/*
    * 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.sql92.visitor.statement.type;
  
  import org.apache.shardingsphere.sql.parser.api.ASTNode;
  import org.apache.shardingsphere.sql.parser.api.visitor.statement.type.DDLStatementVisitor;
  import org.apache.shardingsphere.sql.parser.autogen.SQL92StatementParser.AddColumnSpecificationContext;
  import org.apache.shardingsphere.sql.parser.autogen.SQL92StatementParser.AddConstraintSpecificationContext;
  import org.apache.shardingsphere.sql.parser.autogen.SQL92StatementParser.AlterDefinitionClauseContext;
  import org.apache.shardingsphere.sql.parser.autogen.SQL92StatementParser.AlterTableContext;
  import org.apache.shardingsphere.sql.parser.autogen.SQL92StatementParser.CheckConstraintDefinitionContext;
  import org.apache.shardingsphere.sql.parser.autogen.SQL92StatementParser.ColumnDefinitionContext;
  import org.apache.shardingsphere.sql.parser.autogen.SQL92StatementParser.ConstraintDefinitionContext;
  import org.apache.shardingsphere.sql.parser.autogen.SQL92StatementParser.ConstraintNameContext;
  import org.apache.shardingsphere.sql.parser.autogen.SQL92StatementParser.CreateDefinitionClauseContext;
  import org.apache.shardingsphere.sql.parser.autogen.SQL92StatementParser.CreateDefinitionContext;
  import org.apache.shardingsphere.sql.parser.autogen.SQL92StatementParser.CreateTableContext;
  import org.apache.shardingsphere.sql.parser.autogen.SQL92StatementParser.DataTypeOptionContext;
  import org.apache.shardingsphere.sql.parser.autogen.SQL92StatementParser.DropColumnSpecificationContext;
  import org.apache.shardingsphere.sql.parser.autogen.SQL92StatementParser.DropConstraintSpecificationContext;
  import org.apache.shardingsphere.sql.parser.autogen.SQL92StatementParser.DropTableContext;
  import org.apache.shardingsphere.sql.parser.autogen.SQL92StatementParser.ModifyColumnSpecificationContext;
  import org.apache.shardingsphere.sql.parser.sql.common.segment.ddl.AlterDefinitionSegment;
  import org.apache.shardingsphere.sql.parser.sql.common.segment.ddl.CreateDefinitionSegment;
  import org.apache.shardingsphere.sql.parser.sql.common.segment.ddl.column.ColumnDefinitionSegment;
  import org.apache.shardingsphere.sql.parser.sql.common.segment.ddl.column.alter.AddColumnDefinitionSegment;
  import org.apache.shardingsphere.sql.parser.sql.common.segment.ddl.column.alter.DropColumnDefinitionSegment;
  import org.apache.shardingsphere.sql.parser.sql.common.segment.ddl.column.alter.ModifyColumnDefinitionSegment;
  import org.apache.shardingsphere.sql.parser.sql.common.segment.ddl.constraint.ConstraintDefinitionSegment;
  import org.apache.shardingsphere.sql.parser.sql.common.segment.ddl.constraint.ConstraintSegment;
  import org.apache.shardingsphere.sql.parser.sql.common.segment.ddl.constraint.alter.AddConstraintDefinitionSegment;
  import org.apache.shardingsphere.sql.parser.sql.common.segment.ddl.constraint.alter.DropConstraintDefinitionSegment;
  import org.apache.shardingsphere.sql.parser.sql.common.segment.dml.column.ColumnSegment;
  import org.apache.shardingsphere.sql.parser.sql.common.segment.generic.DataTypeSegment;
  import org.apache.shardingsphere.sql.parser.sql.common.segment.generic.table.SimpleTableSegment;
  import org.apache.shardingsphere.sql.parser.sql.common.value.collection.CollectionValue;
  import org.apache.shardingsphere.sql.parser.sql.common.value.identifier.IdentifierValue;
  import org.apache.shardingsphere.sql.parser.sql.dialect.statement.sql92.ddl.SQL92AlterTableStatement;
  import org.apache.shardingsphere.sql.parser.sql.dialect.statement.sql92.ddl.SQL92CreateTableStatement;
  import org.apache.shardingsphere.sql.parser.sql.dialect.statement.sql92.ddl.SQL92DropTableStatement;
  import org.apache.shardingsphere.sql.parser.sql92.visitor.statement.SQL92StatementVisitor;
  
  import java.util.Collections;
  
