/**
 *    Copyright (C) 2014 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/global_environment_experiment.h"

#include "mongo/bson/bsonobjiterator.h"
#include "mongo/db/operation_context.h"
#include "mongo/util/assert_util.h"
#include "mongo/util/mongoutils/str.h"

namespace mongo {

    namespace {

        GlobalEnvironmentExperiment* globalEnvironmentExperiment = NULL;

    } // namespace

    bool hasGlobalEnvironment() { return globalEnvironmentExperiment; }

    GlobalEnvironmentExperiment* getGlobalEnvironment() {
        fassert(17508, globalEnvironmentExperiment);
        return globalEnvironmentExperiment;
    }

    void setGlobalEnvironment(GlobalEnvironmentExperiment* newGlobalEnvironment) {
        fassert(17509, newGlobalEnvironment);

        if (NULL != globalEnvironmentExperiment) {
            delete globalEnvironmentExperiment;
        }

        globalEnvironmentExperiment = newGlobalEnvironment;
    }

    bool supportsDocLocking() {
        if (hasGlobalEnvironment()) {
            StorageEngine* globalStorageEngine = getGlobalEnvironment()->getGlobalStorageEngine();
            if (globalStorageEngine != NULL) {
                return globalStorageEngine->supportsDocLocking();
            }
        }

        return false;
    }

    bool isMMAPV1() {
        if (hasGlobalEnvironment()) {
            StorageEngine* globalStorageEngine = getGlobalEnvironment()->getGlobalStorageEngine();
            if (globalStorageEngine != NULL) {
                return globalStorageEngine->isMmapV1();
            }
        }

        // For the purpose of unit-tests, which were written to assume MMAP V1-like behaviour
        return true;
    }

    Status validateStorageOptions(const BSONObj& storageEngineOptions,
       stdx::function<Status (const StorageEngine::Factory* const, const BSONObj&)> validateFunc) {

        BSONObjIterator storageIt(storageEngineOptions);
        while (storageIt.more()) {
            BSONElement storageElement = storageIt.next();
            StringData storageEngineName = storageElement.fieldNameStringData();
            if (storageElement.type() != mongo::Object) {
                return Status(ErrorCodes::BadValue, str::stream()
                    << "'storageEngine." << storageElement.fieldNameStringData()
                    << "' has to be an embedded document.");
            }

            boost::scoped_ptr<StorageFactoriesIterator> sfi(getGlobalEnvironment()->
                                                            makeStorageFactoriesIterator());
            invariant(sfi);
            bool found = false;
            while (sfi->more()) {
                const StorageEngine::Factory* const& factory = sfi->next();
                if (storageEngineName != factory->getCanonicalName()) {
                    continue;
                }
                Status status = validateFunc(factory, storageElement.Obj());
                if ( !status.isOK() ) {
                    return status;
                }
                found = true;
            }
            if (!found) {
                return Status(ErrorCodes::InvalidOptions, str::stream() << storageEngineName <<
                              " is not a registered storage engine for this server");
            }
        }
        return Status::OK();
    }

}  // namespace mongo