/*
 * Copyright 2016-2022 the original author or authors.
 *
 * Licensed 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
 *
 *      https://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.springframework.data.cassandra.core;

import java.util.List;
import java.util.function.Consumer;
import java.util.function.Function;
import java.util.function.Supplier;
import java.util.stream.Stream;

import com.datastax.oss.driver.api.core.CqlIdentifier;
import com.datastax.oss.driver.api.core.CqlSession;
import com.datastax.oss.driver.api.core.DriverException;
import com.datastax.oss.driver.api.core.config.DefaultDriverOption;
import com.datastax.oss.driver.api.core.cql.BatchType;
import com.datastax.oss.driver.api.core.cql.BoundStatement;
import com.datastax.oss.driver.api.core.cql.PreparedStatement;
import com.datastax.oss.driver.api.core.cql.ResultSet;
import com.datastax.oss.driver.api.core.cql.Row;
import com.datastax.oss.driver.api.core.cql.SimpleStatement;
import com.datastax.oss.driver.api.core.cql.Statement;
import com.datastax.oss.driver.api.querybuilder.QueryBuilder;
import com.datastax.oss.driver.api.querybuilder.delete.Delete;
import com.datastax.oss.driver.api.querybuilder.insert.Insert;
import com.datastax.oss.driver.api.querybuilder.insert.RegularInsert;
import com.datastax.oss.driver.api.querybuilder.select.Select;
import com.datastax.oss.driver.api.querybuilder.truncate.Truncate;
import com.datastax.oss.driver.api.querybuilder.update.Update;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import org.springframework.beans.BeansException;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.context.ApplicationEventPublisher;
import org.springframework.context.ApplicationEventPublisherAware;
import org.springframework.dao.DataAccessException;
import org.springframework.dao.OptimisticLockingFailureException;
import org.springframework.dao.support.DataAccessUtils;
import org.springframework.data.cassandra.SessionFactory;
import org.springframework.data.cassandra.core.EntityOperations.AdaptibleEntity;
import org.springframework.data.cassandra.core.convert.CassandraConverter;
import org.springframework.data.cassandra.core.convert.MappingCassandraConverter;
import org.springframework.data.cassandra.core.convert.QueryMapper;
import org.springframework.data.cassandra.core.convert.UpdateMapper;
import org.springframework.data.cassandra.core.cql.*;
import org.springframework.data.cassandra.core.cql.session.DefaultSessionFactory;
import org.springframework.data.cassandra.core.cql.util.StatementBuilder;
import org.springframework.data.cassandra.core.mapping.CassandraPersistentEntity;
import org.springframework.data.cassandra.core.mapping.SimpleUserTypeResolver;
import org.springframework.data.cassandra.core.mapping.event.AfterConvertEvent;
import org.springframework.data.cassandra.core.mapping.event.AfterDeleteEvent;
import org.springframework.data.cassandra.core.mapping.event.AfterLoadEvent;
import org.springframework.data.cassandra.core.mapping.event.AfterSaveEvent;
import org.springframework.data.cassandra.core.mapping.event.BeforeConvertCallback;
import org.springframework.data.cassandra.core.mapping.event.BeforeDeleteEvent;
import org.springframework.data.cassandra.core.mapping.event.BeforeSaveCallback;
import org.springframework.data.cassandra.core.mapping.event.BeforeSaveEvent;
import org.springframework.data.cassandra.core.mapping.event.CassandraMappingEvent;
import org.springframework.data.cassandra.core.query.Columns;
import org.springframework.data.cassandra.core.query.Query;
import org.springframework.data.domain.Slice;
import org.springframework.data.mapping.callback.EntityCallbacks;
import org.springframework.data.projection.EntityProjection;
import org.springframework.data.projection.ProjectionFactory;
import org.springframework.data.projection.SpelAwareProxyProjectionFactory;
import org.springframework.lang.Nullable;
import org.springframework.util.Assert;