  /**
   * DDL statement visitor for SQL92.
   */
  public final class SQL92DDLStatementVisitor extends SQL92StatementVisitor implements DDLStatementVisitor {
      
      @SuppressWarnings("unchecked")
      @Override
      public ASTNode visitCreateTable(final CreateTableContext ctx) {
          SQL92CreateTableStatement result = new SQL92CreateTableStatement();
          result.setTable((SimpleTableSegment) visit(ctx.tableName()));
          if (null != ctx.createDefinitionClause()) {
              CollectionValue<CreateDefinitionSegment> createDefinitions = (CollectionValue<CreateDefinitionSegment>) visit(ctx.createDefinitionClause());
              for (CreateDefinitionSegment each : createDefinitions.getValue()) {
                  if (each instanceof ColumnDefinitionSegment) {
                      result.getColumnDefinitions().add((ColumnDefinitionSegment) each);
                  } else if (each instanceof ConstraintDefinitionSegment) {
                      result.getConstraintDefinitions().add((ConstraintDefinitionSegment) each);
                  }
              }
          }
          return result;
      }
      
      @Override
      public ASTNode visitCreateDefinitionClause(final CreateDefinitionClauseContext ctx) {
          CollectionValue<CreateDefinitionSegment> result = new CollectionValue<>();
          for (CreateDefinitionContext each : ctx.createDefinition()) {
              if (null != each.columnDefinition()) {
                  result.getValue().add((ColumnDefinitionSegment) visit(each.columnDefinition()));
              }
              if (null != each.constraintDefinition()) {
                  result.getValue().add((ConstraintDefinitionSegment) visit(each.constraintDefinition()));
              }
              if (null != each.checkConstraintDefinition()) {
                  result.getValue().add((ConstraintDefinitionSegment) visit(each.checkConstraintDefinition()));
              }
          }
          return result;
      }
      
     @Override
     public ASTNode visitColumnDefinition(final ColumnDefinitionContext ctx) {
         ColumnSegment column = (ColumnSegment) visit(ctx.columnName());
         DataTypeSegment dataType = (DataTypeSegment) visit(ctx.dataType());
         boolean isPrimaryKey = ctx.dataTypeOption().stream().anyMatch(each -> null != each.primaryKey());
         // TODO parse not null
         ColumnDefinitionSegment result = new ColumnDefinitionSegment(ctx.getStart().getStartIndex(), ctx.getStop().getStopIndex(), column, dataType, isPrimaryKey, false);
         for (DataTypeOptionContext each : ctx.dataTypeOption()) {
             if (null != each.referenceDefinition()) {
                 result.getReferencedTables().add((SimpleTableSegment) visit(each.referenceDefinition().tableName()));
             }
         }
         return result;
     }
     
     @Override
     public ASTNode visitCheckConstraintDefinition(final CheckConstraintDefinitionContext ctx) {
         return new ConstraintDefinitionSegment(ctx.getStart().getStartIndex(), ctx.getStop().getStopIndex());
     }
     
     @Override
     public ASTNode visitAddConstraintSpecification(final AddConstraintSpecificationContext ctx) {
         return new AddConstraintDefinitionSegment(ctx.getStart().getStartIndex(), ctx.getStop().getStopIndex(), (ConstraintDefinitionSegment) visit(ctx.constraintDefinition()));
     }
     
     @Override
     public ASTNode visitDropConstraintSpecification(final DropConstraintSpecificationContext ctx) {
         return new DropConstraintDefinitionSegment(ctx.getStart().getStartIndex(), ctx.getStop().getStopIndex(), (ConstraintSegment) visit(ctx.constraintDefinition().constraintName()));
     }
     
     @SuppressWarnings("unchecked")
     @Override
     public ASTNode visitConstraintDefinition(final ConstraintDefinitionContext ctx) {
         ConstraintDefinitionSegment result = new ConstraintDefinitionSegment(ctx.getStart().getStartIndex(), ctx.getStop().getStopIndex());
         if (null != ctx.constraintName()) {
             result.setConstraintName((ConstraintSegment) visit(ctx.constraintName()));
         }
         if (null != ctx.primaryKeyOption()) {
             result.getPrimaryKeyColumns().addAll(((CollectionValue<ColumnSegment>) visit(ctx.primaryKeyOption().columnNames())).getValue());
         }
         if (null != ctx.foreignKeyOption()) {
             result.setReferencedTable((SimpleTableSegment) visit(ctx.foreignKeyOption().referenceDefinition().tableName()));
         }
         return result;
     }
     
