package io.trygvis.queue;

import java.sql.Connection;
import java.sql.SQLException;
import java.util.HashMap;
import java.util.Map;

public class JdbcQueueService {

    private final QueueSystem queueSystem;

    private final SqlEffectExecutor sqlEffectExecutor;

    private final Map<String, QueueExecutor> queues = new HashMap<>();

    JdbcQueueService(QueueSystem queueSystem) {
        this.queueSystem = queueSystem;
        this.sqlEffectExecutor = queueSystem.sqlEffectExecutor;
    }

    public synchronized QueueExecutor getQueue(String name) {
        QueueExecutor queueExecutor = queues.get(name);

        if (queueExecutor != null) {
            return queueExecutor;
        }

        throw new IllegalArgumentException("No such queue: " + name);
    }

    public synchronized QueueExecutor lookupQueue(Connection c, String name, long interval, boolean autoCreate) throws SQLException {
        QueueExecutor queueExecutor = queues.get(name);

        if (queueExecutor != null) {
            return queueExecutor;
        }

        QueueDao queueDao = queueSystem.createQueueDao(c);

        Queue q = queueDao.findByName(name);

        if (q == null) {
            if (!autoCreate) {
                throw new SQLException("No such queue: '" + name + "'.");
            }

            q = new Queue(name, interval);
            queueDao.insert(q);
        }

        queueExecutor = new QueueExecutor(queueSystem, sqlEffectExecutor, q);
        queues.put(name, queueExecutor);
        return queueExecutor;
    }
}