/**
 *    Copyright (C) 2018-present MongoDB, Inc.
 *
 *    This program is free software: you can redistribute it and/or modify
 *    it under the terms of the Server Side Public License, version 1,
 *    as published by MongoDB, Inc.
 *
 *    This program is distributed in the hope that it will be useful,
 *    but WITHOUT ANY WARRANTY; without even the implied warranty of
 *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *    Server Side Public License for more details.
 *
 *    You should have received a copy of the Server Side Public License
 *    along with this program. If not, see
 *    <http://www.mongodb.com/licensing/server-side-public-license>.
 *
 *    As a special exception, the copyright holders give permission to link the
 *    code of portions of this program with the OpenSSL library under certain
 *    conditions as described in each individual source file and distribute
 *    linked combinations including the program with the OpenSSL library. You
 *    must comply with the Server Side Public License in all respects for
 *    all of the code used other than as permitted herein. If you modify file(s)
 *    with this exception, you may extend this exception to your version of the
 *    file(s), but you are not obligated to do so. If you do not wish to do so,
 *    delete this exception statement from your version. If you delete this
 *    exception statement from all source files in the program, then also delete
 *    it in the license file.
 */

#define MONGO_LOG_DEFAULT_COMPONENT ::mongo::logger::LogComponent::kReplication

#include "mongo/platform/basic.h"

#include "mongo/db/repl/oplog_applier.h"

#include "mongo/db/auth/authorization_session.h"
#include "mongo/db/namespace_string.h"
#include "mongo/db/repl/repl_server_parameters_gen.h"
#include "mongo/logv2/log.h"
#include "mongo/util/time_support.h"

namespace mongo {
namespace repl {

NoopOplogApplierObserver noopOplogApplierObserver;

using CallbackArgs = executor::TaskExecutor::CallbackArgs;

OplogApplier::OplogApplier(executor::TaskExecutor* executor,
                           OplogBuffer* oplogBuffer,
                           Observer* observer,
                           const Options& options)
    : _executor(executor), _oplogBuffer(oplogBuffer), _observer(observer), _options(options) {
    _oplogBatcher = std::make_unique<OplogBatcher>(this, oplogBuffer);
}

OplogBuffer* OplogApplier::getBuffer() const {
    return _oplogBuffer;
}

Future<void> OplogApplier::startup() {
    auto pf = makePromiseFuture<void>();
    auto callback =
        [ this, promise = std::move(pf.promise) ](const CallbackArgs& args) mutable noexcept {
        invariant(args.status);
        LOGV2(21224, "Starting oplog application");
        _run(_oplogBuffer);
        LOGV2(21225, "Finished oplog application");
        promise.setWith([] {});
    };
    invariant(_executor->scheduleWork(std::move(callback)).getStatus());
    return std::move(pf.future);
}

void OplogApplier::shutdown() {
    // Shutdown will hang if this failpoint is enabled.
    if (globalFailPointRegistry().find("rsSyncApplyStop")->shouldFail()) {
        LOGV2_FATAL(21227, "Turn off rsSyncApplyStop before attempting clean shutdown");
        fassertFailedNoTrace(40304);
    }

    stdx::lock_guard<Latch> lock(_mutex);
    _inShutdown = true;
}

bool OplogApplier::inShutdown() const {
    stdx::lock_guard<Latch> lock(_mutex);
    return _inShutdown;
}

void OplogApplier::waitForSpace(OperationContext* opCtx, std::size_t size) {
    _oplogBuffer->waitForSpace(opCtx, size);
}

/**
 * Pushes operations read from sync source into oplog buffer.
 */
void OplogApplier::enqueue(OperationContext* opCtx,
                           std::vector<OplogEntry>::const_iterator begin,
                           std::vector<OplogEntry>::const_iterator end) {
    OplogBuffer::Batch batch;
    for (auto i = begin; i != end; ++i) {
        batch.push_back(i->getRaw());
    }
    enqueue(opCtx, batch.cbegin(), batch.cend());
}

void OplogApplier::enqueue(OperationContext* opCtx,
                           OplogBuffer::Batch::const_iterator begin,
                           OplogBuffer::Batch::const_iterator end) {
    static Occasionally sampler;
    if (sampler.tick()) {
        LOGV2_DEBUG(21226,
                    2,
                    "oplog buffer has {oplogBuffer_getSize} bytes",
                    "oplogBuffer_getSize"_attr = _oplogBuffer->getSize());
    }
    _oplogBuffer->push(opCtx, begin, end);
}

StatusWith<OpTime> OplogApplier::applyOplogBatch(OperationContext* opCtx,
                                                 std::vector<OplogEntry> ops) {
    _observer->onBatchBegin(ops);
    auto lastApplied = _applyOplogBatch(opCtx, std::move(ops));
    _observer->onBatchEnd(lastApplied, {});
    return lastApplied;
}

StatusWith<std::vector<OplogEntry>> OplogApplier::getNextApplierBatch(
    OperationContext* opCtx, const BatchLimits& batchLimits) {
    return _oplogBatcher->getNextApplierBatch(opCtx, batchLimits);
}

const OplogApplier::Options& OplogApplier::getOptions() const {
    return _options;
}

std::unique_ptr<ThreadPool> makeReplWriterPool() {
    return makeReplWriterPool(replWriterThreadCount);
}

std::unique_ptr<ThreadPool> makeReplWriterPool(int threadCount) {
    ThreadPool::Options options;
    options.threadNamePrefix = "ReplWriterWorker-";
    options.poolName = "ReplWriterWorkerThreadPool";
    options.maxThreads = options.minThreads = static_cast<size_t>(threadCount);
    options.onCreateThread = [](const std::string&) {
        Client::initThread(getThreadName());
        AuthorizationSession::get(cc())->grantInternalAuthorization(&cc());
    };
    auto pool = std::make_unique<ThreadPool>(options);
    pool->startup();
    return pool;
}

}  // namespace repl
}  // namespace mongo