/*
 * 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.kafka.common.requests;

import org.apache.kafka.common.TopicPartition;
import org.apache.kafka.common.protocol.ApiKeys;
import org.apache.kafka.common.protocol.Errors;
import org.apache.kafka.common.protocol.types.Struct;
import org.apache.kafka.common.utils.CollectionUtils;

import java.nio.ByteBuffer;
import java.util.HashMap;
import java.util.Map;

public class WriteTxnMarkersResponse extends AbstractResponse {
    private static final String TXN_MARKER_ENTRY_KEY_NAME = "transaction_markers";

    private static final String PRODUCER_ID_KEY_NAME = "producer_id";
    private static final String TOPIC_PARTITIONS_KEY_NAME = "topics";
    private static final String PARTITIONS_KEY_NAME = "partitions";
    private static final String TOPIC_KEY_NAME = "topic";
    private static final String PARTITION_KEY_NAME = "partition";
    private static final String ERROR_CODE_KEY_NAME = "error_code";

    // Possible error codes:
    //   CorruptRecord
    //   InvalidProducerEpoch
    //   UnknownTopicOrPartition
    //   NotLeaderForPartition
    //   MessageTooLarge
    //   RecordListTooLarge
    //   NotEnoughReplicas
    //   NotEnoughReplicasAfterAppend
    //   InvalidRequiredAcks
    //   TransactionCoordinatorFenced
    //   RequestTimeout

    private final Map<Long, Map<TopicPartition, Errors>> errors;

    public WriteTxnMarkersResponse(Map<Long, Map<TopicPartition, Errors>> errors) {
        this.errors = errors;
    }

    public WriteTxnMarkersResponse(Struct struct) {
        Map<Long, Map<TopicPartition, Errors>> errors = new HashMap<>();

        Object[] responseArray = struct.getArray(TXN_MARKER_ENTRY_KEY_NAME);
        for (Object responseObj : responseArray) {
            Struct responseStruct = (Struct) responseObj;

            long producerId = responseStruct.getLong(PRODUCER_ID_KEY_NAME);

            Map<TopicPartition, Errors> errorPerPartition = new HashMap<>();
            Object[] topicPartitionsArray = responseStruct.getArray(TOPIC_PARTITIONS_KEY_NAME);
            for (Object topicPartitionObj : topicPartitionsArray) {
                Struct topicPartitionStruct = (Struct) topicPartitionObj;
                String topic = topicPartitionStruct.getString(TOPIC_KEY_NAME);
                for (Object partitionObj : topicPartitionStruct.getArray(PARTITIONS_KEY_NAME)) {
                    Struct partitionStruct = (Struct) partitionObj;
                    Integer partition = partitionStruct.getInt(PARTITION_KEY_NAME);
                    Errors error = Errors.forCode(partitionStruct.getShort(ERROR_CODE_KEY_NAME));
                    errorPerPartition.put(new TopicPartition(topic, partition), error);
                }
            }
            errors.put(producerId, errorPerPartition);
        }

        this.errors = errors;
    }

    @Override
    protected Struct toStruct(short version) {
        Struct struct = new Struct(ApiKeys.WRITE_TXN_MARKERS.responseSchema(version));

        Object[] responsesArray = new Object[errors.size()];
        int k = 0;
        for (Map.Entry<Long, Map<TopicPartition, Errors>> responseEntry : errors.entrySet()) {
            Struct responseStruct = struct.instance(TXN_MARKER_ENTRY_KEY_NAME);
            responseStruct.set(PRODUCER_ID_KEY_NAME, responseEntry.getKey());

            Map<TopicPartition, Errors> partitionAndErrors = responseEntry.getValue();
            Map<String, Map<Integer, Errors>> mappedPartitions = CollectionUtils.groupDataByTopic(partitionAndErrors);
            Object[] partitionsArray = new Object[mappedPartitions.size()];
            int i = 0;
            for (Map.Entry<String, Map<Integer, Errors>> topicAndPartitions : mappedPartitions.entrySet()) {
                Struct topicPartitionsStruct = responseStruct.instance(TOPIC_PARTITIONS_KEY_NAME);
                topicPartitionsStruct.set(TOPIC_KEY_NAME, topicAndPartitions.getKey());
                Map<Integer, Errors> partitionIdAndErrors = topicAndPartitions.getValue();

                Object[] partitionAndErrorsArray = new Object[partitionIdAndErrors.size()];
                int j = 0;
                for (Map.Entry<Integer, Errors> partitionAndError : partitionIdAndErrors.entrySet()) {
                    Struct partitionAndErrorStruct = topicPartitionsStruct.instance(PARTITIONS_KEY_NAME);
                    partitionAndErrorStruct.set(PARTITION_KEY_NAME, partitionAndError.getKey());
                    partitionAndErrorStruct.set(ERROR_CODE_KEY_NAME, partitionAndError.getValue().code());
                    partitionAndErrorsArray[j++] = partitionAndErrorStruct;
                }
                topicPartitionsStruct.set(PARTITIONS_KEY_NAME, partitionAndErrorsArray);
                partitionsArray[i++] = topicPartitionsStruct;
            }
            responseStruct.set(TOPIC_PARTITIONS_KEY_NAME, partitionsArray);

            responsesArray[k++] = responseStruct;
        }

        struct.set(TXN_MARKER_ENTRY_KEY_NAME, responsesArray);
        return struct;
    }

    public Map<TopicPartition, Errors> errors(long producerId) {
        return errors.get(producerId);
    }

    public static WriteTxnMarkersResponse parse(ByteBuffer buffer, short version) {
        return new WriteTxnMarkersResponse(ApiKeys.WRITE_TXN_MARKERS.parseResponse(version, buffer));
    }

}