server/protocols/webadmin/webadmin-mailqueue/src/main/java/org/apache/james/webadmin/service/DeleteMailsFromMailQueueTask.java

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package org.apache.james.webadmin.service;

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

import org.apache.james.core.MailAddress;
import org.apache.james.queue.api.MailQueue;
import org.apache.james.queue.api.ManageableMailQueue;
import org.apache.james.task.Task;
import org.apache.james.task.TaskExecutionDetails;
import org.apache.james.task.TaskType;

import com.github.fge.lambdas.Throwing;
import com.google.common.base.Preconditions;
import com.google.common.primitives.Booleans;

public class DeleteMailsFromMailQueueTask implements Task {

    public static class AdditionalInformation implements TaskExecutionDetails.AdditionalInformation {
        private final String mailQueueName;
        private final long remainingCount;
        private final long initialCount;

        private final Optional<String> sender;
        private final Optional<String> name;
        private final Optional<String> recipient;
        private final Instant timestamp;

        public AdditionalInformation(String mailQueueName, long initialCount, long remainingCount,
                                     Optional<MailAddress> maybeSender, Optional<String> maybeName,
                                     Optional<MailAddress> maybeRecipient, Instant timestamp) {
            this.mailQueueName = mailQueueName;
            this.initialCount = initialCount;
            this.remainingCount = remainingCount;

            sender = maybeSender.map(MailAddress::asString);
            name = maybeName;
            recipient = maybeRecipient.map(MailAddress::asString);
            this.timestamp = timestamp;
        }

        public String getMailQueueName() {
            return mailQueueName;
        }

        public long getRemainingCount() {
            return remainingCount;
        }

        public long getInitialCount() {
            return initialCount;
        }

        public Optional<String> getSender() {
            return sender;
        }

        public Optional<String> getName() {
            return name;
        }

        public Optional<String> getRecipient() {
            return recipient;
        }

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

    public static class UnknownSerializedQueue extends RuntimeException {
        public UnknownSerializedQueue(String queueName) {
            super("Unable to retrieve '" + queueName + "' queue");
        }
    }

    public static final TaskType TYPE = TaskType.of("delete-mails-from-mail-queue");

    private final ManageableMailQueue queue;
    private final Optional<MailAddress> maybeSender;
    private final Optional<String> maybeName;
    private final Optional<MailAddress> maybeRecipient;

    private final long initialCount;

    public DeleteMailsFromMailQueueTask(ManageableMailQueue queue, Optional<MailAddress> maybeSender,
                                        Optional<String> maybeName, Optional<MailAddress> maybeRecipient) {
        Preconditions.checkArgument(
            Booleans.countTrue(maybeSender.isPresent(), maybeName.isPresent(), maybeRecipient.isPresent()) == 1,
            "You should provide one and only one of the query parameters 'sender', 'name' or 'recipient'.");

        this.queue = queue;
        this.maybeSender = maybeSender;
        this.maybeName = maybeName;
        this.maybeRecipient = maybeRecipient;
        this.initialCount = getRemainingSize();
    }

    @Override
    public Result run() {
        maybeSender.ifPresent(Throwing.consumer(
            (MailAddress sender) -> queue.remove(ManageableMailQueue.Type.Sender, sender.asString())));
        maybeName.ifPresent(Throwing.consumer(
            (String name) -> queue.remove(ManageableMailQueue.Type.Name, name)));
        maybeRecipient.ifPresent(Throwing.consumer(
            (MailAddress recipient) -> queue.remove(ManageableMailQueue.Type.Recipient, recipient.asString())));

        return Result.COMPLETED;
    }

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

    ManageableMailQueue getQueue() {
        return queue;
    }

    Optional<String> getMaybeName() {
        return maybeName;
    }

    Optional<MailAddress> getMaybeRecipient() {
        return maybeRecipient;
    }

    Optional<MailAddress> getMaybeSender() {
        return maybeSender;
    }

    @Override
    public Optional<TaskExecutionDetails.AdditionalInformation> details() {
        return Optional.of(new AdditionalInformation(queue.getName(),
            initialCount,
            getRemainingSize(), maybeSender,
            maybeName, maybeRecipient, Clock.systemUTC().instant()));
    }

    public long getRemainingSize() {
        try {
            return queue.getSize();
        } catch (MailQueue.MailQueueException e) {
            throw new RuntimeException(e);
        }
    }
}