/**
 *    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.
 */

#include "mongo/platform/basic.h"

#include "mongo/db/catalog/create_collection.h"

#include "mongo/bson/bsonobj.h"
#include "mongo/db/concurrency/write_conflict_exception.h"
#include "mongo/db/curop.h"
#include "mongo/db/db_raii.h"
#include "mongo/db/namespace_string.h"
#include "mongo/db/operation_context.h"
#include "mongo/db/ops/insert.h"
#include "mongo/db/repl/replication_coordinator_global.h"

namespace mongo {
    Status createCollection(OperationContext* txn,
                            const std::string& dbName,
                            const BSONObj& cmdObj) {
        BSONObjIterator it(cmdObj);

        // Extract ns from first cmdObj element.
        BSONElement firstElt = it.next();
        uassert(15888,
                "must pass name of collection to create",
                firstElt.valuestrsafe()[0] != '\0');

        Status status = userAllowedCreateNS(dbName, firstElt.valuestr());
        if (!status.isOK()) {
            return status;
        }

        NamespaceString nss(dbName, firstElt.valuestrsafe());

        // Build options object from remaining cmdObj elements.
        BSONObjBuilder optionsBuilder;
        while (it.more()) {
            optionsBuilder.append(it.next());
        }

        BSONObj options = optionsBuilder.obj();
        uassert(14832,
                "specify size:<n> when capped is true",
                !options["capped"].trueValue() || options["size"].isNumber() ||
                    options.hasField("$nExtents"));

        MONGO_WRITE_CONFLICT_RETRY_LOOP_BEGIN {
            ScopedTransaction transaction(txn, MODE_IX);
            Lock::DBLock dbXLock(txn->lockState(), dbName, MODE_X);
            OldClientContext ctx(txn, nss.ns());
            if (txn->writesAreReplicated() && 
                    !repl::getGlobalReplicationCoordinator()->canAcceptWritesFor(nss)) {
                return Status(ErrorCodes::NotMaster, str::stream() <<
                              "Not primary while creating collection " << nss.ns());
            }

            WriteUnitOfWork wunit(txn);

            // Create collection.
            status = userCreateNS(txn, ctx.db(), nss.ns(), options);
            if (!status.isOK()) {
                return status;
            }

            wunit.commit();
        } MONGO_WRITE_CONFLICT_RETRY_LOOP_END(txn, "create", nss.ns());
        return Status::OK();
    }
} // namespace mongo