
     void setContact(Contact target, Contact editedContact);
 
+    /**
+     * Gives a contact which matches the given id.
+     * Gives null if no such contact is found.
+     * Given id must not be null.
+     */
+    Contact getContactById(Id id);
+
     /** Returns an unmodifiable view of the filtered contact list */
     ObservableList<Contact> getFilteredContactList();
 

src/main/java/seedu/address/model/ModelManager.java

@@ -12,6 +12,7 @@
 import seedu.address.commons.core.GuiSettings;
 import seedu.address.commons.core.LogsCenter;
 import seedu.address.model.person.Contact;
+import seedu.address.model.person.Id;
 
 /**
  * Represents the in-memory model of the address book data.
@@ -111,6 +112,11 @@ public void setContact(Contact target, Contact editedContact) {
         addressBook.setContact(target, editedContact);
     }
 
+    @Override
+    public Contact getContactById(Id id) {
+        return addressBook.getContactById(id);
+    }
+
     //=========== Filtered Contact List Accessors =============================================================
 
     /**