/*
    * 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.data.pipeline.migration.distsql.parser.core;
  
  import com.google.common.base.Splitter;
  import org.antlr.v4.runtime.tree.ParseTree;
  import org.apache.shardingsphere.data.pipeline.migration.distsql.statement.updatable.CheckMigrationStatement;
  import org.apache.shardingsphere.data.pipeline.migration.distsql.statement.updatable.CommitMigrationStatement;
  import org.apache.shardingsphere.data.pipeline.migration.distsql.statement.updatable.DropMigrationCheckStatement;
  import org.apache.shardingsphere.data.pipeline.migration.distsql.statement.updatable.MigrateTableStatement;
  import org.apache.shardingsphere.data.pipeline.migration.distsql.statement.updatable.RegisterMigrationSourceStorageUnitStatement;
  import org.apache.shardingsphere.data.pipeline.migration.distsql.statement.updatable.RollbackMigrationStatement;
  import org.apache.shardingsphere.data.pipeline.migration.distsql.statement.queryable.ShowMigrationCheckStatusStatement;
  import org.apache.shardingsphere.data.pipeline.migration.distsql.statement.queryable.ShowMigrationListStatement;
  import org.apache.shardingsphere.data.pipeline.migration.distsql.statement.queryable.ShowMigrationRuleStatement;
  import org.apache.shardingsphere.data.pipeline.migration.distsql.statement.queryable.ShowMigrationSourceStorageUnitsStatement;
  import org.apache.shardingsphere.data.pipeline.migration.distsql.statement.queryable.ShowMigrationStatusStatement;
  import org.apache.shardingsphere.data.pipeline.migration.distsql.statement.updatable.StartMigrationCheckStatement;
  import org.apache.shardingsphere.data.pipeline.migration.distsql.statement.updatable.StartMigrationStatement;
  import org.apache.shardingsphere.data.pipeline.migration.distsql.statement.updatable.StopMigrationCheckStatement;
  import org.apache.shardingsphere.data.pipeline.migration.distsql.statement.updatable.StopMigrationStatement;
  import org.apache.shardingsphere.data.pipeline.migration.distsql.statement.updatable.UnregisterMigrationSourceStorageUnitStatement;
  import org.apache.shardingsphere.data.pipeline.migration.distsql.statement.pojo.SourceTargetEntry;
  import org.apache.shardingsphere.distsql.parser.autogen.MigrationDistSQLStatementBaseVisitor;
  import org.apache.shardingsphere.distsql.parser.autogen.MigrationDistSQLStatementParser;
  import org.apache.shardingsphere.distsql.parser.autogen.MigrationDistSQLStatementParser.AlgorithmDefinitionContext;
  import org.apache.shardingsphere.distsql.parser.autogen.MigrationDistSQLStatementParser.AlterMigrationRuleContext;
  import org.apache.shardingsphere.distsql.parser.autogen.MigrationDistSQLStatementParser.BatchSizeContext;
  import org.apache.shardingsphere.distsql.parser.autogen.MigrationDistSQLStatementParser.CheckMigrationContext;
  import org.apache.shardingsphere.distsql.parser.autogen.MigrationDistSQLStatementParser.CommitMigrationContext;
  import org.apache.shardingsphere.distsql.parser.autogen.MigrationDistSQLStatementParser.DropMigrationCheckContext;
  import org.apache.shardingsphere.distsql.parser.autogen.MigrationDistSQLStatementParser.MigrateTableContext;
  import org.apache.shardingsphere.distsql.parser.autogen.MigrationDistSQLStatementParser.PasswordContext;
  import org.apache.shardingsphere.distsql.parser.autogen.MigrationDistSQLStatementParser.PropertiesDefinitionContext;
  import org.apache.shardingsphere.distsql.parser.autogen.MigrationDistSQLStatementParser.PropertyContext;
  import org.apache.shardingsphere.distsql.parser.autogen.MigrationDistSQLStatementParser.RateLimiterContext;
