/*
    * 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.sql.parser.mysql.visitor.statement.type;
  
  import org.antlr.v4.runtime.Token;
  import org.apache.shardingsphere.sql.parser.api.ASTNode;
  import org.apache.shardingsphere.sql.parser.api.visitor.statement.type.TCLStatementVisitor;
  import org.apache.shardingsphere.sql.parser.autogen.MySQLStatementParser.BeginTransactionContext;
  import org.apache.shardingsphere.sql.parser.autogen.MySQLStatementParser.CommitContext;
  import org.apache.shardingsphere.sql.parser.autogen.MySQLStatementParser.IsolationTypesContext;
  import org.apache.shardingsphere.sql.parser.autogen.MySQLStatementParser.OptionTypeContext;
  import org.apache.shardingsphere.sql.parser.autogen.MySQLStatementParser.ReleaseSavepointContext;
  import org.apache.shardingsphere.sql.parser.autogen.MySQLStatementParser.RollbackContext;
  import org.apache.shardingsphere.sql.parser.autogen.MySQLStatementParser.SavepointContext;
  import org.apache.shardingsphere.sql.parser.autogen.MySQLStatementParser.SetAutoCommitContext;
  import org.apache.shardingsphere.sql.parser.autogen.MySQLStatementParser.SetTransactionContext;
  import org.apache.shardingsphere.sql.parser.autogen.MySQLStatementParser.TransactionAccessModeContext;
  import org.apache.shardingsphere.sql.parser.autogen.MySQLStatementParser.XaBeginContext;
  import org.apache.shardingsphere.sql.parser.autogen.MySQLStatementParser.XaCommitContext;
  import org.apache.shardingsphere.sql.parser.autogen.MySQLStatementParser.XaEndContext;
  import org.apache.shardingsphere.sql.parser.autogen.MySQLStatementParser.XaPrepareContext;
  import org.apache.shardingsphere.sql.parser.autogen.MySQLStatementParser.XaRecoveryContext;
  import org.apache.shardingsphere.sql.parser.autogen.MySQLStatementParser.XaRollbackContext;
  import org.apache.shardingsphere.sql.parser.mysql.visitor.statement.MySQLStatementVisitor;
  import org.apache.shardingsphere.sql.parser.statement.core.enums.OperationScope;
  import org.apache.shardingsphere.sql.parser.statement.core.enums.TransactionAccessType;
  import org.apache.shardingsphere.sql.parser.statement.core.enums.TransactionIsolationLevel;
  import org.apache.shardingsphere.sql.parser.statement.core.segment.tcl.AutoCommitSegment;
  import org.apache.shardingsphere.sql.parser.statement.core.statement.tcl.BeginTransactionStatement;
  import org.apache.shardingsphere.sql.parser.statement.core.statement.tcl.CommitStatement;
  import org.apache.shardingsphere.sql.parser.statement.core.statement.tcl.ReleaseSavepointStatement;
  import org.apache.shardingsphere.sql.parser.statement.core.statement.tcl.RollbackStatement;
  import org.apache.shardingsphere.sql.parser.statement.core.statement.tcl.SavepointStatement;
  import org.apache.shardingsphere.sql.parser.statement.core.statement.tcl.SetAutoCommitStatement;
  import org.apache.shardingsphere.sql.parser.statement.core.statement.tcl.SetTransactionStatement;
  import org.apache.shardingsphere.sql.parser.statement.core.statement.tcl.xa.XABeginStatement;
  import org.apache.shardingsphere.sql.parser.statement.core.statement.tcl.xa.XACommitStatement;
  import org.apache.shardingsphere.sql.parser.statement.core.statement.tcl.xa.XAEndStatement;
  import org.apache.shardingsphere.sql.parser.statement.core.statement.tcl.xa.XAPrepareStatement;
  import org.apache.shardingsphere.sql.parser.statement.core.statement.tcl.xa.XARecoveryStatement;
  import org.apache.shardingsphere.sql.parser.statement.core.statement.tcl.xa.XARollbackStatement;
  import org.apache.shardingsphere.sql.parser.statement.core.value.identifier.IdentifierValue;
  
  /**
   * TCL statement visitor for MySQL.
   */
  public final class MySQLTCLStatementVisitor extends MySQLStatementVisitor implements TCLStatementVisitor {
      