/**
 * Primary implementation of {@link CassandraOperations}. It simplifies the use of Cassandra usage and helps to avoid
 * common errors. It executes core Cassandra workflow. This class executes CQL queries or updates, initiating iteration
 * over {@link ResultSet} and catching Cassandra exceptions and translating them to the generic, more informative
 * exception hierarchy defined in the {@code org.springframework.dao} package.
 * <p>
 * Can be used within a service implementation via direct instantiation with a {@link CqlSession} reference, or get
 * prepared in an application context and given to services as bean reference.
 * <p>
 * This class supports the use of prepared statements when enabling {@link #setUsePreparedStatements(boolean)}. All
 * statements created by methods of this class (such as {@link #select(Query, Class)} or
 * {@link #update(Query, org.springframework.data.cassandra.core.query.Update, Class)} will be executed as prepared
 * statements. Also, statements accepted by methods (such as {@link #select(String, Class)} or
 * {@link #select(Statement, Class) and others}) will be prepared prior to execution. Note that {@link Statement}
 * objects passed to methods must be {@link SimpleStatement} so that these can be prepared.
 * <p>
 * Note: The {@link CqlSession} should always be configured as a bean in the application context, in the first case
 * given to the service directly, in the second case to the prepared template.
 *
 * @author Mark Paluch
 * @author John Blum
 * @author Lukasz Antoniak
 * @author Sam Lightfoot
 * @see org.springframework.data.cassandra.core.CassandraOperations
 * @since 2.0
 */
public class CassandraTemplate implements CassandraOperations, ApplicationEventPublisherAware, ApplicationContextAware {

	private final Log log = LogFactory.getLog(getClass());

	private final CqlOperations cqlOperations;

	private final CassandraConverter converter;

	private final EntityOperations entityOperations;

	private final StatementFactory statementFactory;

	private final EntityLifecycleEventDelegate eventDelegate;

	private @Nullable EntityCallbacks entityCallbacks;

	private boolean usePreparedStatements = true;

	/**
	 * Creates an instance of {@link CassandraTemplate} initialized with the given {@link CqlSession} and a default
	 * {@link MappingCassandraConverter}.
	 *
	 * @param session {@link CqlSession} used to interact with Cassandra; must not be {@literal null}.
	 * @see CassandraConverter
	 * @see CqlSession
	 */
	public CassandraTemplate(CqlSession session) {
		this(session, newConverter(session));
	}

	/**
	 * Creates an instance of {@link CassandraTemplate} initialized with the given {@link CqlSession} and
	 * {@link CassandraConverter}.
	 *
	 * @param session {@link CqlSession} used to interact with Cassandra; must not be {@literal null}.
	 * @param converter {@link CassandraConverter} used to convert between Java and Cassandra types; must not be
	 *          {@literal null}.
	 * @see CassandraConverter
	 * @see CqlSession
	 */
	public CassandraTemplate(CqlSession session, CassandraConverter converter) {
		this(new DefaultSessionFactory(session), converter);
	}

	/**
	 * Creates an instance of {@link CassandraTemplate} initialized with the given {@link SessionFactory} and
	 * {@link CassandraConverter}.
	 *
	 * @param sessionFactory {@link SessionFactory} used to interact with Cassandra; must not be {@literal null}.
	 * @param converter {@link CassandraConverter} used to convert between Java and Cassandra types; must not be
	 *          {@literal null}.
	 * @see CassandraConverter
	 * @see SessionFactory
	 */
	public CassandraTemplate(SessionFactory sessionFactory, CassandraConverter converter) {
		this(new CqlTemplate(sessionFactory), converter);
	}

	/**
	 * Creates an instance of {@link CassandraTemplate} initialized with the given {@link CqlOperations} and
	 * {@link CassandraConverter}.
	 *
	 * @param cqlOperations {@link CqlOperations} used to interact with Cassandra; must not be {@literal null}.
	 * @param converter {@link CassandraConverter} used to convert between Java and Cassandra types; must not be
	 *          {@literal null}.
	 * @see CassandraConverter
	 * @see CqlSession
	 */
	public CassandraTemplate(CqlOperations cqlOperations, CassandraConverter converter) {

		Assert.notNull(cqlOperations, "CqlOperations must not be null");
		Assert.notNull(converter, "CassandraConverter must not be null");

		this.converter = converter;
		this.cqlOperations = cqlOperations;
		this.entityOperations = new EntityOperations(converter);
		this.statementFactory = new StatementFactory(new QueryMapper(converter), new UpdateMapper(converter));
		this.eventDelegate = new EntityLifecycleEventDelegate();
	}

	@Override
	public CassandraBatchOperations batchOps(BatchType batchType) {
		return new CassandraBatchTemplate(this, batchType);
	}

	@Override
	public void setApplicationEventPublisher(ApplicationEventPublisher applicationEventPublisher) {
		this.eventDelegate.setPublisher(applicationEventPublisher);
	}

	@Override
	public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {

		if (entityCallbacks == null) {
			setEntityCallbacks(EntityCallbacks.create(applicationContext));
		}
	}

	/**
	 * Configure {@link EntityCallbacks} to pre-/post-process entities during persistence operations.
	 *
	 * @param entityCallbacks
	 */
	public void setEntityCallbacks(@Nullable EntityCallbacks entityCallbacks) {
		this.entityCallbacks = entityCallbacks;
	}

