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/commands/DeleteByIdCommand.java

@@ -0,0 +1,34 @@
+package seedu.address.logic.commands;
+
+import seedu.address.model.Model;
+import seedu.address.model.person.Contact;
+import seedu.address.model.person.ContactId;
+
+/**
+ * Deletes a contact identified using its ID from the addressbook.
+ */
+public class DeleteByIdCommand extends DeleteCommand {
+
+    public static final String NO_SUCH_CONTACT_WITH_ID = "No such contact with id: %s";
+    private final ContactId contactId;
+
+    /**
+     * @param id of the contact to be deleted.
+     */
+    public DeleteByIdCommand(ContactId id) {
+        // TODO: Might want to change this since null is dangerous
+        super(null);
+        this.contactId = id;
+    }
+
+    @Override
+    public CommandResult execute(Model model) {
+        // TODO: Implement the get function based on id for the model
+        Contact c = model.getContactById(contactId);
+        if (c == null) {
+            return new CommandResult(String.format(NO_SUCH_CONTACT_WITH_ID, contactId));
+        }
+        model.deleteContact(c);
+        return new CommandResult(String.format(MESSAGE_DELETE_CONTACT_SUCCESS, c));
+    }
+}

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

@@ -0,0 +1,45 @@
+package seedu.address.logic.commands;
+
+import static seedu.address.logic.commands.DeleteByIdCommand.NO_SUCH_CONTACT_WITH_ID;
+
+import java.util.Arrays;
+
+import seedu.address.logic.Messages;
+import seedu.address.model.Model;
+import seedu.address.model.person.Contact;
+import seedu.address.model.person.ContactId;
+
+/**
+ * Deletes a contact identified with its id and also deletes its child contacts.
+ */
+public class DeleteByIdWithChildrenCommand extends DeleteCommand {
+
+    private final ContactId contactId;
+    /**
+     * @param id of the contact to be deleted along with its child contacts.
+     */
+    public DeleteByIdWithChildrenCommand(ContactId id) {
+        super(null);
+        this.contactId = id;
+    }
+
+    @Override
+    public CommandResult execute(Model model) {
+        Contact contactToDelete = model.getContactById(contactId);
+        if (contactToDelete == null) {
+            return new CommandResult(String.format(NO_SUCH_CONTACT_WITH_ID, contactId));
+        }
+        Contact[] childContacts = contactToDelete.getChildren();
+        model.deleteContact(contactToDelete);
+        Arrays.stream(childContacts).forEach(contact -> {
+            model.deleteContact(contactToDelete);
+        });
+        return new CommandResult(String.format(
+                DeleteWithChildrenCommand.MESSAGE_DELETE_CONTACT_SUCCESS,
+                Messages.format(contactToDelete),
+                Arrays.stream(childContacts)
+                        .map(c -> Messages.format(c) + "\n")
+                        .reduce((c1, c2) -> c1 + c2)
+        ));
+    }
+}

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

@@ -10,9 +10,10 @@
 import seedu.address.logic.commands.exceptions.CommandException;
 import seedu.address.model.Model;
 import seedu.address.model.person.Contact;
+import seedu.address.model.person.ContactId;
 
 /**
- * Deletes a contact identified using it's displayed index from the address book.
+ * Deletes a contact identified using its displayed index from the address book.
  */
 public class DeleteCommand extends Command {
 
@@ -31,6 +32,34 @@ public DeleteCommand(Index targetIndex) {
         this.targetIndex = targetIndex;
     }
 
+    /**
+     * 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
+        if (shouldDeleteChildren) {
+            return new DeleteWithChildrenCommand(targetIndex);
+        }
+        return new DeleteCommand(targetIndex);
+    }
+
+    /**
+     * Creates an executable DeleteCommand based on whether to delete recursively.
+     *
+     * @param contactId of the contact to delete in the current list
+     * @param shouldDeleteChildren specifies if child contacts should be deleted
+     */
+    public static DeleteCommand selectId(ContactId contactId, boolean shouldDeleteChildren) {
+        // TODO: Add documentation to DG
+        if (shouldDeleteChildren) {
+            return new DeleteByIdWithChildrenCommand(contactId);
+        }
+        return new DeleteByIdCommand(contactId);
+    }
+
     @Override
     public CommandResult execute(Model model) throws CommandException {
         requireNonNull(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 java.util.List;
+
+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;
+
+/**
+ * Deletes a contact identified with its displayed index 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%s";
+
+    private final Index targetIndex;
+
+    /**
+     * @param targetIndex of the contact to be deleted in the current contact list
+     */
+    public DeleteWithChildrenCommand(Index targetIndex) {
+        // TODO add documentation in DG
+        super(targetIndex);
+        this.targetIndex = targetIndex;
+    }
+
+    @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 = lastShownList.get(targetIndex.getZeroBased());
+        Contact[] childContacts = contactToDelete.getChildren();
+        model.deleteContact(contactToDelete);
+        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)
+        ));
+    }
+}