  import org.apache.shardingsphere.distsql.parser.autogen.MigrationDistSQLStatementParser.ReadDefinitionContext;
  import org.apache.shardingsphere.distsql.parser.autogen.MigrationDistSQLStatementParser.RegisterMigrationSourceStorageUnitContext;
  import org.apache.shardingsphere.distsql.parser.autogen.MigrationDistSQLStatementParser.RollbackMigrationContext;
  import org.apache.shardingsphere.distsql.parser.autogen.MigrationDistSQLStatementParser.ShardingSizeContext;
  import org.apache.shardingsphere.distsql.parser.autogen.MigrationDistSQLStatementParser.ShowMigrationCheckAlgorithmsContext;
  import org.apache.shardingsphere.distsql.parser.autogen.MigrationDistSQLStatementParser.ShowMigrationCheckStatusContext;
  import org.apache.shardingsphere.distsql.parser.autogen.MigrationDistSQLStatementParser.ShowMigrationListContext;
  import org.apache.shardingsphere.distsql.parser.autogen.MigrationDistSQLStatementParser.ShowMigrationRuleContext;
  import org.apache.shardingsphere.distsql.parser.autogen.MigrationDistSQLStatementParser.ShowMigrationSourceStorageUnitsContext;
  import org.apache.shardingsphere.distsql.parser.autogen.MigrationDistSQLStatementParser.ShowMigrationStatusContext;
  import org.apache.shardingsphere.distsql.parser.autogen.MigrationDistSQLStatementParser.SourceTableNameContext;
  import org.apache.shardingsphere.distsql.parser.autogen.MigrationDistSQLStatementParser.StartMigrationCheckContext;
  import org.apache.shardingsphere.distsql.parser.autogen.MigrationDistSQLStatementParser.StartMigrationContext;
  import org.apache.shardingsphere.distsql.parser.autogen.MigrationDistSQLStatementParser.StopMigrationCheckContext;
  import org.apache.shardingsphere.distsql.parser.autogen.MigrationDistSQLStatementParser.StopMigrationContext;
  import org.apache.shardingsphere.distsql.parser.autogen.MigrationDistSQLStatementParser.StorageUnitDefinitionContext;
  import org.apache.shardingsphere.distsql.parser.autogen.MigrationDistSQLStatementParser.StreamChannelContext;
  import org.apache.shardingsphere.distsql.parser.autogen.MigrationDistSQLStatementParser.TargetTableNameContext;
  import org.apache.shardingsphere.distsql.parser.autogen.MigrationDistSQLStatementParser.TransmissionRuleContext;
  import org.apache.shardingsphere.distsql.parser.autogen.MigrationDistSQLStatementParser.UnregisterMigrationSourceStorageUnitContext;
  import org.apache.shardingsphere.distsql.parser.autogen.MigrationDistSQLStatementParser.WorkerThreadContext;
  import org.apache.shardingsphere.distsql.parser.autogen.MigrationDistSQLStatementParser.WriteDefinitionContext;
  import org.apache.shardingsphere.distsql.segment.AlgorithmSegment;
  import org.apache.shardingsphere.distsql.segment.DataSourceSegment;
  import org.apache.shardingsphere.distsql.segment.HostnameAndPortBasedDataSourceSegment;
  import org.apache.shardingsphere.distsql.segment.ReadOrWriteSegment;
  import org.apache.shardingsphere.distsql.segment.TransmissionRuleSegment;
  import org.apache.shardingsphere.distsql.segment.URLBasedDataSourceSegment;
  import org.apache.shardingsphere.distsql.statement.ral.queryable.show.ShowPluginsStatement;
  import org.apache.shardingsphere.data.pipeline.distsql.statement.updatable.AlterTransmissionRuleStatement;
  import org.apache.shardingsphere.infra.database.core.metadata.database.enums.QuoteCharacter;
  import org.apache.shardingsphere.infra.datanode.DataNode;
  import org.apache.shardingsphere.sql.parser.api.ASTNode;
  import org.apache.shardingsphere.sql.parser.api.visitor.SQLVisitor;
  import org.apache.shardingsphere.sql.parser.statement.core.value.identifier.IdentifierValue;
  