      @Override
      public ASTNode visitSetTransaction(final SetTransactionContext ctx) {
          return new SetTransactionStatement(getOperationScope(ctx.optionType()),
                  getTransactionIsolationLevel(null == ctx.transactionCharacteristics().isolationLevel() ? null : ctx.transactionCharacteristics().isolationLevel().isolationTypes()),
                  getTransactionAccessType(ctx.transactionCharacteristics().transactionAccessMode()));
      }
      
      private OperationScope getOperationScope(final OptionTypeContext ctx) {
          if (null == ctx) {
              return null;
          }
          if (null != ctx.SESSION()) {
              return OperationScope.SESSION;
          }
          if (null != ctx.GLOBAL()) {
              return OperationScope.GLOBAL;
          }
          return null;
      }
      
      private TransactionIsolationLevel getTransactionIsolationLevel(final IsolationTypesContext ctx) {
          if (null == ctx) {
              return null;
          }
          if (null != ctx.SERIALIZABLE()) {
              return TransactionIsolationLevel.SERIALIZABLE;
          }
          if (null != ctx.COMMITTED()) {
              return TransactionIsolationLevel.READ_COMMITTED;
          }
          if (null != ctx.UNCOMMITTED()) {
              return TransactionIsolationLevel.READ_UNCOMMITTED;
          }
          if (null != ctx.REPEATABLE()) {
              return TransactionIsolationLevel.REPEATABLE_READ;
          }
         return null;
     }
     
     private TransactionAccessType getTransactionAccessType(final TransactionAccessModeContext ctx) {
         if (null == ctx) {
             return null;
         }
         if (null != ctx.ONLY()) {
             return TransactionAccessType.READ_ONLY;
         }
         if (null != ctx.WRITE()) {
             return TransactionAccessType.READ_WRITE;
         }
         return null;
     }
     
     @Override
     public ASTNode visitSetAutoCommit(final SetAutoCommitContext ctx) {
         return new SetAutoCommitStatement(generateAutoCommitSegment(ctx.autoCommitValue).isAutoCommit());
     }
     
     private AutoCommitSegment generateAutoCommitSegment(final Token ctx) {
         boolean autoCommit = "1".equals(ctx.getText()) || "ON".equals(ctx.getText());
         return new AutoCommitSegment(ctx.getStartIndex(), ctx.getStopIndex(), autoCommit);
     }
     
     @Override
     public ASTNode visitBeginTransaction(final BeginTransactionContext ctx) {
         return new BeginTransactionStatement();
     }
     
     @Override
     public ASTNode visitCommit(final CommitContext ctx) {
         return new CommitStatement();
     }
     
     @Override
     public ASTNode visitRollback(final RollbackContext ctx) {
         return null == ctx.identifier() ? new RollbackStatement() : new RollbackStatement(((IdentifierValue) visit(ctx.identifier())).getValue());
     }
     
     @Override
     public ASTNode visitSavepoint(final SavepointContext ctx) {
         return new SavepointStatement(((IdentifierValue) visit(ctx.identifier())).getValue());
     }
     
     @Override
     public ASTNode visitReleaseSavepoint(final ReleaseSavepointContext ctx) {
         return new ReleaseSavepointStatement(((IdentifierValue) visit(ctx.identifier())).getValue());
     }
     
     @Override
     public ASTNode visitXaBegin(final XaBeginContext ctx) {
         return new XABeginStatement(ctx.xid().getText());
     }
     
     @Override
     public ASTNode visitXaPrepare(final XaPrepareContext ctx) {
         return new XAPrepareStatement(ctx.xid().getText());
     }
     
     @Override
     public ASTNode visitXaCommit(final XaCommitContext ctx) {
         return new XACommitStatement(ctx.xid().getText());
     }
     
     @Override
     public ASTNode visitXaRollback(final XaRollbackContext ctx) {
         return new XARollbackStatement(ctx.xid().getText());
     }
     
     @Override
     public ASTNode visitXaEnd(final XaEndContext ctx) {
         return new XAEndStatement(ctx.xid().getText());
     }
     
     @Override
     public ASTNode visitXaRecovery(final XaRecoveryContext ctx) {
         return new XARecoveryStatement();
     }
 }