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 * 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   *
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 *   http://www.apache.org/licenses/LICENSE-2.0                 *
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 * 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.mailbox.tools.indexer;

import java.time.Clock;
import java.time.Instant;
import java.util.Optional;

import javax.inject.Inject;

import org.apache.james.mailbox.MessageUid;
import org.apache.james.mailbox.model.MailboxId;
import org.apache.james.task.Task;
import org.apache.james.task.TaskExecutionDetails;
import org.apache.james.task.TaskType;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import reactor.core.publisher.Mono;

public class SingleMessageReindexingTask implements Task {
    private static final Logger LOGGER = LoggerFactory.getLogger(SingleMessageReindexingTask.class);

    public static final TaskType MESSAGE_RE_INDEXING = TaskType.of("message-reindexing");

    public static class AdditionalInformation implements TaskExecutionDetails.AdditionalInformation {
        private final MailboxId mailboxId;
        private final MessageUid uid;
        private final Instant timestamp;

        AdditionalInformation(MailboxId mailboxId, MessageUid uid, Instant timestamp) {
            this.mailboxId = mailboxId;
            this.uid = uid;
            this.timestamp = timestamp;
        }

        public String getMailboxId() {
            return mailboxId.serialize();
        }

        public long getUid() {
            return uid.asLong();
        }

        @Override
        public Instant timestamp() {
            return timestamp;
        }
    }

    public static class Factory {

        private final ReIndexerPerformer reIndexerPerformer;
        private final MailboxId.Factory mailboxIdFactory;

        @Inject
        public Factory(ReIndexerPerformer reIndexerPerformer, MailboxId.Factory mailboxIdFactory) {
            this.reIndexerPerformer = reIndexerPerformer;
            this.mailboxIdFactory = mailboxIdFactory;
        }

        public SingleMessageReindexingTask create(SingleMessageReindexingTaskDTO dto) {
            MailboxId mailboxId = mailboxIdFactory.fromString(dto.getMailboxId());
            MessageUid uid = MessageUid.of(dto.getUid());
            return new SingleMessageReindexingTask(reIndexerPerformer, mailboxId, uid);
        }
    }

    private final ReIndexerPerformer reIndexerPerformer;
    private final MailboxId mailboxId;
    private final MessageUid uid;

    @Inject
    SingleMessageReindexingTask(ReIndexerPerformer reIndexerPerformer, MailboxId mailboxId, MessageUid uid) {
        this.reIndexerPerformer = reIndexerPerformer;
        this.mailboxId = mailboxId;
        this.uid = uid;
    }

    @Override
    public Result run() {
        return reIndexerPerformer.reIndexSingleMessage(mailboxId, uid, new ReprocessingContext())
            .onErrorResume(e -> {
                LOGGER.warn("Error encountered while reindexing {} : {}", mailboxId, uid, e);
                return Mono.just(Result.PARTIAL);
            })
            .block();
    }

    MailboxId getMailboxId() {
        return mailboxId;
    }

    MessageUid getUid() {
        return uid;
    }

    @Override
    public TaskType type() {
        return MESSAGE_RE_INDEXING;
    }

    @Override
    public Optional<TaskExecutionDetails.AdditionalInformation> details() {
        return Optional.of(new AdditionalInformation(mailboxId, uid, Clock.systemUTC().instant()));
    }

}
