/**
 * Copyright (C) 2013 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.
 */

#include "mongo/platform/basic.h"

#include "mongo/db/auth/authorization_manager.h"
#include "mongo/db/auth/authorization_manager_global.h"
#include "mongo/db/auth/authz_documents_update_guard.h"
#include "mongo/db/auth/user_management_commands_parser.h"
#include "mongo/db/commands/user_management_commands.h"
#include "mongo/db/repl/multicmd.h"
#include "mongo/db/repl/rs.h"
#include "mongo/db/repl/rs_config.h"
#include "mongo/util/mongoutils/str.h"
#include "mongo/util/version.h"

namespace mongo {
namespace {

    Status checkReplicaMemberVersions() {
        if (!replset::theReplSet)
            return Status::OK();


        std::list<replset::Target> rsMembers;
        try {
            const unsigned rsSelfId = replset::theReplSet->selfId();
            const std::vector<replset::ReplSetConfig::MemberCfg>& rsMemberConfigs =
                replset::theReplSet->config().members;
            for (size_t i = 0; i < rsMemberConfigs.size(); ++i) {
                const unsigned otherId = rsMemberConfigs[i]._id;
                if (rsSelfId == otherId)
                    continue;
                const replset::Member* other = replset::theReplSet->findById(otherId);
                if (!other) {
                    log() << "During authSchemaUpgrade, no information about replica set member "
                        "with id " << otherId << "; ignoring.";
                    continue;
                }
                if (!other->hbinfo().maybeUp()) {
                    log() << "During authSchemaUpgrade, replica set member " << other->h() <<
                        " is down; ignoring.";
                    continue;
                }
                rsMembers.push_back(replset::Target(other->fullName()));
            }

            multiCommand(BSON("buildInfo" << 1), rsMembers);
        }
        catch (const DBException& ex) {
            return ex.toStatus();
        }

        for (std::list<replset::Target>::const_iterator iter = rsMembers.begin();
             iter != rsMembers.end();
             ++iter) {

            if (!iter->ok) {
                logger::LogstreamBuilder wlog = warning();
                wlog << "During authSchemaUpgrade, could not run buildInfo command on " <<
                    iter->toHost;
                if (!iter->result.isEmpty())
                    wlog << "; response was " << iter->result.toString();
                wlog << "; ignoring.";
                continue;
            }

            const char* version = iter->result["version"].valuestrsafe();
            if (!*version) {
                return Status(ErrorCodes::RemoteValidationError, mongoutils::str::stream() <<
                              "Missing or non-string \"version\" field in result of buildInfo "
                              "command sent to " << iter->toHost << "; found " <<
                              iter->result["version"]);
            }

            if (!isSameMajorVersion(version)) {
                BSONArray foundVersionArray = toVersionArray(version);
                return Status(ErrorCodes::RemoteValidationError, mongoutils::str::stream() <<
                              "To upgrade auth schema in a replica set, all members must be "
                              "running the same release series of mongod; found " <<
                              foundVersionArray["0"] << '.' << foundVersionArray["1"] <<
                              " on host  " << iter->toHost << " but expected " <<
                              versionArray["0"] << '.' << versionArray["1"]);
            }
        }
        return Status::OK();
    }

    class CmdAuthSchemaUpgradeD : public CmdAuthSchemaUpgrade {
        virtual bool run(
                OperationContext* txn,
                const string& dbname,
                BSONObj& cmdObj,
                int options,
                string& errmsg,
                BSONObjBuilder& result,
                bool fromRepl) {

            int maxSteps;
            bool upgradeShardServers;
            BSONObj writeConcern;
            Status status = auth::parseAuthSchemaUpgradeStepCommand(
                    cmdObj,
                    dbname,
                    &maxSteps,
                    &upgradeShardServers,
                    &writeConcern);
            if (!status.isOK()) {
                return appendCommandStatus(result, status);
            }

            AuthorizationManager* authzManager = getGlobalAuthorizationManager();

            AuthzDocumentsUpdateGuard updateGuard(authzManager);
            if (!updateGuard.tryLock("auth schema upgrade")) {
                return appendCommandStatus(
                        result,
                        Status(ErrorCodes::LockBusy, "Could not lock auth data update lock."));
            }

            status = checkReplicaMemberVersions();
            if (!status.isOK())
                return appendCommandStatus(result, status);

            status = authzManager->upgradeSchema(maxSteps, writeConcern);
            if (status.isOK())
                result.append("done", true);
            return appendCommandStatus(result, status);
        }

    } cmdAuthSchemaUpgradeStep;

}  // namespace
}  // namespace mongo