	/**
	 * Configure whether lifecycle events such as {@link AfterLoadEvent}, {@link BeforeSaveEvent}, etc. should be
	 * published or whether emission should be suppressed. Enabled by default.
	 *
	 * @param enabled {@code true} to enable entity lifecycle events; {@code false} to disable entity lifecycle events.
	 * @since 4.0
	 * @see CassandraMappingEvent
	 */
	public void setEntityLifecycleEventsEnabled(boolean enabled) {
		this.eventDelegate.setEventsEnabled(enabled);
	}

	@Override
	public CqlOperations getCqlOperations() {
		return this.cqlOperations;
	}

	@Override
	public CassandraConverter getConverter() {
		return this.converter;
	}

	/**
	 * Returns whether this instance is configured to use {@link PreparedStatement prepared statements}. If enabled
	 * (default), then all persistence methods (such as {@link #select}, {@link #update}, and others) will make use of
	 * prepared statements. Note that methods accepting a {@link Statement} must be called with {@link SimpleStatement}
	 * instances to participate in statement preparation.
	 *
	 * @return {@literal true} if prepared statements usage is enabled; {@literal false} otherwise.
	 * @since 3.2
	 */
	public boolean isUsePreparedStatements() {
		return usePreparedStatements;
	}

	/**
	 * Enable/disable {@link PreparedStatement prepared statements} usage. If enabled (default), then all persistence
	 * methods (such as {@link #select}, {@link #update}, and others) will make use of prepared statements. Note that
	 * methods accepting a {@link Statement} must be called with {@link SimpleStatement} instances to participate in
	 * statement preparation.
	 *
	 * @param usePreparedStatements whether to use prepared statements.
	 * @since 3.2
	 */
	public void setUsePreparedStatements(boolean usePreparedStatements) {
		this.usePreparedStatements = usePreparedStatements;
	}

	/**
	 * Returns the {@link EntityOperations} used to perform data access operations on an entity inside a Cassandra data
	 * source.
	 *
	 * @return the configured {@link EntityOperations} for this template.
	 * @see org.springframework.data.cassandra.core.EntityOperations
	 */
	protected EntityOperations getEntityOperations() {
		return this.entityOperations;
	}

	/**
	 * Returns a reference to the configured {@link ProjectionFactory} used by this template to process CQL query
	 * projections.
	 *
	 * @return a reference to the configured {@link ProjectionFactory} used by this template to process CQL query
	 *         projections.
	 * @see org.springframework.data.projection.SpelAwareProxyProjectionFactory
	 * @since 2.1
	 * @deprecated since 3.4, use {@link CassandraConverter#getProjectionFactory()} instead.
	 */
	protected SpelAwareProxyProjectionFactory getProjectionFactory() {
		return (SpelAwareProxyProjectionFactory) getConverter().getProjectionFactory();
	}

	private CassandraPersistentEntity<?> getRequiredPersistentEntity(Class<?> entityType) {
		return getEntityOperations().getRequiredPersistentEntity(entityType);
	}

	/**
	 * Returns the {@link StatementFactory} used by this template to construct and run Cassandra CQL statements.
	 *
	 * @return the {@link StatementFactory} used by this template to construct and run Cassandra CQL statements.
	 * @see org.springframework.data.cassandra.core.StatementFactory
	 * @since 2.1
	 */
	protected StatementFactory getStatementFactory() {
		return this.statementFactory;
	}

	@Override
	public CqlIdentifier getTableName(Class<?> entityClass) {
		return getEntityOperations().getTableName(entityClass);
	}

	// -------------------------------------------------------------------------
	// Methods dealing with static CQL
	// -------------------------------------------------------------------------

	@Override
	public <T> List<T> select(String cql, Class<T> entityClass) {

		Assert.hasText(cql, "CQL must not be empty");

		return select(SimpleStatement.newInstance(cql), entityClass);
	}

	@Override
	public <T> T selectOne(String cql, Class<T> entityClass) {

		Assert.hasText(cql, "CQL must not be empty");
		Assert.notNull(entityClass, "Entity type must not be null");

		return selectOne(SimpleStatement.newInstance(cql), entityClass);
	}

	@Override
	public <T> Stream<T> stream(String cql, Class<T> entityClass) throws DataAccessException {

		Assert.hasText(cql, "CQL must not be empty");
		Assert.notNull(entityClass, "Entity type must not be null");

		return stream(SimpleStatement.newInstance(cql), entityClass);
	}

	// -------------------------------------------------------------------------
	// Methods dealing with com.datastax.oss.driver.api.core.cql.Statement
	// -------------------------------------------------------------------------

