/**
 *    Copyright (C) 2015 MongoDB Inc.
 *
 *    This program is free software: you can redistribute it and/or  modify
 *    it under the terms of the GNU Affero General Public License, version 3,
 *    as published by the Free Software Foundation.
 *
 *    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
 *    GNU Affero General Public License for more details.
 *
 *    You should have received a copy of the GNU Affero General Public License
 *    along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 *    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 GNU Affero General 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/bson/json.h"
#include "mongo/db/jsobj.h"
#include "mongo/db/operation_context_noop.h"
#include "mongo/db/repl/repl_set_heartbeat_args.h"
#include "mongo/db/repl/repl_set_heartbeat_args_v1.h"
#include "mongo/db/repl/replica_set_config.h"
#include "mongo/db/repl/replication_coordinator_external_state_mock.h"
#include "mongo/db/repl/replication_coordinator_impl.h"
#include "mongo/db/repl/replication_coordinator_test_fixture.h"
#include "mongo/db/repl/topology_coordinator_impl.h"
#include "mongo/executor/network_interface_mock.h"
#include "mongo/rpc/metadata/repl_set_metadata.h"
#include "mongo/unittest/unittest.h"
#include "mongo/util/log.h"

namespace mongo {
namespace repl {
namespace {

using executor::NetworkInterfaceMock;
using executor::RemoteCommandRequest;
using executor::RemoteCommandResponse;

class ReplCoordHBV1Test : public ReplCoordTest {
protected:
    void assertMemberState(MemberState expected, std::string msg = "");
    ReplSetHeartbeatResponse receiveHeartbeatFrom(const ReplicaSetConfig& rsConfig,
                                                  int sourceId,
                                                  const HostAndPort& source);
};

void ReplCoordHBV1Test::assertMemberState(const MemberState expected, std::string msg) {
    const MemberState actual = getReplCoord()->getMemberState();
    ASSERT(expected == actual) << "Expected coordinator to report state " << expected.toString()
                               << " but found " << actual.toString() << " - " << msg;
}

ReplSetHeartbeatResponse ReplCoordHBV1Test::receiveHeartbeatFrom(const ReplicaSetConfig& rsConfig,
                                                                 int sourceId,
                                                                 const HostAndPort& source) {
    ReplSetHeartbeatArgsV1 hbArgs;
    hbArgs.setConfigVersion(rsConfig.getConfigVersion());
    hbArgs.setSetName(rsConfig.getReplSetName());
    hbArgs.setSenderHost(source);
    hbArgs.setSenderId(sourceId);
    hbArgs.setTerm(1);
    ASSERT(hbArgs.isInitialized());

    ReplSetHeartbeatResponse response;
    ASSERT_OK(getReplCoord()->processHeartbeatV1(hbArgs, &response));
    return response;
}

TEST_F(ReplCoordHBV1Test,
       NodeJoinsExistingReplSetWhenReceivingAConfigContainingTheNodeViaHeartbeat) {
    logger::globalLogDomain()->setMinimumLoggedSeverity(logger::LogSeverity::Debug(3));
    ReplicaSetConfig rsConfig =
        assertMakeRSConfig(BSON("_id"
                                << "mySet"
                                << "version" << 3 << "members"
                                << BSON_ARRAY(BSON("_id" << 1 << "host"
                                                         << "h1:1")
                                              << BSON("_id" << 2 << "host"
                                                            << "h2:1") << BSON("_id" << 3 << "host"
                                                                                     << "h3:1"))
                                << "protocolVersion" << 1));
    init("mySet");
    addSelf(HostAndPort("h2", 1));
    const Date_t startDate = getNet()->now();
    start();
    enterNetwork();
    assertMemberState(MemberState::RS_STARTUP);
    NetworkInterfaceMock* net = getNet();
    ASSERT_FALSE(net->hasReadyRequests());
    exitNetwork();
    receiveHeartbeatFrom(rsConfig, 1, HostAndPort("h1", 1));

