/*******************************************************************************
 * Copyright (c) 2015-2018 Skymind, Inc.
 *
 * This program and the accompanying materials are made available under the
 * terms of the Apache License, Version 2.0 which is available at
 * https://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.
 *
 * SPDX-License-Identifier: Apache-2.0
 ******************************************************************************/

package org.datavec.api.util.jdbc;

import java.math.BigDecimal;
import java.sql.Types;

import org.datavec.api.writable.BooleanWritable;
import org.datavec.api.writable.DoubleWritable;
import org.datavec.api.writable.FloatWritable;
import org.datavec.api.writable.IntWritable;
import org.datavec.api.writable.LongWritable;
import org.datavec.api.writable.NullWritable;
import org.datavec.api.writable.Text;
import org.datavec.api.writable.Writable;

/**
 * Transform jdbc column data into Writable objects
 *
 * @author Adrien Plagnol
 */
public class JdbcWritableConverter {

    public static Writable convert(final Object columnValue, final int columnType) {
    	if (columnValue == null)
    		return new NullWritable();

    	switch (columnType) {
            case Types.BOOLEAN:
                return new BooleanWritable((boolean) columnValue);

            case Types.DATE:
            case Types.TIME:
            case Types.TIMESTAMP:
            case Types.CHAR:
            case Types.LONGVARCHAR:
            case Types.LONGNVARCHAR:
            case Types.NCHAR:
            case Types.NVARCHAR:
            case Types.VARCHAR:
                return new Text(columnValue.toString());

            case Types.FLOAT:
                return new FloatWritable((float) columnValue);
                
            case Types.REAL:
                return columnValue instanceof Float
                    ? new FloatWritable((float) columnValue)
                    : new DoubleWritable((double) columnValue);

            case Types.DECIMAL:
            case Types.NUMERIC:
                return new DoubleWritable(((BigDecimal) columnValue).doubleValue()); //!\ This may overflow

            case Types.DOUBLE:
                return new DoubleWritable((double) columnValue);

            case Types.INTEGER:
            case Types.SMALLINT:
            case Types.TINYINT:
                return new IntWritable((int) columnValue);

            case Types.BIT:
                return new BooleanWritable((boolean) columnValue);

            case Types.BIGINT:
                return new LongWritable((long) columnValue);

            default:
                throw new IllegalArgumentException("Column type unknown");
        }
    }

    private JdbcWritableConverter() {
    }
}