  import java.util.Collection;
  import java.util.Collections;
  import java.util.LinkedList;
  import java.util.List;
  import java.util.Properties;
  import java.util.stream.Collectors;
  
  /**
   * SQL statement visitor for migration DistSQL.
   */
  public final class MigrationDistSQLStatementVisitor extends MigrationDistSQLStatementBaseVisitor<ASTNode> implements SQLVisitor<ASTNode> {
      
     @Override
     public ASTNode visitShowMigrationRule(final ShowMigrationRuleContext ctx) {
         return new ShowMigrationRuleStatement();
     }
     
     @Override
     public ASTNode visitAlterMigrationRule(final AlterMigrationRuleContext ctx) {
         return new AlterTransmissionRuleStatement("MIGRATION", (TransmissionRuleSegment) visit(ctx.transmissionRule()));
     }
     
     @Override
     public ASTNode visitTransmissionRule(final TransmissionRuleContext ctx) {
         TransmissionRuleSegment result = new TransmissionRuleSegment();
         if (null != ctx.readDefinition()) {
             result.setReadSegment((ReadOrWriteSegment) visit(ctx.readDefinition()));
         }
         if (null != ctx.writeDefinition()) {
             result.setWriteSegment((ReadOrWriteSegment) visit(ctx.writeDefinition()));
         }
         if (null != ctx.streamChannel()) {
             result.setStreamChannel((AlgorithmSegment) visit(ctx.streamChannel()));
         }
         return result;
     }
     
     @Override
     public ASTNode visitReadDefinition(final ReadDefinitionContext ctx) {
         return new ReadOrWriteSegment(getWorkerThread(ctx.workerThread()), getBatchSize(ctx.batchSize()), getShardingSize(ctx.shardingSize()), getAlgorithmSegment(ctx.rateLimiter()));
     }
     
     @Override
     public ASTNode visitWriteDefinition(final WriteDefinitionContext ctx) {
         return new ReadOrWriteSegment(getWorkerThread(ctx.workerThread()), getBatchSize(ctx.batchSize()), getAlgorithmSegment(ctx.rateLimiter()));
     }
     
     private AlgorithmSegment getAlgorithmSegment(final RateLimiterContext ctx) {
         return null == ctx ? null : (AlgorithmSegment) visit(ctx);
     }
     
     @Override
     public ASTNode visitRateLimiter(final RateLimiterContext ctx) {
         return visit(ctx.algorithmDefinition());
     }
     
     @Override
     public ASTNode visitStreamChannel(final StreamChannelContext ctx) {
         return visit(ctx.algorithmDefinition());
     }
     
     private Integer getWorkerThread(final WorkerThreadContext ctx) {
         return null == ctx ? null : Integer.parseInt(ctx.intValue().getText());
     }
     
     private Integer getBatchSize(final BatchSizeContext ctx) {
         return null == ctx ? null : Integer.parseInt(ctx.intValue().getText());
     }
     
     private Integer getShardingSize(final ShardingSizeContext ctx) {
         return null == ctx ? null : Integer.parseInt(ctx.intValue().getText());
     }
     
     @Override
     public ASTNode visitMigrateTable(final MigrateTableContext ctx) {
         SourceTargetEntry sourceTargetEntry = buildSourceTargetEntry(ctx.sourceTableName(), ctx.targetTableName());
         return new MigrateTableStatement(Collections.singletonList(sourceTargetEntry), sourceTargetEntry.getTargetDatabaseName());
     }
     
     private SourceTargetEntry buildSourceTargetEntry(final SourceTableNameContext sourceContext, final TargetTableNameContext targetContext) {
         List<String> source = Splitter.on('.').splitToList(getRequiredIdentifierValue(sourceContext));
         List<String> target = Splitter.on('.').splitToList(getRequiredIdentifierValue(targetContext));
         String sourceResourceName = source.get(0);
         String sourceSchemaName = 3 == source.size() ? source.get(1) : null;
         String sourceTableName = source.get(source.size() - 1);
         String targetDatabaseName = target.size() > 1 ? target.get(0) : null;
         String targetTableName = target.get(target.size() - 1);
         SourceTargetEntry result = new SourceTargetEntry(targetDatabaseName, new DataNode(sourceResourceName, sourceTableName), targetTableName);
         result.getSource().setSchemaName(sourceSchemaName);
         return result;
     }
     
     private String getRequiredIdentifierValue(final ParseTree context) {
         return new IdentifierValue(context.getText()).getValue();
     }
     
     @Override
     public ASTNode visitShowMigrationList(final ShowMigrationListContext ctx) {
         return new ShowMigrationListStatement();
     }
     
     @Override
     public ASTNode visitShowMigrationStatus(final ShowMigrationStatusContext ctx) {
         return new ShowMigrationStatusStatement(getRequiredIdentifierValue(ctx.jobId()));
     }
     
     @Override
     public ASTNode visitStartMigration(final StartMigrationContext ctx) {
         return new StartMigrationStatement(getRequiredIdentifierValue(ctx.jobId()));
     }
     
     @Override
     public ASTNode visitStopMigration(final StopMigrationContext ctx) {
         return new StopMigrationStatement(getRequiredIdentifierValue(ctx.jobId()));
     }
     
     @Override
     public ASTNode visitRollbackMigration(final RollbackMigrationContext ctx) {
         return new RollbackMigrationStatement(getRequiredIdentifierValue(ctx.jobId()));
     }
     
