ListCommitHandler.java

package se.chalmers.dat255.grupp12;

import java.sql.SQLException;

/**
 * Date: 2013-10-16
 * Time: 16:07
 */
public class ListCommitHandler extends CommitHandler {

	public ListCommitHandler(ClientChangeList changes, User user) {
		super(changes,user);
	}

	/**
	 * Insert a new list to the database
	 *
	 * @param m - The modification containing the needed information
	 */
	@Override
	public void insert(Modification m) {
		TaskList oldList = m.getList(); // Negative reference ids from client
		try {
			int oldListId = oldList.getId();
			TaskList newList = db.insertList(oldList, user);
			changes.addIdChange(oldListId, newList.getId()); // Add an id change to the list of id changes

		} catch (SQLException e) {
			e.printStackTrace();
		}
	}

	private int getListId(Modification m) {
		int id = m.getListId();
		if (id < 1) {
			id = changes.getNewId(id); // Occurs when the list is created and changed in the same sync.
		}
		return id;
	}

	/**
	 * Update an existing list on the database
	 * The modification handled contains a Change which contains a String type
	 * which tells what type of update is to be made
	 * The list is updated accordingly
	 *
	 * @param m - The modification containing the needed information
	 */
	@Override
	public void update(Modification m) {
		try {
			int listId = getListId(m);
			TaskList list = db.getList(listId); // Client sends invalid id to server, we need to look them up
			String newValue = m.getChange().getTo();
			String type = m.getChange().getType();
			switch (type) {
				case Constants.LIST_TITLE:
					list.setName(newValue);
					break;
				case Constants.LIST_ADDUSER:
					try {
						db.assignUserToList(db.getUser(newValue), list.getId()); // New value is user's mail
					} catch (DataNotFoundException e) {
						System.err.println("User not found in db -- No danger on the roof!");
					}
					return; // No update in 'lists' table required
				default:
					throw new UnsupportedOperationException("List change property not implemented:" + type);
			}
			db.updateList(listId, list);

		} catch (SQLException | DataNotFoundException e) {
			e.printStackTrace();
		}
	}

	/**
	 * Removes a list from the database
	 *
	 * @param m - The modification containing the needed information
	 */
	@Override
	public void delete(Modification m) {
		try {
			int listId = getListId(m);
			if (db.getUsers(listId).size() > 1) {
				db.removeUserFromList(user.getId(), listId);
			} else {
				db.deleteList(listId);
			}
		} catch (SQLException | DataNotFoundException e) {
			e.printStackTrace();
		}
	}


}