package org.infinispan.configuration.cache;

import static org.infinispan.configuration.cache.StateTransferConfiguration.AWAIT_INITIAL_TRANSFER;
import static org.infinispan.configuration.cache.StateTransferConfiguration.CHUNK_SIZE;
import static org.infinispan.configuration.cache.StateTransferConfiguration.FETCH_IN_MEMORY_STATE;
import static org.infinispan.configuration.cache.StateTransferConfiguration.TIMEOUT;

import java.util.concurrent.TimeUnit;

import org.infinispan.commons.CacheConfigurationException;
import org.infinispan.commons.configuration.Builder;
import org.infinispan.commons.configuration.attributes.Attribute;
import org.infinispan.commons.configuration.attributes.AttributeSet;
import org.infinispan.configuration.global.GlobalConfiguration;
import org.infinispan.util.logging.Log;
import org.infinispan.util.logging.LogFactory;

/**
 * Configures how state is transferred when a cache joins or leaves the cluster. Used in distributed and
 * replication clustered modes.
 *
 * @since 5.1
 */
public class StateTransferConfigurationBuilder extends
      AbstractClusteringConfigurationChildBuilder implements Builder<StateTransferConfiguration> {
   private static final Log log = LogFactory.getLog(StateTransferConfigurationBuilder.class);

   private final AttributeSet attributes;

   StateTransferConfigurationBuilder(ClusteringConfigurationBuilder builder) {
      super(builder);
      attributes = StateTransferConfiguration.attributeDefinitionSet();
   }

   /**
    * If {@code true}, the cache will fetch data from the neighboring caches when it starts up, so
    * the cache starts 'warm', although it will impact startup time.
    * <p/>
    * In distributed mode, state is transferred between running caches as well, as the ownership of
    * keys changes (e.g. because a cache left the cluster). Disabling this setting means a key will
    * sometimes have less than {@code numOwner} owners.
    */
   public StateTransferConfigurationBuilder fetchInMemoryState(boolean b) {
      attributes.attribute(FETCH_IN_MEMORY_STATE).set(b);
      return this;
   }

   /**
    * If {@code true}, this will cause the first call to method {@code CacheManager.getCache()} on the joiner node to
    * block and wait until the joining is complete and the cache has finished receiving state from neighboring caches
    * (if fetchInMemoryState is enabled). This option applies to distributed and replicated caches only and is enabled
    * by default. Please note that setting this to {@code false} will make the cache object available immediately but
    * any access to keys that should be available locally but are not yet transferred will actually cause a (transparent)
    * remote access. While this will not have any impact on the logic of your application it might impact performance.
    */
   public StateTransferConfigurationBuilder awaitInitialTransfer(boolean b) {
      attributes.attribute(AWAIT_INITIAL_TRANSFER).set(b);
      return this;
   }

   /**
    * The state will be transferred in batches of {@code chunkSize} cache entries.
    * If chunkSize is equal to Integer.MAX_VALUE, the state will be transferred in all at once. Not recommended.
    */
   public StateTransferConfigurationBuilder chunkSize(int i) {
      attributes.attribute(CHUNK_SIZE).set(i);
      return this;
   }

   /**
    * This is the maximum amount of time - in milliseconds - to wait for state from neighboring
    * caches, before throwing an exception and aborting startup.
    */
   public StateTransferConfigurationBuilder timeout(long l) {
      attributes.attribute(TIMEOUT).set(l);
      return this;
   }

   /**
    * This is the maximum amount of time - in milliseconds - to wait for state from neighboring
    * caches, before throwing an exception and aborting startup.
    */
   public StateTransferConfigurationBuilder timeout(long l, TimeUnit unit) {
      return timeout(unit.toMillis(l));
   }

   @Override
   public void validate() {
      if (attributes.attribute(CHUNK_SIZE).get() <= 0) {
         throw new CacheConfigurationException("chunkSize can not be <= 0");
      }

      if (clustering().cacheMode().isInvalidation()) {
         Attribute<Boolean> fetchAttribute = attributes.attribute(FETCH_IN_MEMORY_STATE);
         if (fetchAttribute.isModified() && fetchAttribute.get()) {
            throw log.attributeNotAllowedInInvalidationMode(FETCH_IN_MEMORY_STATE.name());
         }
      }

      Attribute<Boolean> awaitInitialTransfer = attributes.attribute(AWAIT_INITIAL_TRANSFER);
      if (awaitInitialTransfer.isModified() && awaitInitialTransfer.get()
            && !getClusteringBuilder().cacheMode().needsStateTransfer())
         throw new CacheConfigurationException(
               "awaitInitialTransfer can be enabled only if cache mode is distributed or replicated.");
   }

   @Override
   public void validate(GlobalConfiguration globalConfig) {
   }

   @Override
   public  StateTransferConfiguration create() {
      return new StateTransferConfiguration(attributes.protect());
   }

   @Override
   public StateTransferConfigurationBuilder read(StateTransferConfiguration template) {
      this.attributes.read(template.attributes());
      return this;
   }

   @Override
   public String toString() {
      return "StateTransferConfigurationBuilder [attributes=" + attributes + "]";
   }
}
