/*
 * 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.streaming.connectors.pulsar.util;

import org.apache.flink.api.common.typeinfo.TypeInformation;
import org.apache.flink.api.java.typeutils.RowTypeInfo;
import org.apache.flink.types.Row;

import org.apache.commons.lang3.reflect.FieldUtils;

import java.lang.reflect.Field;
import java.lang.reflect.Modifier;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;

/** Tool class for getting document field types. */
public class TypeInformationUtils {

    /** Document Field Type Caching. */
    private static final Map<Class<?>, List<TypeInformation<?>>> typeInfoPerDocument =
            new ConcurrentHashMap<>();

    private static final Map<Class<?>, TypeInformation<Row>> rowInfoPerDocument =
            new ConcurrentHashMap<>();

    public static TypeInformation<Row> getTypesAsRow(Class<?> documentFormat) {
        return rowInfoPerDocument.computeIfAbsent(
                documentFormat,
                documentFormat1 -> {
                    List<TypeInformation<?>> columnTypes = getColumnTypes(documentFormat1);
                    TypeInformation<?>[] typeInfos = columnTypes.toArray(new TypeInformation[0]);
                    List<String> fieldNames = getFieldNames(documentFormat1);
                    return new RowTypeInfo(typeInfos, fieldNames.toArray(new String[0]));
                });
    }

    private static List<String> getFieldNames(Class<?> documentFormat) {
        List<Field> fields = FieldUtils.getAllFieldsList(documentFormat);
        List<String> fieldNames = new ArrayList<>();
        for (Field field : fields) {
            if (Modifier.isStatic(field.getModifiers())) {
                continue;
            }
            fieldNames.add(field.getName());
        }
        return fieldNames;
    }

    public static List<TypeInformation<?>> getColumnTypes(Class<?> documentFormat) {
        return typeInfoPerDocument.computeIfAbsent(
                documentFormat,
                documentFormat1 -> {
                    List<Field> fields = FieldUtils.getAllFieldsList(documentFormat1);
                    List<TypeInformation<?>> typeInfos = new ArrayList<>();
                    for (Field field : fields) {
                        if (Modifier.isStatic(field.getModifiers())) {
                            continue;
                        }
                        typeInfos.add(TypeInformation.of(field.getType()));
                    }
                    return typeInfos;
                });
    }
}
