/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.karaf.jaas.modules.osgi;

import java.io.IOException;
import java.security.Principal;
import java.util.Dictionary;
import java.util.HashSet;
import java.util.Map;

import javax.security.auth.Subject;
import javax.security.auth.callback.Callback;
import javax.security.auth.callback.CallbackHandler;
import javax.security.auth.callback.NameCallback;
import javax.security.auth.callback.PasswordCallback;
import javax.security.auth.callback.UnsupportedCallbackException;
import javax.security.auth.login.FailedLoginException;
import javax.security.auth.login.LoginException;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.karaf.jaas.modules.AbstractKarafLoginModule;

import org.apache.karaf.jaas.modules.RolePrincipal;
import org.apache.karaf.jaas.modules.UserPrincipal;
import org.osgi.service.cm.Configuration;

public class OsgiConfigLoginModule extends AbstractKarafLoginModule {

    public static final String PID = "pid";
    public static final String USER_PREFIX = "user.";

    private static final Log LOG = LogFactory.getLog(OsgiConfigLoginModule.class);

    public void initialize(Subject subject, CallbackHandler callbackHandler, Map<String, ?> sharedState, Map<String, ?> options) {
        super.initialize(subject, callbackHandler, options);
    }

    public boolean login() throws LoginException {
        try {
            String pid = (String) options.get(PID);
            Configuration config = ConfigAdminHolder.getService().getConfiguration(pid);
            Dictionary properties = config.getProperties();

            Callback[] callbacks = new Callback[2];

            callbacks[0] = new NameCallback("Username: ");
            callbacks[1] = new PasswordCallback("Password: ", false);
            try {
                callbackHandler.handle(callbacks);
            } catch (IOException ioe) {
                throw new LoginException(ioe.getMessage());
            } catch (UnsupportedCallbackException uce) {
                throw new LoginException(uce.getMessage() + " not available to obtain information from user");
            }
            String user = ((NameCallback) callbacks[0]).getName();
            String password = new String(((PasswordCallback) callbacks[1]).getPassword());

            String userInfos = (String) properties.get(USER_PREFIX + user);
            if (userInfos == null) {
                throw new FailedLoginException("User does not exist");
            }
            String[] infos = userInfos.split(",");
            String storedPassword = infos[0];

            // check the provided password
            if (!checkPassword(password, storedPassword)) {
                throw new FailedLoginException("Password for " + user + " does not match");
            }

            principals = new HashSet<Principal>();
            principals.add(new UserPrincipal(user));
            for (int i = 1; i < infos.length; i++) {
                principals.add(new RolePrincipal(infos[i]));
            }

            return true;
        } catch (LoginException e) {
            throw e;
        } catch (Exception e) {
            throw (LoginException) new LoginException("Unable to authenticate user").initCause(e);
        } finally {
            callbackHandler = null;
            options = null;
        }
    }


    public boolean abort() throws LoginException {
        subject = null;
        principals = null;
        return true;
    }

    public boolean logout() throws LoginException {
        try {
            subject.getPrincipals().removeAll(principals);
            principals.clear();
            return true;
        } finally {
            subject = null;
            principals = null;
        }
    }

}