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.ContactId;
 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(ContactId id) {
+        requireNonNull(id);
+        for (Contact c: contacts) {
+            if (id.equals(c.getContactId())) {
+                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.ContactId;
 
 /**
  * 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(ContactId 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.ContactId;
 
 /**
  * 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(ContactId id) {
+        return addressBook.getContactById(id);
+    }
+
     //=========== Filtered Contact List Accessors =============================================================
 
     /**

src/main/java/seedu/address/model/person/Contact.java

@@ -7,6 +7,7 @@
 import java.util.Objects;
 import java.util.Set;
 
+import seedu.address.commons.exceptions.IllegalOperationException;
 import seedu.address.commons.util.ToStringBuilder;
 import seedu.address.model.tag.Tag;
 
@@ -16,7 +17,10 @@
  */
 public class Contact {
 
+    private static String illegalOperationMessage = "Contact cannot have child contacts";
+
     // Identity fields
+    private final ContactId contactId = null;
     private final Name name;
     private final Phone phone;
     private final Email email;
@@ -37,6 +41,10 @@ public Contact(Name name, Phone phone, Email email, Address address, Set<Tag> ta
         this.tags.addAll(tags);
     }
 
+    public ContactId getContactId() {
+        return contactId;
+    }
+
     public Name getName() {
         return name;
     }
@@ -74,6 +82,25 @@ public boolean isSameContact(Contact otherContact) {
                 && otherContact.getName().equals(getName());
     }
 
+    /**
+     * Gives the array of contacts that are linked under this contact.
+     */
+    public Contact[] getChildren() {
+        // default return value
+        // TODO add to DG
+        return new Contact[]{};
+    }
+
+    /**
+     * Adds a child contact under this contact.
+     * @throws IllegalOperationException if this contact cannot accept child contacts
+     */
+    public void addChild(Contact childContact) throws IllegalOperationException {
+        // Should throw exception if the type of contact cannot have child contacts.
+        // TODO add to DG, do JavaDocs
+        throw new IllegalOperationException(illegalOperationMessage);
+    }
+
     /**
      * Returns true if both contacts have the same identity and data fields.
      * This defines a stronger notion of equality between two contacts.

src/main/java/seedu/address/model/person/ContactId.java

@@ -0,0 +1,62 @@
+package seedu.address.model.person;
+
+import static java.util.Objects.requireNonNull;
+import static seedu.address.commons.util.AppUtil.checkArgument;
+
+/**
+ * Represents a Contact's ID in the address book.
+ * Guarantees: immutable, is valid as declared in {@link #isValidId(String)}
+ */
+public class ContactId {
+
+    public static final String MESSAGE_CONSTRAINTS =
+            "Contact ID should not be blank";
+
+    // TODO: I need help with this part
+    public static final String VALIDATION_REGEX = "^[a-zA-Z0-9\\-_]+$";
+
+    public final String contactId;
+
+    /**
+     * Constructs a {@code ContactId}.
+     *
+     * @param contactId A valid contact id.
+     */
+    public ContactId(String contactId) {
+        requireNonNull(contactId);
+        checkArgument(isValidId(contactId), MESSAGE_CONSTRAINTS);
+        this.contactId = contactId;
+    }
+
+    /**
+     * Returns true if a given string is a valid contact ID.
+     */
+    public static boolean isValidId(String test) {
+        return test.matches(VALIDATION_REGEX);
+    }
+
+    @Override
+    public String toString() {
+        return contactId;
+    }
+
+    @Override
+    public boolean equals(Object other) {
+        if (other == this) {
+            return true;
+        }
+
+        //instanceof handles nulls
+        if (!(other instanceof ContactId)) {
+            return false;
+        }
+
+        ContactId otherId = (ContactId) other;
+        return contactId.equals(otherId.contactId);
+    }
+
+    @Override
+    public int hashCode() {
+        return contactId.hashCode();
+    }
+}