/*
    * 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.sharding.route.engine.type;
  
  import lombok.AccessLevel;
  import lombok.NoArgsConstructor;
  import org.apache.shardingsphere.infra.binder.context.statement.SQLStatementContext;
  import org.apache.shardingsphere.infra.binder.context.statement.ddl.CloseStatementContext;
  import org.apache.shardingsphere.infra.binder.context.type.CursorAvailable;
  import org.apache.shardingsphere.infra.binder.context.type.TableAvailable;
  import org.apache.shardingsphere.infra.config.props.ConfigurationProperties;
  import org.apache.shardingsphere.infra.hint.HintValueContext;
  import org.apache.shardingsphere.infra.metadata.database.ShardingSphereDatabase;
  import org.apache.shardingsphere.infra.metadata.database.rule.RuleMetaData;
  import org.apache.shardingsphere.infra.session.connection.ConnectionContext;
  import org.apache.shardingsphere.infra.session.query.QueryContext;
  import org.apache.shardingsphere.sharding.route.engine.condition.ShardingCondition;
  import org.apache.shardingsphere.sharding.route.engine.condition.ShardingConditions;
  import org.apache.shardingsphere.sharding.route.engine.type.broadcast.ShardingDataSourceGroupBroadcastRoutingEngine;
  import org.apache.shardingsphere.sharding.route.engine.type.broadcast.ShardingDatabaseBroadcastRoutingEngine;
  import org.apache.shardingsphere.sharding.route.engine.type.broadcast.ShardingInstanceBroadcastRoutingEngine;
  import org.apache.shardingsphere.sharding.route.engine.type.broadcast.ShardingTableBroadcastRoutingEngine;
  import org.apache.shardingsphere.sharding.route.engine.type.complex.ShardingComplexRoutingEngine;
  import org.apache.shardingsphere.sharding.route.engine.type.ignore.ShardingIgnoreRoutingEngine;
  import org.apache.shardingsphere.sharding.route.engine.type.standard.ShardingStandardRoutingEngine;
  import org.apache.shardingsphere.sharding.route.engine.type.unicast.ShardingUnicastRoutingEngine;
  import org.apache.shardingsphere.sharding.rule.ShardingRule;
  import org.apache.shardingsphere.sql.parser.sql.common.statement.SQLStatement;
  import org.apache.shardingsphere.sql.parser.sql.common.statement.dal.AnalyzeTableStatement;
  import org.apache.shardingsphere.sql.parser.sql.common.statement.dal.DALStatement;
  import org.apache.shardingsphere.sql.parser.sql.common.statement.dal.LoadStatement;
  import org.apache.shardingsphere.sql.parser.sql.common.statement.dal.ResetParameterStatement;
  import org.apache.shardingsphere.sql.parser.sql.common.statement.dal.SetStatement;
  import org.apache.shardingsphere.sql.parser.sql.common.statement.dcl.DCLStatement;
  import org.apache.shardingsphere.sql.parser.sql.common.statement.ddl.AlterFunctionStatement;
  import org.apache.shardingsphere.sql.parser.sql.common.statement.ddl.AlterProcedureStatement;
  import org.apache.shardingsphere.sql.parser.sql.common.statement.ddl.AlterTablespaceStatement;
  import org.apache.shardingsphere.sql.parser.sql.common.statement.ddl.AlterViewStatement;
  import org.apache.shardingsphere.sql.parser.sql.common.statement.ddl.CreateFunctionStatement;
  import org.apache.shardingsphere.sql.parser.sql.common.statement.ddl.CreateProcedureStatement;
  import org.apache.shardingsphere.sql.parser.sql.common.statement.ddl.CreateTablespaceStatement;
  import org.apache.shardingsphere.sql.parser.sql.common.statement.ddl.CreateViewStatement;
  import org.apache.shardingsphere.sql.parser.sql.common.statement.ddl.DDLStatement;
  import org.apache.shardingsphere.sql.parser.sql.common.statement.ddl.DropFunctionStatement;
  import org.apache.shardingsphere.sql.parser.sql.common.statement.ddl.DropProcedureStatement;
  import org.apache.shardingsphere.sql.parser.sql.common.statement.ddl.DropTablespaceStatement;
  import org.apache.shardingsphere.sql.parser.sql.common.statement.ddl.DropViewStatement;
  import org.apache.shardingsphere.sql.parser.sql.common.statement.dml.DMLStatement;
  import org.apache.shardingsphere.sql.parser.sql.common.statement.tcl.TCLStatement;
  import org.apache.shardingsphere.sql.parser.sql.dialect.statement.mysql.dal.MySQLCreateResourceGroupStatement;
  import org.apache.shardingsphere.sql.parser.sql.dialect.statement.mysql.dal.MySQLOptimizeTableStatement;
  import org.apache.shardingsphere.sql.parser.sql.dialect.statement.mysql.dal.MySQLSetResourceGroupStatement;
  import org.apache.shardingsphere.sql.parser.sql.dialect.statement.mysql.dal.MySQLShowDatabasesStatement;
  import org.apache.shardingsphere.sql.parser.sql.dialect.statement.mysql.dal.MySQLUseStatement;
  import org.apache.shardingsphere.sqlfederation.rule.SQLFederationRule;
  