	@Override
	public ResultSet execute(Statement<?> statement) {

		Assert.notNull(statement, "Statement must not be null");

		return doQueryForResultSet(statement);
	}

	@Override
	public <T> List<T> select(Statement<?> statement, Class<T> entityClass) {

		Assert.notNull(statement, "Statement must not be null");
		Assert.notNull(entityClass, "Entity type must not be null");

		Function<Row, T> mapper = getMapper(EntityProjection.nonProjecting(entityClass),
				EntityQueryUtils.getTableName(statement));

		return doQuery(statement, (row, rowNum) -> mapper.apply(row));
	}

	@Override
	public <T> T selectOne(Statement<?> statement, Class<T> entityClass) {

		List<T> result = select(statement, entityClass);
		return result.isEmpty() ? null : result.get(0);
	}

	@Override
	public <T> Slice<T> slice(Statement<?> statement, Class<T> entityClass) {

		Assert.notNull(statement, "Statement must not be null");
		Assert.notNull(entityClass, "Entity type must not be null");

		ResultSet resultSet = doQueryForResultSet(statement);

		Function<Row, T> mapper = getMapper(EntityProjection.nonProjecting(entityClass),
				EntityQueryUtils.getTableName(statement));

		return EntityQueryUtils.readSlice(resultSet, (row, rowNum) -> mapper.apply(row), 0,
				getEffectivePageSize(statement));
	}

	@Override
	public <T> Stream<T> stream(Statement<?> statement, Class<T> entityClass) throws DataAccessException {

		Assert.notNull(statement, "Statement must not be null");
		Assert.notNull(entityClass, "Entity type must not be null");

		Function<Row, T> mapper = getMapper(EntityProjection.nonProjecting(entityClass),
				EntityQueryUtils.getTableName(statement));
		return doQueryForStream(statement, (row, rowNum) -> mapper.apply(row));
	}

	// -------------------------------------------------------------------------
	// Methods dealing with org.springframework.data.cassandra.core.query.Query
	// -------------------------------------------------------------------------

	@Override
	public <T> List<T> select(Query query, Class<T> entityClass) throws DataAccessException {

		Assert.notNull(query, "Query must not be null");
		Assert.notNull(entityClass, "Entity type must not be null");

		return doSelect(query, entityClass, getTableName(entityClass), entityClass);
	}

	<T> List<T> doSelect(Query query, Class<?> entityClass, CqlIdentifier tableName, Class<T> returnType) {

		CassandraPersistentEntity<?> entity = getRequiredPersistentEntity(entityClass);
		EntityProjection<T, ?> projection = entityOperations.introspectProjection(returnType, entityClass);
		Columns columns = getStatementFactory().computeColumnsForProjection(projection, query.getColumns(), entity,
				returnType);

		Query queryToUse = query.columns(columns);

		StatementBuilder<Select> select = getStatementFactory().select(queryToUse, entity, tableName);
		Function<Row, T> mapper = getMapper(projection, tableName);

		return doQuery(select.build(), (row, rowNum) -> mapper.apply(row));
	}

	@Override
	public <T> T selectOne(Query query, Class<T> entityClass) throws DataAccessException {

		List<T> result = select(query, entityClass);

		return result.isEmpty() ? null : result.get(0);
	}

	@Override
	public <T> Slice<T> slice(Query query, Class<T> entityClass) throws DataAccessException {

		Assert.notNull(query, "Query must not be null");
		Assert.notNull(entityClass, "Entity type must not be null");

		StatementBuilder<Select> select = getStatementFactory().select(query, getRequiredPersistentEntity(entityClass));

		return slice(select.build(), entityClass);
	}

	@Override
	public <T> Stream<T> stream(Query query, Class<T> entityClass) throws DataAccessException {

		Assert.notNull(query, "Query must not be null");
		Assert.notNull(entityClass, "Entity type must not be null");

		return doStream(query, entityClass, getTableName(entityClass), entityClass);
	}

	<T> Stream<T> doStream(Query query, Class<?> entityClass, CqlIdentifier tableName, Class<T> returnType) {

		StatementBuilder<Select> select = getStatementFactory().select(query, getRequiredPersistentEntity(entityClass),
				tableName);
		EntityProjection<T, ?> projection = entityOperations.introspectProjection(returnType, entityClass);

		Function<Row, T> mapper = getMapper(projection, tableName);
		return doQueryForStream(select.build(), (row, rowNum) -> mapper.apply(row));
	}

	@Override
	public boolean update(Query query, org.springframework.data.cassandra.core.query.Update update, Class<?> entityClass)
			throws DataAccessException {

		Assert.notNull(query, "Query must not be null");
		Assert.notNull(update, "Update must not be null");
		Assert.notNull(entityClass, "Entity type must not be null");

