/*
 * 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.jackrabbit.oak.security.authentication;

import org.apache.jackrabbit.oak.api.ContentRepository;
import org.apache.jackrabbit.oak.security.authentication.monitor.LoginModuleMonitorImpl;
import org.apache.jackrabbit.oak.spi.security.ConfigurationBase;
import org.apache.jackrabbit.oak.spi.security.ConfigurationParameters;
import org.apache.jackrabbit.oak.spi.security.SecurityConfiguration;
import org.apache.jackrabbit.oak.spi.security.SecurityProvider;
import org.apache.jackrabbit.oak.spi.security.authentication.AuthenticationConfiguration;
import org.apache.jackrabbit.oak.spi.security.authentication.LoginContextProvider;
import org.apache.jackrabbit.oak.spi.security.authentication.LoginModuleMonitor;
import org.apache.jackrabbit.oak.spi.whiteboard.Whiteboard;
import org.apache.jackrabbit.oak.spi.whiteboard.WhiteboardAware;
import org.apache.jackrabbit.oak.stats.Monitor;
import org.apache.jackrabbit.oak.stats.StatisticsProvider;
import org.jetbrains.annotations.NotNull;
import org.osgi.service.component.annotations.Activate;
import org.osgi.service.component.annotations.Component;
import org.osgi.service.metatype.annotations.AttributeDefinition;
import org.osgi.service.metatype.annotations.Designate;
import org.osgi.service.metatype.annotations.ObjectClassDefinition;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.util.Collections;
import java.util.Map;

/**
 * Default implementation of the {@code AuthenticationConfiguration} with the
 * following characteristics:
 *
 * <ul>
 * <li>
 *     {@link LoginContextProvider}: Returns the default implementation of
 *     {@code LoginContextProvider} that handles standard JAAS based logins and
 *     deals with pre-authenticated subjects.</li>
 * </ul>
 *
 */
@Component(service = {AuthenticationConfiguration.class, SecurityConfiguration.class})
@Designate(ocd = AuthenticationConfigurationImpl.Configuration.class)
public class AuthenticationConfigurationImpl extends ConfigurationBase implements AuthenticationConfiguration {

    @ObjectClassDefinition(name = "Apache Jackrabbit Oak AuthenticationConfiguration")
    @interface Configuration {

        @AttributeDefinition(
                name = "Application Name",
                description = "Application named used for JAAS authentication",
                defaultValue = AuthenticationConfiguration.DEFAULT_APP_NAME
        )
        String org_apache_jackrabbit_oak_authentication_appName() default AuthenticationConfiguration.DEFAULT_APP_NAME;

        @AttributeDefinition(
                name = "JAAS Config SPI Name",
                description = "Name of JAAS Configuration Spi. This needs to be set to JAAS config provider " +
                        "name if JAAS authentication is managed by Felix JAAS Support with its Global " +
                        "Configuration Policy set to 'default'.")
        String org_apache_jackrabbit_oak_authentication_configSpiName();
    }

    private static final Logger log = LoggerFactory.getLogger(AuthenticationConfigurationImpl.class);

    // stats
    private LoginModuleMonitor lmMonitor = LoginModuleMonitor.NOOP;

    /**
     * Constructor for OSGi
     */
    @SuppressWarnings("UnusedDeclaration")
    public AuthenticationConfigurationImpl() {
        super();
    }

    @SuppressWarnings("UnusedDeclaration")
    @Activate
    // reference to @Configuration class needed for correct DS xml generation
    private void activate(Configuration configuration, Map<String, Object> properties) {
        setParameters(ConfigurationParameters.of(properties));
    }

    /**
     * Constructor for non-OSGi
     * @param securityProvider The {@code SecurityProvider} this configuration belongs to.
     */
    public AuthenticationConfigurationImpl(@NotNull SecurityProvider securityProvider) {
        super(securityProvider, securityProvider.getParameters(NAME));
    }

    //----------------------------------------------< SecurityConfiguration >---
    @NotNull
    @Override
    public String getName() {
        return NAME;
    }

    @NotNull
    @Override
    public Iterable<Monitor<?>> getMonitors(@NotNull StatisticsProvider statisticsProvider) {
        lmMonitor = new LoginModuleMonitorImpl(statisticsProvider);
        return Collections.singleton(lmMonitor);
    }

    //----------------------------------------< AuthenticationConfiguration >---
    /**
     * Create a {@code LoginContextProvider} using standard
     * {@link javax.security.auth.login.Configuration#getConfiguration() JAAS}
     * functionality. In case no login configuration for the specified app name
     * can be retrieve this implementation uses the default as defined by
     * {@link org.apache.jackrabbit.oak.spi.security.authentication.ConfigurationUtil#getDefaultConfiguration(org.apache.jackrabbit.oak.spi.security.ConfigurationParameters)}.
     * <p>
     * The {@link LoginContextProvider} implementation is intended to be used with
     * <ul>
     *     <li>Regular login using JAAS {@link javax.security.auth.spi.LoginModule} or</li>
     *     <li>Pre-authenticated subjects in which case any authentication
     *     related validation is omitted</li>
     * </ul>
     *
     * <h3>Configuration Options</h3>
     * <ul>
     *     <li>{@link #PARAM_APP_NAME}: The appName passed to
     *     {@code Configuration#getAppConfigurationEntry(String)}. The default
     *     value is {@link #DEFAULT_APP_NAME}.</li>
     * </ul>
     *
     * @param contentRepository The content repository.
     * @return An new instance of {@link LoginContextProvider}.
     */
    @NotNull
    @Override
    public LoginContextProvider getLoginContextProvider(@NotNull ContentRepository contentRepository) {
        String appName = getParameters().getConfigValue(PARAM_APP_NAME, DEFAULT_APP_NAME);
        SecurityProvider provider = getSecurityProvider();
        Whiteboard whiteboard = null;
        if (provider instanceof WhiteboardAware) {
            whiteboard = ((WhiteboardAware) provider).getWhiteboard();
        } else {
            log.warn("Unable to obtain whiteboard from SecurityProvider");
        }
        return new LoginContextProviderImpl(appName, getParameters(), contentRepository, provider, whiteboard, lmMonitor);
    }
}