package compbio.cassandra;

import java.util.ArrayList;
import java.util.Date;
import java.util.List;

import org.apache.log4j.Logger;
import org.springframework.dao.DataIntegrityViolationException;

import com.datastax.driver.core.Row;
import com.datastax.driver.core.Session;
import com.datastax.driver.core.ResultSet;
import com.datastax.driver.core.exceptions.QueryExecutionException;
import com.datastax.driver.core.exceptions.QueryValidationException;

import compbio.proteocache.users.User;
import compbio.proteocache.users.UserManager;

public class CassandraUserManager implements UserManager {
	private Session session;
	private static Logger log = Logger.getLogger(CassandraNativeConnector.class);

	public CassandraUserManager() {
		Session inis = CassandraNativeConnector.getSession();
		setSession(inis);
	}

	private void setSession(Session s) {
		assert s != null;
		session = s;
	}

	public boolean addUser(User user) throws DataIntegrityViolationException {
		String chkcom = "SELECT * FROM Users WHERE email = '" + user.getEmail() + "';";
		try {
			ResultSet users = session.execute(chkcom);
			if (0 < users.all().size()) {
				throw new DataIntegrityViolationException("A user with email " + user.getEmail() + " exists");
			}

		} catch (QueryExecutionException e) {
			String mess = "CassandraUserManagerImpl.addUser: query execution exception...";
			System.out.println(mess);
			log.error(mess);
			log.error(e.getLocalizedMessage(), e.getCause());
			return false;
		} catch (QueryValidationException e) {
			String mess = "CassandraUserManagerImpl.addUser: query validation exception... Command: " + chkcom;
			System.out.println(mess);
			log.error(mess);
			log.error(e.getLocalizedMessage(), e.getCause());
			return false;
		}

		long id = user.getId().longValue();
		if (id < 1) {
			String com = "SELECT * FROM MainParameters WHERE Name = 'MaxUserId';";
			try {
				ResultSet values = session.execute(com);
				List<Row> list = values.all();
				if (0 < list.size()) {
					String test = list.get(0).getString("Value");
					id = Long.parseLong(test, 10);
				} else {
					// if the MaxUserId parameter does not exist it is inserted
					// with id = 1
					id = 0;
				}
				id++;
				com = "INSERT INTO MainParameters (name,value) VALUES ('MaxUserId','" + id + "');";
				session.execute(com);
			} catch (QueryExecutionException e) {
				String mess = "CassandraUserManagerImpl.addUser: query execution exception...";
				System.out.println(mess);
				log.error(mess);
				log.error(e.getLocalizedMessage(), e.getCause());
				return false;
			} catch (QueryValidationException e) {
				String mess = "CassandraUserManagerImpl.addUser: query validation exception... Command: " + com;
				System.out.println(mess);
				log.error(mess);
				log.error(e.getLocalizedMessage(), e.getCause());
				return false;
			}
		}

		String incom = "INSERT INTO Users (name, id, email, password, organisation, position, signedtolist, registrationdate) VALUES ('"
				+ user.getFullName() + "'," + id + ",'" + user.getEmail() + "','" + user.getPassword() + "','" + user.getOrganisation()
				+ "','" + user.getPosition() + "'," + user.isUpdateByEmail() + "," + user.getRegistrationDate().getTime() + ");";
		try {
			session.execute(incom);
		} catch (QueryExecutionException e) {
			String mess = "CassandraUserManagerImpl.addUser: query execution exception...";
			System.out.println(mess);
			log.error(mess);
			log.error(e.getLocalizedMessage(), e.getCause());
			return false;
		} catch (QueryValidationException e) {
			String mess = "CassandraUserManagerImpl.addUser: query validation exception... Command: " + incom;
			System.out.println(mess);
			log.error(mess);
			log.error(e.getLocalizedMessage(), e.getCause());
			return false;
		}
		return true;
	}