		StatementBuilder<Update> updateStatement = getStatementFactory().update(query, update,
				getRequiredPersistentEntity(entityClass));

		return doExecute(updateStatement.build()).wasApplied();
	}

	@Nullable
	WriteResult doUpdate(Query query, org.springframework.data.cassandra.core.query.Update update, Class<?> entityClass,
			CqlIdentifier tableName) {

		StatementBuilder<Update> updateStatement = getStatementFactory().update(query, update,
				getRequiredPersistentEntity(entityClass), tableName);

		return doExecute(updateStatement.build());
	}

	@Override
	public boolean delete(Query query, Class<?> entityClass) throws DataAccessException {

		Assert.notNull(query, "Query must not be null");
		Assert.notNull(entityClass, "Entity type must not be null");

		WriteResult result = doDelete(query, entityClass, getTableName(entityClass));

		return result != null && result.wasApplied();
	}

	@Nullable
	WriteResult doDelete(Query query, Class<?> entityClass, CqlIdentifier tableName) {

		StatementBuilder<Delete> delete = getStatementFactory().delete(query, getRequiredPersistentEntity(entityClass),
				tableName);
		SimpleStatement statement = delete.build();

		maybeEmitEvent(() -> new BeforeDeleteEvent<>(statement, entityClass, tableName));

		WriteResult writeResult = doExecute(statement);

		maybeEmitEvent(() -> new AfterDeleteEvent<>(statement, entityClass, tableName));

		return writeResult;
	}

	// -------------------------------------------------------------------------
	// Methods dealing with entities
	// -------------------------------------------------------------------------

	@Override
	public long count(Class<?> entityClass) {

		Assert.notNull(entityClass, "Entity type must not be null");

		return count(Query.empty(), entityClass);
	}

	@Override
	public long count(Query query, Class<?> entityClass) throws DataAccessException {

		Assert.notNull(query, "Query must not be null");
		Assert.notNull(entityClass, "Entity type must not be null");

		return doCount(query, entityClass, getTableName(entityClass));
	}

	long doCount(Query query, Class<?> entityClass, CqlIdentifier tableName) {

		StatementBuilder<Select> countStatement = getStatementFactory().count(query,
				getRequiredPersistentEntity(entityClass), tableName);

		return doQueryForObject(countStatement.build(), Long.class);
	}

	@Override
	public boolean exists(Object id, Class<?> entityClass) {

		Assert.notNull(id, "Id must not be null");
		Assert.notNull(entityClass, "Entity type must not be null");

		CassandraPersistentEntity<?> entity = getRequiredPersistentEntity(entityClass);
		StatementBuilder<Select> select = getStatementFactory().selectOneById(id, entity, entity.getTableName());

		return doQueryForResultSet(select.build()).one() != null;
	}

	@Override
	public boolean exists(Query query, Class<?> entityClass) throws DataAccessException {

		Assert.notNull(query, "Query must not be null");
		Assert.notNull(entityClass, "Entity type must not be null");

		return doExists(query, entityClass, getTableName(entityClass));
	}

	boolean doExists(Query query, Class<?> entityClass, CqlIdentifier tableName) {

		StatementBuilder<Select> select = getStatementFactory().select(query.limit(1),
				getRequiredPersistentEntity(entityClass), tableName);

		return doQueryForResultSet(select.build()).one() != null;
	}

	@Override
	public <T> T selectOneById(Object id, Class<T> entityClass) {

		Assert.notNull(id, "Id must not be null");
		Assert.notNull(entityClass, "Entity type must not be null");

		CassandraPersistentEntity<?> entity = getRequiredPersistentEntity(entityClass);
		CqlIdentifier tableName = entity.getTableName();
		StatementBuilder<Select> select = getStatementFactory().selectOneById(id, entity, tableName);
		Function<Row, T> mapper = getMapper(EntityProjection.nonProjecting(entityClass), tableName);
		List<T> result = doQuery(select.build(), (row, rowNum) -> mapper.apply(row));

		return result.isEmpty() ? null : result.get(0);
	}

	@Override
	public <T> T insert(T entity) {
		return insert(entity, InsertOptions.empty()).getEntity();
	}

	@Override
	public <T> EntityWriteResult<T> insert(T entity, InsertOptions options) {

		Assert.notNull(entity, "Entity must not be null");
		Assert.notNull(options, "InsertOptions must not be null");

		return doInsert(entity, options, getTableName(entity.getClass()));
	}

	<T> EntityWriteResult<T> doInsert(T entity, WriteOptions options, CqlIdentifier tableName) {

		AdaptibleEntity<T> source = getEntityOperations().forEntity(maybeCallBeforeConvert(entity, tableName),
				getConverter().getConversionService());