  import java.util.Collection;
  import java.util.stream.Collectors;
  
  /**
   * Sharding routing engine factory.
   */
  @NoArgsConstructor(access = AccessLevel.PRIVATE)
  public final class ShardingRouteEngineFactory {
      
      /**
       * Create new instance of routing engine.
       *
       * @param shardingRule sharding rule
       * @param database database
       * @param queryContext query context
       * @param shardingConditions shardingConditions
       * @param props ShardingSphere properties
       * @param connectionContext connection context
       * @param globalRuleMetaData global rule meta data
       * @return created instance
       */
      public static ShardingRouteEngine newInstance(final ShardingRule shardingRule, final ShardingSphereDatabase database, final QueryContext queryContext,
                                                    final ShardingConditions shardingConditions, final ConfigurationProperties props, final ConnectionContext connectionContext,
                                                    final RuleMetaData globalRuleMetaData) {
          SQLStatementContext sqlStatementContext = queryContext.getSqlStatementContext();
          SQLStatement sqlStatement = sqlStatementContext.getSqlStatement();
          if (sqlStatement instanceof TCLStatement) {
              return new ShardingDatabaseBroadcastRoutingEngine();
         }
         if (sqlStatement instanceof DDLStatement) {
             if (sqlStatementContext instanceof CursorAvailable) {
                 return getCursorRouteEngine(shardingRule, database, sqlStatementContext, queryContext.getHintValueContext(), shardingConditions, props);
             }
             return getDDLRoutingEngine(shardingRule, database, sqlStatementContext, connectionContext, globalRuleMetaData);
         }
         if (sqlStatement instanceof DALStatement) {
             return getDALRoutingEngine(shardingRule, database, sqlStatementContext, connectionContext);
         }
         if (sqlStatement instanceof DCLStatement) {
             return getDCLRoutingEngine(shardingRule, database, sqlStatementContext);
         }
         return getDQLRoutingEngine(shardingRule, database, sqlStatementContext, queryContext.getHintValueContext(), shardingConditions, props, connectionContext);
     }
     
     private static ShardingRouteEngine getDDLRoutingEngine(final ShardingRule shardingRule, final ShardingSphereDatabase database, final SQLStatementContext sqlStatementContext,
                                                            final ConnectionContext connectionContext, final RuleMetaData globalRuleMetaData) {
         SQLStatement sqlStatement = sqlStatementContext.getSqlStatement();
         boolean functionStatement = sqlStatement instanceof CreateFunctionStatement || sqlStatement instanceof AlterFunctionStatement || sqlStatement instanceof DropFunctionStatement;
         boolean procedureStatement = sqlStatement instanceof CreateProcedureStatement || sqlStatement instanceof AlterProcedureStatement || sqlStatement instanceof DropProcedureStatement;
         if (functionStatement || procedureStatement) {
             return new ShardingDatabaseBroadcastRoutingEngine();
         }
         if (sqlStatement instanceof CreateTablespaceStatement || sqlStatement instanceof AlterTablespaceStatement || sqlStatement instanceof DropTablespaceStatement) {
             return new ShardingInstanceBroadcastRoutingEngine(database.getResourceMetaData());
         }
         Collection<String> tableNames = sqlStatementContext instanceof TableAvailable
                 ? ((TableAvailable) sqlStatementContext).getAllTables().stream().map(each -> each.getTableName().getIdentifier().getValue()).collect(Collectors.toSet())
                 : sqlStatementContext.getTablesContext().getTableNames();
         Collection<String> shardingRuleTableNames = shardingRule.getShardingRuleTableNames(tableNames);
         // TODO remove this logic when jdbc adapter can support executing create logic view
         boolean sqlFederationEnabled = globalRuleMetaData.getSingleRule(SQLFederationRule.class).getConfiguration().isSqlFederationEnabled();
         if (sqlFederationEnabled && (sqlStatement instanceof CreateViewStatement || sqlStatement instanceof AlterViewStatement || sqlStatement instanceof DropViewStatement)) {
             return new ShardingUnicastRoutingEngine(sqlStatementContext, shardingRuleTableNames, connectionContext);
         }
         if (!tableNames.isEmpty() && shardingRuleTableNames.isEmpty()) {
             return new ShardingIgnoreRoutingEngine();
         }
         return new ShardingTableBroadcastRoutingEngine(database, sqlStatementContext, shardingRuleTableNames);
     }
     
