package org.infinispan.configuration.cache;

import static org.infinispan.configuration.cache.SitesConfiguration.MERGE_POLICY;
import static org.infinispan.util.logging.Log.CONFIG;

import java.util.ArrayList;
import java.util.HashSet;
import java.util.List;
import java.util.Set;

import org.infinispan.commons.configuration.Builder;
import org.infinispan.commons.configuration.Combine;
import org.infinispan.commons.configuration.attributes.AttributeSet;
import org.infinispan.configuration.global.GlobalConfiguration;
import org.infinispan.xsite.spi.XSiteEntryMergePolicy;
import org.infinispan.xsite.spi.XSiteMergePolicy;

/**
 * @author Mircea.Markus@jboss.com
 * @since 5.2
 */
public class SitesConfigurationBuilder extends AbstractConfigurationChildBuilder implements Builder<SitesConfiguration> {
   private final AttributeSet attributes;
   private final List<BackupConfigurationBuilder> backups = new ArrayList<>(2);
   private final BackupForBuilder backupForBuilder;

   public SitesConfigurationBuilder(ConfigurationBuilder builder) {
      super(builder);
      attributes = SitesConfiguration.attributeDefinitionSet();
      backupForBuilder = new BackupForBuilder(builder);
   }

   public BackupConfigurationBuilder addBackup() {
      BackupConfigurationBuilder bcb = new BackupConfigurationBuilder(getBuilder());
      backups.add(bcb);
      return bcb;
   }

   public List<BackupConfigurationBuilder> backups() {
      return backups;
   }

   /**
    * Returns true if this cache won't backup its data remotely.
    * It would still accept other sites backing up data on this site.
    * @deprecated Since 14.0. To be removed without replacement.
    */
   @Deprecated(forRemoval=true, since = "14.0")
   public SitesConfigurationBuilder disableBackups(boolean disable) {
      //no-op
      return this;
   }

   /**
    * Defines the site names, from the list of sites names defined within 'backups' element, to
    * which this cache backups its data.
    * @deprecated Since 14.0. To be removed without replacement.
    */
   @Deprecated(forRemoval=true, since = "14.0")
   public SitesConfigurationBuilder addInUseBackupSite(String site) {
      return this;
   }

   public BackupForBuilder backupFor() {
      return backupForBuilder;
   }

   /**
    * Configures the {@link XSiteEntryMergePolicy} to be used.
    * <p>
    * {@link XSiteEntryMergePolicy} is invoked when a conflicts is detected between 2 sites. A conflict happens when a
    * key is updated concurrently in 2 sites.
    * <p>
    * {@link XSiteMergePolicy} enum contains implementation available to be used.
    *
    * @param mergePolicy The {@link XSiteEntryMergePolicy} implementation to use.
    * @return {@code this}.
    * @see XSiteEntryMergePolicy
    * @see XSiteMergePolicy
    */
   public SitesConfigurationBuilder mergePolicy(XSiteEntryMergePolicy<?, ?> mergePolicy) {
      attributes.attribute(MERGE_POLICY).set(mergePolicy);
      return this;
   }


   /**
    * Sets the maximum delay, in milliseconds, between which the tombstone cleanup task runs.
    *
    * @param value The maximum delay in milliseconds.
    * @return {@code this}.
    */
   public SitesConfigurationBuilder maxTombstoneCleanupDelay(long value) {
      attributes.attribute(SitesConfiguration.MAX_CLEANUP_DELAY).set(value);
      return this;
   }

   /**
    * Sets the target tombstone map size.
    * <p>
    * The cleanup task checks the current size of the tombstone map before starting, and increases the delay of the next
    * run if the size is less than the target size, or reduces the delay if the size is greater than the target size.
    *
    * @param value The target tombstone map size.
    * @return {@code this}.
    */
   public SitesConfigurationBuilder tombstoneMapSize(int value) {
      attributes.attribute(SitesConfiguration.TOMBSTONE_MAP_SIZE).set(value);
      return this;
   }

   @Override
   public void validate() {
      backupForBuilder.validate();
      attributes.validate();

      //don't allow two backups with the same name
      Set<String> backupNames = new HashSet<>(backups.size());

      for (BackupConfigurationBuilder bcb : backups) {
         if (!backupNames.add(bcb.site())) {
            throw CONFIG.multipleSitesWithSameName(bcb.site());
         }
         bcb.validate();
      }

      //we have backups configured. check if we have a clustered cache
      if (!backupNames.isEmpty() && !builder.clustering().cacheMode().isClustered()) {
         throw CONFIG.xsiteInLocalCache();
      }

      if (attributes.attribute(MERGE_POLICY).get() == null) {
         throw CONFIG.missingXSiteEntryMergePolicy();
      }
   }

   @Override
   public void validate(GlobalConfiguration globalConfig) {
      backupForBuilder.validate(globalConfig);
      attributes.validate();

      for (BackupConfigurationBuilder bcb : backups) {
         bcb.validate(globalConfig);
      }
   }

   @Override
   public SitesConfiguration create() {
      List<BackupConfiguration> backupConfigurations = new ArrayList<>(backups.size());
      for (BackupConfigurationBuilder bcb : this.backups) {
         backupConfigurations.add(bcb.create());
      }
      return new SitesConfiguration(attributes.protect(), backupConfigurations, backupForBuilder.create());
   }

   @Override
   public SitesConfigurationBuilder read(SitesConfiguration template, Combine combine) {
      attributes.read(template.attributes(), combine);
      backupForBuilder.read(template.backupFor(), combine);
      if (combine.repeatedAttributes() == Combine.RepeatedAttributes.OVERRIDE && template.attributes().isTouched()) {
         backups.clear();
      }
      for (BackupConfiguration bc : template.allBackups()) {
         BackupConfigurationBuilder bcb = new BackupConfigurationBuilder(getBuilder());
         bcb.read(bc, combine);
         backups.removeIf(b -> b.site().equals(bcb.site())); // no-op in case of Combine.Children.OVERRIDE
         backups.add(bcb);
      }
      return this;
   }

   @Override
   public AttributeSet attributes() {
      return attributes;
   }

}