		T entityToUse = source.isVersionedEntity() ? source.initializeVersionProperty() : source.getBean();

		StatementBuilder<RegularInsert> builder = getStatementFactory().insert(entityToUse, options,
				source.getPersistentEntity(), tableName);

		if (source.isVersionedEntity()) {

			builder.apply(Insert::ifNotExists);
			return doInsertVersioned(builder.build(), entityToUse, source, tableName);
		}

		return doInsert(builder.build(), entityToUse, tableName);
	}

	private <T> EntityWriteResult<T> doInsertVersioned(SimpleStatement insert, T entity, AdaptibleEntity<T> source,
			CqlIdentifier tableName) {

		return executeSave(entity, tableName, insert, result -> {

			if (!result.wasApplied()) {
				throw new OptimisticLockingFailureException(
						String.format("Cannot insert entity %s with version %s into table %s as it already exists", entity,
								source.getVersion(), tableName));
			}
		});
	}

	private <T> EntityWriteResult<T> doInsert(SimpleStatement insert, T entity, CqlIdentifier tableName) {
		return executeSave(entity, tableName, insert);
	}

	@Override
	public <T> T update(T entity) {
		return update(entity, UpdateOptions.empty()).getEntity();
	}

	@Override
	public <T> EntityWriteResult<T> update(T entity, UpdateOptions options) {

		Assert.notNull(entity, "Entity must not be null");
		Assert.notNull(options, "UpdateOptions must not be null");

		AdaptibleEntity<T> source = getEntityOperations().forEntity(entity, getConverter().getConversionService());
		CassandraPersistentEntity<?> persistentEntity = getRequiredPersistentEntity(entity.getClass());
		CqlIdentifier tableName = persistentEntity.getTableName();

		T entityToUpdate = maybeCallBeforeConvert(entity, tableName);

		return source.isVersionedEntity() ? doUpdateVersioned(entityToUpdate, options, tableName, persistentEntity)
				: doUpdate(entityToUpdate, options, tableName, persistentEntity);
	}

	private <T> EntityWriteResult<T> doUpdateVersioned(T entity, UpdateOptions options, CqlIdentifier tableName,
			CassandraPersistentEntity<?> persistentEntity) {

		AdaptibleEntity<T> source = getEntityOperations().forEntity(entity, getConverter().getConversionService());

		Number previousVersion = source.getVersion();
		T toSave = source.incrementVersion();

		StatementBuilder<Update> builder = getStatementFactory().update(toSave, options, persistentEntity, tableName);
		SimpleStatement update = source.appendVersionCondition(builder, previousVersion).build();

		return executeSave(toSave, tableName, update, result -> {

			if (!result.wasApplied()) {
				throw new OptimisticLockingFailureException(
						String.format("Cannot save entity %s with version %s to table %s; Has it been modified meanwhile", toSave,
								source.getVersion(), tableName));
			}
		});
	}

	private <T> EntityWriteResult<T> doUpdate(T entity, UpdateOptions options, CqlIdentifier tableName,
			CassandraPersistentEntity<?> persistentEntity) {

		StatementBuilder<Update> builder = getStatementFactory().update(entity, options, persistentEntity, tableName);

		return executeSave(entity, tableName, builder.build());
	}

	@Override
	public void delete(Object entity) {
		delete(entity, QueryOptions.empty());
	}

	@Override
	public WriteResult delete(Object entity, QueryOptions options) {

		Assert.notNull(entity, "Entity must not be null");
		Assert.notNull(options, "QueryOptions must not be null");

		AdaptibleEntity<Object> source = getEntityOperations().forEntity(entity, getConverter().getConversionService());
		CassandraPersistentEntity<?> persistentEntity = getRequiredPersistentEntity(entity.getClass());
		CqlIdentifier tableName = persistentEntity.getTableName();

		StatementBuilder<Delete> builder = getStatementFactory().delete(entity, options, getConverter(), tableName);

		return source.isVersionedEntity()
				? doDeleteVersioned(source.appendVersionCondition(builder).build(), entity, source, tableName)
				: doDelete(builder.build(), entity, tableName);

	}

	private WriteResult doDeleteVersioned(SimpleStatement statement, Object entity, AdaptibleEntity<Object> source,
			CqlIdentifier tableName) {

		return executeDelete(entity, tableName, statement, result -> {

			if (!result.wasApplied()) {
				throw new OptimisticLockingFailureException(
						String.format("Cannot delete entity %s with version %s in table %s; Has it been modified meanwhile", entity,
								source.getVersion(), tableName));
			}
		});
	}

	private WriteResult doDelete(SimpleStatement delete, Object entity, CqlIdentifier tableName) {
		return executeDelete(entity, tableName, delete, result -> {});
	}

