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TRAC D.A.P. data library, interfaces and core functionality for working with primary data

There is a newer version: 0.7.0

/*
 * Copyright 2022 Accenture Global Solutions Limited
 *
 * Licensed 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.finos.tracdap.common.codec.csv;

import org.finos.tracdap.common.exception.EDataTypeNotSupported;
import com.fasterxml.jackson.dataformat.csv.CsvSchema;
import org.apache.arrow.vector.types.pojo.ArrowType.ArrowTypeID;
import org.apache.arrow.vector.types.pojo.Schema;

import java.util.Map;


public class CsvSchemaMapping {

    private static final Map ARROW_CSV_TYPE_MAPPING = Map.ofEntries(
            Map.entry(ArrowTypeID.Bool, CsvSchema.ColumnType.BOOLEAN),
            Map.entry(ArrowTypeID.Int, CsvSchema.ColumnType.NUMBER),
            Map.entry(ArrowTypeID.FloatingPoint, CsvSchema.ColumnType.NUMBER),
            Map.entry(ArrowTypeID.Decimal, CsvSchema.ColumnType.NUMBER_OR_STRING),
            Map.entry(ArrowTypeID.Utf8, CsvSchema.ColumnType.STRING),
            Map.entry(ArrowTypeID.Date, CsvSchema.ColumnType.STRING),
            Map.entry(ArrowTypeID.Timestamp, CsvSchema.ColumnType.STRING));

    public static CsvSchema.Builder arrowToCsv(Schema arrowSchema) {

        var csvSchema = CsvSchema.builder();

        for (var arrowField : arrowSchema.getFields()) {

            var fieldName = arrowField.getName();
            var arrowType = arrowField.getType().getTypeID();
            var csvType = ARROW_CSV_TYPE_MAPPING.get(arrowType);

            if (csvType == null) {

                var err = String.format(
                        "Data type not supported for field: [%s] %s",
                        arrowField.getName(), arrowField.getType());

                throw new EDataTypeNotSupported(err);
            }

            csvSchema.addColumn(fieldName, csvType);
        }

        return csvSchema;
    }
}