/*
 * 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.eigenbase.rex;

import java.util.*;

import org.eigenbase.sql.*;
import org.eigenbase.sql.parser.*;
import org.eigenbase.sql.type.*;
import org.eigenbase.util.*;

/**
 * Standard implementation of {@link RexToSqlNodeConverter}.
 */
public class RexToSqlNodeConverterImpl implements RexToSqlNodeConverter {
  //~ Instance fields --------------------------------------------------------

  private final RexSqlConvertletTable convertletTable;

  //~ Constructors -----------------------------------------------------------

  public RexToSqlNodeConverterImpl(RexSqlConvertletTable convertletTable) {
    this.convertletTable = convertletTable;
  }

  //~ Methods ----------------------------------------------------------------

  // implement RexToSqlNodeConverter
  public SqlNode convertNode(RexNode node) {
    if (node instanceof RexLiteral) {
      return convertLiteral((RexLiteral) node);
    } else if (node instanceof RexInputRef) {
      return convertInputRef((RexInputRef) node);
    } else if (node instanceof RexCall) {
      return convertCall((RexCall) node);
    }
    return null;
  }

  // implement RexToSqlNodeConverter
  public SqlNode convertCall(RexCall call) {
    final RexSqlConvertlet convertlet = convertletTable.get(call);
    if (convertlet != null) {
      return convertlet.convertCall(this, call);
    }

    return null;
  }

  // implement RexToSqlNodeConverter
  public SqlNode convertLiteral(RexLiteral literal) {
    // Numeric
    if (SqlTypeFamily.EXACT_NUMERIC.getTypeNames().contains(
        literal.getTypeName())) {
      return SqlLiteral.createExactNumeric(
          literal.getValue().toString(),
          SqlParserPos.ZERO);
    }

    if (SqlTypeFamily.APPROXIMATE_NUMERIC.getTypeNames().contains(
        literal.getTypeName())) {
      return SqlLiteral.createApproxNumeric(
          literal.getValue().toString(),
          SqlParserPos.ZERO);
    }

    // Timestamp
    if (SqlTypeFamily.TIMESTAMP.getTypeNames().contains(
        literal.getTypeName())) {
      return SqlLiteral.createTimestamp(
          (Calendar) literal.getValue(),
          0,
          SqlParserPos.ZERO);
    }

    // Date
    if (SqlTypeFamily.DATE.getTypeNames().contains(
        literal.getTypeName())) {
      return SqlLiteral.createDate(
          (Calendar) literal.getValue(),
          SqlParserPos.ZERO);
    }

    // String
    if (SqlTypeFamily.CHARACTER.getTypeNames().contains(
        literal.getTypeName())) {
      return SqlLiteral.createCharString(
          ((NlsString) (literal.getValue())).getValue(),
          SqlParserPos.ZERO);
    }

    // Boolean
    if (SqlTypeFamily.BOOLEAN.getTypeNames().contains(
        literal.getTypeName())) {
      return SqlLiteral.createBoolean(
          (Boolean) literal.getValue(),
          SqlParserPos.ZERO);
    }

    return null;
  }

  // implement RexToSqlNodeConverter
  public SqlNode convertInputRef(RexInputRef ref) {
    return null;
  }
}

// End RexToSqlNodeConverterImpl.java