    enterNetwork();
    NetworkInterfaceMock::NetworkOperationIterator noi = net->getNextReadyRequest();
    const RemoteCommandRequest& request = noi->getRequest();
    ASSERT_EQUALS(HostAndPort("h1", 1), request.target);
    ReplSetHeartbeatArgs hbArgs;
    ASSERT_OK(hbArgs.initialize(request.cmdObj));
    ASSERT_EQUALS("mySet", hbArgs.getSetName());
    ASSERT_EQUALS(-2, hbArgs.getConfigVersion());
    ReplSetHeartbeatResponse hbResp;
    hbResp.setSetName("mySet");
    hbResp.setState(MemberState::RS_PRIMARY);
    hbResp.setConfigVersion(rsConfig.getConfigVersion());
    hbResp.setConfig(rsConfig);
    BSONObjBuilder responseBuilder;
    responseBuilder << "ok" << 1;
    hbResp.addToBSON(&responseBuilder, true);
    net->scheduleResponse(
        noi, startDate + Milliseconds(200), makeResponseStatus(responseBuilder.obj()));
    assertRunUntil(startDate + Milliseconds(200));

    // Because the new config is stored using an out-of-band thread, we need to perform some
    // extra synchronization to let the executor finish the heartbeat reconfig.  We know that
    // after the out-of-band thread completes, it schedules new heartbeats.  We assume that no
    // other network operations get scheduled during or before the reconfig, though this may
    // cease to be true in the future.
    noi = net->getNextReadyRequest();

    assertMemberState(MemberState::RS_STARTUP2);
    OperationContextNoop txn;
    ReplicaSetConfig storedConfig;
    ASSERT_OK(storedConfig.initialize(
        unittest::assertGet(getExternalState()->loadLocalConfigDocument(&txn))));
    ASSERT_OK(storedConfig.validate());
    ASSERT_EQUALS(3, storedConfig.getConfigVersion());
    ASSERT_EQUALS(3, storedConfig.getNumMembers());
    exitNetwork();

    ASSERT_TRUE(getExternalState()->threadsStarted());
}

TEST_F(ReplCoordHBV1Test,
       ArbiterJoinsExistingReplSetWhenReceivingAConfigContainingTheArbiterViaHeartbeat) {
    logger::globalLogDomain()->setMinimumLoggedSeverity(logger::LogSeverity::Debug(3));
    ReplicaSetConfig rsConfig =
        assertMakeRSConfig(BSON("_id"
                                << "mySet"
                                << "version" << 3 << "members"
                                << BSON_ARRAY(BSON("_id" << 1 << "host"
                                                         << "h1:1")
                                              << BSON("_id" << 2 << "host"
                                                            << "h2:1"
                                                            << "arbiterOnly" << true)
                                              << BSON("_id" << 3 << "host"
                                                            << "h3:1")) << "protocolVersion" << 1));
    init("mySet");
    addSelf(HostAndPort("h2", 1));
    const Date_t startDate = getNet()->now();
    start();
    enterNetwork();
    assertMemberState(MemberState::RS_STARTUP);
    NetworkInterfaceMock* net = getNet();
    ASSERT_FALSE(net->hasReadyRequests());
    exitNetwork();
    receiveHeartbeatFrom(rsConfig, 1, HostAndPort("h1", 1));

    enterNetwork();
    NetworkInterfaceMock::NetworkOperationIterator noi = net->getNextReadyRequest();
    const RemoteCommandRequest& request = noi->getRequest();
    ASSERT_EQUALS(HostAndPort("h1", 1), request.target);
    ReplSetHeartbeatArgs hbArgs;
    ASSERT_OK(hbArgs.initialize(request.cmdObj));
    ASSERT_EQUALS("mySet", hbArgs.getSetName());
    ASSERT_EQUALS(-2, hbArgs.getConfigVersion());
    ReplSetHeartbeatResponse hbResp;
    hbResp.setSetName("mySet");
    hbResp.setState(MemberState::RS_PRIMARY);
    hbResp.setConfigVersion(rsConfig.getConfigVersion());
    hbResp.setConfig(rsConfig);
    BSONObjBuilder responseBuilder;
    responseBuilder << "ok" << 1;
    hbResp.addToBSON(&responseBuilder, true);
    net->scheduleResponse(
        noi, startDate + Milliseconds(200), makeResponseStatus(responseBuilder.obj()));
    assertRunUntil(startDate + Milliseconds(200));