	public boolean saveUser(User user) {
		boolean isSaved = false;
		String com = "SELECT * FROM Users WHERE id = " + user.getId() + ";";
		try {
			ResultSet users = session.execute(com);
			if (1 < users.all().size()) {
				return false;
			}
			isSaved = addUser(user);
		} catch (QueryExecutionException e) {
			String mess = "CassandraUserManagerImpl.saveUser: query execution exception...";
			System.out.println(mess);
			log.error(mess);
			log.error(e.getLocalizedMessage(), e.getCause());
		} catch (QueryValidationException e) {
			String mess = "CassandraUserManagerImpl.saveUser: query validation exception... Command: " + com;
			System.out.println(mess);
			log.error(mess);
			log.error(e.getLocalizedMessage(), e.getCause());
		}
		return isSaved;
	}

	public boolean deleteUser(long id) {
		String com = "DELETE FROM Users WHERE id = " + id + ";";
		try {
			session.execute(com);
		} catch (QueryExecutionException e) {
			String mess = "CassandraUserManagerImpl.deleteUser: query execution exception...";
			System.out.println(mess);
			log.error(mess);
			log.error(e.getLocalizedMessage(), e.getCause());
			return false;
		} catch (QueryValidationException e) {
			String mess = "CassandraUserManagerImpl.deleteUser: query validation exception... Command: " + com;
			System.out.println(mess);
			log.error(mess);
			log.error(e.getLocalizedMessage(), e.getCause());
			return false;
		}
		return true;
	}

	public User getUserById(long id) {
		String com = "SELECT * FROM Users WHERE Id = " + id + ";";
		User user = new User();
		try {
			ResultSet users = session.execute(com);
			if (1 != users.all().size()) {
				return null;
			}
			user = buildUser(users.one());
		} catch (QueryExecutionException e) {
			String mess = "CassandraUserManagerImpl.addUser: query execution exception...";
			System.out.println(mess);
			log.error(mess);
			log.error(e.getLocalizedMessage(), e.getCause());
			return null;
		} catch (QueryValidationException e) {
			String mess = "CassandraUserManagerImpl.addUser: query validation exception... Command: " + com;
			System.out.println(mess);
			log.error(mess);
			log.error(e.getLocalizedMessage(), e.getCause());
			return null;
		}
		return user;
	}

	public User getUserByEmail(String email) {
		String com = "SELECT * FROM Users WHERE Email = '" + email + "';";
		User user = new User();
		try {
			ResultSet users = session.execute(com);
			if (1 != users.all().size()) {
				return null;
			}
			user = buildUser(users.one());
		} catch (QueryExecutionException e) {
			String mess = "CassandraUserManagerImpl.getUserByEmail: query execution exception...";
			System.out.println(mess);
			log.error(mess);
			log.error(e.getLocalizedMessage(), e.getCause());
			return null;
		} catch (QueryValidationException e) {
			String mess = "CassandraUserManagerImpl.getUserByEmail: query validation exception... Command: " + com;
			System.out.println(mess);
			log.error(mess);
			log.error(e.getLocalizedMessage(), e.getCause());
			return null;
		}
		return user;
	}

	public List<User> findAllUsers() {
		List<User> list = new ArrayList<User>();
		String com = "SELECT * FROM Users;";
		try {
			ResultSet results = session.execute(com);
			List<Row> rows = results.all();
			for (Row r : rows) {
				list.add(buildUser(r));
			}
		} catch (QueryExecutionException e) {
			String mess = "CassandraUserManagerImpl.findAllUsers: query execution exception...";
			System.out.println(mess);
			log.error(mess);
			log.error(e.getLocalizedMessage(), e.getCause());
			return null;
		} catch (QueryValidationException e) {
			String mess = "CassandraUserManagerImpl.findAllUsers: query validation exception... Command: " + com;
			System.out.println(mess);
			log.error(mess);
			log.error(e.getLocalizedMessage(), e.getCause());
			return null;
		}
		return list;
	}

	private User buildUser(Row r) {
		User u = new User();
		u.setFullName(r.getString("Name"));
		u.setId(new Long(r.getLong("Id")));
		u.setEmail(r.getString("Email"));
		u.setPassword(r.getString("Password"));
		u.setOrganisation(r.getString("Organisation"));
		u.setPosition(r.getString("Position"));
		u.setUpdateByEmail(r.getBool("SignedToList"));
		u.setRegistrationDate(new Date(r.getLong("RegistrationDate")));
		return u;
	}
}