	@Override
	public boolean deleteById(Object id, Class<?> entityClass) {

		Assert.notNull(id, "Id must not be null");
		Assert.notNull(entityClass, "Entity type must not be null");

		CassandraPersistentEntity<?> entity = getRequiredPersistentEntity(entityClass);
		CqlIdentifier tableName = entity.getTableName();

		StatementBuilder<Delete> delete = getStatementFactory().deleteById(id, entity, tableName);
		SimpleStatement statement = delete.build();

		maybeEmitEvent(() -> new BeforeDeleteEvent<>(statement, entityClass, tableName));

		boolean result = doExecute(statement).wasApplied();

		maybeEmitEvent(() -> new AfterDeleteEvent<>(statement, entityClass, tableName));

		return result;
	}

	@Override
	public void truncate(Class<?> entityClass) {

		Assert.notNull(entityClass, "Entity type must not be null");

		CqlIdentifier tableName = getTableName(entityClass);
		Truncate truncate = QueryBuilder.truncate(tableName);
		SimpleStatement statement = truncate.build();

		maybeEmitEvent(() -> new BeforeDeleteEvent<>(statement, entityClass, tableName));

		doExecute(statement);

		maybeEmitEvent(() -> new AfterDeleteEvent<>(statement, entityClass, tableName));
	}

	// -------------------------------------------------------------------------
	// Fluent API entry points
	// -------------------------------------------------------------------------

	@Override
	public <T> ExecutableSelect<T> query(Class<T> domainType) {
		return new ExecutableSelectOperationSupport(this).query(domainType);
	}

	@Override
	public <T> ExecutableInsert<T> insert(Class<T> domainType) {
		return new ExecutableInsertOperationSupport(this).insert(domainType);
	}

	@Override
	public ExecutableUpdate update(Class<?> domainType) {
		return new ExecutableUpdateOperationSupport(this).update(domainType);
	}

	@Override
	public ExecutableDelete delete(Class<?> domainType) {
		return new ExecutableDeleteOperationSupport(this).delete(domainType);
	}

	// -------------------------------------------------------------------------
	// Implementation hooks and utility methods
	// -------------------------------------------------------------------------

	/**
	 * Create a new statement-based {@link PreparedStatementHandler} using the statement passed in.
	 * <p>
	 * This method allows for the creation to be overridden by subclasses.
	 *
	 * @param statement the statement to be prepared.
	 * @return the new {@link PreparedStatementHandler} to use.
	 * @since 3.3.3
	 */
	protected PreparedStatementHandler createPreparedStatementHandler(Statement<?> statement) {
		return new PreparedStatementHandler(statement);
	}

	private <T> EntityWriteResult<T> executeSave(T entity, CqlIdentifier tableName, SimpleStatement statement) {
		return executeSave(entity, tableName, statement, ignore -> {});
	}

	private <T> EntityWriteResult<T> executeSave(T entity, CqlIdentifier tableName, SimpleStatement statement,
			Consumer<WriteResult> resultConsumer) {

		maybeEmitEvent(() -> new BeforeSaveEvent<>(entity, tableName, statement));
		T entityToSave = maybeCallBeforeSave(entity, tableName, statement);

		WriteResult result = doExecute(statement);
		resultConsumer.accept(result);

		maybeEmitEvent(() -> new AfterSaveEvent<>(entityToSave, tableName));

		return EntityWriteResult.of(result, entityToSave);
	}

	private WriteResult executeDelete(Object entity, CqlIdentifier tableName, SimpleStatement statement,
			Consumer<WriteResult> resultConsumer) {

		maybeEmitEvent(() -> new BeforeDeleteEvent<>(statement, entity.getClass(), tableName));

		WriteResult result = doExecute(statement);

		resultConsumer.accept(result);

		maybeEmitEvent(() -> new AfterDeleteEvent<>(statement, entity.getClass(), tableName));

		return result;
	}

	private <T> List<T> doQuery(Statement<?> statement, RowMapper<T> rowMapper) {

		if (PreparedStatementDelegate.canPrepare(isUsePreparedStatements(), statement, log)) {

			PreparedStatementHandler statementHandler = createPreparedStatementHandler(statement);
			return getCqlOperations().query(statementHandler, statementHandler, rowMapper);
		}

		return getCqlOperations().query(statement, rowMapper);
	}

	private <T> T doQueryForObject(Statement<?> statement, Class<T> resultType) {
		return DataAccessUtils.requiredSingleResult(doQuery(statement, SingleColumnRowMapper.newInstance(resultType)));
	}

	private <T> Stream<T> doQueryForStream(Statement<?> statement, RowMapper<T> rowMapper) {

		if (PreparedStatementDelegate.canPrepare(isUsePreparedStatements(), statement, log)) {

