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package org.apache.james.mailbox.cassandra.user;

import static com.datastax.driver.core.querybuilder.QueryBuilder.eq;
import static com.datastax.driver.core.querybuilder.QueryBuilder.insertInto;
import static com.datastax.driver.core.querybuilder.QueryBuilder.select;
import static org.apache.james.mailbox.cassandra.table.CassandraSubscriptionTable.FIELDS;
import static org.apache.james.mailbox.cassandra.table.CassandraSubscriptionTable.MAILBOX;
import static org.apache.james.mailbox.cassandra.table.CassandraSubscriptionTable.TABLE_NAME;
import static org.apache.james.mailbox.cassandra.table.CassandraSubscriptionTable.USER;

import java.util.List;
import java.util.stream.Collectors;

import org.apache.james.backends.cassandra.utils.CassandraUtils;
import org.apache.james.mailbox.store.transaction.NonTransactionalMapper;
import org.apache.james.mailbox.store.user.SubscriptionMapper;
import org.apache.james.mailbox.store.user.model.Subscription;
import org.apache.james.mailbox.store.user.model.impl.SimpleSubscription;

import com.datastax.driver.core.ResultSet;
import com.datastax.driver.core.Session;
import com.datastax.driver.core.querybuilder.QueryBuilder;

public class CassandraSubscriptionMapper extends NonTransactionalMapper implements SubscriptionMapper {
    private final Session session;
    private CassandraUtils cassandraUtils;

    public CassandraSubscriptionMapper(Session session, CassandraUtils cassandraUtils) {
        this.session = session;
        this.cassandraUtils = cassandraUtils;
    }

    @Override
    public synchronized void delete(Subscription subscription) {
        session.execute(QueryBuilder.delete()
            .from(TABLE_NAME)
            .where(eq(USER, subscription.getUser()))
            .and(eq(MAILBOX, subscription.getMailbox())));
    }

    @Override
    public Subscription findMailboxSubscriptionForUser(String user, String mailbox) {
        ResultSet results = session.execute(select(MAILBOX)
            .from(TABLE_NAME)
            .where(eq(USER, user))
            .and(eq(MAILBOX, mailbox)));
        return !results.isExhausted() ? new SimpleSubscription(user, mailbox) : null;
    }

    @Override
    public List<Subscription> findSubscriptionsForUser(String user) {
        return cassandraUtils.convertToStream(
            session.execute(select(MAILBOX)
                .from(TABLE_NAME)
                .where(eq(USER, user))))
            .map((row) -> new SimpleSubscription(user, row.getString(MAILBOX)))
            .collect(Collectors.toList());
    }

    @Override
    public synchronized void save(Subscription subscription) {
        session.execute(insertInto(TABLE_NAME)
            .value(USER, subscription.getUser())
            .value(MAILBOX, subscription.getMailbox()));
    }

    public List<SimpleSubscription> list() {
        return cassandraUtils.convertToStream(
            session.execute(select(FIELDS)
                .from(TABLE_NAME)))
            .map((row) -> new SimpleSubscription(row.getString(USER), row.getString(MAILBOX)))
            .collect(Collectors.toList());
    }

    @Override
    public void endRequest() {
        // nothing to do
    }

}