    // Because the new config is stored using an out-of-band thread, we need to perform some
    // extra synchronization to let the executor finish the heartbeat reconfig.  We know that
    // after the out-of-band thread completes, it schedules new heartbeats.  We assume that no
    // other network operations get scheduled during or before the reconfig, though this may
    // cease to be true in the future.
    noi = net->getNextReadyRequest();

    assertMemberState(MemberState::RS_ARBITER);
    OperationContextNoop txn;
    ReplicaSetConfig storedConfig;
    ASSERT_OK(storedConfig.initialize(
        unittest::assertGet(getExternalState()->loadLocalConfigDocument(&txn))));
    ASSERT_OK(storedConfig.validate());
    ASSERT_EQUALS(3, storedConfig.getConfigVersion());
    ASSERT_EQUALS(3, storedConfig.getNumMembers());
    exitNetwork();

    ASSERT_FALSE(getExternalState()->threadsStarted());
}

TEST_F(ReplCoordHBV1Test,
       NodeDoesNotJoinExistingReplSetWhenReceivingAConfigNotContainingTheNodeViaHeartbeat) {
    // Tests that a node in RS_STARTUP will not transition to RS_REMOVED if it receives a
    // configuration that does not contain it.
    logger::globalLogDomain()->setMinimumLoggedSeverity(logger::LogSeverity::Debug(3));
    ReplicaSetConfig rsConfig =
        assertMakeRSConfig(BSON("_id"
                                << "mySet"
                                << "version" << 3 << "members"
                                << BSON_ARRAY(BSON("_id" << 1 << "host"
                                                         << "h1:1")
                                              << BSON("_id" << 2 << "host"
                                                            << "h2:1") << BSON("_id" << 3 << "host"
                                                                                     << "h3:1"))
                                << "protocolVersion" << 1));
    init("mySet");
    addSelf(HostAndPort("h4", 1));
    const Date_t startDate = getNet()->now();
    start();
    enterNetwork();
    assertMemberState(MemberState::RS_STARTUP, "1");
    NetworkInterfaceMock* net = getNet();
    ASSERT_FALSE(net->hasReadyRequests());
    exitNetwork();
    receiveHeartbeatFrom(rsConfig, 1, HostAndPort("h1", 1));

    enterNetwork();
    NetworkInterfaceMock::NetworkOperationIterator noi = net->getNextReadyRequest();
    const RemoteCommandRequest& request = noi->getRequest();
    ASSERT_EQUALS(HostAndPort("h1", 1), request.target);
    ReplSetHeartbeatArgs hbArgs;
    ASSERT_OK(hbArgs.initialize(request.cmdObj));
    ASSERT_EQUALS("mySet", hbArgs.getSetName());
    ASSERT_EQUALS(-2, hbArgs.getConfigVersion());
    ReplSetHeartbeatResponse hbResp;
    hbResp.setSetName("mySet");
    hbResp.setState(MemberState::RS_PRIMARY);
    hbResp.setConfigVersion(rsConfig.getConfigVersion());
    hbResp.setConfig(rsConfig);
    BSONObjBuilder responseBuilder;
    responseBuilder << "ok" << 1;
    hbResp.addToBSON(&responseBuilder, true);
    net->scheduleResponse(
        noi, startDate + Milliseconds(200), makeResponseStatus(responseBuilder.obj()));
    assertRunUntil(startDate + Milliseconds(2200));

    // Because the new config is stored using an out-of-band thread, we need to perform some
    // extra synchronization to let the executor finish the heartbeat reconfig.  We know that
    // after the out-of-band thread completes, it schedules new heartbeats.  We assume that no
    // other network operations get scheduled during or before the reconfig, though this may
    // cease to be true in the future.
    noi = net->getNextReadyRequest();

    assertMemberState(MemberState::RS_STARTUP, "2");
    OperationContextNoop txn;

    StatusWith<BSONObj> loadedConfig(getExternalState()->loadLocalConfigDocument(&txn));
    ASSERT_NOT_OK(loadedConfig.getStatus()) << loadedConfig.getValue();
    exitNetwork();
}