			PreparedStatementHandler statementHandler = createPreparedStatementHandler(statement);
			return getCqlOperations().queryForStream(statementHandler, statementHandler, rowMapper);
		}

		return getCqlOperations().queryForStream(statement, rowMapper);
	}

	private WriteResult doExecute(SimpleStatement statement) {
		return doExecute(statement, WriteResult::of);
	}

	private ResultSet doQueryForResultSet(Statement<?> statement) {
		return doExecute(statement, Function.identity());
	}

	private <T> T doExecute(Statement<?> statement, Function<ResultSet, T> mappingFunction) {

		if (PreparedStatementDelegate.canPrepare(isUsePreparedStatements(), statement, log)) {

			PreparedStatementHandler statementHandler = createPreparedStatementHandler(statement);
			return getCqlOperations().query(statementHandler, statementHandler, mappingFunction::apply);
		}

		return mappingFunction.apply(getCqlOperations().queryForResultSet(statement));
	}

	private int getConfiguredPageSize(CqlSession session) {
		return session.getContext().getConfig().getDefaultProfile().getInt(DefaultDriverOption.REQUEST_PAGE_SIZE, 5000);
	}

	@SuppressWarnings("ConstantConditions")
	private int getEffectivePageSize(Statement<?> statement) {

		if (statement.getPageSize() > 0) {
			return statement.getPageSize();
		}

		if (getCqlOperations() instanceof CassandraAccessor) {

			CassandraAccessor accessor = (CassandraAccessor) getCqlOperations();

			if (accessor.getFetchSize() != -1) {
				return accessor.getFetchSize();
			}
		}

		class GetConfiguredPageSize implements SessionCallback<Integer>, CqlProvider {
			@Override
			public Integer doInSession(CqlSession session) {
				return getConfiguredPageSize(session);
			}

			@Override
			public String getCql() {
				return QueryExtractorDelegate.getCql(statement);
			}
		}

		return getCqlOperations().execute(new GetConfiguredPageSize());
	}

	@SuppressWarnings("unchecked")
	private <T> Function<Row, T> getMapper(EntityProjection<T, ?> projection, CqlIdentifier tableName) {

		Class<T> targetType = projection.getMappedType().getType();

		return row -> {

			maybeEmitEvent(() -> new AfterLoadEvent<>(row, targetType, tableName));

			T result = getConverter().project(projection, row);

			if (result != null) {
				maybeEmitEvent(() -> new AfterConvertEvent<>(row, result, tableName));
			}

			return result;
		};
	}

	private static MappingCassandraConverter newConverter(CqlSession session) {

		MappingCassandraConverter converter = new MappingCassandraConverter();
		converter.setUserTypeResolver(new SimpleUserTypeResolver(session));
		converter.setCodecRegistry(session.getContext().getCodecRegistry());

		converter.afterPropertiesSet();

		return converter;
	}

	protected <E extends CassandraMappingEvent<T>, T> void maybeEmitEvent(Supplier<E> event) {
		this.eventDelegate.publishEvent(event);
	}

	protected <T> T maybeCallBeforeConvert(T object, CqlIdentifier tableName) {

		if (null != entityCallbacks) {
			return (T) entityCallbacks.callback(BeforeConvertCallback.class, object, tableName);
		}

		return object;
	}

	protected <T> T maybeCallBeforeSave(T object, CqlIdentifier tableName, Statement<?> statement) {

		if (null != entityCallbacks) {
			return (T) entityCallbacks.callback(BeforeSaveCallback.class, object, tableName, statement);
		}

		return object;
	}

	/**
	 * Utility class to prepare a {@link SimpleStatement} and bind values associated with the statement to a
	 * {@link BoundStatement}.
	 *
	 * @since 3.2
	 */
	public static class PreparedStatementHandler
			implements PreparedStatementCreator, PreparedStatementBinder, CqlProvider {

		private final SimpleStatement statement;

		public PreparedStatementHandler(Statement<?> statement) {
			this.statement = PreparedStatementDelegate.getStatementForPrepare(statement);
		}

		@Override
		public PreparedStatement createPreparedStatement(CqlSession session) throws DriverException {
			return session.prepare(statement.getQuery());
		}

		@Override
		public BoundStatement bindValues(PreparedStatement ps) throws DriverException {
			return PreparedStatementDelegate.bind(statement, ps);
		}

		@Override
		public String getCql() {
			return statement.getQuery();
		}
	}
}
