/**
*    Copyright (C) 2012 10gen 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/db/commands/rename_collection.h"

#include <string>
#include <vector>

#include "mongo/db/auth/action_set.h"
#include "mongo/db/auth/action_type.h"
#include "mongo/db/auth/authorization_session.h"
#include "mongo/db/auth/privilege.h"
#include "mongo/db/client_basic.h"
#include "mongo/db/jsobj.h"
#include "mongo/db/namespace_string.h"

namespace mongo {
namespace rename_collection {

    Status checkAuthForRenameCollectionCommand(ClientBasic* client,
                                               const std::string& dbname,
                                               const BSONObj& cmdObj) {
        NamespaceString sourceNS = NamespaceString(cmdObj.getStringField("renameCollection"));
        NamespaceString targetNS = NamespaceString(cmdObj.getStringField("to"));
        bool dropTarget = cmdObj["dropTarget"].trueValue();

        if (sourceNS.db() == targetNS.db() && !sourceNS.isSystem() && !targetNS.isSystem()) {
            // If renaming within the same database, then if you have renameCollectionSameDB and
            // either can read both of source and dest collections or *can't* read either of source
            // or dest collection, then you get can do the rename, even without insert on the
            // destination collection.
            bool canRename = client->getAuthorizationSession()->isAuthorizedForActionsOnResource(
                    ResourcePattern::forDatabaseName(sourceNS.db()),
                    ActionType::renameCollectionSameDB);

            bool canDropTargetIfNeeded = true;
            if (dropTarget) {
                canDropTargetIfNeeded =
                        client->getAuthorizationSession()->isAuthorizedForActionsOnResource(
                            ResourcePattern::forExactNamespace(targetNS),
                            ActionType::dropCollection);
            }

            bool canReadSrc = client->getAuthorizationSession()->isAuthorizedForActionsOnResource(
                    ResourcePattern::forExactNamespace(sourceNS), ActionType::find);
            bool canReadDest = client->getAuthorizationSession()->isAuthorizedForActionsOnResource(
                    ResourcePattern::forExactNamespace(targetNS), ActionType::find);

            if (canRename && canDropTargetIfNeeded && (canReadSrc || !canReadDest)) {
                return Status::OK();
            }
        }

        // Check privileges on source collection
        ActionSet actions;
        actions.addAction(ActionType::find);
        actions.addAction(ActionType::dropCollection);
        if (!client->getAuthorizationSession()->isAuthorizedForActionsOnResource(
                ResourcePattern::forExactNamespace(sourceNS), actions)) {
            return Status(ErrorCodes::Unauthorized, "Unauthorized");
        }

        // Check privileges on dest collection
        actions.removeAllActions();
        actions.addAction(ActionType::insert);
        actions.addAction(ActionType::createIndex);
        if (dropTarget) {
            actions.addAction(ActionType::dropCollection);
        }
        if (!client->getAuthorizationSession()->isAuthorizedForActionsOnResource(
                ResourcePattern::forExactNamespace(targetNS), actions)) {
            return Status(ErrorCodes::Unauthorized, "Unauthorized");
        }

        return Status::OK();
    }

} // namespace rename_collection
} // namespace mongo