TEST_F(ReplCoordHBV1Test,
       NodeReturnsNotYetInitializedInResponseToAHeartbeatReceivedPriorToAConfig) {
    // ensure that if we've yet to receive an initial config, we return NotYetInitialized
    init("mySet");
    ReplSetHeartbeatArgsV1 hbArgs;
    hbArgs.setConfigVersion(3);
    hbArgs.setSetName("mySet");
    hbArgs.setSenderHost(HostAndPort("h1:1"));
    hbArgs.setSenderId(1);
    hbArgs.setTerm(1);
    ASSERT(hbArgs.isInitialized());

    ReplSetHeartbeatResponse response;
    Status status = getReplCoord()->processHeartbeatV1(hbArgs, &response);
    ASSERT_EQUALS(ErrorCodes::NotYetInitialized, status.code());
}

TEST_F(ReplCoordHBV1Test,
       NodeChangesToRecoveringStateWhenAllNodesRespondToHeartbeatsWithUnauthorized) {
    // Tests that a node that only has auth error heartbeats is recovering
    logger::globalLogDomain()->setMinimumLoggedSeverity(logger::LogSeverity::Debug(3));
    assertStartSuccess(BSON("_id"
                            << "mySet"
                            << "version" << 1 << "members"
                            << BSON_ARRAY(BSON("_id" << 1 << "host"
                                                     << "node1:12345")
                                          << BSON("_id" << 2 << "host"
                                                        << "node2:12345"))),
                       HostAndPort("node1", 12345));
    ASSERT(getReplCoord()->setFollowerMode(MemberState::RS_SECONDARY));

    // process heartbeat
    enterNetwork();
    const NetworkInterfaceMock::NetworkOperationIterator noi = getNet()->getNextReadyRequest();
    const RemoteCommandRequest& request = noi->getRequest();
    log() << request.target.toString() << " processing " << request.cmdObj;
    getNet()->scheduleResponse(
        noi,
        getNet()->now(),
        makeResponseStatus(BSON("ok" << 0.0 << "errmsg"
                                     << "unauth'd"
                                     << "code" << ErrorCodes::Unauthorized)));

    if (request.target != HostAndPort("node2", 12345) &&
        request.cmdObj.firstElement().fieldNameStringData() != "replSetHeartbeat") {
        error() << "Black holing unexpected request to " << request.target << ": "
                << request.cmdObj;
        getNet()->blackHole(noi);
    }
    getNet()->runReadyNetworkOperations();
    exitNetwork();

    ASSERT_TRUE(getTopoCoord().getMemberState().recovering());
    assertMemberState(MemberState::RS_RECOVERING, "0");
}

TEST_F(ReplCoordHBV1Test, ArbiterRecordsCommittedOpTimeFromHeartbeatMetadata) {
    // Tests that an arbiter will update its committed optime from the heartbeat metadata
    assertStartSuccess(fromjson(
                           "{_id:'mySet', version:1, protocolVersion:1, members:["
                           "{_id:1, host:'node1:12345', arbiterOnly:true}, "
                           "{_id:2, host:'node2:12345'}]}"),
                       HostAndPort("node1", 12345));
    ASSERT(getReplCoord()->setFollowerMode(MemberState::RS_ARBITER));

    // calls processReplSetMetadata with the "committed" optime and verifies that the arbiter sets
    // its current optime to 'expected'
    auto test = [this](OpTime committedOpTime, OpTime expected) {
        // process heartbeat metadata directly
        StatusWith<rpc::ReplSetMetadata> metadata = rpc::ReplSetMetadata::readFromMetadata(BSON(
            rpc::kReplSetMetadataFieldName
            << BSON("lastOpCommitted" << BSON("ts" << committedOpTime.getTimestamp() << "t"
                                                   << committedOpTime.getTerm()) << "lastOpVisible"
                                      << BSON("ts" << committedOpTime.getTimestamp() << "t"
                                                   << committedOpTime.getTerm()) << "configVersion"
                                      << 1 << "primaryIndex" << 1 << "term"
                                      << committedOpTime.getTerm() << "syncSourceIndex" << 1)));
        ASSERT_OK(metadata.getStatus());
        getReplCoord()->processReplSetMetadata(metadata.getValue(), true);

        ASSERT_EQ(getReplCoord()->getMyLastAppliedOpTime().getTimestamp(), expected.getTimestamp());
    };

