package org.openslx.imagemaster.server;

import java.io.File;

import org.apache.log4j.Logger;
import org.apache.thrift.TException;
import org.openslx.imagemaster.Globals;
import org.openslx.imagemaster.db.DbSatellite;
import org.openslx.imagemaster.serversession.ServerAuthenticator;
import org.openslx.imagemaster.serversession.ServerSession;
import org.openslx.imagemaster.serversession.ServerSessionManager;
import org.openslx.imagemaster.serversession.ServerUser;
import org.openslx.imagemaster.session.Authenticator;
import org.openslx.imagemaster.session.Session;
import org.openslx.imagemaster.session.SessionManager;
import org.openslx.imagemaster.session.User;
import org.openslx.imagemaster.thrift.iface.AuthenticationError;
import org.openslx.imagemaster.thrift.iface.AuthenticationException;
import org.openslx.imagemaster.thrift.iface.AuthorizationException;
import org.openslx.imagemaster.thrift.iface.FtpCredentials;
import org.openslx.imagemaster.thrift.iface.ImageData;
import org.openslx.imagemaster.thrift.iface.InvalidTokenException;
import org.openslx.imagemaster.thrift.iface.ServerSessionData;
import org.openslx.imagemaster.thrift.iface.SessionData;
import org.openslx.imagemaster.thrift.iface.UserInfo;
import org.openslx.imagemaster.util.RandomString;

/**
 * API Server This is where all the requests from the outside arrive. We don't
 * handle them directly in the Thrift handlers, as we might be adding other APIs
 * later, like JSON/SOAP/REST/HTTP/XML or some other stuff. They'd all just
 * interface with this static class here. Note that we use the exceptions from
 * the thrift interface that you can simply catch in any other API handler and
 * eg. transform into error codes, if the API doesn't support exceptions.
 * 
 * This will be accessed from multiple threads, so use synchronization when
 * needed (or in doubt)
 */
public class ApiServer {
	private static Logger log = Logger.getLogger(ApiServer.class);

	/**
	 * Request for authentication
	 * 
	 * @param login
	 *            (username@organization)
	 * @param password
	 * @return SessionData struct with session id/token iff login successful
	 * @throws AuthenticationException
	 *             if login not successful
	 */
	public static SessionData authenticate(String login, String password)
			throws AuthenticationException {
		if (login == null || password == null) {
			throw new AuthenticationException(
					AuthenticationError.INVALID_CREDENTIALS,
					"Empty username or password!");
		}
		final User user = Authenticator.authenticate(login, password);

		final Session session = new Session(user);
		return SessionManager.addSession(session);
	}

	/**
	 * Request information about user for given token
	 * 
	 * @param token
	 *            - a user's token
	 * @return UserInfo struct for given token's user
	 * @throws InvalidTokenException
	 *             if no user matches the given token
	 */
	public static UserInfo getUserFromToken(String token)
			throws InvalidTokenException {
		final Session session = SessionManager.getSession(token);
		if (session == null)
			throw new InvalidTokenException();
		return new UserInfo(session.getUserId(), session.getFirstName(),
				session.getLastName(), session.getEMail());
	}

	public static FtpCredentials submitImage(ImageData imageDescription,
			ServerSessionData serverSessionData) throws AuthorizationException,
			TException {
		/*
		 * TODO:
		 * Check if session is ok.
		 * create and return FtpCredentials
		 */

		/*
		 * FTP Users can be added later with: ftpServer.addUser(username,
		 * password, ftp_root);
		 * 
		 * And removed with: removeUser(username);
		 */

		String generatedUser = RandomString.generate(10, false);
		String generatedPass = RandomString.generate(16, true);
		String dir = Globals.properties.getProperty("ftp_base_dir") + "/"
				+ generatedUser + "/";
		if (new File(dir).mkdir()) {
			Globals.ftpServer.addUser(generatedUser, generatedPass, dir, true);
			log.info("Generated user/pass: " + generatedUser + "\t"
					+ generatedPass + "\n with home dir: " + dir);
		}
		// TODO: remove old user

		return new FtpCredentials(generatedUser, generatedPass);
	}

	public static String startServerAuthentication(String organization)
			throws TException {
		if (organization == null || organization == "") {
			throw new TException("Empty organization");
		}
		if (DbSatellite.fromOrganization(organization) == null) {
			throw new TException("Unkown organization");
		}
		return ServerAuthenticator.startServerAuthentication(organization);
	}

	public static ServerSessionData serverAuthenticate(String organization,
			String challengeResponse) throws AuthenticationException,
			TException {
		if (organization == null || challengeResponse == null) {
			throw new TException("Empty organization org challengeResponse");
		}
		DbSatellite satellite = DbSatellite.fromOrganization(organization);
		if (satellite == null) {
			throw new TException("Unkown organization");
		}
		final ServerUser serverUser = ServerAuthenticator.serverAuthenticate(
				organization, satellite.getAddress(), challengeResponse);
		
		final ServerSession session = new ServerSession(serverUser);
		return ServerSessionManager.addSession(session);
	}

}