/*
 * 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.flink.connector.file.table;

import org.apache.flink.annotation.Internal;
import org.apache.flink.connector.file.src.FileSourceSplit;
import org.apache.flink.table.types.logical.LogicalType;
import org.apache.flink.table.utils.PartitionPathUtils;

import java.io.Serializable;
import java.util.LinkedHashMap;

/** Interface to extract partition field from split. */
@FunctionalInterface
@Internal
public interface PartitionFieldExtractor<T extends FileSourceSplit> extends Serializable {

    Object extract(T split, String fieldName, LogicalType fieldType);

    static PartitionFieldExtractor<FileSourceSplit> forFileSystem(String defaultPartValue) {
        return (split, fieldName, fieldType) -> {
            LinkedHashMap<String, String> partitionSpec =
                    PartitionPathUtils.extractPartitionSpecFromPath(split.path());
            if (!partitionSpec.containsKey(fieldName)) {
                throw new RuntimeException(
                        "Cannot find the partition value from path for partition: " + fieldName);
            }

            String valueStr = partitionSpec.get(fieldName);
            valueStr = valueStr.equals(defaultPartValue) ? null : valueStr;
            return RowPartitionComputer.restorePartValueFromType(valueStr, fieldType);
        };
    }
}