    OpTime committedOpTime{Timestamp{10, 10}, 10};
    test(committedOpTime, committedOpTime);
    OpTime olderOpTime{Timestamp{2, 2}, 9};
    test(olderOpTime, committedOpTime);
}

TEST_F(ReplCoordHBV1Test, IgnoreTheContentsOfMetadataWhenItsReplicaSetIdDoesNotMatchOurs) {
    // Tests that a secondary node will not update its committed optime from the heartbeat metadata
    // if the replica set ID is inconsistent with the existing configuration.
    HostAndPort host2("node2:12345");
    assertStartSuccess(BSON("_id"
                            << "mySet"
                            << "version" << 1 << "members"
                            << BSON_ARRAY(BSON("_id" << 1 << "host"
                                                     << "node1:12345")
                                          << BSON("_id" << 2 << "host" << host2.toString()))
                            << "settings" << BSON("replicaSetId" << OID::gen()) << "protocolVersion"
                            << 1),
                       HostAndPort("node1", 12345));
    ASSERT(getReplCoord()->setFollowerMode(MemberState::RS_SECONDARY));

    auto rsConfig = getReplCoord()->getConfig();

    // Prepare heartbeat response.
    OID unexpectedId = OID::gen();
    OpTime opTime{Timestamp{10, 10}, 10};
    ReplicationExecutor::ResponseStatus heartbeatResponse(ErrorCodes::InternalError,
                                                          "not initialized");
    {
        ReplSetHeartbeatResponse hbResp;
        hbResp.setSetName(rsConfig.getReplSetName());
        hbResp.setState(MemberState::RS_PRIMARY);
        hbResp.setConfigVersion(rsConfig.getConfigVersion());

        BSONObjBuilder responseBuilder;
        responseBuilder << "ok" << 1;
        hbResp.addToBSON(&responseBuilder, true);

        rpc::ReplSetMetadata metadata(
            opTime.getTerm(), opTime, opTime, rsConfig.getConfigVersion(), unexpectedId, 1, -1);
        BSONObjBuilder metadataBuilder;
        metadata.writeToMetadata(&metadataBuilder);

        heartbeatResponse = makeResponseStatus(responseBuilder.obj(), metadataBuilder.obj());
    }

    // process heartbeat
    enterNetwork();
    auto net = getNet();
    while (net->hasReadyRequests()) {
        const NetworkInterfaceMock::NetworkOperationIterator noi = net->getNextReadyRequest();
        const RemoteCommandRequest& request = noi->getRequest();
        if (request.target == host2 &&
            request.cmdObj.firstElement().fieldNameStringData() == "replSetHeartbeat") {
            log() << request.target.toString() << " processing " << request.cmdObj;
            net->scheduleResponse(noi, net->now(), heartbeatResponse);
        } else {
            log() << "blackholing request to " << request.target.toString() << ": "
                  << request.cmdObj;
            net->blackHole(noi);
        }
        net->runReadyNetworkOperations();
    }
    exitNetwork();

    ASSERT_NOT_EQUALS(opTime, getReplCoord()->getLastCommittedOpTime());
    ASSERT_NOT_EQUALS(opTime.getTerm(), getTopoCoord().getTerm());

    BSONObjBuilder statusBuilder;
    ASSERT_OK(getReplCoord()->processReplSetGetStatus(&statusBuilder));
    auto statusObj = statusBuilder.obj();
    unittest::log() << "replica set status = " << statusObj;

    ASSERT_EQ(mongo::Array, statusObj["members"].type());
    auto members = statusObj["members"].Array();
    ASSERT_EQ(2U, members.size());
    ASSERT_TRUE(members[1].isABSONObj());
    auto member = members[1].Obj();
    ASSERT_EQ(host2, HostAndPort(member["name"].String()));
    ASSERT_EQ(MemberState(MemberState::RS_DOWN).toString(),
              MemberState(member["state"].numberInt()).toString());
    ASSERT_EQ(member["lastHeartbeatMessage"].String(),
              std::string(str::stream()
                          << "replica set IDs do not match, ours: " << rsConfig.getReplicaSetId()
                          << "; remote node's: " << unexpectedId));
}

}  // namespace
}  // namespace repl
}  // namespace mongo
