/*
    * 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.shardingsphere.infra.executor.sql.execute.engine.raw;
  
  import lombok.RequiredArgsConstructor;
  import org.apache.shardingsphere.infra.executor.kernel.ExecutorEngine;
  import org.apache.shardingsphere.infra.executor.kernel.model.ExecutionGroupContext;
  import org.apache.shardingsphere.infra.executor.sql.execute.engine.SQLExecutorExceptionHandler;
  import org.apache.shardingsphere.infra.executor.sql.execute.engine.raw.callback.RawSQLExecutorCallback;
  import org.apache.shardingsphere.infra.executor.sql.execute.result.ExecuteResult;
  import org.apache.shardingsphere.infra.executor.sql.execute.result.update.UpdateResult;
  import org.apache.shardingsphere.infra.executor.sql.process.ProcessEngine;
  import org.apache.shardingsphere.infra.session.connection.ConnectionContext;
  import org.apache.shardingsphere.infra.session.query.QueryContext;
  
  import java.sql.SQLException;
  import java.util.Collections;
  import java.util.List;
  
  /**
   * Raw executor.
   */
  @RequiredArgsConstructor
  public final class RawExecutor {
      
      private final ExecutorEngine executorEngine;
      
      private final ConnectionContext connectionContext;
      
      private final ProcessEngine processEngine = new ProcessEngine();
      
      /**
       * Execute.
       *
       * @param executionGroupContext execution group context
       * @param queryContext query context
       * @param callback raw SQL executor callback
       * @return execute results
       * @throws SQLException SQL exception
       */
      public List<ExecuteResult> execute(final ExecutionGroupContext<RawSQLExecutionUnit> executionGroupContext,
                                         final QueryContext queryContext, final RawSQLExecutorCallback callback) throws SQLException {
          try {
              processEngine.executeSQL(executionGroupContext, queryContext);
              // TODO Load query header for first query
              List<ExecuteResult> results = execute(executionGroupContext, (RawSQLExecutorCallback) null, callback);
              return results.isEmpty() || null == results.get(0) ? Collections.singletonList(new UpdateResult(0, 0L)) : results;
          } finally {
              processEngine.completeSQLExecution(executionGroupContext.getReportContext().getProcessId());
          }
      }
      
      @SuppressWarnings("unchecked")
      private <T> List<T> execute(final ExecutionGroupContext<RawSQLExecutionUnit> executionGroupContext,
                                  final RawSQLExecutorCallback firstCallback, final RawSQLExecutorCallback callback) throws SQLException {
          try {
              return (List<T>) executorEngine.execute(executionGroupContext, firstCallback, callback, connectionContext.getTransactionContext().isInTransaction());
          } catch (final SQLException ex) {
              SQLExecutorExceptionHandler.handleException(ex);
              return Collections.emptyList();
          }
      }
  }