/*
 * 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.pulsar.client.impl.transaction;

import java.util.concurrent.CompletableFuture;
import java.util.concurrent.TimeUnit;
import lombok.extern.slf4j.Slf4j;
import org.apache.pulsar.client.api.PulsarClientException;
import org.apache.pulsar.client.api.transaction.Transaction;
import org.apache.pulsar.client.api.transaction.TransactionBuilder;
import org.apache.pulsar.client.impl.PulsarClientImpl;
import org.apache.pulsar.common.util.FutureUtil;

/**
 * The default implementation of transaction builder to build transactions.
 */
@Slf4j
public class TransactionBuilderImpl implements TransactionBuilder {

    private final PulsarClientImpl client;
    private final TransactionCoordinatorClientImpl transactionCoordinatorClient;
    private long txnTimeout = 60000; // 1 minute
    private TimeUnit timeUnit = TimeUnit.MILLISECONDS;

    public TransactionBuilderImpl(PulsarClientImpl client, TransactionCoordinatorClientImpl tcClient) {
        this.client = client;
        this.transactionCoordinatorClient = tcClient;
    }

    @Override
    public TransactionBuilder withTransactionTimeout(long txnTimeout, TimeUnit timeoutUnit) {
        this.txnTimeout = txnTimeout;
        this.timeUnit = timeoutUnit;
        return this;
    }

    @Override
    public CompletableFuture<Transaction> build() {
        if (!client.getConfiguration().isEnableTransaction()) {
            return FutureUtil.failedFuture(
                    new PulsarClientException.InvalidConfigurationException("Transactions are not enabled"));
        }
        // talk to TC to begin a transaction
        //       the builder is responsible for locating the transaction coordinator (TC)
        //       and start the transaction to get the transaction id.
        //       After getting the transaction id, all the operations are handled by the
        //       `TransactionImpl`
        CompletableFuture<Transaction> future = new CompletableFuture<>();
        transactionCoordinatorClient
                .newTransactionAsync(txnTimeout, timeUnit)
                .whenComplete((txnID, throwable) -> {
                    if (throwable != null) {
                        log.error("New transaction error.", throwable);
                        future.completeExceptionally(throwable);
                        return;
                    }
                    if (log.isDebugEnabled()) {
                        log.debug("'newTransaction' command completed successfully for transaction: {}", txnID);
                    }
                    TransactionImpl transaction = new TransactionImpl(client, timeUnit.toMillis(txnTimeout),
                            txnID.getLeastSigBits(), txnID.getMostSigBits());
                    future.complete(transaction);
                });
        return future;
    }
}