     @Override
     public ASTNode visitConstraintName(final ConstraintNameContext ctx) {
         return new ConstraintSegment(ctx.getStart().getStartIndex(), ctx.getStop().getStopIndex(), (IdentifierValue) visit(ctx.identifier()));
     }
     
     @SuppressWarnings("unchecked")
     @Override
     public ASTNode visitAlterTable(final AlterTableContext ctx) {
         SQL92AlterTableStatement result = new SQL92AlterTableStatement();
         result.setTable((SimpleTableSegment) visit(ctx.tableName()));
         if (null != ctx.alterDefinitionClause()) {
             for (AlterDefinitionSegment each : ((CollectionValue<AlterDefinitionSegment>) visit(ctx.alterDefinitionClause())).getValue()) {
                 if (each instanceof AddColumnDefinitionSegment) {
                     result.getAddColumnDefinitions().add((AddColumnDefinitionSegment) each);
                 } else if (each instanceof ModifyColumnDefinitionSegment) {
                     result.getModifyColumnDefinitions().add((ModifyColumnDefinitionSegment) each);
                 } else if (each instanceof DropColumnDefinitionSegment) {
                     result.getDropColumnDefinitions().add((DropColumnDefinitionSegment) each);
                 } else if (each instanceof AddConstraintDefinitionSegment) {
                     result.getAddConstraintDefinitions().add((AddConstraintDefinitionSegment) each);
                 } else if (each instanceof DropConstraintDefinitionSegment) {
                     result.getDropConstraintDefinitions().add((DropConstraintDefinitionSegment) each);
                 }
             }
         }
         return result;
     }
     
     @SuppressWarnings("unchecked")
     @Override
     public ASTNode visitAlterDefinitionClause(final AlterDefinitionClauseContext ctx) {
         CollectionValue<AlterDefinitionSegment> result = new CollectionValue<>();
         if (null != ctx.addColumnSpecification()) {
             result.getValue().addAll(((CollectionValue<AddColumnDefinitionSegment>) visit(ctx.addColumnSpecification())).getValue());
         }
         if (null != ctx.modifyColumnSpecification()) {
             result.getValue().add((ModifyColumnDefinitionSegment) visit(ctx.modifyColumnSpecification()));
         }
         if (null != ctx.dropColumnSpecification()) {
             result.getValue().add((DropColumnDefinitionSegment) visit(ctx.dropColumnSpecification()));
         }
         return result;
     }
     
     @Override
     public ASTNode visitAddColumnSpecification(final AddColumnSpecificationContext ctx) {
         CollectionValue<AddColumnDefinitionSegment> result = new CollectionValue<>();
         AddColumnDefinitionSegment addColumnDefinition = new AddColumnDefinitionSegment(
                 ctx.columnDefinition().getStart().getStartIndex(), ctx.columnDefinition().getStop().getStopIndex(),
                 Collections.singletonList((ColumnDefinitionSegment) visit(ctx.columnDefinition())));
         result.getValue().add(addColumnDefinition);
         return result;
     }
     
     @Override
     public ASTNode visitModifyColumnSpecification(final ModifyColumnSpecificationContext ctx) {
         // TODO visit pk and table ref
         return new ModifyColumnDefinitionSegment(ctx.getStart().getStartIndex(), ctx.getStop().getStopIndex(), (ColumnDefinitionSegment) visit(ctx.columnDefinition()));
     }
     
     @Override
     public ASTNode visitDropColumnSpecification(final DropColumnSpecificationContext ctx) {
         return new DropColumnDefinitionSegment(ctx.getStart().getStartIndex(), ctx.getStop().getStopIndex(), Collections.singleton((ColumnSegment) visit(ctx.columnName())));
     }
     
     @SuppressWarnings("unchecked")
     @Override
     public ASTNode visitDropTable(final DropTableContext ctx) {
         SQL92DropTableStatement result = new SQL92DropTableStatement();
         result.getTables().addAll(((CollectionValue<SimpleTableSegment>) visit(ctx.tableNames())).getValue());
         return result;
     }
 }