     @Override
     public ASTNode visitCommitMigration(final CommitMigrationContext ctx) {
         return new CommitMigrationStatement(getRequiredIdentifierValue(ctx.jobId()));
     }
     
     @Override
     public ASTNode visitCheckMigration(final CheckMigrationContext ctx) {
         return new CheckMigrationStatement(getRequiredIdentifierValue(ctx.jobId()), null == ctx.algorithmDefinition() ? null : (AlgorithmSegment) visit(ctx.algorithmDefinition()));
     }
     
     @Override
     public ASTNode visitShowMigrationCheckAlgorithms(final ShowMigrationCheckAlgorithmsContext ctx) {
         return new ShowPluginsStatement("MIGRATION_CHECK");
     }
     
     @Override
     public ASTNode visitAlgorithmDefinition(final AlgorithmDefinitionContext ctx) {
         return new AlgorithmSegment(getIdentifierValue(ctx.algorithmTypeName()), getProperties(ctx.propertiesDefinition()));
     }
     
     private String getIdentifierValue(final ParseTree context) {
         return new IdentifierValue(context.getText()).getValue();
     }
     
     @Override
     public ASTNode visitStorageUnitDefinition(final MigrationDistSQLStatementParser.StorageUnitDefinitionContext ctx) {
         String user = getIdentifierValue(ctx.user());
         String password = null == ctx.password() ? "" : getPassword(ctx.password());
         Properties props = getProperties(ctx.propertiesDefinition());
         return null == ctx.urlSource()
                 ? new HostnameAndPortBasedDataSourceSegment(getIdentifierValue(ctx.storageUnitName()),
                         getIdentifierValue(ctx.simpleSource().hostname()), ctx.simpleSource().port().getText(), getIdentifierValue(ctx.simpleSource().dbName()), user, password, props)
                 : new URLBasedDataSourceSegment(getIdentifierValue(ctx.storageUnitName()), getIdentifierValue(ctx.urlSource().url()), user, password, props);
     }
     
     private String getPassword(final PasswordContext ctx) {
         return getIdentifierValue(ctx);
     }
     
     private Properties getProperties(final PropertiesDefinitionContext ctx) {
         Properties result = new Properties();
         if (null == ctx || null == ctx.properties()) {
             return result;
         }
         for (PropertyContext each : ctx.properties().property()) {
             result.setProperty(QuoteCharacter.unwrapAndTrimText(each.key.getText()), QuoteCharacter.unwrapAndTrimText(each.value.getText()));
         }
         return result;
     }
     
     @Override
     public ASTNode visitRegisterMigrationSourceStorageUnit(final RegisterMigrationSourceStorageUnitContext ctx) {
         Collection<DataSourceSegment> dataSources = new LinkedList<>();
         for (StorageUnitDefinitionContext each : ctx.storageUnitDefinition()) {
             dataSources.add((DataSourceSegment) visit(each));
         }
         return new RegisterMigrationSourceStorageUnitStatement(dataSources);
     }
     
     @Override
     public ASTNode visitUnregisterMigrationSourceStorageUnit(final UnregisterMigrationSourceStorageUnitContext ctx) {
         return new UnregisterMigrationSourceStorageUnitStatement(ctx.storageUnitName().stream().map(ParseTree::getText).map(each -> new IdentifierValue(each).getValue()).collect(Collectors.toList()));
     }
     
     @Override
     public ASTNode visitShowMigrationSourceStorageUnits(final ShowMigrationSourceStorageUnitsContext ctx) {
         return new ShowMigrationSourceStorageUnitsStatement();
     }
     
     @Override
     public ASTNode visitShowMigrationCheckStatus(final ShowMigrationCheckStatusContext ctx) {
         return new ShowMigrationCheckStatusStatement(getRequiredIdentifierValue(ctx.jobId()));
     }
     
     @Override
     public ASTNode visitStartMigrationCheck(final StartMigrationCheckContext ctx) {
         return new StartMigrationCheckStatement(getRequiredIdentifierValue(ctx.jobId()));
     }
     
     @Override
     public ASTNode visitStopMigrationCheck(final StopMigrationCheckContext ctx) {
         return new StopMigrationCheckStatement(getRequiredIdentifierValue(ctx.jobId()));
     }
     
     @Override
     public ASTNode visitDropMigrationCheck(final DropMigrationCheckContext ctx) {
         return new DropMigrationCheckStatement(getRequiredIdentifierValue(ctx.jobId()));
     }
 }