     private static ShardingRouteEngine getCursorRouteEngine(final ShardingRule shardingRule, final ShardingSphereDatabase database, final SQLStatementContext sqlStatementContext,
                                                             final HintValueContext hintValueContext, final ShardingConditions shardingConditions, final ConfigurationProperties props) {
         if (sqlStatementContext instanceof CloseStatementContext && ((CloseStatementContext) sqlStatementContext).getSqlStatement().isCloseAll()) {
             return new ShardingDatabaseBroadcastRoutingEngine();
         }
         Collection<String> tableNames = sqlStatementContext.getTablesContext().getTableNames();
         Collection<String> logicTableNames = shardingRule.getShardingLogicTableNames(tableNames);
         boolean allBindingTables = logicTableNames.size() > 1 && shardingRule.isAllBindingTables(database, sqlStatementContext, logicTableNames);
         if (isShardingStandardQuery(shardingRule, logicTableNames, allBindingTables)) {
             return new ShardingStandardRoutingEngine(getLogicTableName(shardingConditions, logicTableNames), shardingConditions, sqlStatementContext, hintValueContext, props);
         }
         return new ShardingIgnoreRoutingEngine();
     }
     
     private static ShardingRouteEngine getDALRoutingEngine(final ShardingRule shardingRule, final ShardingSphereDatabase database, final SQLStatementContext sqlStatementContext,
                                                            final ConnectionContext connectionContext) {
         SQLStatement sqlStatement = sqlStatementContext.getSqlStatement();
         if (sqlStatement instanceof MySQLUseStatement) {
             return new ShardingIgnoreRoutingEngine();
         }
         if (sqlStatement instanceof SetStatement || sqlStatement instanceof ResetParameterStatement
                 || sqlStatement instanceof MySQLShowDatabasesStatement || sqlStatement instanceof LoadStatement) {
             return new ShardingDatabaseBroadcastRoutingEngine();
         }
         if (isResourceGroupStatement(sqlStatement)) {
             return new ShardingInstanceBroadcastRoutingEngine(database.getResourceMetaData());
         }
         Collection<String> tableNames = sqlStatementContext.getTablesContext().getTableNames();
         Collection<String> shardingRuleTableNames = shardingRule.getShardingRuleTableNames(tableNames);
         if (!tableNames.isEmpty() && shardingRuleTableNames.isEmpty()) {
             return new ShardingIgnoreRoutingEngine();
         }
         if (sqlStatement instanceof MySQLOptimizeTableStatement) {
             return new ShardingTableBroadcastRoutingEngine(database, sqlStatementContext, shardingRuleTableNames);
         }
         if (sqlStatement instanceof AnalyzeTableStatement) {
             return shardingRuleTableNames.isEmpty() ? new ShardingDatabaseBroadcastRoutingEngine()
                     : new ShardingTableBroadcastRoutingEngine(database, sqlStatementContext, shardingRuleTableNames);
         }
         if (!shardingRuleTableNames.isEmpty()) {
             return new ShardingUnicastRoutingEngine(sqlStatementContext, shardingRuleTableNames, connectionContext);
         }
         return new ShardingDataSourceGroupBroadcastRoutingEngine();
     }
     
