/*
 * 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.seatunnel.connectors.seatunnel.amazondynamodb.source;

import org.apache.seatunnel.api.source.Collector;
import org.apache.seatunnel.api.table.type.SeaTunnelRow;
import org.apache.seatunnel.api.table.type.SeaTunnelRowType;
import org.apache.seatunnel.connectors.seatunnel.amazondynamodb.config.AmazonDynamoDBSourceOptions;
import org.apache.seatunnel.connectors.seatunnel.amazondynamodb.serialize.DefaultSeaTunnelRowDeserializer;
import org.apache.seatunnel.connectors.seatunnel.amazondynamodb.serialize.SeaTunnelRowDeserializer;
import org.apache.seatunnel.connectors.seatunnel.common.source.AbstractSingleSplitReader;
import org.apache.seatunnel.connectors.seatunnel.common.source.SingleSplitReaderContext;

import lombok.extern.slf4j.Slf4j;
import software.amazon.awssdk.auth.credentials.AwsBasicCredentials;
import software.amazon.awssdk.auth.credentials.StaticCredentialsProvider;
import software.amazon.awssdk.regions.Region;
import software.amazon.awssdk.services.dynamodb.DynamoDbClient;
import software.amazon.awssdk.services.dynamodb.model.ScanRequest;
import software.amazon.awssdk.services.dynamodb.model.ScanResponse;

import java.io.IOException;
import java.net.URI;

@Slf4j
public class AmazonDynamoDBSourceReader extends AbstractSingleSplitReader<SeaTunnelRow> {

    protected DynamoDbClient dynamoDbClient;
    protected SingleSplitReaderContext context;
    protected AmazonDynamoDBSourceOptions amazondynamodbSourceOptions;
    protected SeaTunnelRowDeserializer seaTunnelRowDeserializer;

    public AmazonDynamoDBSourceReader(
            SingleSplitReaderContext context,
            AmazonDynamoDBSourceOptions amazondynamodbSourceOptions,
            SeaTunnelRowType typeInfo) {
        this.context = context;
        this.amazondynamodbSourceOptions = amazondynamodbSourceOptions;
        this.seaTunnelRowDeserializer = new DefaultSeaTunnelRowDeserializer(typeInfo);
    }

    @Override
    public void open() throws Exception {
        dynamoDbClient =
                DynamoDbClient.builder()
                        .endpointOverride(URI.create(amazondynamodbSourceOptions.getUrl()))
                        // The region is meaningless for local DynamoDb but required for client
                        // builder validation
                        .region(Region.of(amazondynamodbSourceOptions.getRegion()))
                        .credentialsProvider(
                                StaticCredentialsProvider.create(
                                        AwsBasicCredentials.create(
                                                amazondynamodbSourceOptions.getAccessKeyId(),
                                                amazondynamodbSourceOptions.getSecretAccessKey())))
                        .build();
    }

    @Override
    public void close() throws IOException {
        dynamoDbClient.close();
    }

    @Override
    @SuppressWarnings("magicnumber")
    public void pollNext(Collector<SeaTunnelRow> output) throws Exception {
        ScanResponse scan =
                dynamoDbClient.scan(
                        ScanRequest.builder()
                                .tableName(amazondynamodbSourceOptions.getTable())
                                .build());
        if (scan.hasItems()) {
            scan.items()
                    .forEach(
                            item -> {
                                output.collect(seaTunnelRowDeserializer.deserialize(item));
                            });
        }
        context.signalNoMoreElement();
    }
}
