/**
*    Copyright (C) 2008 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/pch.h"

#include "mongo/base/init.h"
#include "mongo/base/status.h"
#include "mongo/bson/util/builder.h"
#include "mongo/client/dbclientinterface.h"
#include "mongo/db/auth/action_set.h"
#include "mongo/db/auth/resource_pattern.h"
#include "mongo/db/auth/authorization_session.h"
#include "mongo/db/catalog/collection.h"
#include "mongo/db/cloner.h"
#include "mongo/db/commands.h"
#include "mongo/db/commands/copydb.h"
#include "mongo/db/commands/rename_collection.h"
#include "mongo/db/db.h"
#include "mongo/db/dbhelpers.h"
#include "mongo/db/index_builder.h"
#include "mongo/db/instance.h"
#include "mongo/db/jsobj.h"
#include "mongo/db/namespace_string.h"
#include "mongo/db/repl/oplog.h"
#include "mongo/db/repl/oplogreader.h"
#include "mongo/db/operation_context_impl.h"
#include "mongo/db/storage_options.h"

namespace mongo {

    /* Usage:
       mydb.$cmd.findOne( { clone: "fromhost" } );
       Note: doesn't work with authentication enabled, except as internal operation or for
       old-style users for backwards compatibility.
    */
    class CmdClone : public Command {
    public:
        CmdClone() : Command("clone") { }

        virtual bool slaveOk() const {
            return false;
        }

        virtual bool isWriteCommandForConfigServer() const { return true; }

        virtual void help( stringstream &help ) const {
            help << "clone this database from an instance of the db on another host\n";
            help << "{ clone : \"host13\" }";
        }

        virtual Status checkAuthForCommand(ClientBasic* client,
                                           const std::string& dbname,
                                           const BSONObj& cmdObj) {
            ActionSet actions;
            actions.addAction(ActionType::insert);
            actions.addAction(ActionType::createIndex);
            if (!client->getAuthorizationSession()->isAuthorizedForActionsOnResource(
                    ResourcePattern::forDatabaseName(dbname), actions)) {
                return Status(ErrorCodes::Unauthorized, "Unauthorized");
            }
            return Status::OK();
        }

        virtual bool run(OperationContext* txn,
                         const string& dbname,
                         BSONObj& cmdObj,
                         int,
                         string& errmsg,
                         BSONObjBuilder& result,
                         bool fromRepl) {

            string from = cmdObj.getStringField("clone");
            if ( from.empty() )
                return false;

            CloneOptions opts;
            opts.fromDB = dbname;
            opts.logForRepl = ! fromRepl;

            // See if there's any collections we should ignore
            if( cmdObj["collsToIgnore"].type() == Array ){
                BSONObjIterator it( cmdObj["collsToIgnore"].Obj() );

                while( it.more() ){
                    BSONElement e = it.next();
                    if( e.type() == String ){
                        opts.collsToIgnore.insert( e.String() );
                    }
                }
            }

            set<string> clonedColls;

            Lock::DBWrite dbXLock(txn->lockState(), dbname);

            Cloner cloner;
            bool rval = cloner.go(txn, dbname, from, opts, &clonedColls, errmsg);

            BSONArrayBuilder barr;
            barr.append( clonedColls );

            result.append( "clonedColls", barr.arr() );

            return rval;

        }
    } cmdClone;

} // namespace mongo