     private static boolean isResourceGroupStatement(final SQLStatement sqlStatement) {
         // TODO add dropResourceGroupStatement, alterResourceGroupStatement
         return sqlStatement instanceof MySQLCreateResourceGroupStatement || sqlStatement instanceof MySQLSetResourceGroupStatement;
     }
     
     private static ShardingRouteEngine getDCLRoutingEngine(final ShardingRule shardingRule, final ShardingSphereDatabase database, final SQLStatementContext sqlStatementContext) {
         if (isDCLForSingleTable(sqlStatementContext)) {
             Collection<String> shardingRuleTableNames = shardingRule.getShardingRuleTableNames(sqlStatementContext.getTablesContext().getTableNames());
             return shardingRuleTableNames.isEmpty() ? new ShardingIgnoreRoutingEngine() : new ShardingTableBroadcastRoutingEngine(database, sqlStatementContext, shardingRuleTableNames);
         }
         return new ShardingInstanceBroadcastRoutingEngine(database.getResourceMetaData());
     }
     
     private static boolean isDCLForSingleTable(final SQLStatementContext sqlStatementContext) {
         if (sqlStatementContext instanceof TableAvailable) {
             TableAvailable tableSegmentsAvailable = (TableAvailable) sqlStatementContext;
             return 1 == tableSegmentsAvailable.getAllTables().size() && !"*".equals(tableSegmentsAvailable.getAllTables().iterator().next().getTableName().getIdentifier().getValue());
         }
         return false;
     }
     
     private static ShardingRouteEngine getDQLRoutingEngine(final ShardingRule shardingRule, final ShardingSphereDatabase database, final SQLStatementContext sqlStatementContext,
                                                            final HintValueContext hintValueContext, final ShardingConditions shardingConditions, final ConfigurationProperties props,
                                                            final ConnectionContext connectionContext) {
         Collection<String> tableNames = sqlStatementContext.getTablesContext().getTableNames();
         if (sqlStatementContext.getSqlStatement() instanceof DMLStatement && shardingConditions.isAlwaysFalse() || tableNames.isEmpty()) {
             return new ShardingUnicastRoutingEngine(sqlStatementContext, tableNames, connectionContext);
         }
         Collection<String> shardingLogicTableNames = shardingRule.getShardingLogicTableNames(tableNames);
         if (shardingLogicTableNames.isEmpty()) {
             return new ShardingIgnoreRoutingEngine();
         }
         return getDQLRouteEngineForShardingTable(shardingRule, database, sqlStatementContext, hintValueContext, shardingConditions, props, shardingLogicTableNames);
     }
     
     private static ShardingRouteEngine getDQLRouteEngineForShardingTable(final ShardingRule shardingRule, final ShardingSphereDatabase database,
                                                                          final SQLStatementContext sqlStatementContext, final HintValueContext hintValueContext,
                                                                          final ShardingConditions shardingConditions, final ConfigurationProperties props, final Collection<String> tableNames) {
         boolean allBindingTables = tableNames.size() > 1 && shardingRule.isAllBindingTables(database, sqlStatementContext, tableNames);
         if (isShardingStandardQuery(shardingRule, tableNames, allBindingTables)) {
             return new ShardingStandardRoutingEngine(getLogicTableName(shardingConditions, tableNames), shardingConditions, sqlStatementContext, hintValueContext, props);
         }
         // TODO config for cartesian set
         return new ShardingComplexRoutingEngine(shardingConditions, sqlStatementContext, hintValueContext, props, tableNames);
     }
     
     private static String getLogicTableName(final ShardingConditions shardingConditions, final Collection<String> tableNames) {
         if (shardingConditions.getConditions().isEmpty()) {
             return tableNames.iterator().next();
         }
         ShardingCondition shardingCondition = shardingConditions.getConditions().iterator().next();
         return shardingCondition.getValues().isEmpty() ? tableNames.iterator().next() : shardingCondition.getValues().iterator().next().getTableName();
     }
     
     private static boolean isShardingStandardQuery(final ShardingRule shardingRule, final Collection<String> tableNames, final boolean allBindingTables) {
         return 1 == tableNames.size() && shardingRule.isAllShardingTables(tableNames) || allBindingTables;
     }
 }