package org.apache.kafka.connect.connector.policy;

import org.apache.kafka.common.Configurable;
import org.apache.kafka.common.config.ConfigValue;

import java.util.List;

/**
 * An interface for enforcing a policy on overriding of Kafka client configs via the connector configs.
 * <p>
 * Common use cases are ability to provide principal per connector, <code>sasl.jaas.config</code>
 * and/or enforcing that the producer/consumer configurations for optimizations are within acceptable ranges.
 * <p>Kafka Connect discovers implementations of this interface using the Java {@link java.util.ServiceLoader} mechanism.
 * To support this, implementations of this interface should also contain a service provider configuration file in
 * {@code META-INF/services/org.apache.kafka.connect.connector.policy.ConnectorClientConfigOverridePolicy}.
 * <p>
 * Implement {@link org.apache.kafka.common.metrics.Monitorable} to enable the policy to register metrics.
 * The following tags are automatically added to all metrics registered: <code>config</code> set to
 * <code>connector.client.config.override.policy</code>, and <code>class</code> set to the
 * ConnectorClientConfigOverridePolicy class name.
 */
public interface ConnectorClientConfigOverridePolicy extends Configurable, AutoCloseable, ConfigSpecifier {


    /**
     * Workers will invoke this before configuring per-connector Kafka admin, producer, and consumer client instances
     * to validate if all the overridden client configurations are allowed per the policy implementation.
     * This would also be invoked during the validation of connector configs via the REST API.
     * <p>
     * If there are any policy violations, the connector will not be started.
     *
     * @param connectorClientConfigRequest an instance of {@link ConnectorClientConfigRequest} that provides the configs
     *                                     to be overridden and its context; never {@code null}
     * @return list of {@link ConfigValue} instances that describe each client configuration in the request and includes an 
               {@link ConfigValue#errorMessages() error} if the configuration is not allowed by the policy; never null
     */
    List<ConfigValue> validate(ConnectorClientConfigRequest connectorClientConfigRequest);  
  
    /**     
    * Configuration specification for this predicate.     
    *     
    * @return the configuration definition for this predicate; never null     
    */    
    @Override    
    default ConfigDef config() { return new ConfigDef();}
}  

package org.apache.kafka.connect.rest;

import org.apache.kafka.common.Configurable;
import org.apache.kafka.connect.components.Versioned;
import org.apache.kafka.connect.health.ConnectClusterState;

import java.io.Closeable;
import java.util.Map;

/**
 * A plugin interface to allow registration of new JAX-RS resources like Filters, REST endpoints, providers, etc. The implementations will
 * be discovered using the standard Java {@link java.util.ServiceLoader} mechanism by  Connect's plugin class loading mechanism.
 *
 * <p>Kafka Connect discovers implementations of this interface using the Java {@link java.util.ServiceLoader} mechanism.
 * To support this, implementations of this interface should also contain a service provider configuration file in
 * {@code META-INF/services/org.apache.kafka.connect.rest.ConnectRestExtension}.
 * <p>The extension class(es) must be packaged as a plugin, including the JARs of all dependencies except those
 * already provided by the Connect framework.
 *
 * <p>To install into a Connect installation, add a directory named for the plugin and containing the plugin's JARs into a directory that is
 * on Connect's {@code plugin.path}, and (re)start the Connect worker.
 *
 * <p>When the Connect worker process starts up, it will read its configuration and instantiate all of the REST extension implementation
 * classes that are specified in the `rest.extension.classes` configuration property. Connect will then pass its configuration to each
 * extension via the {@link Configurable#configure(Map)} method, and will then call {@link #register} with a provided context.
 *
 * <p>When the Connect worker shuts down, it will call the extension's {@link #close} method to allow the implementation to release all of
 * its resources.
 *
 * <p>Implement {@link org.apache.kafka.common.metrics.Monitorable} to enable the extension to register metrics.
 * The following tags are automatically added to all metrics registered: <code>config</code> set to
 * <code>rest.extension.classes</code>, and <code>class</code> set to the ConnectRestExtension class name.
 */
public interface ConnectRestExtension extends Configurable, Versioned, Closeable, ConfigSpecifier {

    /**
     * ConnectRestExtension implementations can register custom JAX-RS resources via this method. The Connect framework
     * will invoke this method after registering the default Connect resources. If the implementations attempt
     * to re-register any of the Connect resources, it will be ignored and will be logged.
     *
     * @param restPluginContext The context provides access to JAX-RS {@link jakarta.ws.rs.core.Configurable} and {@link
     *                          ConnectClusterState}.The custom JAX-RS resources can be registered via the {@link
     *                          ConnectRestExtensionContext#configurable()}
     */
    void register(ConnectRestExtensionContext restPluginContext);
  
    /**     
    * Configuration specification for this predicate.     
    *     
    * @return the configuration definition for this predicate; never null     
    */    
    @Override    
    default ConfigDef config() { return new ConfigDef();}
}